Complement pathway alternative. Medical search

Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.

Complement activation initiated by the binding of COMPLEMENT C1 to ANTIGEN-ANTIBODY COMPLEXES at the COMPLEMENT C1Q subunit. This leads to the sequential activation of COMPLEMENT C1R and COMPLEMENT C1S subunits. Activated C1s cleaves COMPLEMENT C4 and COMPLEMENT C2 forming the membrane-bound classical C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.

The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.

A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.

Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).

A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.

A glycine-rich, heat-labile serum glycoprotein that contains a component of the C3 CONVERTASE ALTERNATE PATHWAY (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.

A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.

Complement activation triggered by the interaction of microbial POLYSACCHARIDES with serum MANNOSE-BINDING LECTIN resulting in the activation of MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. As in the classical pathway, MASPs cleave COMPLEMENT C4 and COMPLEMENT C2 to form C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.

A component of the CLASSICAL COMPLEMENT PATHWAY. C2 is cleaved by activated COMPLEMENT C1S into COMPLEMENT C2B and COMPLEMENT C2A. C2a, the COOH-terminal fragment containing a SERINE PROTEASE, combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE. It is a constituent of the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb), and COMPLEMENT C5 CONVERTASES in both the classical (C4b2a3b) and the alternative (C3bBb3b) pathway. C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS. It can be inactivated (iC3b) or cleaved by various proteases to yield fragments such as COMPLEMENT C3C; COMPLEMENT C3D; C3e; C3f; and C3g.

The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.

C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.

Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.

A serum protein which is important in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. This enzyme cleaves the COMPLEMENT C3B-bound COMPLEMENT FACTOR B to form C3bBb which is ALTERNATIVE PATHWAY C3 CONVERTASE.

Serine proteases that cleave COMPLEMENT C3 into COMPLEMENT C3A and COMPLEMENT C3B, or cleave COMPLEMENT C5 into COMPLEMENT C5A and COMPLEMENT C5B. These include the different forms of C3/C5 convertases in the classical and the alternative pathways of COMPLEMENT ACTIVATION. Both cleavages take place at the C-terminal of an ARGININE residue.

A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.

An important soluble regulator of the alternative pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It is a 139-kDa glycoprotein expressed by the liver and secreted into the blood. It binds to COMPLEMENT C3B and makes iC3b (inactivated complement 3b) susceptible to cleavage by COMPLEMENT FACTOR I. Complement factor H also inhibits the association of C3b with COMPLEMENT FACTOR B to form the C3bB proenzyme, and promotes the dissociation of Bb from the C3bBb complex (COMPLEMENT C3 CONVERTASE, ALTERNATIVE PATHWAY).

Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b components of complement.

A product of COMPLEMENT ACTIVATION cascade, regardless of the pathways, that forms transmembrane channels causing disruption of the target CELL MEMBRANE and cell lysis. It is formed by the sequential assembly of terminal complement components (COMPLEMENT C5B; COMPLEMENT C6; COMPLEMENT C7; COMPLEMENT C8; and COMPLEMENT C9) into the target membrane. The resultant C5b-8-poly-C9 is the "membrane attack complex" or MAC.

A 105-kDa serum glycoprotein with significant homology to the other late complement components, C7-C9. It is a polypeptide chain cross-linked by 32 disulfide bonds. C6 is the next complement component to bind to the membrane-bound COMPLEMENT C5B in the assembly of MEMBRANE ATTACK COMPLEX. It is encoded by gene C6.

The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound C4b binds COMPLEMENT C2A, a SERINE PROTEASE, to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

Endogenous proteins that inhibit or inactivate COMPLEMENT C3B. They include COMPLEMENT FACTOR H and COMPLEMENT FACTOR I (C3b/C4b inactivator). They cleave or promote the cleavage of C3b into inactive fragments, and thus are important in the down-regulation of COMPLEMENT ACTIVATION and its cytolytic sequence.

Enzymes that activate one or more COMPLEMENT PROTEINS in the complement system leading to the formation of the COMPLEMENT MEMBRANE ATTACK COMPLEX, an important response in host defense. They are enzymes in the various COMPLEMENT ACTIVATION pathways.

A screening assay for circulating COMPLEMENT PROTEINS. Diluted SERUM samples are added to antibody-coated ERYTHROCYTES and the percentage of cell lysis is measured. The values are expressed by the so called CH50, in HEMOLYTIC COMPLEMENT units per milliliter, which is the dilution of serum required to lyse 50 percent of the erythrocytes in the assay.

A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.

Compounds that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host.

A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.

Serum serine proteases which participate in COMPLEMENT ACTIVATION. They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). They cleave COMPLEMENT C4 and COMPLEMENT C2 to form C4b2a, the CLASSICAL PATHWAY C3 CONVERTASE.

The smaller fragment generated from the cleavage of complement C3 by C3 CONVERTASE. C3a, a 77-amino acid peptide, is a mediator of local inflammatory process. It induces smooth MUSCLE CONTRACTION, and HISTAMINE RELEASE from MAST CELLS and LEUKOCYTES. C3a is considered an anaphylatoxin along with COMPLEMENT C4A; COMPLEMENT C5A; and COMPLEMENT C5A, DES-ARGININE.

A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.

A 206-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c (749-954), and C3dg (955-1303) in the presence COMPLEMENT FACTOR H.

Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.

A 302-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c, and C3dg (955-1303) in the presence COMPLEMENT FACTOR H. Serum proteases further degrade C3dg into C3d (1002-1303) and C3g (955-1001).

The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.

The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.

Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.

The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.

Molecular sites on or in some B-lymphocytes and macrophages that recognize and combine with COMPLEMENT C3B. The primary structure of these receptors reveal that they contain transmembrane and cytoplasmic domains, with their extracellular portion composed entirely of thirty short consensus repeats each having 60 to 70 amino acids.

Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.

A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).

A plasma serine proteinase that cleaves the alpha-chains of C3b and C4b in the presence of the cofactors COMPLEMENT FACTOR H and C4-binding protein, respectively. It is a 66-kDa glycoprotein that converts C3b to inactivated C3b (iC3b) followed by the release of two fragments, C3c (150-kDa) and C3dg (41-kDa). It was formerly called KAF, C3bINF, or enzyme 3b inactivator.

A serum protein that regulates the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It binds as a cofactor to COMPLEMENT FACTOR I which then hydrolyzes the COMPLEMENT C4B in the CLASSICAL PATHWAY C3 CONVERTASE (C4bC2a).

Zymosan is a polysaccharide derived from yeast cell walls that is used in medical research to induce an inflammatory response in animals.

A serine protease that is the complex of COMPLEMENT C3B and COMPLEMENT FACTOR BB. It cleaves multiple COMPLEMENT C3 into COMPLEMENT C3A (anaphylatoxin) and COMPLEMENT C3B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY.

The larger fragment generated from the cleavage of C5 by C5 CONVERTASE that yields COMPLEMENT C5A and C5b (beta chain + alpha' chain, the residual alpha chain, bound by disulfide bond). C5b remains bound to the membrane and initiates the spontaneous assembly of the late complement components to form C5b-8-poly-C9, the MEMBRANE ATTACK COMPLEX.

The smaller fragment formed when complement C4 is cleaved by COMPLEMENT C1S. It is an anaphylatoxin that causes symptoms of immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE) but its activity is weaker than that of COMPLEMENT C3A or COMPLEMENT C5A.

GPI-linked membrane proteins broadly distributed among hematopoietic and non-hematopoietic cells. CD55 prevents the assembly of C3 CONVERTASE or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex.

The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).

Venoms from snakes of the genus Naja (family Elapidae). They contain many specific proteins that have cytotoxic, hemolytic, neurotoxic, and other properties. Like other elapid venoms, they are rich in enzymes. They include cobramines and cobralysins.

The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.

The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.

A class of C-type lectins that target the carbohydrate structures found on invading pathogens. Binding of collectins to microorganisms results in their agglutination and enhanced clearance. Collectins form trimers that may assemble into larger oligomers. Each collectin polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen-like region, an alpha-helical coiled-coil region, and carbohydrate-binding region.

A 80-kDa subcomponent of complement C1, existing as a SERINE PROTEASE proenzyme in the intact complement C1 complex. When COMPLEMENT C1Q is bound to antibodies, the changed tertiary structure causes autolytic activation of complement C1r which is cleaved into two chains, A (heavy) and B (light, the serine protease), connected by disulfide bonds. The activated C1r serine protease, in turn, activates COMPLEMENT C1S proenzyme by cleaving the Arg426-Ile427 bond. No fragment is released when either C1r or C1s is cleaved.

A 93-kDa serum glycoprotein encoded by C7 gene. It is a polypeptide chain with 28 disulfide bridges. In the formation of MEMBRANE ATTACK COMPLEX; C7 is the next component to bind the C5b-6 complex forming a trimolecular complex C5b-7 which is lipophilic, resembles an integral membrane protein, and serves as an anchor for the late complement components, C8 and C9.

Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.

A 150-kDa serum glycoprotein composed of three subunits with each encoded by a different gene (C8A; C8B; and C8G). This heterotrimer contains a disulfide-linked C8alpha-C8gamma heterodimer and a noncovalently associated C8beta chain. C8 is the next component to bind the C5-7 complex forming C5b-8 that binds COMPLEMENT C9 and acts as a catalyst in the polymerization of C9.

Serum peptides derived from certain cleaved COMPLEMENT PROTEINS during COMPLEMENT ACTIVATION. They induce smooth MUSCLE CONTRACTION; mast cell HISTAMINE RELEASE; PLATELET AGGREGATION; and act as mediators of the local inflammatory process. The order of anaphylatoxin activity from the strongest to the weakest is C5a, C3a, C4a, and C5a des-arginine.

A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.

Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)

Molecular sites on or in B-lymphocytes, follicular dendritic cells, lymphoid cells, and epithelial cells that recognize and combine with COMPLEMENT C3D. Human complement receptor 2 (CR2) serves as a receptor for both C3dg and the gp350/220 glycoprotein of HERPESVIRUS 4, HUMAN, and binds the monoclonal antibody OKB7, which blocks binding of both ligands to the receptor.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.

A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.

Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

Polysaccharides found in bacteria and in capsules thereof.

Limbless REPTILES of the suborder Serpentes.

Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

A species of gram-negative, anaerobic, rod-shaped bacteria originally classified within the BACTEROIDES genus. This bacterium has been isolated from the mouth, urine, feces, and infections of the mouth, soft tissue, respiratory tract, urogenital tract, and intestinal tract. It is pathogenic, but usually in association with other kinds of organisms.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.

The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.

Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.

C57BL mice are a commonly used strain of laboratory mice that are inbred to produce consistent and predictable results in scientific research.

Physiological processes and properties of the BLOOD.

A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.

A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.

Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.

Polysaccharides consisting of mannose units.

An adhesion-promoting leukocyte surface membrane heterodimer. The alpha subunit consists of the CD11b ANTIGEN and the beta subunit the CD18 ANTIGEN. The antigen, which is an integrin, functions both as a receptor for complement 3 and in cell-cell and cell-substrate adhesive interactions.

Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).

Amyloid P component is a small, non-fibrillar glycoprotein found in normal serum and in all amyloid deposits. It has a pentagonal (pentaxin) structure. It is an acute phase protein, modulates immunologic responses, inhibits ELASTASE, and has been suggested as an indicator of LIVER DISEASE.

Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.

A subclass of lectins that are specific for CARBOHYDRATES that contain MANNOSE.

The clear portion of BLOOD that is left after BLOOD COAGULATION to remove BLOOD CELLS and clotting proteins.

Antibodies produced by a single clone of cells.

A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.

Chronic glomerulonephritis characterized histologically by proliferation of MESANGIAL CELLS, increase in the MESANGIAL EXTRACELLULAR MATRIX, and a thickening of the glomerular capillary walls. This may appear as a primary disorder or secondary to other diseases including infections and autoimmune disease SYSTEMIC LUPUS ERYTHEMATOSUS. Various subtypes are classified by their abnormal ultrastructures and immune deposits. Hypocomplementemia is a characteristic feature of all types of MPGN.

Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.

Inflammation of the renal glomeruli (KIDNEY GLOMERULUS) that can be classified by the type of glomerular injuries including antibody deposition, complement activation, cellular proliferation, and glomerulosclerosis. These structural and functional abnormalities usually lead to HEMATURIA; PROTEINURIA; HYPERTENSION; and RENAL INSUFFICIENCY.

Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.

The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.

The rate dynamics in chemical or physical systems.

Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.

An endogenous 105-kDa plasma glycoprotein produced primarily by the LIVER and MONOCYTES. It inhibits a broad spectrum of proteases, including the COMPLEMENT C1R and the COMPLEMENT C1S proteases of the CLASSICAL COMPLEMENT PATHWAY, and the MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. C1-INH-deficient individuals suffer from HEREDITARY ANGIOEDEMA TYPES I AND II.

An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.

Substances elaborated by bacteria that have antigenic activity.

A mitosporic Tremellales fungal genus whose species usually have a capsule and do not form pseudomycellium. Teleomorphs include Filobasidiella and Fidobasidium.

Poisonous animal secretions forming fluid mixtures of many different enzymes, toxins, and other substances. These substances are produced in specialized glands and secreted through specialized delivery systems (nematocysts, spines, fangs, etc.) for disabling prey or predator.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

Proteins prepared by recombinant DNA technology.

Established cell cultures that have the potential to propagate indefinitely.

The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.

Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)

The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.

Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.

A species of the fungus CRYPTOCOCCUS. Its teleomorph is Filobasidiella neoformans.

A genus of gram-negative, anaerobic, rod-shaped bacteria. Its organisms are normal inhabitants of the oral, respiratory, intestinal, and urogenital cavities of humans, animals, and insects. Some species may be pathogenic.

Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.

Proteins found in any species of bacterium.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)

The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.

A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.

Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.

Physiologically inactive substances that can be converted to active enzymes.

Transport proteins that carry specific substances in the blood or across cell membranes.

A G-protein-coupled receptor that signals an increase in intracellular calcium in response to the potent ANAPHYLATOXIN peptide COMPLEMENT C5A.

The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)

BALB/C is a commonly used strain of inbred mice in medical research, known for their genetic uniformity and susceptibility to various diseases.

Procedures, such as TISSUE CULTURE TECHNIQUES; mathematical models; etc., when used or advocated for use in place of the use of animals in research or diagnostic laboratories.

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

The processes triggered by interactions of ANTIBODIES with their ANTIGENS.

A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.

Elements of limited time intervals, contributing to particular results or situations.

A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.

Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.

Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (REPERFUSION), including swelling; HEMORRHAGE; NECROSIS; and damage from FREE RADICALS. The most common instance is MYOCARDIAL REPERFUSION INJURY.

Presence of warmth or heat or a temperature notably higher than an accustomed norm.

A plasma protein that circulates in increased amounts during inflammation and after tissue damage.

Bacterial polysaccharides that are rich in phosphodiester linkages. They are the major components of the cell walls and membranes of many bacteria.

An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)

Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.

Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.

Toxins closely associated with the living cytoplasm or cell wall of certain microorganisms, which do not readily diffuse into the culture medium, but are released upon lysis of the cells.

Therapeutic practices which are not currently considered an integral part of conventional allopathic medical practice. They may lack biomedical explanations but as they become better researched some (PHYSICAL THERAPY MODALITIES; DIET; ACUPUNCTURE) become widely accepted whereas others (humors, radium therapy) quietly fade away, yet are important historical footnotes. Therapies are termed as Complementary when used in addition to conventional treatments and as Alternative when used instead of conventional treatment.

Polysaccharides are complex carbohydrates composed of long chains of monosaccharide units, with important functions in the body including energy storage, structural support, and immune response.

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

Infections with bacteria of the species STREPTOCOCCUS PNEUMONIAE.

The sum of the weight of all the atoms in a molecule.

Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.

Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.

Glycoproteins found on the membrane or surface of cells.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.

The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.

The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

Proteins isolated from the outer membrane of Gram-negative bacteria.

CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.

Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.

The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).

A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.

Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.

The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.

Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.

Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

An immune response with both cellular and humoral components, directed against an allogeneic transplant, whose tissue antigens are not compatible with those of the recipient.

The relationship between the dose of an administered drug and the response of the organism to the drug.

A derivative of complement C5a, generated when the carboxy-terminal ARGININE is removed by CARBOXYPEPTIDASE B present in normal human serum. C5a des-Arg shows complete loss of spasmogenic activity though it retains some chemotactic ability (CHEMOATTRACTANTS).

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

Interaction between terminal complement proteins C5b-7 and anionic phospholipids. (1/625)

We have recently shown that C5b-6 binds to the erythrocyte membrane via an ionic interaction with sialic acid before the addition of C7 and subsequent membrane insertion. In this study we assessed the role of anionic lipids in the binding of the terminal complement proteins to the membrane and the efficiency of subsequent hemolysis. Human erythrocytes were modified by insertion of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylserine (DPPS), dipalmitoyl phosphatidylethanolamine (DPPE), or dipalmitoyl phosphatidic acid (DPPA). Lipid incorporation and the hemolytic assays were done in the presence of 100 micromol/L sodium orthovanadate to prevent enzymatic redistribution of lipid. We found that the neutral lipids, DPPC and DPPE, did not affect C5b-7 uptake or hemolysis by C5b-9. In contrast, the two acidic phospholipids, DPPS and DPPA, caused a dose-dependent increase in both lysis and C5b-7 uptake. We conclude that the presence of anionic lipids on the exterior face of the membrane increases C5b-7 uptake and subsequent hemolysis. It is known that sickle cell erythrocytes have increased exposure of phosphatidylserine on their external face and are abnormally sensitive to lysis by C5b-9. The data presented here provide a plausible mechanism for this increased sensitivity. (+info)

Role of antibody and complement in opsonization of group B streptococci. (2/625)

A requirement for the classic complement pathway in opsonization of group B streptococci was observed by using both a chemiluminescence and a radiolabeled bacterial uptake technique. The classic pathway increased levels of opsonization for types Ia and II stock and wild strains and for some type III wild strains. In contrast, other type III wild strains and the type III stock strain had accelerated kinetics of uptake in the presence of an intact classic pathway, but the level of opsonization was unchanged from that with antibody alone. We could not demonstrate a significant role for the alternative pathway in opsonizing stock or wild strains of group B streptococci. Futhermore, electrophoretic and complement consumption analysis by hemolytic titration failed to reveal alternative pathway activation by the majority of strains of this group. Therapy aimed at supplying opsonins for these organisms will require the presence of type-specific antibody. (+info)

Cutting edge: C1q protects against the development of glomerulonephritis independently of C3 activation. (3/625)

C1q-deficient (C1qa-/-) mice develop antinuclear Abs and glomerulonephritis (GN) characterized by multiple apoptotic bodies. To explore the contribution of C3 activation to the induction of spontaneous GN, C1qa-/- mice were crossed with factor B- and C2-deficient (H2-Bf/C2-/-) mice. GN was present in 64% of the 45 C1qa/H2-Bf/C2-/- mice compared with 8% of the 65 H2-Bf/C2-/- mice and none of the 24 wild-type controls. IgG was detected in the glomeruli of diseased C1qa/H2-Bf/C2-/- kidneys. However, glomerular staining for C3 was absent. Increased numbers of glomerular apoptotic bodies were detected in undiseased C1qa/H2-Bf/C2-/- kidneys. These findings support the hypothesis that C1q may play a role in the clearance of apoptotic cells without the necessity for C3 activation and demonstrate that the activation of C3 is not essential for the development of GN in this spontaneous model of lupus-like disease. (+info)

The surface properties of Neisseria gonorrhoeae: determinants of susceptibility to antibody complement killing. (4/625)

Monovalent rabbit antisera were prepared to highly purified gonococcal lipopolysaccharide (LPS), to pili and to two major purified outer envelope proteins. All these antisera were free from significant specific IgM antibody and were standardized to 4 microgram specific IgG antibody per test, permitting accurate comparisons between the different gonococcal surface antigens as triggers of the complement-dependent bactericidal reaction. LPS was the most effective antigen at inducing a bactericidal response to homologous and heterologous gonococci, followed by the two individual outer envelope proteins. Pili were relatively ineffective. Strain P9 gonococci grown in vivo or which possessed a 'capsule' in vitro were more resistant to serum killing than the non-capsulated parent strain. One highly susceptible strain, F62, which was killed by complement in the absence of any LPS antibody, was able to directly activate complement by the alternative pathway. (+info)

Alterations in C3 activation and binding caused by phosphorylation by a casein kinase released from activated human platelets. (5/625)

A casein kinase released from activated human platelets phosphorylates a number of plasma proteins extracellularly, and that activation of platelets in systemic lupus erythematosus patients parallels an increase in the phosphate content of plasma proteins, including C3. The present study was undertaken to characterize this platelet protein kinase and to further elucidate the effect(s) on C3 function of phosphorylation by platelet casein kinase. The phosphate content of human plasma C3 was increased from 0.15 to 0.60 mol phosphate/mol of C3 after platelet activation in whole blood or platelet-rich plasma. The platelet casein kinase was distinct from other casein kinases in terms of its dependence on cations, inhibition by specific protein kinase inhibitors, and immunological reactivity. C3 that had been phosphorylated with platelet casein kinase was tested for its susceptibility to cleavage by trypsin or the classical and alternative pathway convertases and its binding to EAC and IgG. Phosphorylation did not affect the cleavage of C3 into C3a and C3b, but the binding of fragments from phosphorylated C3 to EAC14oxy2 cells and to IgG in purified systems and in serum was increased by 1.6-4.5 times over that of unphosphorylated C3. A covariation was seen between the enhanced binding of C3 fragments to IgG after phosphorylation and an increased ratio of glycerol/glycine binding, from 2.0 for unphosphorylated C3 to 4.9 for phosphorylated C3. The present study suggests that an overall effect of phosphorylation of C3 by platelet casein kinase is to enhance the opsonization of immune complexes. (+info)

Granzyme A initiates an alternative pathway for granule-mediated apoptosis. (6/625)

Granzyme (gzm) B-deficient cytotoxic lymphocytes (CTL) have a severe defect in the rapid induction of target cell apoptosis that is almost completely corrected by prolonged incubation of the CTL effectors and their targets. We show in this report that perforin-dependent, gzmB-independent cytotoxicity is caused by gzmA (or tightly linked genes). CTL deficient for gzmA and gzmB retain normal perforin function, but these CTL have a cytotoxic defect in vivo that is as severe as perforin-deficient CTL. Collectively, these results suggest that perforin provides target cell access and/or trafficking signals for the gzms, and that the gzms themselves deliver the lethal hits. The gzmA pathway appears to function independently from gzmB and may therefore provide a critical "back-up" system when gzmB is inhibited in the target cell. (+info)

The influence of complement receptor type 1 (CD35) and decay-accelerating factor (CD55) on complement receptor type 2- (CD21) mediated alternative pathway activation by B cells. (7/625)

The influence of complement receptor type 1 (CR1; CD35) and decay-accelerating factor (DAF; CD55), both down-regulators of complement activation, on the complement receptor type 2- (CR2) mediated alternative pathway (AP) activation of complement on normal B cells, was assessed. The data indicate that, while neither DAF nor CR1 hinder the function of the AP convertase formed on CR2, CR1 plays a significant role in the remodelling of C3b fragments, generated by the convertase and deposited at secondary acceptor sites on the B-cell surface, such that they become suitable ligands for CR2. The significance of this finding is briefly discussed. (+info)

Calcium-independent haemolysis via the lectin pathway of complement activation in the guinea-pig and other species*. (8/625)

We previously reported that complement-dependent haemolysis of sheep erythrocytes (E) coated with mannan (M) and sensitized with human mannan-binding lectin (MBL) via the lectin pathway in man occurs in Mg-EGTA and requires alternative pathway amplification. Calcium was required for MBL binding to E-M, but once the E-M-MBL intermediate was formed, MBL was retained and haemolysis occurred in the absence of calcium. Comparable or greater lectin pathway haemolysis in the absence of calcium was observed upon incubation of E-M-MBL in guinea-pig, rat, dog and pig sera, and was further investigated in the guinea-pig, in which titres were much higher ( approximately 14-fold) than in man, and in contrast to humans, greater than classical pathway haemolytic activity. As in human serum, no lysis was observed in C4- or C2-deficient guinea-pig serum until purified C4 or C2, respectively, were restored. However, lectin pathway haemolytic activity in the guinea-pig did not require the alternative pathway. Removal (>98%) of factor D activity by three sequential passages through Sephadex G-75, resulting in serum which retained a normal classical pathway but no alternative pathway haemolytic activity, did not reduce the ability of guinea-pig serum to mediate haemolysis via the lectin pathway. Further, the C3-convertase formed via the lectin pathway (E-M-MBL-C4,2) lysed in C2-deficient guinea-pig but not human serum chelated with EDTA, a condition which precludes alternative pathway amplification. Thus, lectin pathway haemolysis occurs efficiently in guinea-pig serum, in the absence of calcium and without requirement for alternative pathway amplification. The guinea-pig provides a model for studying the assembly and haemolytic function of a lectin pathway which contrasts with the lectin pathway of man, and allows for comparisons that may help clarify the role of this pathway in complement biology. (+info)

The complement pathway, alternative, is a series of proteins that are part of the body's immune system. It is an alternative to the classical complement pathway and is activated by the binding of mannose-binding lectin (MBL) or ficolins to specific carbohydrate patterns on the surface of pathogens. The alternative pathway plays a role in the clearance of pathogens and the recruitment of immune cells to the site of infection. It is also involved in the formation of the membrane attack complex (MAC), which can directly kill certain types of pathogens.

The complement pathway, classical, is a series of proteins that are part of the body's immune system. It is one of three pathways that work together to help the body fight off infections and remove damaged cells. The classical pathway begins when antibodies bind to specific proteins on the surface of a pathogen, such as a virus or bacteria. This binding triggers a series of reactions that ultimately lead to the destruction of the pathogen. The complement pathway is an important part of the body's defense against infection and is also involved in the inflammatory response.

Complement activation is a complex process that occurs in the immune system in response to the presence of foreign substances, such as bacteria, viruses, or other pathogens. The complement system is a group of proteins that circulate in the blood and are activated when they encounter a pathogen. There are three main pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a series of steps that ultimately lead to the formation of a membrane attack complex (MAC), which can directly destroy the pathogen or cause it to be engulfed and destroyed by immune cells. Complement activation is an important part of the immune response and helps to protect the body against infection. However, in some cases, the complement system can be overactive and cause damage to healthy cells and tissues. This can occur in conditions such as autoimmune diseases, where the immune system mistakenly attacks the body's own cells, or in certain types of infections, where the complement system is activated inappropriately.

Complement C3 is a protein that plays a crucial role in the immune system's defense against infections. It is one of the proteins that make up the complement system, a series of proteins that work together to help the immune system identify and destroy invading pathogens. C3 is synthesized in the liver and circulates in the bloodstream. When it encounters a pathogen, it becomes activated and splits into two fragments: C3a and C3b. C3a is a small protein that acts as a signaling molecule, attracting immune cells to the site of infection and promoting inflammation. C3b, on the other hand, binds to the surface of the pathogen and helps to recruit other immune cells to destroy it. In medical testing, the level of complement C3 in the blood can be measured to help diagnose and monitor certain medical conditions. For example, low levels of C3 can be a sign of complement deficiency, which can increase the risk of infections. High levels of C3 can be a sign of certain autoimmune disorders, such as lupus or rheumatoid arthritis.

The complement system is a complex network of proteins that plays a crucial role in the immune system's defense against infections. Complement system proteins are a group of proteins that are produced by the liver and other cells in the body and circulate in the blood. These proteins work together to identify and destroy invading pathogens, such as bacteria and viruses, by forming a membrane attack complex (MAC) that punctures the pathogen's cell membrane, causing it to burst and die. There are several different types of complement system proteins, including: 1. Complement proteins: These are the primary components of the complement system and include C1, C2, C3, C4, C5, C6, C7, C8, and C9. 2. Complement regulatory proteins: These proteins help to control the activation of the complement system and prevent it from attacking healthy cells. Examples include C1 inhibitor, C4 binding protein, and decay-accelerating factor. 3. Complement receptors: These proteins are found on the surface of immune cells and help to bind to and activate complement proteins. Examples include CR1, CR2, and CR3. Complement system proteins play a critical role in the immune response and are involved in a wide range of diseases, including autoimmune disorders, infections, and cancer.

Complement C4 is a protein that is part of the complement system, which is a group of proteins that work together to help the immune system fight off infections. The complement system is activated when the body recognizes a foreign substance, such as a virus or bacteria, and begins to attack it. Complement C4 is one of several proteins that are produced in response to this activation, and it plays a role in the destruction of the foreign substance by helping to recruit other immune cells to the site of the infection.

Complement Factor B (CFB) is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and remove damaged cells. CFB is a soluble protein that is produced by the liver and circulates in the bloodstream. In the complement system, CFB is involved in the activation of the alternative pathway, which is one of three pathways that can activate the complement system. The alternative pathway is activated when antibodies bind to foreign substances on the surface of cells, and CFB helps to amplify the immune response by promoting the formation of a complex that leads to the activation of other complement proteins. Deficiencies in CFB can lead to a condition called complement factor B deficiency, which can result in recurrent infections and other immune system disorders.

Complement C1q is a protein that plays a central role in the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. C1q is a component of the C1 complex, which is the first step in the activation of the complement system. When C1q binds to a pathogen or damaged cell, it triggers a cascade of events that leads to the destruction of the pathogen or cell by the immune system. C1q is also involved in the regulation of the complement system, helping to prevent overactivation and damage to healthy cells.

The complement pathway, mannose-binding lectin (MBL) is a part of the innate immune system that helps to defend the body against infections. It is a complex protein that recognizes and binds to specific carbohydrates on the surface of microorganisms, such as bacteria and viruses. When MBL binds to these carbohydrates, it triggers a cascade of chemical reactions that ultimately leads to the destruction of the microorganism. The complement pathway, MBL is an important part of the body's defense against infections and plays a role in the development of certain autoimmune diseases.

Complement C2 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. Complement C2 is a component of the classical pathway of the complement system, which is activated by the binding of antibodies to the surface of pathogens or damaged cells. Complement C2 is synthesized in the liver and circulates in the blood as a soluble protein. When the classical pathway is activated, Complement C2 is cleaved into two fragments, C2a and C2b. C2b then binds to C4b, which is another component of the complement system, to form a complex that can bind to the surface of pathogens or damaged cells. Once bound to the surface of a pathogen or damaged cell, the complement system is activated, leading to the formation of a membrane attack complex (MAC) that can destroy the pathogen or cell. Complement C2 is also involved in other immune responses, such as the recruitment of immune cells to sites of infection or injury. In summary, Complement C2 is a protein that plays a critical role in the complement system, which helps to defend the body against infections and other harmful substances.

Complement C3b is a protein fragment that is generated when the complement system, a part of the immune system, is activated. The complement system is a complex network of proteins that work together to help the body fight off infections and remove damaged or abnormal cells. C3b is produced when the complement protein C3 is cleaved by enzymes in the complement system. C3b plays an important role in the complement system by binding to the surface of pathogens or damaged cells and marking them for destruction by immune cells. It also helps to recruit immune cells to the site of infection or injury and can activate other components of the complement system to enhance the immune response. In the medical field, C3b is often measured as a marker of complement system activation. Abnormal levels of C3b can be associated with a variety of medical conditions, including autoimmune disorders, infections, and certain types of cancer.

Complement C1 is a protein complex that plays a central role in the complement system, which is a part of the immune system that helps to defend the body against infections. C1 is composed of three proteins: C1q, C1r, and C1s. When a pathogen enters the body, the complement system is activated, and C1 binds to the pathogen's surface. This binding triggers a series of chemical reactions that ultimately lead to the destruction of the pathogen. C1 is also involved in the regulation of the complement system, helping to prevent excessive activation and damage to healthy cells. Deficiencies in C1 can lead to increased susceptibility to infections and other immune-related disorders.

Complement C5 is a protein that plays a crucial role in the immune system's response to infections and inflammation. It is one of the proteins in the complement system, a group of proteins that work together to help the immune system identify and destroy invading pathogens. Complement C5 is produced by immune cells and is activated when it comes into contact with the surface of a pathogen. Once activated, it cleaves into two fragments, C5a and C5b, which then trigger a series of reactions that lead to the destruction of the pathogen. C5a is a potent inflammatory mediator that attracts immune cells to the site of infection and stimulates the release of other inflammatory molecules. C5b, on the other hand, is a key component of the membrane attack complex (MAC), which forms a pore in the membrane of the pathogen, leading to its destruction. Complement C5 is also involved in other immune processes, such as the clearance of immune complexes from the bloodstream and the regulation of inflammation. Deficiencies in complement C5 can lead to increased susceptibility to infections and autoimmune diseases.

Complement inactivator proteins are a group of proteins that regulate the complement system, a part of the immune system that helps to defend the body against infections. These proteins act as inhibitors, preventing the complement system from attacking healthy cells and tissues. They are important for maintaining immune homeostasis and preventing autoimmune diseases. Examples of complement inactivator proteins include C1 inhibitor, C4 binding protein, and decay accelerating factor.

Complement Factor D (CFD) is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and remove damaged cells. CFD is also known as complement factor Bb or membrane attack complex (MAC) convertase. CFD is synthesized in the liver and circulates in the blood as an inactive form. When it encounters a pathogen or damaged cell, it is activated by proteolytic cleavage, which generates two active fragments: C3 convertase and C5 convertase. These convertases cleave other complement proteins, leading to the formation of the membrane attack complex (MAC), which can directly lyse the pathogen or damaged cell. In addition to its role in the complement system, CFD has also been implicated in the development of various diseases, including age-related macular degeneration, atherosclerosis, and systemic lupus erythematosus. Therefore, CFD is an important target for the development of new therapies for these diseases.

In the medical field, Complement C3-C5 Convertases are enzymes that play a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. The complement system consists of a series of proteins that work together to identify and eliminate pathogens, such as bacteria and viruses. Complement C3-C5 Convertases are enzymes that cleave and activate certain complement proteins, including C3 and C5, which are essential components of the complement system. There are two types of Complement C3-C5 Convertases: the classical pathway convertase and the alternative pathway convertase. The classical pathway convertase is formed when antibodies bind to antigens on the surface of a pathogen, while the alternative pathway convertase is activated spontaneously. Once activated, Complement C3-C5 Convertases cleave C3 and C5 into smaller fragments, which then interact with other complement proteins to form a membrane attack complex (MAC) that can directly destroy the pathogen. The complement system also plays a role in inflammation and the recruitment of immune cells to the site of infection. Complement C3-C5 Convertases are important for the proper functioning of the complement system, and defects in these enzymes can lead to a variety of immune disorders, such as complement deficiency diseases and autoimmune diseases.

Properdin is a protein that plays a crucial role in the innate immune system. It is produced by the liver and circulates in the blood. Properdin is a component of the alternative pathway of complement activation, which is a series of chemical reactions that help to destroy invading pathogens. Properdin enhances the ability of the complement system to activate the alternative pathway by binding to the surface of pathogens and promoting the assembly of a complex called the "membrane attack complex" (MAC). The MAC is a group of proteins that form a pore in the membrane of the pathogen, leading to its destruction. Properdin is also involved in the regulation of the complement system, helping to prevent excessive activation and damage to host cells. It has been implicated in a number of autoimmune and inflammatory diseases, including lupus, rheumatoid arthritis, and vasculitis.

Complement Factor H (CFH) is a protein that plays a critical role in the complement system, which is a part of the immune system that helps to defend the body against infections. CFH is a soluble protein that is present in the blood and helps to regulate the activity of the complement system by inhibiting the formation of the membrane attack complex (MAC), which is a group of proteins that can cause damage to cells and tissues. CFH is also involved in the regulation of inflammation and the immune response, and it has been implicated in a number of diseases, including age-related macular degeneration (AMD), a common eye disorder that can lead to vision loss, and atypical hemolytic uremic syndrome (aHUS), a rare and life-threatening disorder that can cause kidney failure and other complications. In addition to its role in the complement system, CFH has also been shown to have anti-inflammatory and anti-apoptotic effects, and it may play a role in the development of other diseases, such as cancer and neurodegenerative disorders.

Receptors, Complement refers to a group of proteins that are part of the complement system, a complex network of proteins in the blood that helps to defend the body against infections. These receptors are located on the surface of immune cells, such as macrophages and neutrophils, and bind to specific molecules on the surface of pathogens, such as bacteria and viruses. This binding triggers a series of reactions that ultimately lead to the destruction of the pathogen. The complement receptors play a crucial role in the immune response and are important for the clearance of pathogens from the body.

The Complement Membrane Attack Complex (MAC) is a group of proteins that are part of the complement system, a complex series of proteins in the blood that help the immune system fight off infections. The MAC is formed when certain complement proteins, called terminal complement proteins, come together to form a pore in the membrane of a pathogen, such as a virus or bacteria. This pore allows ions, water, and other molecules to flow out of the pathogen, ultimately leading to its destruction. The MAC is an important part of the body's defense against infections and is also involved in the regulation of the immune response.

Complement C6 is a protein that is part of the complement system, which is a complex network of proteins in the blood that helps to defend the body against infections. The complement system is activated when pathogens, such as bacteria or viruses, enter the body, and it works to destroy them by forming a membrane attack complex (MAC) that punctures the pathogen's cell membrane, causing it to burst and die. Complement C6 is one of several proteins that are involved in the formation of the MAC. It is produced by the liver and other cells in the body, and it plays a critical role in the complement system by helping to stabilize the MAC and promote its insertion into the pathogen's cell membrane. Abnormalities in the complement system, including defects in complement C6, can lead to a variety of medical conditions, including complement-mediated diseases such as atypical hemolytic uremic syndrome (aHUS) and membranoproliferative glomerulonephritis (MPGN). These conditions can cause a range of symptoms, including kidney damage, blood clots, and an increased risk of infections.

Complement C4b is a protein that is part of the complement system, a complex series of proteins that plays a role in the body's immune response. The complement system helps to identify and destroy foreign substances, such as bacteria and viruses, that enter the body. C4b is one of several proteins that are produced when the complement system is activated. It is produced when C4, another protein in the complement system, is cleaved by an enzyme called C1s. C4b is then attached to the surface of a pathogen, marking it for destruction by other components of the complement system. C4b is also involved in the formation of the membrane attack complex (MAC), which is a group of proteins that form a pore in the membrane of a pathogen, causing it to burst and be destroyed. The MAC is one of the most powerful weapons in the complement system, and it is able to destroy even highly resistant pathogens. In addition to its role in the immune response, C4b has been implicated in a number of other biological processes, including inflammation, cell signaling, and the regulation of the complement system itself.

Complement C3b Inactivator Proteins (C3bI) are a group of proteins that play a role in regulating the complement system, which is a part of the immune system that helps to defend the body against infections. The complement system is activated when pathogens enter the body, and it works by tagging pathogens with molecules that mark them for destruction by immune cells. C3bI proteins help to inactivate a specific complement protein called C3b, which is involved in this tagging process. By inactivating C3b, C3bI proteins help to prevent the overactivation of the complement system, which can cause damage to healthy cells and tissues. C3bI proteins are important for maintaining the balance of the immune system and preventing it from attacking the body's own cells.

Complement activating enzymes are a group of proteins that are part of the complement system, a complex series of proteins that plays a crucial role in the immune response. These enzymes are responsible for activating the complement system, which helps to destroy pathogens and remove damaged cells from the body. There are several different complement activating enzymes, including: 1. Complement C1: This enzyme is composed of three subunits, C1q, C1r, and C1s. When it binds to a pathogen or damaged cell, it triggers a cascade of reactions that ultimately leads to the destruction of the target. 2. Mannose-binding lectin (MBL): This enzyme is part of the lectin pathway of the complement system, which is activated by the presence of specific carbohydrates on the surface of pathogens. MBL binds to these carbohydrates and triggers a series of reactions that lead to the destruction of the pathogen. 3. Complement C3 convertase: This enzyme is responsible for converting the complement protein C3 into C3a and C3b, which are key components of the complement system. C3a is an anaphylatoxin that helps to recruit immune cells to the site of infection, while C3b helps to bind the pathogen to immune cells and facilitate its destruction. Complement activating enzymes play a critical role in the immune response and are involved in a wide range of diseases, including autoimmune disorders, infections, and cancer.

The Complement Hemolytic Activity Assay (CH50) is a laboratory test used to measure the ability of the complement system to lyse (break down) red blood cells. The complement system is a group of proteins that work together to help the body fight infections and remove damaged cells. The CH50 test is often used to diagnose and monitor certain types of autoimmune diseases, such as lupus, and to evaluate the effectiveness of certain medications that affect the complement system. The test involves mixing a sample of a person's blood with a solution that contains complement proteins and measuring the amount of hemolysis (breakdown of red blood cells) that occurs over time. The results of the test can help healthcare providers determine the underlying cause of a person's symptoms and guide treatment decisions.

Complement C9 is a protein that is part of the complement system, which is a group of proteins that plays a role in the immune system's defense against infections. The complement system is activated when pathogens, such as bacteria or viruses, enter the body, and it helps to destroy the pathogens by forming a membrane attack complex (MAC) that punctures the pathogen's cell membrane, causing it to burst and die. Complement C9 is the final component of the MAC, and it is responsible for forming the central pore in the complex that allows the other components to pass through and puncture the pathogen's cell membrane. Complement C9 is produced by the liver and other cells in the body, and it is stored in inactive form until it is activated by the complement system. Deficiencies in complement C9 can lead to increased susceptibility to infections, while excessive activation of the complement system can cause damage to healthy cells and tissues.

Complement inactivating agents are substances that interfere with the complement system, a part of the immune system that helps to destroy pathogens and remove damaged cells. The complement system consists of a series of proteins that are activated in response to an infection or injury. Complement inactivating agents can either prevent the activation of the complement system or inhibit the activity of the complement proteins once they have been activated. There are several types of complement inactivating agents, including: 1. Complement inhibitors: These are proteins that bind to and inhibit the activity of complement proteins. Examples include C1 esterase inhibitors, which prevent the activation of the complement component C1, and factor H, which inhibits the activity of C3 convertase, an enzyme that cleaves the complement protein C3. 2. Complement receptor blockers: These are molecules that bind to complement receptors on the surface of immune cells and prevent them from activating the complement system. Examples include soluble complement receptor 1 (sCR1), which binds to C3b, a complement protein that is involved in the opsonization of pathogens, and complement receptor 2 (CR2), which binds to C3d, a complement protein that is involved in the activation of B cells. 3. Complement depleting agents: These are substances that remove complement proteins from the blood or tissue. Examples include eculizumab, a monoclonal antibody that targets complement protein C5 and is used to treat paroxysmal nocturnal hemoglobinuria (PNH), a rare blood disorder, and rituximab, a monoclonal antibody that targets CD20, a protein on the surface of B cells, and is used to treat certain types of cancer. Complement inactivating agents are used to treat a variety of conditions, including autoimmune diseases, inflammatory disorders, and certain types of cancer. They can help to reduce inflammation and prevent the destruction of healthy cells by the immune system. However, they can also increase the risk of infections, as the complement system plays an important role in the body's defense against pathogens.

Alternative splicing is a process that occurs during the maturation of messenger RNA (mRNA) molecules in eukaryotic cells. It involves the selective inclusion or exclusion of specific exons (coding regions) from the final mRNA molecule, resulting in the production of different protein isoforms from a single gene. In other words, alternative splicing allows a single gene to code for multiple proteins with different functions, structures, and cellular locations. This process is essential for the regulation of gene expression and the diversification of protein functions in eukaryotic organisms. Mutations or abnormalities in the splicing machinery can lead to the production of abnormal protein isoforms, which can contribute to the development of various diseases, including cancer, neurological disorders, and genetic diseases. Therefore, understanding the mechanisms of alternative splicing is crucial for the development of new therapeutic strategies for these diseases.

Mannose-binding protein-associated serine proteases (MASPs) are a family of proteases that are involved in the complement system, a part of the immune system that helps to protect the body against infections. These proteases are activated by mannose-binding protein (MBP), a protein that is produced by the liver and circulates in the blood.（MBP），。

Complement C3a is a protein that is produced as a result of the activation of the complement system, which is a part of the immune system. The complement system is a series of proteins that work together to help the body fight off infections and other foreign substances. C3a is one of several complement proteins that are produced when the complement system is activated. It is a small protein that is released from the larger complement protein C3 when it is cleaved by enzymes. C3a has several functions in the immune system, including attracting immune cells to the site of an infection, promoting the release of other immune system molecules, and helping to regulate the immune response. In the medical field, C3a is often measured as a way to assess the activity of the complement system. Abnormal levels of C3a can be associated with a variety of medical conditions, including autoimmune disorders, infections, and certain types of cancer.

Mannose-binding lectin (MBL) is a protein that plays a role in the innate immune system. It is produced by the liver and circulates in the blood, where it binds to specific carbohydrate structures on the surface of microorganisms, such as bacteria and viruses. This binding triggers a series of immune responses, including the activation of complement proteins and the recruitment of immune cells to the site of infection. MBL is also involved in the clearance of damaged or apoptotic cells from the body. Deficiencies in MBL can increase the risk of infections and autoimmune diseases.

Complement C3c is a protein that is a part of the complement system, which is a complex series of proteins that plays a role in the body's immune response. The complement system helps to identify and destroy foreign substances, such as bacteria and viruses, that enter the body. Complement C3c is a cleavage product of the larger complement protein C3, which is produced by the liver and other cells in the body. When the complement system is activated, C3 is cleaved into several smaller fragments, including C3c. C3c is an important component of the complement system because it can bind to the surface of pathogens and help to recruit immune cells to the site of infection. It can also help to activate other components of the complement system, which can lead to the destruction of the pathogen. Abnormal levels of complement C3c can be associated with a variety of medical conditions, including autoimmune disorders, infections, and certain types of cancer. In some cases, measuring complement C3c levels may be useful for diagnosing or monitoring these conditions.

Complement C1 Inactivator Proteins (C1INH) are a group of proteins that play a crucial role in regulating the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. The complement system consists of a series of proteins that work together to identify and eliminate pathogens, such as bacteria and viruses. C1INH is a plasma protein that is produced by the liver and circulates in the bloodstream. It functions as an inhibitor of the complement system by binding to and neutralizing the activity of complement protein C1, which is the first protein activated in the complement cascade. By inhibiting the activity of C1, C1INH helps to prevent the overactivation of the complement system, which can lead to tissue damage and inflammation. Deficiencies or mutations in C1INH can lead to a condition called hereditary angioedema (HAE), which is characterized by recurrent episodes of swelling in the face, extremities, and other parts of the body. HAE can be life-threatening if left untreated, as it can cause difficulty breathing and other serious complications. Treatment for HAE typically involves the administration of C1INH replacement therapy, which can help to prevent or reduce the severity of attacks.

Complement C3d is a protein fragment that is generated when the complement system, a part of the immune system, is activated. The complement system is a complex network of proteins that work together to help the body fight off infections and remove damaged or abnormal cells. C3d is produced when the complement protein C3 is cleaved by an enzyme called C3 convertase. This cleavage event releases C3d from the larger C3 protein molecule. C3d is an important component of the complement system because it helps to bind complement proteins to the surface of pathogens or damaged cells, marking them for destruction by other components of the complement system. In the medical field, C3d is often measured as a marker of complement activation. Abnormal levels of C3d in the blood can be an indication of certain medical conditions, such as autoimmune disorders, infections, or kidney disease.

Complement C5a is a protein that is produced as a result of the activation of the complement system, which is a part of the immune system. The complement system is a series of proteins that work together to help the body fight off infections and other foreign substances. Complement C5a is a potent inflammatory mediator that is involved in the recruitment of immune cells to the site of infection or injury. It does this by binding to receptors on the surface of immune cells, such as neutrophils and macrophages, and triggering a signaling cascade that leads to the release of these cells from the blood vessels and their migration to the site of inflammation. Complement C5a also has other functions, such as promoting the activation of the complement system and enhancing the ability of immune cells to phagocytose (engulf and destroy) pathogens. In the medical field, complement C5a is often measured as a marker of inflammation and immune system activation. It is also being studied as a potential therapeutic target for a variety of conditions, including autoimmune diseases, infections, and cancer.

Hemolysis is the breakdown of red blood cells (RBCs) in the bloodstream. This process can occur due to various factors, including mechanical stress, exposure to certain medications or toxins, infections, or inherited genetic disorders. When RBCs are damaged or destroyed, their contents, including hemoglobin, are released into the bloodstream. Hemoglobin is a protein that carries oxygen from the lungs to the body's tissues and carbon dioxide from the tissues back to the lungs. When hemoglobin is released into the bloodstream, it can cause the blood to appear dark brown or black, a condition known as hemoglobinuria. Hemolysis can lead to a variety of symptoms, including jaundice (yellowing of the skin and eyes), fatigue, shortness of breath, abdominal pain, and dark urine. In severe cases, hemolysis can cause life-threatening complications, such as kidney failure or shock. Treatment for hemolysis depends on the underlying cause. In some cases, treatment may involve medications to slow down the breakdown of RBCs or to remove excess hemoglobin from the bloodstream. In other cases, treatment may involve blood transfusions or other supportive therapies to manage symptoms and prevent complications.

Opsonin proteins are a type of immune system protein that play a role in the process of phagocytosis, which is the process by which immune cells called phagocytes engulf and destroy foreign particles, such as bacteria or viruses. Opsonins bind to the surface of these foreign particles, marking them for destruction by phagocytes. This process is known as opsonization. There are several different types of opsonin proteins, including antibodies, complement proteins, and mannose-binding lectin (MBL). Antibodies are proteins produced by the immune system in response to the presence of a foreign substance, such as a virus or bacteria. They bind to specific molecules on the surface of these foreign particles, marking them for destruction by phagocytes. Complement proteins are a group of proteins that are part of the innate immune system. They are produced by the liver and other organs and circulate in the blood. Complement proteins can bind to foreign particles and mark them for destruction by phagocytes. MBL is a protein that is produced by the liver and circulates in the blood. It binds to specific molecules on the surface of foreign particles, marking them for destruction by phagocytes. Opsonin proteins play an important role in the immune system by helping to identify and destroy foreign particles. They are an important part of the body's defense against infection and disease.

Blood bactericidal activity refers to the ability of the immune system to destroy and eliminate bacteria present in the bloodstream. This process is primarily carried out by white blood cells, such as neutrophils and monocytes, which release enzymes and other substances that can break down and kill bacteria. The blood bactericidal activity is an important defense mechanism against bacterial infections that can spread throughout the body and cause serious illness or even death. It is also a key factor in determining the outcome of sepsis, a life-threatening condition that occurs when the body's response to an infection leads to widespread inflammation and organ damage. In medical research, blood bactericidal activity is often measured in vitro, using laboratory cultures of bacteria and blood samples from patients. This can help researchers understand how the immune system responds to different types of bacteria and identify potential targets for new treatments.

Receptors, Complement 3b (CR3b) are a type of immune cell receptor found on the surface of certain white blood cells, such as neutrophils and macrophages. These receptors bind to complement protein C3b, which is a component of the complement system, a part of the immune system that helps to identify and destroy pathogens. CR3b receptors play an important role in the immune response by recognizing and binding to C3b-coated pathogens, such as bacteria and viruses. This binding triggers a series of events that lead to the destruction of the pathogen, including the release of chemicals that attract other immune cells to the site of infection and the formation of a membrane attack complex that can directly damage the pathogen. CR3b receptors are also involved in the process of phagocytosis, in which immune cells engulf and destroy pathogens. By binding to C3b-coated pathogens, CR3b receptors help to facilitate the engulfment of the pathogen by the immune cell. In addition to their role in the immune response, CR3b receptors have been implicated in a number of other physiological processes, including the regulation of blood clotting and the clearance of apoptotic cells (cells that are undergoing programmed cell death).

Complement fixation tests are a type of serological test used in the medical field to detect the presence of specific antibodies in a patient's blood. These tests are based on the principle that antibodies can bind to specific antigens, causing a change in the complement system, a group of proteins that play a role in the immune response. In a complement fixation test, a known amount of antigen is mixed with a patient's serum, and the mixture is then incubated to allow the antibodies in the serum to bind to the antigen. The bound antibodies then activate the complement system, which leads to the formation of a visible precipitate or clot. The amount of precipitate or clot formed is proportional to the amount of antibodies present in the serum. Complement fixation tests are used to diagnose a variety of infectious diseases, including syphilis, rheumatic fever, and Lyme disease. They are also used to detect the presence of certain types of cancer, such as Hodgkin's lymphoma and multiple myeloma. These tests are generally considered to be highly specific, meaning that they are less likely to produce false-positive results than other types of serological tests. However, they may be less sensitive, meaning that they may produce false-negative results in some cases.

In the medical field, "Complement C1s" refers to a specific protein component of the complement system, which is a group of proteins that play a crucial role in the immune system's defense against infections and other harmful substances. The complement system is activated when pathogens or damaged cells are present in the body, and it works by forming a membrane attack complex (MAC) that can directly destroy the pathogen or infected cell. Complement C1s is one of the first proteins to be activated in the complement cascade, and it helps to initiate the formation of the MAC. Complement C1s is typically measured in blood tests as a way to assess the overall function of the complement system and to diagnose or monitor certain medical conditions, such as autoimmune disorders, infections, and certain types of cancer. Abnormal levels of complement C1s can indicate problems with the complement system, which may require further investigation and treatment.

Complement Factor I (C1) is a protein complex that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and remove damaged cells. C1 is composed of three subunits: C1q, C1r, and C1s. When a pathogen enters the body, it triggers the activation of the complement system, which leads to the formation of a cascade of proteins that ultimately results in the destruction of the pathogen. C1 is the first protein in this cascade to be activated, and it plays a critical role in identifying and binding to the pathogen. Once C1 binds to the pathogen, it triggers the activation of C1r and C1s, which then cleave and activate other complement proteins, leading to the formation of a membrane attack complex (MAC) that can directly destroy the pathogen. C1 also plays a role in regulating the complement system by inhibiting its activation in the absence of a pathogen. In summary, Complement Factor I (C1) is a protein complex that plays a critical role in the complement system, which helps to defend the body against infections and remove damaged cells. It is the first protein in the complement cascade to be activated and plays a critical role in identifying and binding to pathogens.

Complement C4b-Binding Protein (C4BP) is a plasma protein that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections. C4BP is a soluble protein that binds to the complement protein C4b, which is a key component of the complement cascade. The complement system is a complex network of proteins that work together to identify and eliminate pathogens, such as bacteria and viruses, from the body. When a pathogen enters the body, the complement system is activated, leading to the production of various proteins that help to destroy the pathogen. C4BP plays a critical role in regulating the complement system by inhibiting the activity of the complement protein C3 convertase, which is responsible for cleaving the complement protein C3 into C3a and C3b. C3b is an important component of the complement cascade that helps to opsonize pathogens and promote their clearance by phagocytic cells. In addition to its role in regulating the complement system, C4BP has been implicated in a number of other biological processes, including inflammation, coagulation, and the regulation of immune cell function. Dysregulation of C4BP has been associated with a number of diseases, including autoimmune disorders, thrombotic disorders, and infections.

Zymosan is a polysaccharide derived from the cell walls of yeasts and other fungi. It is commonly used in medical research as an activator of the immune system, particularly in the study of inflammation and autoimmune diseases. When zymosan is injected into the body, it triggers an immune response that involves the release of various inflammatory mediators, such as cytokines and chemokines. This response can be used to study the function of immune cells and the signaling pathways involved in inflammation. Zymosan has also been used in clinical trials as a potential treatment for various conditions, including rheumatoid arthritis, psoriasis, and sepsis. However, more research is needed to fully understand its therapeutic potential and potential side effects.

Complement C3 convertase, alternative pathway is an enzyme that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections. The complement system is made up of a series of proteins that work together to identify and destroy foreign substances, such as bacteria and viruses. The alternative pathway is one of three pathways that can activate the complement system. It is activated when the complement protein C3 is cleaved into two fragments, C3a and C3b, by the enzyme complement C3 convertase, alternative pathway. This cleavage event triggers a cascade of reactions that ultimately leads to the formation of the membrane attack complex (MAC), which can destroy the cell membrane of invading pathogens. Complement C3 convertase, alternative pathway is composed of two proteins, C3b and factor B, which are activated by the binding of the complement protein C3 to the surface of a pathogen. Once activated, the enzyme cleaves C3 into C3a and C3b, which then triggers the rest of the complement cascade. In summary, complement C3 convertase, alternative pathway is an enzyme that plays a critical role in activating the complement system and helping to defend the body against infections.

Complement C5b is a protein that plays a central role in the complement system, which is a part of the immune system that helps to defend the body against infections. C5b is produced when the complement system is activated, and it is involved in the formation of a membrane attack complex (MAC) that can cause lysis (rupture) of cells. The MAC is formed by the assembly of multiple complement proteins, including C5b, on the surface of a pathogen or infected cell. The MAC can then create pores in the cell membrane, leading to the influx of water and ions and ultimately causing the cell to burst. C5b is also involved in the recruitment of immune cells to the site of infection and in the clearance of immune complexes from the body.

Complement C4a is a protein that is produced as part of the complement system, which is a group of proteins that plays a role in the immune response. C4a is produced when the complement system is activated, and it functions as an inflammatory mediator, helping to recruit immune cells to the site of infection or injury. C4a can also help to activate other components of the complement system, amplifying the immune response. In the medical field, levels of C4a can be measured in blood tests as a way to assess the activity of the complement system and to diagnose or monitor certain conditions, such as autoimmune diseases or infections.

CD55 is a protein that is expressed on the surface of many different types of cells in the body, including immune cells, blood cells, and cells in the nervous system. It is also known as decay-accelerating factor (DAF) because it has the ability to accelerate the decay of complement proteins, which are part of the body's immune system. Antigens, CD55 refers to molecules that bind to the CD55 protein on the surface of cells. These antigens can be recognized by the immune system as foreign and can trigger an immune response. In some cases, the immune system may attack cells that express CD55 as a result of an autoimmune disorder, which is a condition in which the immune system mistakenly attacks healthy cells in the body.

Cobra venoms are toxic substances produced by cobras, a group of venomous snakes found in various parts of the world. These venoms contain a complex mixture of proteins, enzymes, and other molecules that can cause a range of physiological effects in humans and other animals. The effects of cobra venom can vary depending on the species of cobra, the dose of venom injected, and the individual's health status. Some common effects of cobra venom include pain, swelling, and muscle spasms at the site of the bite, as well as more systemic effects such as nausea, vomiting, dizziness, and difficulty breathing. In the medical field, cobra venom is studied for its potential therapeutic uses, such as in the development of new drugs for pain management, anti-inflammatory treatments, and cancer therapies. However, cobra venom is also a significant health hazard, and bites from venomous cobras can be life-threatening if not treated promptly and appropriately. Treatment typically involves antivenom therapy, which is designed to neutralize the venom and prevent its harmful effects on the body.

An antigen-antibody complex is a type of immune complex that forms when an antigen (a foreign substance that triggers an immune response) binds to an antibody (a protein produced by the immune system to recognize and neutralize antigens). When an antigen enters the body, it is recognized by specific antibodies that bind to it, forming an antigen-antibody complex. This complex can then be targeted by other immune cells, such as phagocytes, which engulf and destroy the complex. Antigen-antibody complexes can also deposit in tissues, leading to inflammation and damage. This can occur in conditions such as immune complex-mediated diseases, where the immune system mistakenly attacks healthy tissues that have been coated with antigens and antibodies. Overall, the formation of antigen-antibody complexes is a normal part of the immune response, but when it becomes dysregulated, it can lead to a variety of medical conditions.

Immunoglobulin G (IgG) is a type of protein that is produced by the immune system in response to the presence of foreign substances, such as bacteria, viruses, and toxins. It is the most abundant type of immunoglobulin in the blood and is responsible for the majority of the body's defense against infections. IgG is produced by B cells, which are a type of white blood cell that plays a key role in the immune response. When a B cell encounters a foreign substance, it produces IgG antibodies that can recognize and bind to the substance, marking it for destruction by other immune cells. IgG antibodies can also be transferred from mother to child through the placenta during pregnancy, providing the baby with some protection against infections during the first few months of life. In addition, some vaccines contain IgG antibodies to help stimulate the immune system and provide protection against specific diseases. Overall, IgG is an important component of the immune system and plays a critical role in protecting the body against infections and diseases.

Collectins are a family of proteins that are part of the innate immune system. They are found in the extracellular fluid, including the blood, and are involved in the recognition and clearance of pathogens, such as bacteria and viruses. Collectins are characterized by their ability to bind to carbohydrates on the surface of microorganisms, which helps to aggregate them and facilitate their clearance by immune cells. There are several different types of collectins, including mannose-binding lectin (MBL), surfactant protein D (SP-D), and collectin-11 (CL-11). Collectins play an important role in the body's defense against infection and are also involved in the regulation of inflammation.

Complement C1r is a protein that plays a role in the complement system, which is a part of the immune system that helps to defend the body against infections. The complement system is made up of a series of proteins that work together to identify and destroy foreign substances, such as bacteria and viruses. C1r is one of several proteins that make up the first step in the complement system, known as the classical pathway. When C1r is activated, it cleaves another protein called C1s, which then cleaves a third protein called C4. This cleavage event triggers a cascade of reactions that ultimately leads to the destruction of the foreign substance. Complement C1r is encoded by the "C1R" gene, which is located on chromosome 19 in humans. Mutations in the "C1R" gene can lead to a deficiency in C1r, which can result in a weakened immune system and an increased susceptibility to infections.

Complement C7 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. The complement system is made up of a series of proteins that work together to identify and destroy foreign invaders, such as bacteria and viruses. Complement C7 is one of the proteins in the terminal complement pathway, which is the final stage of the complement system's attack on invaders. In this pathway, Complement C7 is activated by the binding of other complement proteins to the surface of a pathogen, and it then helps to form a membrane attack complex (MAC) that punctures the pathogen's cell membrane, leading to its destruction. Complement C7 deficiency can result in a weakened immune system and an increased susceptibility to infections. It is a rare genetic disorder that is inherited in an autosomal recessive pattern, meaning that an individual must inherit two copies of the defective gene (one from each parent) in order to develop the condition.

Lectins are a class of proteins that are found in many plants, animals, and microorganisms. They are characterized by their ability to bind to specific carbohydrates, such as sugars and starches, on the surface of cells. In the medical field, lectins have been studied for their potential therapeutic applications. For example, some lectins have been shown to have antiviral, antibacterial, and antifungal properties, and may be useful in the development of new drugs to treat infections. Lectins have also been used as research tools to study cell-cell interactions and to identify specific cell surface markers. In addition, some lectins have been used in diagnostic tests to detect specific diseases or conditions, such as cancer or diabetes. However, it is important to note that not all lectins are safe or effective for medical use, and some may even be toxic. Therefore, the use of lectins in medicine requires careful consideration and testing to ensure their safety and efficacy.

Complement C8 is a protein that is part of the complement system, which is a group of proteins that work together to help the immune system fight off infections. The complement system is made up of several proteins, including C8, that are present in the blood and other body fluids. When the immune system detects the presence of a pathogen, such as a virus or bacteria, it triggers the complement system to activate and help destroy the pathogen. C8 plays a role in this process by helping to form a membrane attack complex, which is a structure that punctures the cell membrane of the pathogen, causing it to burst and be destroyed.

Anaphylatoxins are a group of small proteins that are released by mast cells and basophils in response to an allergen or other inflammatory stimulus. They are also known as complement system activation products because they are produced as part of the complement system, a complex series of proteins that plays a role in the immune response. There are five main anaphylatoxins: histamine, heparin, platelet-activating factor (PAF), leukotrienes, and prostaglandins. These molecules act on various cells in the body, including blood vessels, smooth muscle cells, and immune cells, to cause a range of symptoms, including itching, redness, swelling, and constriction of blood vessels. Anaphylatoxins are involved in many allergic reactions, including hay fever, food allergies, and asthma. They can also play a role in other inflammatory conditions, such as sepsis and shock. Treatment for anaphylatoxin reactions typically involves antihistamines, corticosteroids, and other medications to reduce inflammation and counteract the effects of the anaphylatoxins.

CD46 is a protein found on the surface of many different types of cells in the body, including immune cells, epithelial cells, and endothelial cells. It is a member of the complement regulatory protein family and plays a role in regulating the immune system's response to infections and other stimuli. Antigens, CD46 refers to molecules that bind to the CD46 protein on the surface of cells. These antigens can be recognized by the immune system as foreign and trigger an immune response. In some cases, the immune system may mistakenly attack cells that express CD46, leading to autoimmune diseases such as lupus or Goodpasture's syndrome. CD46 is also a target for certain viruses, such as measles virus, which uses it to enter and infect cells. Vaccines against measles virus often contain a small amount of inactivated or weakened measles virus that binds to CD46 on cells, triggering an immune response without causing the disease. Overall, CD46 plays an important role in regulating the immune system and is a target for both the immune system and certain viruses.

CD59 is a protein that is expressed on the surface of many types of cells in the body, including red blood cells, white blood cells, and platelets. It is a member of the complement regulatory protein family, which helps to control the activation of the complement system, a part of the immune system that helps to fight off infections. Antigens, CD59 refers to molecules that bind to the CD59 protein on the surface of cells. These antigens can be recognized by the immune system as foreign and can trigger an immune response, leading to the production of antibodies that can bind to and neutralize the antigens. In some cases, the immune system may mistakenly recognize CD59 itself as an antigen and attack cells that express it, leading to a condition known as autoimmune hemolytic anemia, in which the immune system destroys red blood cells.

Receptors, Complement 3d, also known as C3d receptors, are proteins found on the surface of certain immune cells, such as B cells and macrophages. These receptors bind to the complement protein C3d, which is generated during the complement cascade, a series of chemical reactions that occurs in response to an infection or injury. The binding of C3d to its receptor on immune cells triggers a signaling cascade that activates the immune response. This can include the activation of B cells, which leads to the production of antibodies, and the recruitment of immune cells to the site of infection or injury. C3d receptors are important for the proper functioning of the immune system, as they help to amplify and direct the immune response. Mutations in the genes encoding C3d receptors have been associated with various immune disorders, including autoimmune diseases and infections.

Immunoglobulin M (IgM) is a type of antibody that is produced by B cells in response to an infection or foreign substance. It is the first antibody to be produced during an immune response and is present in the blood and other body fluids in relatively low concentrations. IgM antibodies are large, Y-shaped molecules that can bind to multiple antigens at once, making them highly effective at neutralizing pathogens and marking them for destruction by other immune cells. They are also able to activate the complement system, a series of proteins that can directly destroy pathogens or mark them for destruction by immune cells. IgM antibodies are often used as a diagnostic tool in medical testing, as they are typically the first antibodies to be produced in response to a new infection. They can also be used to monitor the effectiveness of vaccines and to detect the presence of certain diseases, such as viral or bacterial infections, autoimmune disorders, and certain types of cancer.

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Polysaccharides, bacterial are complex carbohydrates that are produced by bacteria. They are composed of long chains of sugar molecules and can be found in the cell walls of many bacterial species. Some common examples of bacterial polysaccharides include peptidoglycan, lipopolysaccharide, and teichoic acid. These molecules play important roles in the structure and function of bacterial cells, and they can also have medical significance. For example, lipopolysaccharide is a component of the outer membrane of certain gram-negative bacteria and can trigger an immune response in the body. In some cases, bacterial polysaccharides can also be used as vaccines to protect against bacterial infections.

Cryoglobulins are abnormal proteins that form deposits in the blood vessels when the temperature drops. They are typically found in the blood plasma and can cause a variety of symptoms, including joint pain, skin rashes, and fatigue. Cryoglobulins are often associated with certain medical conditions, such as hepatitis C, lymphoma, and autoimmune disorders. Treatment for cryoglobulinemia typically involves addressing the underlying cause of the condition and managing the symptoms.

In the medical field, an amino acid sequence refers to the linear order of amino acids in a protein molecule. Proteins are made up of chains of amino acids, and the specific sequence of these amino acids determines the protein's structure and function. The amino acid sequence is determined by the genetic code, which is a set of rules that specifies how the sequence of nucleotides in DNA is translated into the sequence of amino acids in a protein. Each amino acid is represented by a three-letter code, and the sequence of these codes is the amino acid sequence of the protein. The amino acid sequence is important because it determines the protein's three-dimensional structure, which in turn determines its function. Small changes in the amino acid sequence can have significant effects on the protein's structure and function, and this can lead to diseases or disorders. For example, mutations in the amino acid sequence of a protein involved in blood clotting can lead to bleeding disorders.

Antibodies, Bacterial are proteins produced by the immune system in response to bacterial infections. They are also known as bacterial antibodies or bacterial immunoglobulins. These antibodies are specific to bacterial antigens, which are molecules found on the surface of bacteria that trigger an immune response. When the immune system detects a bacterial infection, it produces antibodies that bind to the bacterial antigens and mark them for destruction by other immune cells. This helps to neutralize the bacteria and prevent them from causing harm to the body. Bacterial antibodies can be detected in the blood or other bodily fluids using laboratory tests. These tests are often used to diagnose bacterial infections and to monitor the effectiveness of antibiotic treatments.

Macular degeneration is a medical condition that affects the macula, which is the central part of the retina in the eye responsible for sharp, central vision. There are two main types of macular degeneration: dry and wet. Dry macular degeneration is the most common form and is characterized by the gradual accumulation of small yellow deposits called drusen in the macula. These deposits can cause the retina to thin and the macula to become damaged, leading to a loss of central vision. Wet macular degeneration is less common but more severe. It occurs when abnormal blood vessels grow beneath the retina and leak fluid or blood, causing damage to the macula and leading to a rapid loss of vision. Both forms of macular degeneration can be treated, but the best course of action depends on the severity of the condition and the individual patient's needs. Treatment options may include lifestyle changes, medications, or surgery.

Blood physiological phenomena refer to the various processes and functions that occur within the circulatory system, which is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. These phenomena include: 1. Blood flow: The movement of blood through the circulatory system, which is regulated by the heart and blood vessels. 2. Blood pressure: The force exerted by blood against the walls of blood vessels, which is influenced by factors such as heart rate, blood volume, and resistance in the blood vessels. 3. Blood viscosity: The thickness or stickiness of blood, which is influenced by factors such as the concentration of red blood cells and plasma proteins. 4. Hemodynamics: The study of the mechanical and physiological properties of blood flow, including blood pressure, blood flow rate, and resistance in the blood vessels. 5. Oxygen transport: The process by which oxygen is transported from the lungs to the body's tissues, which involves the binding of oxygen to hemoglobin in red blood cells. 6. Carbon dioxide transport: The process by which carbon dioxide is transported from the body's tissues to the lungs for elimination, which involves the binding of carbon dioxide to hemoglobin in red blood cells. 7. Coagulation: The process by which blood clots form to prevent excessive bleeding, which involves a complex series of chemical reactions involving platelets, clotting factors, and fibrin. 8. Hemostasis: The process by which blood flow is restored after injury or damage to a blood vessel, which involves the formation of a clot to seal the damaged area. Overall, blood physiological phenomena are essential for maintaining the health and function of the circulatory system and the body as a whole.

Edetic acid, also known as ethylenediaminetetraacetic acid (EDTA), is a synthetic organic acid that is commonly used in the medical field as a chelating agent. It is a colorless, water-soluble solid that is used to dissolve minerals and other metal ions in solution. In medicine, EDTA is often used to treat heavy metal poisoning, such as lead or mercury poisoning, by binding to the metal ions and facilitating their excretion from the body. It is also used as an anticoagulant in blood tests and as a component of certain contrast agents used in diagnostic imaging procedures. EDTA is available in various forms, including tablets, capsules, and intravenous solutions. It is generally considered safe when used as directed, but high doses or prolonged use can cause side effects such as nausea, vomiting, and allergic reactions.

Immunoglobulins, also known as antibodies, are proteins produced by the immune system in response to the presence of foreign substances, such as viruses, bacteria, and toxins. They are Y-shaped molecules that recognize and bind to specific antigens, which are molecules found on the surface of pathogens. There are five main classes of immunoglobulins: IgG, IgA, IgM, IgD, and IgE. Each class has a unique structure and function, and they are produced by different types of immune cells in response to different types of pathogens. Immunoglobulins play a critical role in the immune response by neutralizing pathogens, marking them for destruction by other immune cells, and activating the complement system, which helps to destroy pathogens. They are also used in medical treatments, such as immunoglobulin replacement therapy for patients with primary immunodeficiencies, and in the development of vaccines and monoclonal antibodies for the treatment of various diseases.

Mannans are a type of polysaccharide, which are complex carbohydrates made up of long chains of sugar molecules. In the medical field, mannans are often used as a dietary supplement or as an ingredient in certain medications. Mannans are found in many foods, including fruits, vegetables, and grains, but they are also produced by certain types of fungi and bacteria. Some studies have suggested that mannans may have immune-boosting properties and may be beneficial for people with certain health conditions, such as allergies, autoimmune disorders, and cancer. In the medical field, mannans are sometimes used as an ingredient in dietary supplements or as an active ingredient in certain medications. For example, some dietary supplements contain mannan-chitosan complexes, which are believed to help reduce cholesterol levels and improve digestion. Mannans are also used in some medications to treat certain types of infections, such as fungal infections of the skin and nails. It's important to note that while mannans may have potential health benefits, more research is needed to fully understand their effects on the body. As with any dietary supplement or medication, it's important to talk to a healthcare provider before starting to take mannans or any other supplement or medication.

Macrophage-1 Antigen (Mac-1) is a protein that is expressed on the surface of certain immune cells, including macrophages and neutrophils. It is also known as CD11b/CD18 or CR3 (complement receptor 3). Mac-1 plays a role in the immune system by mediating the adhesion and migration of immune cells to sites of inflammation or infection. It also plays a role in the recognition and phagocytosis of pathogens by immune cells. In the medical field, Mac-1 is often used as a diagnostic marker for certain diseases, such as sepsis, and as a target for the development of new therapies for inflammatory and infectious diseases.

Antibodies, also known as immunoglobulins, are proteins produced by the immune system in response to the presence of foreign substances, such as viruses, bacteria, and other pathogens. Antibodies are designed to recognize and bind to specific molecules on the surface of these foreign substances, marking them for destruction by other immune cells. There are five main classes of antibodies: IgG, IgA, IgM, IgD, and IgE. Each class of antibody has a unique structure and function, and they are produced by different types of immune cells in response to different types of pathogens. Antibodies play a critical role in the immune response, helping to protect the body against infection and disease. They can neutralize pathogens by binding to them and preventing them from entering cells, or they can mark them for destruction by other immune cells. In some cases, antibodies can also help to stimulate the immune response by activating immune cells or by recruiting other immune cells to the site of infection. Antibodies are often used in medical treatments, such as in the development of vaccines, where they are used to stimulate the immune system to produce a response to a specific pathogen. They are also used in diagnostic tests to detect the presence of specific pathogens or to monitor the immune response to a particular treatment.

Serum Amyloid P-Component (SAP) is a glycoprotein that is produced by the liver and secreted into the bloodstream. It is a component of amyloid deposits, which are abnormal protein aggregates that can form in various tissues throughout the body. SAP is a key component of the amyloid fibrils that are found in amyloidosis, a group of diseases characterized by the accumulation of amyloid deposits in various organs and tissues. SAP is also involved in the immune response and has been shown to play a role in the pathogenesis of certain inflammatory and autoimmune diseases.

Mannose-binding lectins (MBLs) are a group of proteins that are produced by the liver and play an important role in the innate immune system. They are part of the complement system, which is a complex network of proteins that helps to defend the body against infections. MBLs are able to bind to specific carbohydrate structures on the surface of microorganisms, such as bacteria and viruses, and mark them for destruction by other components of the immune system. They also play a role in activating the complement system, which helps to recruit immune cells to the site of infection and promote inflammation. In the medical field, MBLs are often measured as a way to assess the body's ability to mount an immune response. Low levels of MBLs have been associated with an increased risk of infections, while high levels have been linked to certain autoimmune disorders. MBLs are also being studied as potential targets for the development of new treatments for infectious diseases and other conditions.

Monoclonal antibodies (mAbs) are laboratory-made proteins that can mimic the immune system's ability to fight off harmful pathogens, such as viruses and bacteria. They are produced by genetically engineering cells to produce large quantities of a single type of antibody, which is specific to a particular antigen (a molecule that triggers an immune response). In the medical field, monoclonal antibodies are used to treat a variety of conditions, including cancer, autoimmune diseases, and infectious diseases. They can be administered intravenously, intramuscularly, or subcutaneously, depending on the condition being treated. Monoclonal antibodies work by binding to specific antigens on the surface of cells or pathogens, marking them for destruction by the immune system. They can also block the activity of specific molecules involved in disease processes, such as enzymes or receptors. Overall, monoclonal antibodies have revolutionized the treatment of many diseases, offering targeted and effective therapies with fewer side effects than traditional treatments.

Sialic acids are a group of nine-carbon sugar molecules that are commonly found on the surface of many types of cells in the human body. They are attached to proteins and lipids on the surface of cells, and play important roles in a variety of biological processes. In the medical field, sialic acids are often studied in relation to a number of different diseases and conditions. For example, certain types of cancer cells are known to overproduce sialic acids, which can make them more resistant to immune system attack. Sialic acids have also been linked to the development of autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis. In addition, sialic acids are important for the function of the immune system. They are involved in the recognition and binding of pathogens by immune cells, and play a role in the activation of immune responses. Sialic acids are also important for the proper functioning of the nervous system, and have been linked to the development of neurological disorders such as Alzheimer's disease. Overall, sialic acids are an important class of molecules that play a variety of roles in the human body, and are the subject of ongoing research in the medical field.

Membranoproliferative glomerulonephritis (MPGN) is a type of kidney disease that affects the glomeruli, which are the tiny filtering units in the kidneys. In MPGN, there is inflammation and proliferation of cells in the glomerular basement membrane, which can lead to thickening and scarring of the membrane. This can impair the glomeruli's ability to filter waste products from the blood, leading to a buildup of toxins in the body. MPGN can be caused by a variety of factors, including infections, autoimmune disorders, and certain medications. Treatment typically involves managing symptoms and addressing the underlying cause of the disease.

Glomerulonephritis is a type of kidney disease that involves inflammation of the glomeruli, which are tiny blood vessels in the kidneys responsible for filtering waste products from the blood. This inflammation can cause damage to the glomeruli, leading to a range of symptoms and complications. There are many different types of glomerulonephritis, which can be classified based on their underlying cause. Some common causes include infections (such as strep throat or hepatitis B), autoimmune disorders (such as lupus or rheumatoid arthritis), and certain medications or toxins. Symptoms of glomerulonephritis can vary depending on the severity and underlying cause of the condition. Common symptoms may include blood in the urine, swelling in the legs or feet, high blood pressure, fatigue, and changes in urine output. Treatment for glomerulonephritis typically involves managing symptoms and addressing the underlying cause of the inflammation. This may include medications to reduce inflammation, control blood pressure, and prevent further damage to the kidneys. In some cases, more aggressive treatments such as dialysis or kidney transplantation may be necessary.

Glycoproteins are a type of protein that contains one or more carbohydrate chains covalently attached to the protein molecule. These carbohydrate chains are made up of sugars and are often referred to as glycans. Glycoproteins play important roles in many biological processes, including cell signaling, cell adhesion, and immune response. They are found in many different types of cells and tissues throughout the body, and are often used as markers for various diseases and conditions. In the medical field, glycoproteins are often studied as potential targets for the development of new drugs and therapies.

In the medical field, a base sequence refers to the specific order of nucleotides (adenine, thymine, cytosine, and guanine) that make up the genetic material (DNA or RNA) of an organism. The base sequence determines the genetic information encoded within the DNA molecule and ultimately determines the traits and characteristics of an individual. The base sequence can be analyzed using various techniques, such as DNA sequencing, to identify genetic variations or mutations that may be associated with certain diseases or conditions.

Blood proteins are proteins that are found in the blood plasma of humans and other animals. They play a variety of important roles in the body, including transporting oxygen and nutrients, regulating blood pressure, and fighting infections. There are several different types of blood proteins, including albumin, globulins, and fibrinogen. Each type of blood protein has a specific function and is produced by different cells in the body. For example, albumin is produced by the liver and helps to maintain the osmotic pressure of the blood, while globulins are produced by the immune system and help to fight infections. Fibrinogen, on the other hand, is produced by the liver and is involved in the clotting of blood.

Complement C1 Inhibitor Protein (C1INH) is a plasma protein that plays a crucial role in regulating the complement system, which is a part of the immune system that helps to defend the body against infections and other harmful substances. C1INH acts as an inhibitor of the complement component C1, which is the first enzyme activated in the complement cascade. When C1 is activated, it triggers a series of reactions that can lead to inflammation and tissue damage. C1INH binds to C1 and prevents it from activating, thus inhibiting the complement cascade and reducing inflammation. C1INH deficiency or dysfunction can lead to a condition called hereditary angioedema (HAE), which is characterized by recurrent episodes of swelling in the face, extremities, and other parts of the body. HAE can be life-threatening if left untreated.

In the medical field, "Antigens, Bacterial" refers to substances that are produced by bacteria and can trigger an immune response in the body. These antigens can be proteins, polysaccharides, lipids, or nucleic acids that are unique to a particular bacterial species or strain. When bacteria enter the body, the immune system recognizes these antigens as foreign and mounts a defense against them. This response can include the production of antibodies by B cells, which can neutralize the bacteria or mark them for destruction by other immune cells. The immune response to bacterial antigens is an important part of the body's defense against bacterial infections. Bacterial antigens are used in a variety of medical applications, including the development of vaccines to prevent bacterial infections. By introducing a small amount of a bacterial antigen into the body, vaccines can stimulate the immune system to produce a response that will protect against future infections by the same bacteria.

Cryptococcus is a genus of fungi that can cause a variety of infections in humans and animals. Cryptococcus species are commonly found in soil, bird droppings, and the air, and can be transmitted to humans through inhalation of spores or by contact with contaminated surfaces. Cryptococcosis is the medical term used to describe infections caused by Cryptococcus. The most common form of cryptococcosis is cryptococcal meningitis, which occurs when the fungus enters the brain and spinal cord through the bloodstream. Other forms of cryptococcosis include pulmonary cryptococcosis (infection of the lungs), disseminated cryptococcosis (infection of multiple organs), and cryptococcal skin infections. Cryptococcosis can be a serious and potentially life-threatening infection, particularly in people with weakened immune systems, such as those with HIV/AIDS or cancer. Treatment typically involves antifungal medications, such as fluconazole or amphotericin B, and may also include supportive care to manage symptoms and complications.

In the medical field, venoms are toxic substances produced by certain animals, such as snakes, spiders, scorpions, and some fish, that are injected into their prey or predators through specialized structures called venom glands. These venoms contain a complex mixture of proteins, enzymes, and other molecules that can cause a range of physiological effects in the victim, including pain, swelling, paralysis, and even death. Venoms are often used as a defense mechanism by animals to protect themselves from predators or to subdue their prey. In some cases, venoms are also used for hunting or as a means of communication between animals. In medicine, venoms are studied for their potential therapeutic uses, such as in the development of new drugs for pain relief, anti-inflammatory, and anti-cancer treatments. However, venoms can also be dangerous and can cause serious harm or death if not treated properly. Therefore, medical professionals must be trained in the proper handling and treatment of venomous animals and their bites or stings.

Recombinant proteins are proteins that are produced by genetically engineering bacteria, yeast, or other organisms to express a specific gene. These proteins are typically used in medical research and drug development because they can be produced in large quantities and are often more pure and consistent than proteins that are extracted from natural sources. Recombinant proteins can be used for a variety of purposes in medicine, including as diagnostic tools, therapeutic agents, and research tools. For example, recombinant versions of human proteins such as insulin, growth hormones, and clotting factors are used to treat a variety of medical conditions. Recombinant proteins can also be used to study the function of specific genes and proteins, which can help researchers understand the underlying causes of diseases and develop new treatments.

In the medical field, a cell line refers to a group of cells that have been derived from a single parent cell and have the ability to divide and grow indefinitely in culture. These cells are typically grown in a laboratory setting and are used for research purposes, such as studying the effects of drugs or investigating the underlying mechanisms of diseases. Cell lines are often derived from cancerous cells, as these cells tend to divide and grow more rapidly than normal cells. However, they can also be derived from normal cells, such as fibroblasts or epithelial cells. Cell lines are characterized by their unique genetic makeup, which can be used to identify them and compare them to other cell lines. Because cell lines can be grown in large quantities and are relatively easy to maintain, they are a valuable tool in medical research. They allow researchers to study the effects of drugs and other treatments on specific cell types, and to investigate the underlying mechanisms of diseases at the cellular level.

In the medical field, blood refers to the liquid component of the circulatory system that carries oxygen, nutrients, hormones, and waste products throughout the body. It is composed of red blood cells, white blood cells, platelets, and plasma. Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs. White blood cells, also known as leukocytes, are part of the immune system and help protect the body against infections and diseases. Platelets, also known as thrombocytes, are involved in blood clotting and help prevent excessive bleeding. Plasma is the liquid portion of blood that contains water, proteins, electrolytes, and other substances. Blood is collected through a process called phlebotomy, which involves drawing blood from a vein using a needle. Blood can be used for a variety of medical tests and procedures, including blood typing, blood transfusions, and the diagnosis of various medical conditions.

Lipopolysaccharides (LPS) are a type of complex carbohydrate found on the surface of gram-negative bacteria. They are composed of a lipid A moiety, a core polysaccharide, and an O-specific polysaccharide. LPS are important components of the bacterial cell wall and play a role in the innate immune response of the host. In the medical field, LPS are often studied in the context of sepsis, a life-threatening condition that occurs when the body's response to an infection causes widespread inflammation. LPS can trigger a strong immune response in the host, leading to the release of pro-inflammatory cytokines and other mediators that can cause tissue damage and organ failure. As a result, LPS are often used as a model for studying the pathophysiology of sepsis and for developing new treatments for this condition. LPS are also used in research as a tool for studying the immune system and for developing vaccines against bacterial infections. They can be purified from bacterial cultures and used to stimulate immune cells in vitro or in animal models, allowing researchers to study the mechanisms of immune responses to bacterial pathogens. Additionally, LPS can be used as an adjuvant in vaccines to enhance the immune response to the vaccine antigen.

Antibody specificity refers to the ability of an antibody to recognize and bind to a specific antigen or foreign substance. Antibodies are proteins produced by the immune system in response to the presence of an antigen, such as a virus or bacteria. Each antibody is unique and has a specific shape that allows it to recognize and bind to a specific antigen. Antibody specificity is important in the immune response because it ensures that the immune system can distinguish between self and non-self molecules. This helps to prevent the immune system from attacking the body's own cells and tissues, which can lead to autoimmune diseases. Antibody specificity is also important in the development of vaccines. Vaccines contain weakened or inactivated forms of a pathogen or its antigens, which stimulate the immune system to produce antibodies that can recognize and neutralize the pathogen if it is encountered in the future. By selecting antigens that are specific to a particular pathogen, vaccines can help to protect against a wide range of infections.

In the medical field, RNA, Messenger (mRNA) refers to a type of RNA molecule that carries genetic information from DNA in the nucleus of a cell to the ribosomes, where proteins are synthesized. During the process of transcription, the DNA sequence of a gene is copied into a complementary RNA sequence called messenger RNA (mRNA). This mRNA molecule then leaves the nucleus and travels to the cytoplasm of the cell, where it binds to ribosomes and serves as a template for the synthesis of a specific protein. The sequence of nucleotides in the mRNA molecule determines the sequence of amino acids in the protein that is synthesized. Therefore, changes in the sequence of nucleotides in the mRNA molecule can result in changes in the amino acid sequence of the protein, which can affect the function of the protein and potentially lead to disease. mRNA molecules are often used in medical research and therapy as a way to introduce new genetic information into cells. For example, mRNA vaccines work by introducing a small piece of mRNA that encodes for a specific protein, which triggers an immune response in the body.

Magnesium is a mineral that is essential for many bodily functions. It is involved in over 300 enzymatic reactions in the body, including the production of energy, the synthesis of proteins and DNA, and the regulation of muscle and nerve function. In the medical field, magnesium is used to treat a variety of conditions, including: 1. Hypomagnesemia: A deficiency of magnesium in the blood. This can cause symptoms such as muscle cramps, spasms, and seizures. 2. Cardiac arrhythmias: Abnormal heart rhythms that can be caused by low levels of magnesium. 3. Pre-eclampsia: A condition that can occur during pregnancy and is characterized by high blood pressure and protein in the urine. Magnesium supplementation may be used to treat this condition. 4. Chronic kidney disease: Magnesium is often lost in the urine of people with chronic kidney disease, and supplementation may be necessary to maintain adequate levels. 5. Alcohol withdrawal: Magnesium supplementation may be used to treat symptoms of alcohol withdrawal, such as tremors and seizures. 6. Muscle spasms: Magnesium can help to relax muscles and relieve spasms. 7. Anxiety and depression: Some studies have suggested that magnesium supplementation may help to reduce symptoms of anxiety and depression. Magnesium is available in various forms, including oral tablets, capsules, and intravenous solutions. It is important to note that high levels of magnesium can also be toxic, so it is important to use magnesium supplements under the guidance of a healthcare provider.

In the medical field, binding sites refer to specific locations on the surface of a protein molecule where a ligand (a molecule that binds to the protein) can attach. These binding sites are often formed by a specific arrangement of amino acids within the protein, and they are critical for the protein's function. Binding sites can be found on a wide range of proteins, including enzymes, receptors, and transporters. When a ligand binds to a protein's binding site, it can cause a conformational change in the protein, which can alter its activity or function. For example, a hormone may bind to a receptor protein, triggering a signaling cascade that leads to a specific cellular response. Understanding the structure and function of binding sites is important in many areas of medicine, including drug discovery and development, as well as the study of diseases caused by mutations in proteins that affect their binding sites. By targeting specific binding sites on proteins, researchers can develop drugs that modulate protein activity and potentially treat a wide range of diseases.

Immune sera refers to a type of blood serum that contains antibodies produced by the immune system in response to an infection or vaccination. These antibodies are produced by B cells, which are a type of white blood cell that plays a key role in the immune response. Immune sera can be used to diagnose and treat certain infections, as well as to prevent future infections. For example, immune sera containing antibodies against a specific virus or bacteria can be used to diagnose a current infection or to prevent future infections in people who have been exposed to the virus or bacteria. Immune sera can also be used as a research tool to study the immune response to infections and to develop new vaccines and treatments. In some cases, immune sera may be used to treat patients with severe infections or allergies, although this is less common than using immune sera for diagnostic or preventive purposes.

In the medical field, "Disease Models, Animal" refers to the use of animals to study and understand human diseases. These models are created by introducing a disease or condition into an animal, either naturally or through experimental manipulation, in order to study its progression, symptoms, and potential treatments. Animal models are used in medical research because they allow scientists to study diseases in a controlled environment and to test potential treatments before they are tested in humans. They can also provide insights into the underlying mechanisms of a disease and help to identify new therapeutic targets. There are many different types of animal models used in medical research, including mice, rats, rabbits, dogs, and monkeys. Each type of animal has its own advantages and disadvantages, and the choice of model depends on the specific disease being studied and the research question being addressed.

Cryptococcus neoformans is a type of fungus that can cause a serious infection in humans and animals. It is commonly found in the environment, particularly in soil and bird droppings, and can be inhaled into the lungs. The fungus can also cause infections in other parts of the body, such as the brain and spinal cord, and can be life-threatening if left untreated. Infections caused by Cryptococcus neoformans are typically treated with antifungal medications.

Bacteroides is a genus of Gram-negative, rod-shaped bacteria that are commonly found in the human gut microbiota. They are one of the most abundant bacterial groups in the human colon and play an important role in the digestion of complex carbohydrates. Bacteroides are known for their ability to break down complex polysaccharides, such as cellulose and pectin, into simpler sugars that can be absorbed by the body. They also produce short-chain fatty acids, such as butyrate, propionate, and acetate, which are important for maintaining gut health and regulating the immune system. In the medical field, Bacteroides are sometimes associated with certain diseases, such as periodontitis (gum disease) and colorectal cancer. However, most strains of Bacteroides are considered to be harmless or even beneficial to human health. In fact, some strains of Bacteroides are being studied for their potential use in probiotics and other therapeutic applications.

Bacterial proteins are proteins that are synthesized by bacteria. They are essential for the survival and function of bacteria, and play a variety of roles in bacterial metabolism, growth, and pathogenicity. Bacterial proteins can be classified into several categories based on their function, including structural proteins, metabolic enzymes, regulatory proteins, and toxins. Structural proteins provide support and shape to the bacterial cell, while metabolic enzymes are involved in the breakdown of nutrients and the synthesis of new molecules. Regulatory proteins control the expression of other genes, and toxins can cause damage to host cells and tissues. Bacterial proteins are of interest in the medical field because they can be used as targets for the development of antibiotics and other antimicrobial agents. They can also be used as diagnostic markers for bacterial infections, and as vaccines to prevent bacterial diseases. Additionally, some bacterial proteins have been shown to have therapeutic potential, such as enzymes that can break down harmful substances in the body or proteins that can stimulate the immune system.

Mannose is a simple sugar that is a monosaccharide with the chemical formula C6H12O6. It is a component of many complex carbohydrates, including glycans and glycoproteins, which are found in the human body and play important roles in various biological processes. In the medical field, mannose is used as a diagnostic tool to detect certain diseases and conditions. For example, it is used in the diagnosis of certain types of cancer, such as ovarian cancer, by detecting changes in the levels of mannose in the blood or urine. Mannose is also used in the treatment of certain conditions, such as diabetes, by helping to regulate blood sugar levels. It is also used in the development of vaccines and as a component of some dietary supplements. In addition, mannose has been shown to have anti-inflammatory and immune-boosting properties, which may make it useful in the treatment of a variety of conditions, including infections, autoimmune diseases, and allergies.

Binding sites, antibody, refer to the specific regions on the surface of an antibody molecule that are responsible for recognizing and binding to a particular antigen or foreign substance. These binding sites are highly specific and complementary in shape and charge to the antigen they recognize, allowing for a strong and stable interaction between the antibody and antigen. The binding of an antibody to its specific antigen is a key step in the immune response, as it allows the immune system to identify and neutralize foreign invaders such as viruses and bacteria.

Enzyme precursors are the inactive forms of enzymes that are synthesized in the body and need to be activated before they can perform their specific functions. Enzymes are proteins that catalyze chemical reactions in the body, and they play a crucial role in various physiological processes such as digestion, metabolism, and energy production. Enzyme precursors are usually synthesized in the liver and other organs and are transported to the cells where they are needed. Once inside the cells, they are activated by a process called proteolysis, which involves the cleavage of specific amino acid bonds in the enzyme precursor molecule. Enzyme precursors are important for maintaining proper enzyme function and activity in the body. Deficiencies in enzyme precursors can lead to enzyme deficiencies, which can cause a range of health problems. For example, a deficiency in the enzyme precursor for the enzyme lactase can lead to lactose intolerance, a condition in which the body is unable to digest lactose, a sugar found in milk and other dairy products.

In the medical field, carrier proteins are proteins that transport molecules across cell membranes or within cells. These proteins bind to specific molecules, such as hormones, nutrients, or waste products, and facilitate their movement across the membrane or within the cell. Carrier proteins play a crucial role in maintaining the proper balance of molecules within cells and between cells. They are involved in a wide range of physiological processes, including nutrient absorption, hormone regulation, and waste elimination. There are several types of carrier proteins, including facilitated diffusion carriers, active transport carriers, and ion channels. Each type of carrier protein has a specific function and mechanism of action. Understanding the role of carrier proteins in the body is important for diagnosing and treating various medical conditions, such as genetic disorders, metabolic disorders, and neurological disorders.

The receptor for Anaphylatoxin C5a, also known as C5aR, is a protein found on the surface of various cells in the immune system. It is a G protein-coupled receptor that binds to the inflammatory mediator Anaphylatoxin C5a, which is produced during the complement cascade, a series of chemical reactions that occurs in response to an infection or injury. When C5a binds to its receptor, it triggers a cascade of intracellular signaling events that activate various immune cells, such as neutrophils and macrophages, and promote inflammation. This can lead to the recruitment of immune cells to the site of infection or injury, the release of inflammatory mediators, and the destruction of pathogens. C5aR is also expressed on non-immune cells, such as endothelial cells and epithelial cells, and can play a role in regulating various physiological processes, such as blood pressure and inflammation. In some cases, excessive activation of C5aR can lead to the development of various inflammatory diseases, such as atherosclerosis and asthma.

Animal testing alternatives refer to methods used in the medical field to conduct research and testing on drugs, medical devices, and other products without using animals. These alternatives are designed to reduce or eliminate the use of animals in research and testing, while still providing accurate and reliable results. There are several types of animal testing alternatives, including: 1. In vitro testing: This involves using cells, tissues, or organs from animals or humans to test the safety and efficacy of drugs or other products. 2. Computer modeling and simulation: This involves using computer programs to simulate the effects of drugs or other products on the human body. 3. Microdosing: This involves giving very small doses of a drug to humans to test its safety and efficacy. 4. Human volunteer studies: This involves testing drugs or other products on human volunteers to gather data on their safety and efficacy. 5. Non-animal testing methods: This includes methods such as the use of alternative models, such as organ-on-a-chip technology, to test the safety and efficacy of drugs and other products. Animal testing alternatives are becoming increasingly popular in the medical field as more people recognize the ethical concerns associated with animal testing and the potential for alternative methods to provide accurate and reliable results.

In the medical field, a peptide fragment refers to a short chain of amino acids that are derived from a larger peptide or protein molecule. Peptide fragments can be generated through various techniques, such as enzymatic digestion or chemical cleavage, and are often used in diagnostic and therapeutic applications. Peptide fragments can be used as biomarkers for various diseases, as they may be present in the body at elevated levels in response to specific conditions. For example, certain peptide fragments have been identified as potential biomarkers for cancer, neurodegenerative diseases, and cardiovascular disease. In addition, peptide fragments can be used as therapeutic agents themselves. For example, some peptide fragments have been shown to have anti-inflammatory or anti-cancer properties, and are being investigated as potential treatments for various diseases. Overall, peptide fragments play an important role in the medical field, both as diagnostic tools and as potential therapeutic agents.

In the medical field, "Cells, Cultured" refers to cells that have been grown and maintained in a controlled environment outside of their natural biological context, typically in a laboratory setting. This process is known as cell culture and involves the isolation of cells from a tissue or organism, followed by their growth and proliferation in a nutrient-rich medium. Cultured cells can be derived from a variety of sources, including human or animal tissues, and can be used for a wide range of applications in medicine and research. For example, cultured cells can be used to study the behavior and function of specific cell types, to develop new drugs and therapies, and to test the safety and efficacy of medical products. Cultured cells can be grown in various types of containers, such as flasks or Petri dishes, and can be maintained at different temperatures and humidity levels to optimize their growth and survival. The medium used to culture cells typically contains a combination of nutrients, growth factors, and other substances that support cell growth and proliferation. Overall, the use of cultured cells has revolutionized medical research and has led to many important discoveries and advancements in the field of medicine.

In the medical field, an antigen-antibody reaction refers to the interaction between a foreign substance, called an antigen, and a protein produced by the immune system called an antibody. Antigens are typically proteins or carbohydrates found on the surface of viruses, bacteria, or other foreign substances that enter the body. When the immune system detects an antigen, it produces antibodies that specifically bind to that antigen. This binding can neutralize the antigen, mark it for destruction by immune cells, or activate other immune responses. Antibodies are produced by B cells, a type of white blood cell in the immune system. Each B cell produces a specific type of antibody that can bind to a specific antigen. Once an antibody binds to an antigen, it forms an antigen-antibody complex, which can be detected by laboratory tests. Antigen-antibody reactions play a critical role in the immune response to infections and other foreign substances. They are also used in medical treatments, such as immunotherapy, where antibodies are used to target specific antigens on cancer cells or other harmful substances.

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder that affects multiple organs and systems in the body. It is characterized by the production of autoantibodies that attack healthy cells and tissues, leading to inflammation and damage. The symptoms of SLE can vary widely and may include joint pain and swelling, skin rashes, fatigue, fever, and kidney problems. Other possible symptoms may include chest pain, shortness of breath, headaches, and memory problems. SLE can affect people of all ages and ethnicities, but it is more common in women than in men. There is no known cure for SLE, but treatment can help manage symptoms and prevent complications. Treatment may include medications to reduce inflammation, suppress the immune system, and prevent blood clots. In some cases, hospitalization may be necessary to manage severe symptoms or complications.

Immunoglobulin Fab fragments, also known as Fab fragments or Fabs, are a type of protein that is derived from the variable regions of the heavy and light chains of an immunoglobulin (antibody). They are composed of two antigen-binding sites, which are responsible for recognizing and binding to specific antigens. Fab fragments are often used in medical research and diagnostic testing because they have a high specificity for their target antigens and can be easily produced and purified. They are also used in the development of therapeutic antibodies, as they can be engineered to have a variety of functions, such as delivering drugs to specific cells or tissues. In addition to their use in research and diagnostic testing, Fab fragments have also been used in the treatment of various diseases, including cancer, autoimmune disorders, and infectious diseases. They are typically administered intravenously or intramuscularly and can be used alone or in combination with other therapies.

Reperfusion injury is a type of damage that occurs when blood flow is restored to an organ or tissue that has been deprived of oxygen for a prolonged period of time. This can happen during a heart attack, stroke, or other conditions that cause blood flow to be blocked to a particular area of the body. When blood flow is restored, it can cause an inflammatory response in the affected tissue, leading to the release of free radicals and other harmful substances that can damage cells and tissues. This can result in a range of symptoms, including swelling, pain, and organ dysfunction. Reperfusion injury can be particularly damaging to the heart and brain, as these organs are highly sensitive to oxygen deprivation and have a limited ability to repair themselves. Treatment for reperfusion injury may involve medications to reduce inflammation and prevent further damage, as well as supportive care to manage symptoms and promote healing.

C-Reactive Protein (CRP) is a protein that is produced by the liver in response to inflammation or infection in the body. It is a nonspecific marker of inflammation and is often used as a diagnostic tool in the medical field. CRP levels can be measured in the blood using a blood test. Elevated levels of CRP are often seen in people with infections, autoimmune diseases, and certain types of cancer. However, it is important to note that CRP levels can also be elevated in response to other factors such as exercise, injury, and stress. In addition to its diagnostic role, CRP has also been studied as a potential predictor of future health outcomes. For example, high levels of CRP have been associated with an increased risk of cardiovascular disease, stroke, and other chronic conditions. Overall, CRP is an important biomarker in the medical field that can provide valuable information about a person's health and help guide treatment decisions.

Teichoic acids are acidic polysaccharides that are found in the cell walls of certain bacteria, including Gram-positive bacteria. They are covalently linked to the peptidoglycan layer of the cell wall and play a role in maintaining the integrity and structure of the cell wall. Teichoic acids can also serve as a source of nutrients for bacteria and can play a role in bacterial adhesion and colonization of host tissues. In the medical field, teichoic acids are of interest because they are potential targets for the development of new antibiotics and other antimicrobial agents.

Neuraminidase is an enzyme that cleaves sialic acid residues from the terminal ends of glycoproteins and glycolipids. It plays a crucial role in the replication and spread of influenza viruses, as well as other viruses and bacteria. In the medical field, neuraminidase inhibitors are used to treat influenza infections by blocking the activity of the enzyme, preventing the virus from spreading to uninfected cells. Neuraminidase is also used as a diagnostic tool in the detection of certain viral infections, such as influenza and some types of cancer.

Serine endopeptidases are a class of enzymes that cleave peptide bonds in proteins, specifically at the carboxyl side of serine residues. These enzymes are involved in a wide range of biological processes, including digestion, blood clotting, and immune response. In the medical field, serine endopeptidases are often studied for their potential therapeutic applications, such as in the treatment of cancer, inflammation, and neurological disorders. They are also used as research tools to study protein function and regulation. Some examples of serine endopeptidases include trypsin, chymotrypsin, and elastase.

Complementary therapies are a diverse range of non-conventional medical treatments that are used in conjunction with conventional medical treatments to enhance their effectiveness or to manage symptoms. These therapies are not considered a substitute for conventional medical treatments, but rather as a complementary approach to healthcare. Complementary therapies can include a wide range of practices such as acupuncture, massage therapy, chiropractic care, herbal medicine, yoga, meditation, and aromatherapy. These therapies are often used to manage chronic pain, stress, anxiety, and other conditions that may not respond well to conventional medical treatments. The use of complementary therapies is becoming increasingly popular in the medical field, as more and more people are seeking alternative ways to manage their health and well-being. However, it is important to note that not all complementary therapies are supported by scientific evidence, and some may even be harmful if used improperly. Therefore, it is important to consult with a qualified healthcare professional before starting any complementary therapy.

Polysaccharides are complex carbohydrates that are composed of long chains of monosaccharide units linked together by glycosidic bonds. They are found in many different types of biological materials, including plant cell walls, animal tissues, and microorganisms. In the medical field, polysaccharides are often used as drugs or therapeutic agents, due to their ability to modulate immune responses, promote wound healing, and provide other beneficial effects. Some examples of polysaccharides that are used in medicine include hyaluronic acid, chondroitin sulfate, heparin, and dextran.

Pneumococcal infections are a group of illnesses caused by the bacterium Streptococcus pneumoniae. These infections can affect various parts of the body, including the lungs, sinuses, ears, bloodstream, and brain. The most common type of pneumococcal infection is pneumonia, which is an inflammation of the lungs caused by bacteria. Other types of pneumococcal infections include meningitis (inflammation of the lining of the brain and spinal cord), otitis media (middle ear infection), sinusitis (sinus infection), and bacteremia (presence of bacteria in the bloodstream). Pneumococcal infections can be serious, especially in people with weakened immune systems, such as young children, older adults, and people with chronic medical conditions. Vaccines are available to prevent some types of pneumococcal infections, and antibiotics are used to treat them.

Blotting, Western is a laboratory technique used to detect specific proteins in a sample by transferring proteins from a gel to a membrane and then incubating the membrane with a specific antibody that binds to the protein of interest. The antibody is then detected using an enzyme or fluorescent label, which produces a visible signal that can be quantified. This technique is commonly used in molecular biology and biochemistry to study protein expression, localization, and function. It is also used in medical research to diagnose diseases and monitor treatment responses.

Membrane glycoproteins are proteins that are attached to the cell membrane through a glycosyl group, which is a complex carbohydrate. These proteins play important roles in cell signaling, cell adhesion, and cell recognition. They are involved in a wide range of biological processes, including immune response, cell growth and differentiation, and nerve transmission. Membrane glycoproteins can be classified into two main types: transmembrane glycoproteins, which span the entire cell membrane, and peripheral glycoproteins, which are located on one side of the membrane.

Cricetinae is a subfamily of rodents that includes hamsters, voles, and lemmings. These animals are typically small to medium-sized and have a broad, flat head and a short, thick body. They are found in a variety of habitats around the world, including grasslands, forests, and deserts. In the medical field, Cricetinae are often used as laboratory animals for research purposes, as they are easy to care for and breed, and have a relatively short lifespan. They are also used in studies of genetics, physiology, and behavior.

Cytotoxicity, immunologic refers to the ability of immune cells, such as T cells and natural killer (NK) cells, to directly kill or damage other cells in the body. This process is an important part of the immune response and is involved in the elimination of infected or cancerous cells. Cytotoxic T cells, for example, recognize and kill cells that are infected with viruses or have mutated in a way that makes them cancerous. NK cells can also recognize and kill abnormal cells, such as those that are missing the normal "self" markers on their surface. Cytotoxicity, immunologic can be measured in the laboratory using various assays, such as the lactate dehydrogenase (LDH) release assay or the chromium release assay.

In the medical field, the cell wall is a rigid layer that surrounds the cell membrane of certain types of cells, such as plant cells and some bacteria. The cell wall provides structural support and protection to the cell, and helps to maintain its shape and integrity. It is composed of various polysaccharides, proteins, and other molecules, and is essential for the survival and function of these types of cells. In some cases, the cell wall may also play a role in cell division and communication with other cells.

Cloning, molecular, in the medical field refers to the process of creating identical copies of a specific DNA sequence or gene. This is achieved through a technique called polymerase chain reaction (PCR), which amplifies a specific DNA sequence to produce multiple copies of it. Molecular cloning is commonly used in medical research to study the function of specific genes, to create genetically modified organisms for therapeutic purposes, and to develop new drugs and treatments. It is also used in forensic science to identify individuals based on their DNA. In the context of human cloning, molecular cloning is used to create identical copies of a specific gene or DNA sequence from one individual and insert it into the genome of another individual. This technique has been used to create transgenic animals, but human cloning is currently illegal in many countries due to ethical concerns.

Bacterial outer membrane proteins (OMPs) are proteins that are located on the outer surface of the cell membrane of bacteria. They play important roles in the survival and pathogenicity of bacteria, as well as in their interactions with the environment and host cells. OMPs can be classified into several categories based on their function, including porins, which allow the passage of small molecules and ions across the outer membrane, and lipoproteins, which are anchored to the outer membrane by a lipid moiety. Other types of OMPs include adhesins, which mediate the attachment of bacteria to host cells or surfaces, and toxins, which can cause damage to host cells. OMPs are important targets for the development of new antibiotics and other antimicrobial agents, as they are often essential for bacterial survival and can be differentially expressed by different bacterial strains or species. They are also the subject of ongoing research in the fields of microbiology, immunology, and infectious diseases.

CHO cells are a type of Chinese hamster ovary (CHO) cell line that is commonly used in the biotechnology industry for the production of recombinant proteins. These cells are derived from the ovaries of Chinese hamsters and have been genetically modified to produce large amounts of a specific protein or protein complex. CHO cells are often used as a host cell for the production of therapeutic proteins, such as monoclonal antibodies, growth factors, and enzymes. They are also used in research to study the structure and function of proteins, as well as to test the safety and efficacy of new drugs. One of the advantages of using CHO cells is that they are relatively easy to culture and can be grown in large quantities. They are also able to produce high levels of recombinant proteins, making them a popular choice for the production of biopharmaceuticals. However, like all cell lines, CHO cells can also have limitations and may not be suitable for all types of protein production.

Immunoglobulin A (IgA) is a type of antibody that plays a crucial role in the body's immune system. It is the most abundant antibody in the mucous membranes, which line the surfaces of the respiratory, gastrointestinal, and genitourinary tracts. IgA is produced by plasma cells in the bone marrow and is secreted into the bloodstream and mucous membranes. It is particularly important in protecting against infections in the respiratory and gastrointestinal tracts, where it helps to neutralize and eliminate pathogens such as bacteria, viruses, and fungi. IgA can also be found in tears, saliva, and breast milk, where it provides protection against infections in the eyes, mouth, and digestive tract. In addition, IgA plays a role in the immune response to certain types of cancer and autoimmune diseases. Overall, IgA is a critical component of the body's immune system and plays a vital role in protecting against infections and diseases.

Inflammation is a complex biological response of the body to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a protective mechanism that helps to eliminate the cause of injury, remove damaged tissue, and initiate the healing process. Inflammation involves the activation of immune cells, such as white blood cells, and the release of chemical mediators, such as cytokines and prostaglandins. This leads to the characteristic signs and symptoms of inflammation, including redness, heat, swelling, pain, and loss of function. Inflammation can be acute or chronic. Acute inflammation is a short-term response that lasts for a few days to a few weeks and is usually beneficial. Chronic inflammation, on the other hand, is a prolonged response that lasts for months or years and can be harmful if it persists. Chronic inflammation is associated with many diseases, including cancer, cardiovascular disease, and autoimmune disorders.

Protein isoforms refer to different forms of a protein that are produced by alternative splicing of the same gene. Alternative splicing is a process by which different combinations of exons (coding regions) are selected from the pre-mRNA transcript of a gene, resulting in the production of different protein isoforms with slightly different amino acid sequences. Protein isoforms can have different functions, localization, and stability, and can play distinct roles in cellular processes. For example, the same gene may produce a protein isoform that is expressed in the nucleus and another isoform that is expressed in the cytoplasm. Alternatively, different isoforms of the same protein may have different substrate specificity or binding affinity for other molecules. Dysregulation of alternative splicing can lead to the production of abnormal protein isoforms, which can contribute to the development of various diseases, including cancer, neurological disorders, and cardiovascular diseases. Therefore, understanding the mechanisms of alternative splicing and the functional consequences of protein isoforms is an important area of research in the medical field.

Complement C5a, des-Arginine is a fragment of the complement protein C5 that is generated during the activation of the complement system. It is a potent mediator of inflammation and immune responses, and plays a role in the recruitment of immune cells to sites of infection or injury. Des-Arginine refers to the removal of an arginine residue from the C5a molecule, which can affect its biological activity. Complement C5a, des-Arginine is often used as a biomarker of complement activation in various diseases, including sepsis, autoimmune disorders, and cardiovascular disease.

The alternative pathway is one of three complement pathways that opsonize and kill pathogens. The pathway is triggered when the ... The alternative pathway is a type of cascade reaction of the complement system and is a component of the innate immune system, ... Alternative pathway activation also plays a significant role in complement-mediated renal disorders such as atypical hemolytic ... Classical complement pathway Lectin pathway Conrad DH, Carlo JR, Ruddy S (June 1978). "Interaction of beta1H globulin with cell ...

https://en.wikipedia.org/wiki/Alternative_complement_pathway

Alternative complement pathway - another complement system pathway Lectin pathway - another complement system pathway Noris, ... Activation of the complement pathway through the classical, lectin or alternative complement pathway is followed by a cascade ... The classical complement pathway is one of three pathways which activate the complement system, which is part of the immune ... The classical pathway is distinct from the other complement pathways in its unique activation triggers and cascade sequence. ...

https://en.wikipedia.org/wiki/Classical_complement_pathway

... the classical complement pathway, the alternative complement pathway, and the lectin pathway. The alternative pathway accounts ... Accordingly, the alternative complement pathway is one element of innate immunity.[citation needed] Once the alternative C3 ... Alternative Complement Pathway) Inflammation - by attracting macrophages and neutrophils. (Lectin pathway) Most of the proteins ... Polymorphisms of complement component 3, complement factor B, and complement factor I, as well as deletion of complement factor ...

https://en.wikipedia.org/wiki/Complement_system

In the alternative complement pathway, C3 is cleaved by C3bBb, another form of C3-convertase composed of activated forms of C3 ... Its activation is required for both classical and alternative complement activation pathways. People with C3 deficiency are ... The resultant complex, C3bBb, is called the alternative pathway (AP) C3 convertase. C3bBb is deactivated in steps. First, the ... "Entrez Gene: C3 complement component 3". Sahu A, Lambris JD (Apr 2001). "Structure and biology of complement protein C3, a ...

https://en.wikipedia.org/wiki/Complement_component_3

"Biosynthesis of the complement components and the regulatory proteins of the alternative complement pathway by human peripheral ... Maga TK, Nishimura CJ, Weaver AE, Frees KL, Smith RJ (June 2010). "Mutations in alternative pathway complement proteins in ... This contribution is thought to be due to the dysregulation of the alternative pathway, leading to increased inflammation in ... Complement factor I, also known as C3b/C4b inactivator, is a protein that in humans is encoded by the CFI gene. Complement ...

https://en.wikipedia.org/wiki/Complement_factor_I

Most cases are associated with the dysregulation of the alternative complement pathway. DDD is associated with deposition of ... immunoglobulin suggested to early investigators that DDD was due to abnormal activation of the complement alternative pathway ( ... It is believed to be associated with the classical complement pathway. Also called recently as 'C3 nephropathy' The preferred ... Type III is very rare, it is characterized by a mixture of subepithelial and subendothelial immune and/or complement deposits. ...

https://en.wikipedia.org/wiki/Membranoproliferative_glomerulonephritis

Hourcade D (2006). "The Role of Properdin in the Assembly of the Alternative Pathway C3 Convertases of Complement". J Biol Chem ... The alternative pathway is not dependent on antibodies. This branch of the complement system is activated by IgA immune ... a Positive Regulator of the Alternative Pathway of Complement". J Biol Chem. 259 (7): R4582-4588. doi:10.1016/S0021-9258(17) ... It binds to preformed alternative pathway C3-convertases. Properdin also inhibits the Factor H - mediated cleavage of C3b by ...

https://en.wikipedia.org/wiki/Properdin

This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in ... Upon activation of the alternative pathway, it is cleaved by complement factor D yielding the noncatalytic chain Ba and the ... components of the alternative-pathway C3 convertase of complement". The Biochemical Journal. 253 (3): 667-75. doi:10.1042/ ... the major zymogen protease of the alternative complement pathway". The Journal of Investigative Dermatology. 98 (3): 379-83. ...

https://en.wikipedia.org/wiki/Complement_factor_B

"Activation of the alternative pathway of complement by a phosphorothioate oligonucleotide: potential mechanism of action". The ... Cytosolic nucleic acid-sensing pathways can enhance immune response to cancer. RIG-I agonist, stem loop RNA (SLR) 14. Tumor ... As a therapeutic, miRNA has the potential to affect biochemical pathways throughout the organism. With more than 400 miRNA ... Houseley J, Tollervey D (February 2009). "The many pathways of RNA degradation". Cell. 136 (4): 763-76. doi:10.1016/j.cell. ...

https://en.wikipedia.org/wiki/RNA_therapeutics

A Type III Complement Factor D Deficiency: Structural insights for inhibition of the alternative pathway. J. Allergy Clin. ...

https://en.wikipedia.org/wiki/Yorgo_Modis

Alternative pathway hemolytic assay ("AH50") can be used in conjunction to indicate if there is a terminal pathway deficiency ( ... "Simplified assays of hemolytic activity of the classical and alternative complement pathways". Journal of Immunological Methods ... CH50 and AH50 both are low), classical pathway deficiency (CH50 low, AH50 normal) or alternative pathway deficiency (AH50 low, ... For example, if and individual has normal C3/C4 values but a decreased CH50, that can indicate a terminal complement pathway ...

https://en.wikipedia.org/wiki/Total_complement_activity

The alternative pathway of complement activation is typically always active at low levels in blood plasma through a process ... The classical pathway of complement activation is initiated when the C1 complex, made up of C1r and C1s serine proteases, ... Other than the alternative pathway, which is constantly active, C3a formation is triggered by pathogenic infection. ... 12th European Meeting on Complement in Human Disease12th European Meeting on CHD12th European Meeting on Complement in Human ...

https://en.wikipedia.org/wiki/C3a_(complement)

M protein also inhibits opsonization by the alternative complement pathway by binding to host complement regulators. The M ... Whilst Rgg2/3 pathway increases biofilm, the RopB pathway disrupts it. RopB is another Rgg-like protein (Rgg1) that directly ... One of the biofilm forming pathways in GAS is the Rgg2/3 pathway. It regulates SHP's (short hydrophobic peptides) that are ... In the cytosol the pheromones have two functions in the Rgg2/3 pathway. Firstly, they inhibit the activity of Rgg3 which is a ...

https://en.wikipedia.org/wiki/Streptococcus_pyogenes

Hourcade D (2006). "The Role of Properdin in the Assembly of the Alternative Pathway C3 Convertases of Complement". J Biol Chem ... C3 convertase can be used to refer to the form produced in the alternative pathway (C3bBb) or the classical and lectin pathways ... C3 convertase formation can occur in three different pathways: the classical, lectin, and alternative pathways. Cleavage of ... "C3b deposition during activation of the alternative complement pathway and the effect of deposition on the activating surface ...

https://en.wikipedia.org/wiki/C3-convertase

A NOVEL ORAL COMPLEMENT ALTERNATIVE PATHWAY FACTOR B INHIBITOR FOR THE TREATMENT OF GLOMERULAR DISEASE. Nephrology Dialysis ...

https://en.wikipedia.org/wiki/Börje_Haraldsson

Different complement receptors can participate in either the classical complement pathway, the alternative complement pathway, ... All four complement receptors can bind to fragments of complement component 3 or complement component 4 coated on pathogen ... A complement receptor is a membrane-bound receptor belonging to the complement system, which is part of the innate immune ... Mutations in complement receptors which alter receptor function can also increase risk of certain diseases. Complement system ...

https://en.wikipedia.org/wiki/Complement_receptor

The complement system can be activated through three pathways: the classical pathway, the alternative pathway, and the lectin ... Binding of MBL to a micro-organism results in activation of the lectin pathway of the complement system. Another important ... The subsequent complement cascade catalyzed by C3-convertase results in creating a membrane attack complex, which causes lysis ... In order to activate the complement system when MBL binds to its target (for example, mannose on the surface of a bacterium), ...

https://en.wikipedia.org/wiki/Mannan-binding_lectin

... is involved in the alternative complement pathway of the complement system where it cleaves factor B. The protein ... The encoded protein is a component of the alternative complement pathway best known for its role in humoral suppression of ... Lesavre, PH; Müller-Eberhard, HJ (1 December 1978). "Mechanism of action of factor D of the alternative complement pathway". ... Role of MASP-3 in the Physiological Activation of Factor D of the Alternative Complement Pathway". Journal of Immunology. 203 ( ...

https://en.wikipedia.org/wiki/Factor_D

C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. C3 ... Complement dysfunction may predispose some patients to bacterial infections. The diagnosis of the disease is mainly clinical ( ... Around 83% of APL patients had low complement 3 (C3) levels and the presence of polyclonal immunoglobulin C3 nephritic factor. ... Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic ...

https://en.wikipedia.org/wiki/Barraquer–Simons_syndrome

The complement pathway is composed of several subset pathways: the lectin/mannose pathway, alternative pathway and the ... classical complement pathway). In brief, the crucial role of C1q in the pathway is its importance as the first protein to start ... in the complement pathway) named C1-inhibitor. The inhibition of C1-inhibitor leads to over-activation of the complement ... which instigates activation of the entire complement pathway. Consequently, levels of all complement proteins become low. ...

https://en.wikipedia.org/wiki/Urticarial_vasculitis

The formation of the MAC occurs through three distinct pathways: the classical, alternative, and lectin pathways. Pore ... Complement component 9 (C9) is a MACPF protein involved in the complement system, which is part of the innate immune system. ... C9 is one member of the complement membrane attack complex (MAC), which also includes complement components C5b, C6, C7 and C8 ... Complement+9 at the U.S. National Library of Medicine Medical Subject Headings (MeSH) PDBe-KB provides an overview of all the ...

https://en.wikipedia.org/wiki/Complement_component_9

... thus preventing amplification of the complement cascade through the alternative pathway. Complement factor I can further cleave ... iC3b is produced when complement factor I cleaves C3b. Complement receptors on white blood cells are able to bind iC3b, so iC3b ... iC3b is a protein fragment that is part of the complement system, a component of the vertebrate immune system. ... v t e (Complement system, All stub articles, Biochemistry stubs). ...

https://en.wikipedia.org/wiki/IC3b

All three pathways of the complement system (classical, lectin and alternative pathways) initiate the formation of MAC. Another ... Terminal complement pathway deficiency Paroxysmal nocturnal haemoglobinuria Perforin Pore-forming toxin Xie CB, Jane-Wit D, ... ISBN 978-0-323-54943-1. Media related to Complement membrane attack complex at Wikimedia Commons Complement+Membrane+Attack+ ... two regulators of complement. The membrane attack complex is initiated when the complement protein C5 convertase cleaves C5 ...

https://en.wikipedia.org/wiki/Complement_membrane_attack_complex

The classical pathway, lectin pathway, and alternative pathway of complement are all involved in glomerulonephritis, depending ... There are no current clinical trials for DPGN happening.[citation needed] Activating complement pathways plays a large role in ... There are currently drugs available that will target the complement pathway. It has been proposed that if fluorescently tagged ... then identification of specific pathways involved and the accumulated complement proteins in the glomeruli should be achievable ...

https://en.wikipedia.org/wiki/Diffuse_proliferative_nephritis

To support this thesis, he has 1) determined how the alternative complement pathway of innate immunity attaches C3 to microbial ...

https://en.wikipedia.org/wiki/Douglas_Fearon

... alternative pathway). Interaction of DAF with cell-associated C4b of the classical and lectin pathways interferes with the ... Complement decay-accelerating factor, also known as CD55 or DAF, is a protein that, in humans, is encoded by the CD55 gene. DAF ... and interaction of DAF with C3b of the alternative pathway interferes with the conversion of factor B to Bb by factor D, ... thereby preventing formation of the C3bBb C3 convertase of the alternative pathway. Thus, by limiting the amplification ...

https://en.wikipedia.org/wiki/Decay-accelerating_factor

Complement Factor D is a member of the trypsin family of peptidases and is a component of the alternative complement pathway. ... The product candidate is also referred to as "FCFD4514S" or "RG7417". The drug is designed to inhibit complement activation and ... Other than the therapeutic antibodies, which target the IgE allergic pathway, immune factors, and CD4, Tanox also possessed ... an Fab fragment of a humanized antibody against Factor D of the human immune complement system to be tested for treating ...

https://en.wikipedia.org/wiki/Tanox

Binding to the complement factor H allows for meningococcus to grow in human blood while blocking alternative pathways. This ... Reverse vaccinology also led to the discovery of factor G binding protein in meningococcus, which binds to complement factor H ... The Pathway from Genomes and Epitope Predictions to Tailored Recombinant Vaccines", Vaccine Design: Methods and Protocols: ... model does not fit many animal species, which do not have the same complement factor H as humans, indicating differentiation of ...

https://en.wikipedia.org/wiki/Reverse_vaccinology

... directly activates the alternative complement pathway and also interferes with complement regulation by binding to complement ... 2009). "Alternative pathway of complement in children with diarrhea-associated hemolytic uremic syndrome". Clin J Am Soc ... Later, mutations in complement factor H, complement factor I, membrane cofactor protein, factor B, C3, and thrombomodulin have ... 2009). "Complement inhibitor eculizumab in atypical hemolytic uremic syndrome". Clin J Am Soc Nephrol. 4 (8): 1312-1316. doi: ...

https://en.wikipedia.org/wiki/Hemolytic–uremic_syndrome

Croize J, Arvieux J, Berche P, Colomb MG (December 1993). "Activation of the human complement alternative pathway by Listeria ... The three different complement systems are classical, alternative and lectin. Classical: starts when antibody binds to bacteria ... The complement system is a biochemical cascade of the immune system that helps, or "complements", the ability of antibodies to ... Alternative: starts "spontaneously" Lectin: starts when lectins bind to mannose on bacteria Elements of the complement cascade ...

https://en.wikipedia.org/wiki/Innate_immune_system

https://en.wikipedia.org/wiki/Alternative_complement_pathway

Evasion of the alternative complement pathway by Photorhabdus spp. / Beeton, Michael L; Vlisidou, Isabella; Spiller, O et al. ... Evasion of the alternative complement pathway by Photorhabdus spp. In: Molecular Immunology. 2011 ; Vol. 48, No. 14. pp. 1703- ... Evasion of the alternative complement pathway by Photorhabdus spp. Michael L Beeton, Isabella Vlisidou, O Spiller, R Waterfield ... Beeton ML, Vlisidou I, Spiller O, Waterfield R. Evasion of the alternative complement pathway by Photorhabdus spp. Molecular ...

https://researchportal.bath.ac.uk/en/publications/evasion-of-the-alternative-complement-pathway-by-photorhabdus-spp

... and inhibits complement activation via classical (IC50 = 110.8 nM) and alternative (IC50 = 291.3 nM) pathways in Wieslab assays ... Nanofitins® efficiently inhibit complement pathway by targeting C3/C3b. Affilogic discovery process was engaged to identify ... The proof of concept of inhibition of different complement pathways has been demonstrated in rodents and non-human-primate (NHP ... Garlich et al., Discovery of APL-1030, a Novel, High-Affinity Nanofitin Inhibitor of C3-Mediated Complement Activation, ...

https://www.affilogic.com/nanofitins-as-alternative-scaffold-for-complement-pathway-inhibition

Complement Pathway ELISA is a qualitative/semiquantitative test that detects activation of the complement system alternative ... Mouse Alternative Complement Pathway ELISA Assay Kit. $1,190.00. The Mouse Alternative Complement Pathway ELISA Assay Kit is a ... Mouse Alternative Complement Pathway ELISA Assay Kit. The Mouse Alternative Complement Pathway ELISA Assay Kit is For Research ... Rat Alternative Complement Pathway ELISA Assay Kit. Pig Alternative Complement Pathway ELISA Assay Kit. Mouse Classical ...

https://eaglebio.com/product/mouse-alternative-complement-pathway-elisa-assay-kit/

The top scored pathway was "complement activation, alternative pathway", and several proteins involved in this pathway were ... Gingival Exudatome Dynamics Implicate Inhibition of the Alternative Complement Pathway in the Protective Action of the C3 ... exudate of cynomolgus monkey periodontitis in response to C3 inhibition and identified the alternative pathway of complement ... Although complement inhibition has been successfully used to treat periodontitis in animal models, studies globally analyzing ...

https://pesquisa.bvsalud.org/odontologia/resource/pt/mdl-30111112

Kinetic analysis of the interaction between the complement regulators CD46 and CD55 and components of the alternative pathway ... Kinetic analysis of the interaction between the complement regulators CD46 and CD55 and components of the alternative pathway ...

https://www.immunology.ox.ac.uk/publications/14832

Inefficient binding of alternative pathway complement components to serotypes B and C may contribute to the relative difficulty ... Inefficient binding of alternative pathway complement components to serotypes B and C may contribute to the relative difficulty ... Inefficient binding of alternative pathway complement components to serotypes B and C may contribute to the relative difficulty ... Inefficient binding of alternative pathway complement components to serotypes B and C may contribute to the relative difficulty ...

https://pure.johnshopkins.edu/en/publications/differences-in-cryptococcus-neoformans-capsular-polysaccharide-st-4

... of the alternative complement pathway and that a novel complement activation site targeted inhibitor of the alternative pathway ... Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is ... Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is ... Results: RPE- but not RGC-mediated secretion of CR2-fH was found to reduce SIOP and complement activation in RPE/choroid. ...

https://marclab.org/blog/2021/04/13/subretinal-rather-than-intravitreal-adeno-associated-virus-mediated-delivery-of-a-complement-alternative-pathway-inhibitor-is-effective-in-a-mouse-model-of-rpe-damage/

Another big bucket is complement inhibitors. As best we can tell, the alternative and lectin pathway are both involved in IgA ... The classical pathway is not. People are testing different drugs that inhibit either the alternative pathway alone, like a ... factor B inhibitor, for example, the lectin pathway alone, or the terminal complement cascade. We should keep an eye on those ...

https://www.medscape.com/viewarticle/991603

The normal complement system consists of the classic and alternative pathways. The classic pathway is activated by the ... The alternative pathway utilizes C3 and factors B and D to form the alternative pathway convertase C3b,Bb. ... indicating activation of the alternative complement pathway. Signs of activation of the classic pathway are minimal, and ... NFa stabilizes the alternative pathway convertase and results in complement activation and chronic C3 consumption. Deficiency ...

https://emedicine.medscape.com/article/240056-overview

We investigated ADAMTS13 and complement alternative pathway (CAP) activity as previously described (16). ... Frémeaux-Bacchi V, Sellier-Leclerc A-L, Vieira-Martins P, Limou S, Kwon T, Lahoche A, et al. Complement gene variants and Shiga ... Screening for variants in complement genes is not usually conducted among children with STEC-associated HUS. Similarly, it ... However, a decrease in the concentration of complement factors, the interpretation of which remains equivocal, might be ...

https://wwwnc.cdc.gov/eid/article/27/7/20-4638_article

Complement System and Immunology; Allergic Disorders - Learn about from the MSD Manuals - Medical Professional Version. ... Complement activation pathways. The classical, lectin, and alternative pathways converge into a final common pathway when C3 ... There are 3 pathways of complement activation (see figure Complement activation pathways Complement activation pathways ): ... see figure Complement activation pathways Complement activation pathways ). C3 cleavage may result in formation of the membrane ...

https://www.msdmanuals.com/professional/immunology-allergic-disorders/biology-of-the-immune-system/complement-system

Inefficiency in the neonates alternative complement pathway compromises their defense against encapsulated bacteria [3] ...

https://emedicine.medscape.com/article/1176960-overview

Complement is a blood test that measures the activity of certain proteins in the liquid portion of your blood. ... with some bacterial blood infections and shock often have very low C3 and components of whats known as the alternative pathway ... The "complement cascade" is a series of reactions that take place in the blood. The cascade activates the complement proteins. ... Total complement activity (CH50, CH100) looks at the overall activity of the complement system. In most cases, other tests that ...

https://medlineplus.gov/ency/article/003456.htm

aHUS is a condition associated with alternative pathway complement dysregulation. It is characterized by thrombotic ... Complement C3. Complement C4. ADAMTS 13 Activity. Initial results. 1.7mg/dl. 45mg/dl. 9.4g/dl. 37000/ul. 1+. 341U/L. 27.4SGU. > ...

https://www.asn-online.org/education/kidneyweek/2018/program-abstract.aspx?controlId=3008274

Teoh CW, Riedl M, Licht C. The alternative pathway of complement and the thrombotic microangiopathies. The Journal of ... Guidelines, pathways and other documents to guide health care professionals in the management of specific health conditions. ... complement-mediated injury in transplantation and improving long-term outcomes in paediatric transplantation. ... University of Toronto studying the role of complement in calcineurin inhibitor-induced endothelial cell toxicity. ...

https://www.sickkids.ca/en/staff/t/chia-wei-teoh/

In vitro activation of the alternative pathway of complement by settled grain dust. ...

http://www2a.cdc.gov/nioshtic-2/BuildQyr.asp?s1=ethylene+glycol&f1=%2A&Startyear=&Adv=0&terms=1&EndYear=&Limit=10000&sort=&D1=10&PageNo=113&RecNo=113&View=b&

A Complement Atlas identifies interleukin 6 dependent alternative pathway dysregulation as a key druggable feature of COVID-19 ... Efficacy and safety of the investigational complement C5 inhibitor zilucoplan in patients hospitalized with COVID-19 : an open- ...

https://biblio.ugent.be/person/3BDEB928-F0EE-11E1-A9DE-61C894A0A6B4

Data from Mold et al indicate that CRP decreases the activation of the alternative pathway of complement.34 It is intriguing, ... thus activating complement.32,33 CRP may also activate complement via the classical pathway.2,7 However, the potential ... 6 CRP may induce complement activation via the classical pathway,7 which may lead to further progression and destabilisation of ... Lagrand WK, Niessen HWM, Wolbink G-J, et al. C-reactive protein colocalizes with complement in human hearts during acute ...

https://jcp.bmj.com/content/59/2/196?ijkey=63b5783df7b7609f716b1d92ce2c3b56790c63fc&keytype2=tf_ipsecsha

Persistently elevated complement alternative pathway biomarkers in COVID-19 correlate with hypoxemia and predict in-hospital ... View Persistently elevated complement alternative pathway biomarkers in COVID-19 correlate with hypoxemia and predict in- ...

https://www.blood.ca/en/research/our-research-activities/our-research-publications

Adipocytes synthesize factor D, the limiting component of the alternative complement pathway, which cleaves C3-bound factor B ... Adipocytes synthesize factor D, the limiting component of the alternative complement pathway, which cleaves C3-bound factor B ... in which subendothelial deposits of immunoglobulin and C3 are probably due to a deregulated alternative complement pathway. ... C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. ...

https://reference.medscape.com/article/1082489-overview

In this study, we investigated the role of properdin (P), a positive alternative pathway complement regulator, in allergen- ... Complement C3a/biosynthesis*; Complement C3a/immunology; Eosinophils/immunology; Humans; Inflammation/immunology; Leukocyte ... Abstract: Complement is implicated in asthma pathogenesis, but its mechanism of action in this disease remains incompletely ...

https://tools.niehs.nih.gov/portfolio/index.cfm?do=portfolio.publicationDetail&id=2289534

The alternative complement pathway provides innate protection against microbial agents in the absence of specific antibody. ... The alternative complement pathway provides innate protection against microbial agents in the absence of specific antibody.1-5 ... Ratnoff, W.E., Fearon, D.T., and Austen, K.F. The role of antibody in the activation of the alternative complement pathway. ... Factor H is involved in the regulation of the alternative pathway of complement. In blood, activation of C3, under normal ...

https://www.quidel.com/research/elisa-kits/microvue-factor-h-eia

Properdin is a serum glycoprotein that up-regulates the alternative pathway of complement by stabilizing the C3b-Bb complex. It ... Now a number of proteins involved in the complement pathway (properdin, C6, C7, C8A, C8B, C9) [ (PUBMED:2459396) ] as well as ... Metabolism (metabolic pathways involving proteins which contain this domain). * % proteins involved. KEGG pathway ID. ... p53 signaling pathway. This information is based on mapping of SMART genomic protein database to KEGG orthologous groups. ...

https://smart.embl.de/smart/do_annotation.pl?DOMAIN=TSP1&START=294&END=343&E_VALUE=2.1e-12&TYPE=SMART&BLAST=VEEWSQWSACSVTCGQGSQVRTRTCVSPYGTHCSGPLRESRVCNNTALCP

... which is a rate-limiting enzyme involved in the activation of the alternative complement pathway. This drug is about to enter a ... Another complement inhibitor is LFG316, which is a fully human antibody that also targets the complement factor C5. A phase 1 ... AMD and genes encoding complement proteins.This has led to strategies to inhibit complement activation by targeting complement ... The complement cascade is likely to play a major role in causing AMD. Studies have demonstrated a clear and unambiguous ...

https://mvrf.org/the-disease/geographic-atrophy/

... previous studies link it to an increased resistance to the alternative serum complement pathway, due to variations in the outer ...

https://www.frontiersin.org/articles/10.3389/fmicb.2016.00289/full

Utopian? I can see a network of wide meandering alternative transportation pathways and byways to complement our huge ... Not just around town but linking communities with alternatives. Reducing our dependence on oil, biodiesel motorized bikes, ...

https://motoredbikes.com/threads/how-to-build-the-utopian-motorized-bicycle-forum.3762/page-3

A. M. Lynch, J. R. Murphy, T. Byers et al., "Alternative complement pathway activation fragment Bb in early pregnancy as a ... V. M. Holers, "The spectrum of complement alternative pathway-mediated diseases," Immunological Reviews, vol. 223, no. 1, pp. ... reflecting alternative complement pathway activation) at a single point in early pregnancy (less than 20 weeks gestation) were ... indicating excess activation of both the classical and alternative complement pathway [32]. Lynch et al. conducted a large ...

https://www.hindawi.com/journals/jp/2012/374047/

... the Achillion rare disease development program for novel small-molecule complement factor D inhibitors for alternative pathway- ...

https://salesandmarketingnetwork.com/news_release_bs.html?pipe=0000ac177000191&ID=2042642&key=entecavir

This convertase, the alternative pathway C3-convertase, although only produced in small amounts, can cleave multiple C3 proteins into C3a and C3b. (wikipedia.org)
The addition of properdin forms the complex C3bBbP, a stable compound which can bind an additional C3b to form alternative pathway C5-convertase. (wikipedia.org)
The C5-convertase of the alternative pathway consists of (C3b)2BbP (sometimes referred to as C3b2Bb). (wikipedia.org)
After the creation of C5 convertase (either as (C3b)2BbP or C4b2b3b from the classical pathway), the complement system follows the same path regardless of the means of activation (alternative, classical, or lectin). (wikipedia.org)
We conclude that the relatively high degree of side chain substitution of capsular polysaccharide from C. neoformans variety gattii contributes to inefficient surface assembly of the alternative pathway C3 convertase. (johnshopkins.edu)
This interaction results in the formation of C4b2a, which is the classic pathway C3b convertase. (medscape.com)
The alternative pathway utilizes C3 and factors B and D to form the alternative pathway convertase C3b,Bb. (medscape.com)
Small amounts of C3b are constantly being formed in the circulation, which are inactivated by factors H and I. The binding of C3b to a foreign antigen decreases its affinity for factor H and allows for the formation of increasing amounts of the alternate pathway convertase. (medscape.com)
C3b is an opsonin itself, and C3 convertase facilitates the activation of the terminal pathway and the formation of the membrane attack complex C5b-9. (medscape.com)
The classical, lectin, and alternative pathways converge into a final common pathway when C3 convertase (C3 con) cleaves C3 into C3a and C3b. (msdmanuals.com)
C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. (medscape.com)
Adipocytes synthesize C3, factor B, and factor D (adipsin), which allows C3bBb to be formed locally, but which usually does not result in the activation of the terminal lytic part of the complement pathway (C5-9).The IgG antibody, C3Nef, prevents the alternative complement C3-convertase C3Bb from dissociative inactivation, resulting in adipocyte lysis. (medscape.com)
Factor H binds to C3b, accelerates the decay of the alternative pathway C3-convertase and acts as a cofactor for the factor Imediated proteolyticinac-tivation of C3b. (biovendor.com)

The proof of concept of inhibition of different complement pathways has been demonstrated in rodents and non-human-primate (NHP) models. (affilogic.com)
Gingival Exudatome Dynamics Implicate Inhibition of the Alternative Complement Pathway in the Protective Action of the C3 Inhibitor Cp40 in Nonhuman Primate Periodontitis. (bvsalud.org)
Although complement inhibition has been successfully used to treat periodontitis in animal models , studies globally analyzing inflamed tissue proteins to glean insight into possible mechanisms of action are missing. (bvsalud.org)
We mapped the proteomic fingerprint changes in local tissue exudate of cynomolgus monkey periodontitis in response to C3 inhibition and identified the alternative pathway of complement activation and leukocyte degranulation as main targets, which are thus likely to play significant roles in periodontal disease pathogenesis . (bvsalud.org)
Conclusions: Our results suggest that complement inhibition for AMD-like pathology is required basal to the RPE and argues in favor of AAV vector delivery to the RPE or outside the blood-retina barrier. (marclab.org)
1 Most recently, a drug from Genentech/Roche known as FCFD4514S (lampalizumab) provided the first evidence that the growth of GA could be slowed down by complement inhibition. (mvrf.org)
Sutimlimab, a first-in-class investigational C1s inhibitor, met the primary and secondary endpoints in the study and demonstrated sustained inhibition of classical complement pathway mediated hemolysis with improvements in anemia within one week of treatment. (sanofi.com)
Considering the destructive potential of the complement system, it is no surprise that nearly half of the system's proteins are involved in its inhibition. (lu.se)

GCF), before and after local administration of an inhibitor of the central complement component, C3, in nonhuman primates . (bvsalud.org)
We have a new manuscript out in iOVS, Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is Effective in a Mouse Model of RPE Damage . (marclab.org)
We have previously demonstrated that pathology in the smoke-induced ocular pathology (SIOP) model, a model with similarities to dry AMD, is dependent on activation of the alternative complement pathway and that a novel complement activation site targeted inhibitor of the alternative pathway can be delivered to ocular tissues via an adeno-associated virus (AAV). (marclab.org)
This pathway is regulated by C1 inhibitor (C1-INH). (msdmanuals.com)
Omeros' lead MASP-2 inhibitor narsoplimab targets the lectin pathway of complement and is the subject of a biologics license application pending before FDA for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy. (biospace.com)
OMS906, Omeros' inhibitor of MASP-3, the key activator of the alternative pathway of complement, is in a Phase 1 clinical trial. (biospace.com)
C4b-binding protein (C4BP) is the major soluble inhibitor of the classical and lectin pathways whereas factor H (FH) inhibits the alternative route. (lu.se)

Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor. (medscape.com)
The low non-Sg1 sensitivity of the commonly used diagnostic method could be a reason for Sg1 clinical prevalence, however, previous studies link it to an increased resistance to the alternative serum complement pathway, due to variations in the outer-membrane O -antigen segment of the lipopolysaccharide. (frontiersin.org)
Direct measurement of individual serum complement proteins, such as C3 and C4, can also be performed and is helpful in determining the diagnosis. (medscape.com)
Peerschke EI, Yin W, Alpert DR, Roubey RA, Salmon JE, Ghebrehiwet B. Serum complement activation on heterologous platelets is associated with arterial thrombosis in patients with systemic lupus erythematosus and antiphospholipid antibodies. (medscape.com)

Dysregulation of the complement system has been implicated in several diseases and pathologies, including Atypical hemolytic uremic syndrome in which kidney function is compromised. (wikipedia.org)
aHUS is a condition associated with alternative pathway complement dysregulation. (asn-online.org)

Classical complement pathway Lectin pathway Conrad DH, Carlo JR, Ruddy S (June 1978). (wikipedia.org)
The classical pathway is initiated by binding of C1q to antibody complexes, whereas the alternative and lectin pathway are activated in an antibody-independent fashion through the interaction of complement components with respectively specific carbohydrate groups and lipopolysaccharides (LPS) on the surface of foreign pathogens. (eaglebio.com)
Mannose binding lectin (MBL), a major component of the lectin pathway, is associated with bacterial, fungal and viral infection. (eaglebio.com)

Complement deficiencies or other defects in the complement system can easily be screened by running an assay for each pathway in parallel or separately. (eaglebio.com)
Ram S. Complement and deficiencies. (medlineplus.gov)
One can screen for deficiencies in complement by performing the total serum classic hemolytic complement (CH 50 ) test or the alternative hemolytic complement (AP 50 ) test. (medscape.com)
The CH 50 test specifically tests for deficiencies in the classic pathway by measuring the ability of the patient's serum to lyse antibody-coated sheep erythrocytes. (medscape.com)
Patients with classic complement pathway deficiencies should be screened for sequelae of immune complex diseases. (medscape.com)
Grumach AS, Kirschfink M. Are complement deficiencies really rare? (medscape.com)
Complement deficiencies in systemic lupus erythematosus. (medscape.com)
Complement genetics, deficiencies, and disease associations. (medscape.com)

The alternative pathway is one of three complement pathways that opsonize and kill pathogens. (wikipedia.org)
However, only in recent years it has become apparent that complement not only plays a major role in innate defense against pathogens but also identifies foreign materials and removes waste (immune complexes and dying cells). (lu.se)
Invading pathogens activate complement either spontaneously due to differences in envelope/membrane composition compared to host (alternative and lectin pathways) or through antibody binding (classical pathway). (lu.se)

Fearon, D.T. and Austen, K.F. Current concepts in immunology: the alternative pathway of complement - a system for host resistance to microbial infection. (quidel.com)

Alterations in the alternative pathway, like properdin or ficolin deficiency, increase the susceptibility to infection. (eaglebio.com)
Alternative pathway components are often lettered (eg, factor B, factor D) or named (eg, properdin). (msdmanuals.com)
This pathway is regulated by properdin, factor H, and decay-accelerating factor (CD55). (msdmanuals.com)
In this study, we investigated the role of properdin (P), a positive alternative pathway complement regulator, in allergen-induced airway inflammation. (nih.gov)
Properdin is a serum glycoprotein that up-regulates the alternative pathway of complement by stabilizing the C3b-Bb complex. (embl.de)

Age related macular degeneration (AMD) is now believed to be caused, at least in part, by complement overactivation in retinal tissues. (wikipedia.org)
Purpose: The risk for age-related macular degeneration has been tied to an overactive complement system. (marclab.org)

Alternative pathway activation also plays a significant role in complement-mediated renal disorders such as atypical hemolytic uremic syndrome, C3 glomerulopathy, and C3 glomerulonephritis (Dense Deposit Disease or MPGN Type II). (wikipedia.org)
Narsoplimab is also in multiple late-stage clinical development programs focused on other complement-mediated disorders, including IgA nephropathy, atypical hemolytic uremic syndrome and COVID-19. (biospace.com)
Complement factor H has revealed an association with two different renal diseases, glomerulonephri-tisand atypical hemolytic uremicsyndrome (aHUS). (biovendor.com)

The three pathways, designated classical, lectin and alternative pathway, converge at a central component into a final common pathway. (eaglebio.com)

Adipocytes synthesize factor D, the limiting component of the alternative complement pathway, which cleaves C3-bound factor B to its active enzymatic form. (medscape.com)

Studies have demonstrated a clear and unambiguous association between AMD and genes encoding complement proteins.This has led to strategies to inhibit complement activation by targeting complement proteins. (mvrf.org)

A common way to measure the activity of the classical or alternative pathway is the hemolysis of erythrocytes. (eaglebio.com)
"The New England Journal of Medicine's publication of these pivotal results underscore the clear and clinically meaningful treatment effect of sutimlimab on classical complement pathway activation, which triggers chronic hemolysis and anemia experienced by people living with cold agglutinin disease," said principal investigator and author Alexander Röth, MD, Department of Hematology and Stem Cell Transplantation, West German Cancer Center, University Hospital, University of Duisburg-Essen, Germany. (sanofi.com)

Bean KV, Massey D, Gupta G. Mediators of inflammation: complement. (medlineplus.gov)
Curcumin, a natural polyphenolic compound derived from turmeric (Curcuma longa L), has proven to be a modulator of multiple intercellular signalling pathways linked to inflammation, to proliferation, growth, invasion, drug sensitivity, angiogenesis and metastasis of cancer cells. (researchgate.net)
Omeros is an innovative biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market and orphan indications targeting inflammation, immunologic diseases (e.g., complement-mediated diseases) and cancers. (biospace.com)

The alternative pathway is a type of cascade reaction of the complement system and is a component of the innate immune system, a natural defense against infections. (wikipedia.org)
The complement system is a crucial component of the innate immunity against microbial infection. (biovendor.com)

Model of the adipocyte destruction in acquired partial lipodystrophy showing complement activation at the adipocyte surface resulting in adipocyte lysis. (medscape.com)

Complement activation proceeds in a sequential fashion through the proteolytic cleavage of a series of proteins leading to the generation of activated products that mediate various biological activities through their interaction with specific cellular receptors and other serum proteins. (eaglebio.com)
This cleavage activates the terminal complement pathway leading to eventually the formation of the terminal C5b-9 complement complex (TCC). (eaglebio.com)
C3 cleavage may result in formation of the membrane attack complex (MAC), the cytotoxic component of the complement system. (msdmanuals.com)
Most inhibitors act on complement convertases through increased dissociation of these enzymatic complexes (acceleration of decay) or through promoting enzymatic cleavage of activated complement factors C3b or C4b by a serine proteinase factor I (FI). (lu.se)

The complement system consist of a complex family of proteins and receptors which are found in the circulation, in tissues and other body-fluids. (eaglebio.com)
Complement factor H, a 155 kDaplasma glycoprotein, is an essential regulatory protein that plays a critical role in the homeostasis of the complement system in plasma and in the protection of bystander host cells and tissues from damage by complement activation. (biovendor.com)
Regrettably, uncontrolled complement activation also contributes significantly to pathology of many diseases (some examples: rheumatoid arthritis, ischemia/reperfusion injury, glomerulonephritis, multiple sclerosis, Alzheimer´s, hyperacute rejection of grafts) due to the fact that complement sometimes misdirects its activities towards own tissues. (lu.se)

The ELISA contains a positive control which can be used as control to ensure that the alternative complement cascade has run completely. (eaglebio.com)
The "complement cascade" is a series of reactions that take place in the blood. (medlineplus.gov)
The cascade activates the complement proteins. (medlineplus.gov)
The complement system is an enzyme cascade that helps defend against infection. (msdmanuals.com)
The complement cascade is likely to play a major role in causing AMD. (mvrf.org)

Rarely, people may inherit deficiency of some complement proteins. (medlineplus.gov)
Skattum L, van Deuren M, van der Poll T, Truedsson L. Complement deficiency states and associated infections. (medscape.com)
Arnold DF, Roberts AG, Thomas A, Ferry B, Morgan BP, Chapel H. A novel mutation in a patient with a deficiency of the eighth component of complement associated with recurrent meningococcal meningitis. (medscape.com)
C5 Complement Deficiency in a Saudi Family, Molecular Characterization of Mutation and Literature Review. (medscape.com)
Complement C4 deficiency--a plausible risk factor for non-tuberculous mycobacteria (NTM) infection in apparently immunocompetent patients. (medscape.com)

The top scored pathway was " complement activation , alternative pathway", and several proteins involved in this pathway were down-regulated at 6 weeks. (bvsalud.org)

The physiological relevance of complement is demonstrated by diseases affecting patients lacking complement components: recurrent infections, autoimmune diseases and glomerulonephritis. (lu.se)

The classic pathway is activated by the interaction of C1 with an antigen-antibody complex. (medscape.com)

Under certain conditions, the complement system can be unfavorable to the host leading to e.g. autoimmune diseases and infections. (eaglebio.com)
A complement test may be used to monitor people with an autoimmune disorder . (medlineplus.gov)
In autoimmune diseases, the alternative complement pathway may contribute directly to tissue damage. (quidel.com)
Complement Factor H has been implicated in the research of many autoimmune diseases. (quidel.com)

The classic and alternate pathway convertases cause C3 activation, forming C3a and C3b. (medscape.com)

Currently, he is leading the Achillion rare disease development program for novel small-molecule complement factor D inhibitors for alternative pathway-mediated diseases. (salesandmarketingnetwork.com)
Several of these inhibitors circulate in blood whereas others are expressed on virtually all cells of the body to protect self-tissue from complement attack. (lu.se)

The pathway is triggered when the C3b protein directly binds a microbe. (wikipedia.org)
CFHR5 (Complement Factor H-Related protein 5) is able to bind to act as a cofactor for factor I, has decay accelerating activity and is able to bind preferentially to C3b at host surfaces. (wikipedia.org)
Protein chemistry was used to assess complement activation, CR2-fH tissue distribution, and CR2-fH transport across the RPE. (marclab.org)
Dried blood spot samples from newborns, which are already widely used in neonatal screening for selected metabolic diseases, may be employed in the future using reverse phase protein microarrays for determination of complement component C3 levels collected at birth. (medscape.com)
Some microorganisms either produce a functional mimic of a complement regulatory protein or hijack host's regulatory proteins. (lu.se)

APL-1030 is thermostable, binds C3 (KD, 1.59 nM) and C3b (KD, 1.11 nM), and inhibits complement activation via classical (IC50 = 110.8 nM) and alternative (IC50 = 291.3 nM) pathways in Wieslab assays. (affilogic.com)
Furthermore some assays have been described to measure the activity of the MBL pathway. (eaglebio.com)

Complement factor H preferentially binds to vertebrate cells (because of affinity for sialic acid residues), allowing preferential protection of host (as opposed to bacterial) cells from complement-mediated damage. (wikipedia.org)

The Mouse Alternative Complement Pathway ELISA Assay Kit is a qualitative/ semiquantitative ELISA to be used for the in vitro determination of activation of the alternative pathway of the complement system in serum and plasma samples. (eaglebio.com)
A major component of this response is the complement system. (eaglebio.com)
The system consist of three defined pathways which are activated by a pathway specific panel of molecules. (eaglebio.com)
Binding of complement component C3 and Factor B to Cryptococcus neoformans serotypes A through D via the alternative complement pathway was measured in a system containing fresh nonimmune human serum. (johnshopkins.edu)
The normal complement system consists of the classic and alternative pathways. (medscape.com)
The complement system is a group of nearly 60 proteins that are in blood plasma or on the surface of some cells. (medlineplus.gov)
Total complement activity (CH50, CH100) looks at the overall activity of the complement system. (medlineplus.gov)
The complement system. (medlineplus.gov)
Degn SE, Jensenius JC, Thiel S. Disease-causing mutations in genes of the complement system. (medscape.com)
Our group investigates the physiological regulation of human complement system as well as pathologic situations when this regulation fails. (lu.se)

Inefficient binding of alternative pathway complement components to serotypes B and C may contribute to the relative difficulty in successfully treating infections caused by these organisms. (johnshopkins.edu)
People with some bacterial blood infections and shock often have very low C3 and components of what's known as the alternative pathway. (medlineplus.gov)

Alternate pathway activation occurs when components of microbial cell surfaces (eg, yeast walls, bacterial cell wall lipopolysaccharide [endotoxin]) or immunoglobulin (eg, nephritic factor, aggregated IgA) cleave small amounts of C3. (msdmanuals.com)
The alternative complement pathway provides innate protection against microbial agents in the absence of specific antibody. (quidel.com)
1-5 The activation of this complement pathway can be triggered by a variety of substances including microbial polysaccharides or lipids, gram negative bacterial lipopolysaccharides, and surface determinants present on some viruses, parasites, virally infected mammalian cells, and cancer cells. (quidel.com)

The alternative pathway also acts as an amplification loop of the other pathways. (eaglebio.com)

Functional complement C1q abnormality leads to impaired immune complexes and apoptotic cell clearance. (medscape.com)

MBL, a member of the collectins, is an important element in innate immunity and is able to activate the complement activation pathway independent of the classical and alternative pathways. (labmate-online.com)

gattii) bound approximately half as many molecules of both complement components as serotypes A and D (C. neoformans var. (johnshopkins.edu)

The mouse pathway ELISAs are easy to use and specific per pathway by making use of a combination of specialized coatings and buffers. (eaglebio.com)

C3 and C4 are the complement components measured most often. (medlineplus.gov)
Classical pathway components are labeled with a C and a number (eg, C1, C3), based on the order in which they were identified. (msdmanuals.com)
Therefore, when concentrations of Factor H fall below normal levels, there is rapid fluid-phase activation and consumption of complement components both in vivo and in vitro . (quidel.com)
At low ionic concentrations, RBCs absorb complement components from serum. (medscape.com)

Complement activation by commercial allergen extracts of cereal grains. (cdc.gov)

This pathway otherwise resembles the classical pathway structurally and functionally. (msdmanuals.com)

Beware that complement activity levels are mouse strain dependent and might be affected by the way the samples are collected and processed. (eaglebio.com)

note = "Meeting abstract from 13th European Meeting on Complement in Human Disease. (bath.ac.uk)

C3 nephritic factor induces the lysis of adipocytes that secrete adipsin, a product identical to complement factor D. The distribution of the lipoatrophy is postulated to be dictated by the variable amounts of adipsin secreted by the adipocytes at different locations. (medscape.com)

Anatomy13

Organisms17

Diseases9

Chemicals and Drugs93

Analytical, Diagnostic and Therapeutic Techniques and Equipment18

Phenomena and Processes30

Disciplines and Occupations1

Information Science3

Health Care1

Interaction between terminal complement proteins C5b-7 and anionic phospholipids. (1/625)

Role of antibody and complement in opsonization of group B streptococci. (2/625)

Cutting edge: C1q protects against the development of glomerulonephritis independently of C3 activation. (3/625)

The surface properties of Neisseria gonorrhoeae: determinants of susceptibility to antibody complement killing. (4/625)

Alterations in C3 activation and binding caused by phosphorylation by a casein kinase released from activated human platelets. (5/625)

Granzyme A initiates an alternative pathway for granule-mediated apoptosis. (6/625)

The influence of complement receptor type 1 (CD35) and decay-accelerating factor (CD55) on complement receptor type 2- (CD21) mediated alternative pathway activation by B cells. (7/625)

Calcium-independent haemolysis via the lectin pathway of complement activation in the guinea-pig and other species*. (8/625)

Complement Pathway, Alternative

Complement Pathway, Classical

Complement Activation

Complement C3

Complement System Proteins

Complement C4

Complement Factor B

Complement C1q

Complement Pathway, Mannose-Binding Lectin

Complement C2

Complement C3b

Complement C1

Complement C5

Complement Inactivator Proteins

Complement Factor D

Complement C3-C5 Convertases

Properdin

Complement Factor H

Receptors, Complement

Complement Membrane Attack Complex

Complement C6

Complement C4b

Complement C3b Inactivator Proteins

Complement Activating Enzymes

Complement Hemolytic Activity Assay

Complement C9

Complement Inactivating Agents

Alternative Splicing

Mannose-Binding Protein-Associated Serine Proteases

Complement C3a

Mannose-Binding Lectin

Complement C3c

Complement C1 Inactivator Proteins

Complement C3d

Complement C5a

Hemolysis

Opsonin Proteins

Blood Bactericidal Activity

Receptors, Complement 3b

Complement Fixation Tests

Complement C1s

Complement Factor I

Complement C4b-Binding Protein

Zymosan

Complement C3 Convertase, Alternative Pathway

Complement C5b

Complement C4a

Antigens, CD55

Phagocytosis

Cobra Venoms

Antigen-Antibody Complex

Immunoglobulin G

Collectins

Complement C1r

Complement C7

Lectins

Complement C8

Anaphylatoxins

Antigens, CD46

Antigens, CD59

Receptors, Complement 3d

Molecular Sequence Data

Immunoglobulin M

Erythrocytes

Guinea Pigs

Egtazic Acid

Neutrophils

Polysaccharides, Bacterial

Snakes

Cryoglobulins

Amino Acid Sequence

Prevotella melaninogenica

Antibodies, Bacterial

Protein Binding

Rabbits

Streptococcus pneumoniae

Macular Degeneration

Mice, Inbred C57BL

Blood Physiological Phenomena

Immunoelectrophoresis