Complement c3b. Medical search

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.

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.

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.

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 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.

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 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.

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).

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.

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.

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 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.

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.

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).

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).

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.

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 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 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 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.

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 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.

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 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.

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.

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.

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.

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.

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).

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 COOH-terminal fragment of COMPLEMENT 2, released by the action of activated COMPLEMENT C1S. It is a SERINE PROTEASE. C2a combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

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

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.

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

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.

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

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.

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.

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 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.

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).

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.

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.

Important enzymes in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. They cleave COMPLEMENT C3 and COMPLEMENT C5.

The N-terminal fragment of COMPLEMENT 2, released by the action of activated COMPLEMENT C1S.

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)

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.

An adrenal microsomal cytochrome P450 enzyme that catalyzes the 21-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP21 gene, converts progesterones to precursors of adrenal steroid hormones (CORTICOSTERONE; HYDROCORTISONE). Defects in CYP21 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).

Important enzymes in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. They cleave COMPLEMENT C3 and COMPLEMENT C5.

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.

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

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

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.

A serine protease that cleaves multiple COMPLEMENT 5 into COMPLEMENT 5A (anaphylatoxin) and COMPLEMENT 5B in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It is a complex of CLASSICAL PATHWAY C3 CONVERTASE (C4b2a) with an additional COMPLEMENT C3B, or C4b2a3b.

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 serine protease that cleaves multiple COMPLEMENT 3 into COMPLEMENT 3A (anaphylatoxin) and COMPLEMENT 3B in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It is a complex of COMPLEMENT 4B and COMPLEMENT 2A (C4b2a).

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.

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.

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

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.

A serine protease that cleaves multiple COMPLEMENT C5 into COMPLEMENT C5A (anaphylatoxin) and COMPLEMENT C5B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. It is the complex of ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) with an additional COMPLEMENT C3B, or C3bBb3b.

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

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.

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 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.

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).

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.

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.

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.

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

A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.

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

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.

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.

A genus of trematode flukes belonging to the family Schistosomatidae. There are over a dozen species. These parasites are found in man and other mammals. Snails are the intermediate hosts.

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.

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.

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.

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.

Thickening of the walls of small ARTERIES or ARTERIOLES due to cell proliferation or HYALINE deposition.

Antibodies produced by a single clone of cells.

The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.

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

Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.

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.

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.

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.)

Established cell cultures that have the potential to propagate indefinitely.

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.

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

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.

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.

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.

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.

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

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.

Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.

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

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.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

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).

Proteins prepared by recombinant DNA technology.

An IgG autoantibody against the ALTERNATIVE PATHWAY C3 CONVERTASE, found in serum of patients with MESANGIOCAPILLARY GLOMERULONEPHRITIS. The binding of this autoantibody to C3bBb stabilizes the enzyme thus reduces the actions of C3b inactivators (COMPLEMENT FACTOR H; COMPLEMENT FACTOR I). This abnormally stabilized enzyme induces a continuous COMPLEMENT ACTIVATION and generation of C3b thereby promoting the assembly of MEMBRANE ATTACK COMPLEX and cytolysis.

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

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.

Plasma glycoproteins that form a stable complex with hemoglobin to aid the recycling of heme iron. They are encoded in man by a gene on the short arm of chromosome 16.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

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.

Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).

Glomerulonephritis associated with autoimmune disease SYSTEMIC LUPUS ERYTHEMATOSUS. Lupus nephritis is histologically classified into 6 classes: class I - normal glomeruli, class II - pure mesangial alterations, class III - focal segmental glomerulonephritis, class IV - diffuse glomerulonephritis, class V - diffuse membranous glomerulonephritis, and class VI - advanced sclerosing glomerulonephritis (The World Health Organization classification 1982).

Autoantibodies directed against various nuclear antigens including DNA, RNA, histones, acidic nuclear proteins, or complexes of these molecular elements. Antinuclear antibodies are found in systemic autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, scleroderma, polymyositis, and mixed connective tissue disease.

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

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.

Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

Proteins found in any species of bacterium.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.

Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.

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.

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

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.

A group of inherited disorders of the ADRENAL GLANDS, caused by enzyme defects in the synthesis of cortisol (HYDROCORTISONE) and/or ALDOSTERONE leading to accumulation of precursors for ANDROGENS. Depending on the hormone imbalance, congenital adrenal hyperplasia can be classified as salt-wasting, hypertensive, virilizing, or feminizing. Defects in STEROID 21-HYDROXYLASE; STEROID 11-BETA-HYDROXYLASE; STEROID 17-ALPHA-HYDROXYLASE; 3-beta-hydroxysteroid dehydrogenase (3-HYDROXYSTEROID DEHYDROGENASES); TESTOSTERONE 5-ALPHA-REDUCTASE; or steroidogenic acute regulatory protein; among others, underlie these disorders.

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.

An individual in which both alleles at a given locus are identical.

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

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

Biologically active substances whose activities affect or play a role in the functioning of the immune system.

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

The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.

Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.

The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.

Glycoproteins found on the membrane or surface of cells.

The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.

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

The rate dynamics in chemical or physical systems.

Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.

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.

Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.

The presence of proteins in the urine, an indicator of KIDNEY DISEASES.

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.

The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.

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

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.

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.

Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.

A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

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

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

A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.

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)

Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.

Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.

Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.

Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.

Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.

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.

A constitution or condition of the body which makes the tissues react in special ways to certain extrinsic stimuli and thus tends to make the individual more than usually susceptible to certain diseases.

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

A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.

A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.

Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.

Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.

The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.

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 method for the detection of very small quantities of antibody in which the antigen-antibody-complement complex adheres to indicator cells, usually primate erythrocytes or nonprimate blood platelets. The reaction is dependent on the number of bound C3 molecules on the C3b receptor sites of the indicator cell.

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 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.

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.

The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.

A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.

The systematic study of the complete complement of proteins (PROTEOME) of organisms.

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.

A cytokine that stimulates the growth and differentiation of B-LYMPHOCYTES and is also a growth factor for HYBRIDOMAS and plasmacytomas. It is produced by many different cells including T-LYMPHOCYTES; MONOCYTES; and FIBROBLASTS.

The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).

Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.

The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.

A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.

A condition characterized by the recurrence of HEMOGLOBINURIA caused by intravascular HEMOLYSIS. In cases occurring upon cold exposure (paroxysmal cold hemoglobinuria), usually after infections, there is a circulating antibody which is also a cold hemolysin. In cases occurring during or after sleep (paroxysmal nocturnal hemoglobinuria), the clonal hematopoietic stem cells exhibit a global deficiency of cell membrane proteins.

A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.

Group of diseases mediated by the deposition of large soluble complexes of antigen and antibody with resultant damage to tissue. Besides SERUM SICKNESS and the ARTHUS REACTION, evidence supports a pathogenic role for immune complexes in many other IMMUNE SYSTEM DISEASES including GLOMERULONEPHRITIS, systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC) and POLYARTERITIS NODOSA.

Mutations of the type A domain of complement factor B that promote high-affinity C3b-binding. (1/656)

Factor B is a zymogen that carries the catalytic site of the complement alternative pathway convertases. During C3 convertase assembly, factor B associates with C3b and is cleaved at a single site by factor D. The Ba fragment is released, leaving the active complex, C3bBb. During the course of this process, the protease domain becomes activated. The type A domain of factor B, also part of Bb, is similar in structure to the type A domain of the complement receptor and integrin, CR3. Previously, mutations in the factor B type A domain were described that impair C3b-binding. This report describes "gain of function" mutations obtained by substituting factor B type A domain amino acids with homologous ones derived from the type A domain of CR3. Replacement of the betaA-alpha1 Mg2+ binding loop residue D254 with smaller amino acids, especially glycine, increased hemolytic activity and C3bBb stability. The removal of the oligosaccharide at position 260, near the Mg2+ binding cleft, when combined with the D254G substitution, resulted in increased affinity for C3b and iC3b, a C3b derivative. These findings offer strong evidence for the direct involvement of the type A domain in C3b binding, and are suggestive that steric effects of the D254 sidechain and the N260-linked oligosaccharide may contribute to the regulation of ligand binding. (+info)

Capsular sialic acid limits C5a production on type III group B streptococci. (2/656)

The majority of type III group B streptococcus (GBS) human neonatal infections are caused by a genetically related subgroup called III-3. We have proposed that a bacterial enzyme, C5a-ase, contributes to the pathogenesis of neonatal infections with GBS by rapidly inactivating C5a, a potent pro-inflammatory molecule, but many III-3 strains do not express C5a-ase. The amount of C5a produced in serum following incubation with representative type III strains was quantitated in order to better understand the relationship between C5a production and C5a-ase expression. C5a production following incubation of bacteria with serum depleted of antibody to the bacterial surface was inversely proportional to the sialic acid content of the bacterial capsule, with the more heavily sialylated III-3 strains generating less C5a than the less-virulent, less-sialylated III-2 strains. The amount of C5a produced correlated significantly with C3 deposition on each bacterial strain. Repletion with type-specific antibody caused increased C3b deposition and C5a production through alternative pathway activation, but C5a was functionally inactivated by strains that expressed C5a-ase. The increased virulence of III-3 strains compared to that of III-2 strains results at least partially from the higher sialic acid content of III-3 strains, which inhibits both opsonophagocytic killing and C5a production in the absence of type-specific antibody. We propose that C5a-ase is not necessary for III-3 strains to cause invasive disease because the high sialic acid content of III-3 strains inhibits C5a production. (+info)

Amplification of the antibody response by C3b complexed to antigen through an ester link. (3/656)

Complement C3 has been described as playing an important role in the cell-mediated immune response. C3b has the capacity to covalently bind Ag and then to stimulate in vitro Ag presentation to T lymphocytes. To verify this observation in vivo, we prepared and purified covalent human C3b-Ag complexes using lysozyme (HEL) as Ag. The characterization of these HEL-C3b complexes indicates that they are representative of those susceptible to be generated in physiological conditions. Mice were immunized with 0.1 to 0.6 microgram of either free HEL, HEL + C3b, HEL-C3b, or HEL + CFA. Response was assessed after two i.p. injections by quantification of specific Ab production. Immunization with either HEL-C3b complexes or HEL + CFA leads to anti-HEL IgG production whereas free HEL or HEL + C3b was ineffective. Either HEL-C3b or HEL + CFA immunizations led to a similar Ig subclass patterns, including IgG1, IgG2a, IgA, and IgM. Our experiments provide the first evidence for modulation of specific Ab response by C3b when it is bound to Ag through a physiological-like link. Taken together with previous data concerning Ab response following recombinant HEL-C3d immunization, cellular events such as processing of C3b-Ag by APC and recognition by T lymphocytes, this present result underlines the importance of C3b and its fragments in stimulation of the immune system, through the multiplicity and complementarity of its interactions. (+info)

A novel glycosylphosphatidyl inositol-anchored protein on human leukocytes: a possible role for regulation of neutrophil adherence and migration. (4/656)

We report here a novel glycosylphosphatidyl-inositol (GPI)-anchored glycoprotein on human leukocytes. Treatment of neutrophils with a mAb (3H9) to this molecule sequentially up-regulates and down-regulates beta2 integrin-dependent adhesion of these cells as well as their transendothelial migration in vitro. In addition, this mAb simultaneously modulates the avidity of beta2 integrin for its ligand, iC3b, with kinetics similar to those observed in 3H9 modulation of neutrophil adherence. This mAb also induces beta2 integrin-dependent cytoskeletal remodeling. This novel GPI-anchored protein (GPI-80) is highly homologous with Vanin-1, a recently reported GPI-anchored protein that is expressed on perivascular thymic stromal cells and is involved in thymus homing in mice. The finding that both GPI-80 and Vanin-1 are 40% homologous with human biotinidase suggests the existence of a biotinidase superfamily of molecules that may be involved in the regulation of leukocyte trafficking. (+info)

Binding of soluble immune complexes to Raji lymphocytes. Role of receptors for complement components, C1q and C3-C3b. (5/656)

We have found that, although the binding of particulate antigen-antibody complement complexes such as EAC to lymphoblastoid Raji cells is mediated largely through receptors for C3b, the binding of complement-containing soluble complexes such as those prepared with aggregated human IgG (AHG) occurs also via receptors for C1q. Evidence supporting this conclusion included: (1) Binding of AHG to Raji cells takes place after incubation in EDTA serum; (2) Binding of AHG does not occur in C1q deficient EDTA serum but does take place after addition of C1q; (3) The extent of binding of AHG in EDTA serum is a function of the amount of C1q present; (4) Raji cells can bind up to 5-4 times 10(5) molecules of 125I C1q per cell which can be blocked by unlabelled C1q; (5) AHG pre-incubated with C can bind to a T-cell line MOLT, which lacks receptors for C3b but possesses receptors for C1q to the same extent as Raji cells; (6) Immunoassays for immune complexes in human sera yield similar results whether Raji cells, MOLT cells or C1q precipitation is used for assay; (7) EAC-Raji cell rosettes can be inhibited with inulin-treated, C1q deficient serum containing C3b or C3d whereas binding of AHG or immune complexes in patient samples to Raji or MOLT cells is not inhibited by this reagent. We conclude that receptors for C1q on certain B and T lymphocytes may play an important role in physiologic functions of lymphocytes depending on binding of soluble immune complexes to their surfaces. (+info)

Complement activation and increased systemic and pulmonary vascular resistance indices during infusion of postoperatively drained untreated blood. (6/656)

In nine healthy young patients, operated on for thoracic scoliosis, a pulmonary artery catheter was inserted for the study of haemodynamic variables and blood sampling during autologous transfusion of postoperatively drained blood. At 1-3 h after wound closure, 10 ml kg/body weight of drained untreated blood from the wound was collected and recirculated over a l-h period. The concentration of the complement activation product, C3bc, increased from a mean of 5.4 (SD 1.5) AU ml-1 before infusion to 11.1 (3.9) AU ml-1 during infusion and then returned to 7.8 (2.8) AU ml-1 after infusion. The concentration of the terminal complement complex (TCC) increased from 0.5 (0.2) to 1.3 (0.5) AU ml-1 and was reduced to 0.7 (0.3) AU ml-1 after infusion. Only TCC exceeded the reference values which are 14 AU ml-1 for C3bc and 1.0 AU ml-1 for TCC. Pulmonary vascular resistance index concomitantly increased from a mean of 130 (SD 52) to 195 (88) dyn s cm-5 m-2 and was reduced to 170 (86) dyn s cm-5 m-2 after infusion. Systemic vascular resistance index increased from a mean of 1238 (SD 403) to 1349 (473) dyn s cm-5 m-2 and returned to 1196 (401) dyn s cm-5 m-2 after infusion. White blood cell count (WCC) increased from 14.4 (4.3) x 10(9) litre-1 before infusion to 17.8 (7.2) x 10(9) litre-1 during and after infusion. No change in platelet count during infusion was observed. There were no differences in WCC or platelet count between mixed venous or peripheral arterial blood. Pulmonary and systemic vascular resistance indices may be influenced by activated complement in drained untreated blood when it is recirculated. (+info)

Complement activation and expression of membrane regulators in the middle ear mucosa in otitis media with effusion. (7/656)

The aetiopathogenesis of chronic otitis media with effusion (OME) in children is not yet fully understood. OME is characterized by metaplasia of the epithelium and accumulation of sticky, glue-like effusion in the middle ear containing different mediators of inflammation, including activation fragments of the complement system. Here we examined whether the fluid phase complement activation is reflected in the middle ear mucosa and how the mucosa is protected against the cytolytic activity of complement. Mucosal biopsies from 18 middle ears of children with a history of chronic OME were taken. The biopsies were analysed by immunofluorescence microscopy after staining for complement fragments iC3b/C3c, C3d and C9, and regulators membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55) and protectin (CD59). There was a strong staining for iC3b/C3c, and a weaker one for C3d and C9 on the surface of the middle ear epithelial cells of OME patients but not in controls without OME. MCP was expressed on the hyperplastic three to four outer cell layers of the epithelium, while CD59 was expressed throughout the middle ear mucosa. The results suggest a strong ongoing complement activation and consequent inflammation in the middle ear cavity. Unrestricted complement damage of the epithelial lining is prevented by the strong expression of MCP and CD59. (+info)

Pneumococcal surface protein A inhibits complement activation by Streptococcus pneumoniae. (8/656)

Pneumococcal surface protein A (PspA) is a surface-exposed protein virulence factor for Streptococcus pneumoniae. In this study, no significant depletion of serum complement was observed for the serum of mice infected with pneumococci that express PspA. In contrast, in mice infected with an isogenic strain of pneumococci lacking PspA, significant activation of serum complement was detected within 30 min after infection. Also, the PspA-deficient strain but not the PspA-expressing strain was cleared from the blood within 6 h. The contribution of PspA to pneumococcal virulence was further investigated by using mice deficient for C5, C3, or factor B. In mice deficient for C3 or factor B, PspA-negative pneumococci became fully virulent. In contrast, in C5-deficient mice as in wild-type mice, PspA-deficient pneumococci were avirulent. These in vivo data suggest that, in nonimmune mice infected with pneumococci, PspA interferes with complement-dependent host defense mechanisms mediated by factor B. Immunoblots of pneumococci opsonized in vitro suggested that more C3b was deposited on PspA-negative than on PspA-positive pneumococci. This was observed with and without anticapsular antibody. Furthermore, processing of the alpha chain of C3b was reduced in the presence of PspA. We propose that PspA exerts its virulence function by interfering with deposition of C3b onto pneumococci and/or by inhibiting formation of a fully functional alternative pathway C3 convertase. By blocking recruitment of the alternative pathway, PspA reduces the amount of C3b deposited onto pneumococci, thereby reducing the effectiveness of complement receptor-mediated pathways of clearance. (+info)

There are two main types of hemolysis:

1. Intravascular hemolysis: This type occurs within the blood vessels and is caused by factors such as mechanical injury, oxidative stress, and certain infections.
2. Extravascular hemolysis: This type occurs outside the blood vessels and is caused by factors such as bone marrow disorders, splenic rupture, and certain medications.

Hemolytic anemia is a condition that occurs when there is excessive hemolysis of RBCs, leading to a decrease in the number of healthy red blood cells in the body. This can cause symptoms such as fatigue, weakness, pale skin, and shortness of breath.

Some common causes of hemolysis include:

1. Genetic disorders such as sickle cell anemia and thalassemia.
2. Autoimmune disorders such as autoimmune hemolytic anemia (AIHA).
3. Infections such as malaria, babesiosis, and toxoplasmosis.
4. Medications such as antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and blood thinners.
5. Bone marrow disorders such as aplastic anemia and myelofibrosis.
6. Splenic rupture or surgical removal of the spleen.
7. Mechanical injury to the blood vessels.

Diagnosis of hemolysis is based on a combination of physical examination, medical history, and laboratory tests such as complete blood count (CBC), blood smear examination, and direct Coombs test. Treatment depends on the underlying cause and may include supportive care, blood transfusions, and medications to suppress the immune system or prevent infection.

The term "systemic" refers to the fact that the disease affects multiple organ systems, including the skin, joints, kidneys, lungs, and nervous system. LES is a complex condition, and its symptoms can vary widely depending on which organs are affected. Common symptoms include fatigue, fever, joint pain, rashes, and swelling in the extremities.

There are several subtypes of LES, including:

1. Systemic lupus erythematosus (SLE): This is the most common form of the disease, and it can affect anyone, regardless of age or gender.
2. Discoid lupus erythematosus (DLE): This subtype typically affects the skin, causing a red, scaly rash that does not go away.
3. Drug-induced lupus erythematosus: This form of the disease is caused by certain medications, and it usually resolves once the medication is stopped.
4. Neonatal lupus erythematosus: This rare condition affects newborn babies of mothers with SLE, and it can cause liver and heart problems.

There is no cure for LES, but treatment options are available to manage the symptoms and prevent flares. Treatment may include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, immunosuppressive medications, and antimalarial drugs. In severe cases, hospitalization may be necessary to monitor and treat the disease.

It is important for people with LES to work closely with their healthcare providers to manage their condition and prevent complications. With proper treatment and self-care, many people with LES can lead active and fulfilling lives.

Idiopathic membranous nephropathy (IMN) is an autoimmune disorder that causes GNM without any identifiable cause. Secondary membranous nephropathy, on the other hand, is caused by systemic diseases such as lupus or cancer.

The symptoms of GNM can vary depending on the severity of the disease and may include blood in the urine, proteinuria, edema, high blood pressure, and decreased kidney function. The diagnosis of GNM is based on a combination of clinical findings, laboratory tests, and renal biopsy.

Treatment for GNM is aimed at slowing the progression of the disease and managing symptoms. Medications such as corticosteroids, immunosuppressive drugs, and blood pressure-lowering drugs may be used to treat GNM. In some cases, kidney transplantation may be necessary.

The prognosis for GNM varies depending on the severity of the disease and the underlying cause. In general, the prognosis for IMN is better than for secondary membranous nephropathy. With proper treatment, some patients with GNM can experience a slowing or stabilization of the disease, while others may progress to end-stage renal disease (ESRD).

The cause of GNM is not fully understood, but it is believed to be an autoimmune disorder that leads to inflammation and damage to the glomerular membrane. Genetic factors and environmental triggers may also play a role in the development of GNM.

There are several risk factors for developing GNM, including family history, age (GMN is more common in adults), and certain medical conditions such as hypertension and diabetes.

The main complications of GNM include:

1. ESRD: Progression to ESRD is a common outcome of untreated GNM.
2. High blood pressure: GNM can lead to high blood pressure, which can further damage the kidneys.
3. Infections: GNM increases the risk of infections due to impaired immune function.
4. Kidney failure: GNM can cause chronic kidney failure, leading to the need for dialysis or a kidney transplant.
5. Cardiovascular disease: GNM is associated with an increased risk of cardiovascular disease, including heart attack and stroke.
6. Malnutrition: GNM can lead to malnutrition due to decreased appetite, nausea, and vomiting.
7. Bone disease: GNM can cause bone disease, including osteoporosis and bone pain.
8. Anemia: GNM can cause anemia, which can lead to fatigue, weakness, and shortness of breath.
9. Increased risk of infections: GNM increases the risk of infections due to impaired immune function.
10. Decreased quality of life: GNM can significantly decrease a person's quality of life, leading to decreased mobility, pain, and discomfort.

It is important for individuals with GNM to receive early diagnosis and appropriate treatment to prevent or delay the progression of these complications.

The symptoms of glomerulonephritis can vary depending on the underlying cause of the disease, but may include:

* Blood in the urine (hematuria)
* Proteinuria (excess protein in the urine)
* Reduced kidney function
* Swelling in the legs and ankles (edema)
* High blood pressure

Glomerulonephritis can be caused by a variety of factors, including:

* Infections such as staphylococcal or streptococcal infections
* Autoimmune disorders such as lupus or rheumatoid arthritis
* Allergic reactions to certain medications
* Genetic defects
* Certain diseases such as diabetes, high blood pressure, and sickle cell anemia

The diagnosis of glomerulonephritis typically involves a physical examination, medical history, and laboratory tests such as urinalysis, blood tests, and kidney biopsy.

Treatment for glomerulonephritis depends on the underlying cause of the disease and may include:

* Antibiotics to treat infections
* Medications to reduce inflammation and swelling
* Diuretics to reduce fluid buildup in the body
* Immunosuppressive medications to suppress the immune system in cases of autoimmune disorders
* Dialysis in severe cases

The prognosis for glomerulonephritis depends on the underlying cause of the disease and the severity of the inflammation. In some cases, the disease may progress to end-stage renal disease, which requires dialysis or a kidney transplant. With proper treatment, however, many people with glomerulonephritis can experience a good outcome and maintain their kidney function over time.

Arteriolosclerosis is often associated with conditions such as hypertension, diabetes, and atherosclerosis, which is the buildup of plaque in the arteries. It can also be caused by other factors such as smoking, high cholesterol levels, and inflammation.

The symptoms of arteriolosclerosis can vary depending on the location and severity of the condition, but may include:

* Decreased blood flow to organs or tissues
* Fatigue
* Weakness
* Shortness of breath
* Dizziness or lightheadedness
* Pain in the affected limbs or organs

Arteriolosclerosis is typically diagnosed through a combination of physical examination, medical history, and diagnostic tests such as ultrasound, angiography, or blood tests. Treatment for the condition may include lifestyle changes such as exercise and dietary modifications, medications to control risk factors such as hypertension and high cholesterol, and in some cases, surgical intervention to open or bypass blocked arterioles.

In summary, arteriolosclerosis is a condition where the arterioles become narrowed or obstructed, leading to decreased blood flow to organs and tissues and potentially causing a range of health problems. It is often associated with other conditions such as hypertension and atherosclerosis, and can be diagnosed through a combination of physical examination, medical history, and diagnostic tests. Treatment may include lifestyle changes and medications to control risk factors, as well as surgical intervention in some cases.

1) They share similarities with humans: Many animal species share similar biological and physiological characteristics with humans, making them useful for studying human diseases. For example, mice and rats are often used to study diseases such as diabetes, heart disease, and cancer because they have similar metabolic and cardiovascular systems to humans.

2) They can be genetically manipulated: Animal disease models can be genetically engineered to develop specific diseases or to model human genetic disorders. This allows researchers to study the progression of the disease and test potential treatments in a controlled environment.

3) They can be used to test drugs and therapies: Before new drugs or therapies are tested in humans, they are often first tested in animal models of disease. This allows researchers to assess the safety and efficacy of the treatment before moving on to human clinical trials.

4) They can provide insights into disease mechanisms: Studying disease models in animals can provide valuable insights into the underlying mechanisms of a particular disease. This information can then be used to develop new treatments or improve existing ones.

5) Reduces the need for human testing: Using animal disease models reduces the need for human testing, which can be time-consuming, expensive, and ethically challenging. However, it is important to note that animal models are not perfect substitutes for human subjects, and results obtained from animal studies may not always translate to humans.

6) They can be used to study infectious diseases: Animal disease models can be used to study infectious diseases such as HIV, TB, and malaria. These models allow researchers to understand how the disease is transmitted, how it progresses, and how it responds to treatment.

7) They can be used to study complex diseases: Animal disease models can be used to study complex diseases such as cancer, diabetes, and heart disease. These models allow researchers to understand the underlying mechanisms of the disease and test potential treatments.

8) They are cost-effective: Animal disease models are often less expensive than human clinical trials, making them a cost-effective way to conduct research.

9) They can be used to study drug delivery: Animal disease models can be used to study drug delivery and pharmacokinetics, which is important for developing new drugs and drug delivery systems.

10) They can be used to study aging: Animal disease models can be used to study the aging process and age-related diseases such as Alzheimer's and Parkinson's. This allows researchers to understand how aging contributes to disease and develop potential treatments.

There are several types of lupus nephritis, each with its own unique characteristics and symptoms. The most common forms include:

* Class I (mesangial proliferative glomerulonephritis): This type is characterized by the growth of abnormal cells in the glomeruli (blood-filtering units of the kidneys).
* Class II (active lupus nephritis): This type is characterized by widespread inflammation and damage to the kidneys, with or without the presence of antibodies.
* Class III (focal lupus nephritis): This type is characterized by localized inflammation in certain areas of the kidneys.
* Class IV (lupus nephritis with crescentic glomerulonephritis): This type is characterized by widespread inflammation and damage to the kidneys, with crescent-shaped tissue growth in the glomeruli.
* Class V (lupus nephritis with sclerotic changes): This type is characterized by hardening and shrinkage of the glomeruli due to scarring.

Lupus Nephritis can cause a range of symptoms, including:

* Proteinuria (excess protein in the urine)
* Hematuria (blood in the urine)
* Reduced kidney function
* Swelling (edema)
* Fatigue
* Fever
* Joint pain

Lupus Nephritis can be diagnosed through a combination of physical examination, medical history, laboratory tests, and kidney biopsy. Treatment options for lupus nephritis include medications to suppress the immune system, control inflammation, and prevent further damage to the kidneys. In severe cases, dialysis or a kidney transplant may be necessary.

There are several key features of inflammation:

1. Increased blood flow: Blood vessels in the affected area dilate, allowing more blood to flow into the tissue and bringing with it immune cells, nutrients, and other signaling molecules.
2. Leukocyte migration: White blood cells, such as neutrophils and monocytes, migrate towards the site of inflammation in response to chemical signals.
3. Release of mediators: Inflammatory mediators, such as cytokines and chemokines, are released by immune cells and other cells in the affected tissue. These molecules help to coordinate the immune response and attract more immune cells to the site of inflammation.
4. Activation of immune cells: Immune cells, such as macrophages and T cells, become activated and start to phagocytose (engulf) pathogens or damaged tissue.
5. Increased heat production: Inflammation can cause an increase in metabolic activity in the affected tissue, leading to increased heat production.
6. Redness and swelling: Increased blood flow and leakiness of blood vessels can cause redness and swelling in the affected area.
7. Pain: Inflammation can cause pain through the activation of nociceptors (pain-sensing neurons) and the release of pro-inflammatory mediators.

Inflammation can be acute or chronic. Acute inflammation is a short-term response to injury or infection, which helps to resolve the issue quickly. Chronic inflammation is a long-term response that can cause ongoing damage and diseases such as arthritis, asthma, and cancer.

There are several types of inflammation, including:

1. Acute inflammation: A short-term response to injury or infection.
2. Chronic inflammation: A long-term response that can cause ongoing damage and diseases.
3. Autoimmune inflammation: An inappropriate immune response against the body's own tissues.
4. Allergic inflammation: An immune response to a harmless substance, such as pollen or dust mites.
5. Parasitic inflammation: An immune response to parasites, such as worms or fungi.
6. Bacterial inflammation: An immune response to bacteria.
7. Viral inflammation: An immune response to viruses.
8. Fungal inflammation: An immune response to fungi.

There are several ways to reduce inflammation, including:

1. Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying anti-rheumatic drugs (DMARDs).
2. Lifestyle changes, such as a healthy diet, regular exercise, stress management, and getting enough sleep.
3. Alternative therapies, such as acupuncture, herbal supplements, and mind-body practices.
4. Addressing underlying conditions, such as hormonal imbalances, gut health issues, and chronic infections.
5. Using anti-inflammatory compounds found in certain foods, such as omega-3 fatty acids, turmeric, and ginger.

It's important to note that chronic inflammation can lead to a range of health problems, including:

1. Arthritis
2. Diabetes
3. Heart disease
4. Cancer
5. Alzheimer's disease
6. Parkinson's disease
7. Autoimmune disorders, such as lupus and rheumatoid arthritis.

Therefore, it's important to manage inflammation effectively to prevent these complications and improve overall health and well-being.

There are three main forms of ACH:

1. Classic congenital adrenal hyperplasia (CAH): This is the most common form of ACH, accounting for about 90% of cases. It is caused by mutations in the CYP21 gene, which codes for an enzyme that converts cholesterol into cortisol and aldosterone.
2. Non-classic CAH (NCAH): This form of ACH is less common than classic CAH and is caused by mutations in other genes involved in cortisol and aldosterone production.
3. Mineralocorticoid excess (MOE) or glucocorticoid deficiency (GD): These are rare forms of ACH that are characterized by excessive production of mineralocorticoids (such as aldosterone) or a deficiency of glucocorticoids (such as cortisol).

The symptoms of ACH can vary depending on the specific form of the disorder and the age at which it is diagnosed. In classic CAH, symptoms typically appear in infancy and may include:

* Premature puberty (in girls) or delayed puberty (in boys)
* Abnormal growth patterns
* Distended abdomen
* Fatigue
* Weight gain or obesity
* Easy bruising or bleeding

In NCAH and MOE/GD, symptoms may be less severe or may not appear until later in childhood or adulthood. They may include:

* High blood pressure
* Low blood sugar (hypoglycemia)
* Weight gain or obesity
* Fatigue
* Mood changes

If left untreated, ACH can lead to serious complications, including:

* Adrenal gland insufficiency
* Heart problems
* Bone health problems
* Increased risk of infections
* Mental health issues (such as depression or anxiety)

Treatment for ACH typically involves hormone replacement therapy to restore the balance of hormones in the body. This may involve taking medications such as cortisol, aldosterone, or other hormones to replace those that are deficient or imbalanced. In some cases, surgery may be necessary to remove an adrenal tumor or to correct physical abnormalities.

With proper treatment, many individuals with ACH can lead healthy, active lives. However, it is important for individuals with ACH to work closely with their healthcare providers to manage their condition and prevent complications. This may involve regular check-ups, hormone level monitoring, and lifestyle changes such as a healthy diet and regular exercise.

Proteinuria is usually diagnosed by a urine protein-to-creatinine ratio (P/C ratio) or a 24-hour urine protein collection. The amount and duration of proteinuria can help distinguish between different underlying causes and predict prognosis.

Proteinuria can have significant clinical implications, as it is associated with increased risk of cardiovascular disease, kidney damage, and malnutrition. Treatment of the underlying cause can help reduce or eliminate proteinuria.

There are two main types of MD:

1. Dry Macular Degeneration (DMD): This is the most common form of MD, accounting for about 90% of cases. It is caused by the gradual accumulation of waste material in the macula, which can lead to cell death and vision loss over time.
2. Wet Macular Degeneration (WMD): This type of MD is less common but more aggressive, accounting for about 10% of cases. It occurs when new blood vessels grow underneath the retina, leaking fluid and causing damage to the macula. This can lead to rapid vision loss if left untreated.

The symptoms of MD can vary depending on the severity and type of the condition. Common symptoms include:

* Blurred vision
* Distorted vision (e.g., straight lines appearing wavy)
* Difficulty reading or recognizing faces
* Difficulty adjusting to bright light
* Blind spots in central vision

MD can have a significant impact on daily life, making it difficult to perform everyday tasks such as driving, reading, and recognizing faces.

There is currently no cure for MD, but there are several treatment options available to slow down the progression of the disease and manage its symptoms. These include:

* Anti-vascular endothelial growth factor (VEGF) injections: These medications can help prevent the growth of new blood vessels and reduce inflammation in the macula.
* Photodynamic therapy: This involves the use of a light-sensitive drug and low-intensity laser to damage and shrink the abnormal blood vessels in the macula.
* Vitamin supplements: Certain vitamins, such as vitamin C, E, and beta-carotene, have been shown to slow down the progression of MD.
* Laser surgery: This can be used to reduce the number of abnormal blood vessels in the macula and improve vision.

It is important for individuals with MD to receive regular monitoring and treatment from an eye care professional to manage their condition and prevent complications.

There are several types of disease susceptibility, including:

1. Genetic predisposition: This refers to the inherent tendency of an individual to develop a particular disease due to their genetic makeup. For example, some families may have a higher risk of developing certain diseases such as cancer or heart disease due to inherited genetic mutations.
2. Environmental susceptibility: This refers to the increased risk of developing a disease due to exposure to environmental factors such as pollutants, toxins, or infectious agents. For example, someone who lives in an area with high levels of air pollution may be more susceptible to developing respiratory problems.
3. Lifestyle susceptibility: This refers to the increased risk of developing a disease due to unhealthy lifestyle choices such as smoking, lack of exercise, or poor diet. For example, someone who smokes and is overweight may be more susceptible to developing heart disease or lung cancer.
4. Immune system susceptibility: This refers to the increased risk of developing a disease due to an impaired immune system. For example, people with autoimmune disorders such as HIV/AIDS or rheumatoid arthritis may be more susceptible to opportunistic infections.

Understanding disease susceptibility can help healthcare providers identify individuals who are at risk of developing certain diseases and provide preventive measures or early intervention to reduce the risk of disease progression. Additionally, genetic testing can help identify individuals with a high risk of developing certain diseases, allowing for earlier diagnosis and treatment.

In summary, disease susceptibility refers to the predisposition of an individual to develop a particular disease or condition due to various factors such as genetics, environment, lifestyle choices, and immune system function. Understanding disease susceptibility can help healthcare providers identify individuals at risk and provide appropriate preventive measures or early intervention to reduce the risk of disease progression.

There are several symptoms of RA, including:

1. Joint pain and stiffness, especially in the hands and feet
2. Swollen and warm joints
3. Redness and tenderness in the affected areas
4. Fatigue, fever, and loss of appetite
5. Loss of range of motion in the affected joints
6. Firm bumps of tissue under the skin (rheumatoid nodules)

RA can be diagnosed through a combination of physical examination, medical history, blood tests, and imaging studies such as X-rays or ultrasound. Treatment typically involves a combination of medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), and biologic agents. Lifestyle modifications such as exercise and physical therapy can also be helpful in managing symptoms and improving quality of life.

There is no cure for RA, but early diagnosis and aggressive treatment can help to slow the progression of the disease and reduce symptoms. With proper management, many people with RA are able to lead active and fulfilling lives.

Explanation: Genetic predisposition to disease is influenced by multiple factors, including the presence of inherited genetic mutations or variations, environmental factors, and lifestyle choices. The likelihood of developing a particular disease can be increased by inherited genetic mutations that affect the functioning of specific genes or biological pathways. For example, inherited mutations in the BRCA1 and BRCA2 genes increase the risk of developing breast and ovarian cancer.

The expression of genetic predisposition to disease can vary widely, and not all individuals with a genetic predisposition will develop the disease. Additionally, many factors can influence the likelihood of developing a particular disease, such as environmental exposures, lifestyle choices, and other health conditions.

Inheritance patterns: Genetic predisposition to disease can be inherited in an autosomal dominant, autosomal recessive, or multifactorial pattern, depending on the specific disease and the genetic mutations involved. Autosomal dominant inheritance means that a single copy of the mutated gene is enough to cause the disease, while autosomal recessive inheritance requires two copies of the mutated gene. Multifactorial inheritance involves multiple genes and environmental factors contributing to the development of the disease.

Examples of diseases with a known genetic predisposition:

1. Huntington's disease: An autosomal dominant disorder caused by an expansion of a CAG repeat in the Huntingtin gene, leading to progressive neurodegeneration and cognitive decline.
2. Cystic fibrosis: An autosomal recessive disorder caused by mutations in the CFTR gene, leading to respiratory and digestive problems.
3. BRCA1/2-related breast and ovarian cancer: An inherited increased risk of developing breast and ovarian cancer due to mutations in the BRCA1 or BRCA2 genes.
4. Sickle cell anemia: An autosomal recessive disorder caused by a point mutation in the HBB gene, leading to defective hemoglobin production and red blood cell sickling.
5. Type 1 diabetes: An autoimmune disease caused by a combination of genetic and environmental factors, including multiple genes in the HLA complex.

Understanding the genetic basis of disease can help with early detection, prevention, and treatment. For example, genetic testing can identify individuals who are at risk for certain diseases, allowing for earlier intervention and preventive measures. Additionally, understanding the genetic basis of a disease can inform the development of targeted therapies and personalized medicine."

The disorder is caused by mutations in the HBB gene that codes for the beta-globin subunit of hemoglobin. These mutations result in the production of abnormal hemoglobins that are unstable and prone to breakdown, leading to the release of free hemoglobin into the urine.

HP is classified into two types based on the severity of symptoms:

1. Type 1 HP: This is the most common form of the disorder and is characterized by mild to moderate anemia, occasional hemoglobinuria, and a normal life expectancy.
2. Type 2 HP: This is a more severe form of the disorder and is characterized by severe anemia, recurrent hemoglobinuria, and a shorter life expectancy.

There is no cure for HP, but treatment options are available to manage symptoms and prevent complications. These may include blood transfusions, folic acid supplements, and medications to reduce the frequency and severity of hemoglobinuria episodes.

The term "immune complex disease" was first used in the 1960s to describe a group of conditions that were thought to be caused by the formation of immune complexes. These diseases include:

1. Systemic lupus erythematosus (SLE): an autoimmune disorder that can affect multiple organ systems and is characterized by the presence of anti-nuclear antibodies.
2. Rheumatoid arthritis (RA): an autoimmune disease that causes inflammation in the joints and can lead to joint damage.
3. Type III hypersensitivity reaction: a condition in which immune complexes are deposited in tissues, leading to inflammation and tissue damage.
4. Pemphigus: a group of autoimmune diseases that affect the skin and mucous membranes, characterized by the presence of autoantibodies against desmosomal antigens.
5. Bullous pemphigoid: an autoimmune disease that affects the skin and is characterized by the formation of large blisters.
6. Myasthenia gravis: an autoimmune disorder that affects the nervous system, causing muscle weakness and fatigue.
7. Goodpasture's syndrome: a rare autoimmune disease that affects the kidneys and lungs, characterized by the presence of immune complexes in the glomeruli of the kidneys.
8. Hemolytic uremic syndrome (HUS): a condition in which red blood cells are destroyed and waste products accumulate in the kidneys, leading to kidney failure.

Immune complex diseases can be caused by various factors, including genetic predisposition, environmental triggers, and exposure to certain drugs or toxins. Treatment options for these diseases include medications that suppress the immune system, such as corticosteroids and immunosuppressive drugs, and plasmapheresis, which is a process that removes harmful antibodies from the blood. In some cases, organ transplantation may be necessary.

In conclusion, immune complex diseases are a group of disorders that occur when the body's immune system mistakenly attacks its own tissues and organs, leading to inflammation and damage. These diseases can affect various parts of the body, including the skin, kidneys, lungs, and nervous system. Treatment options vary depending on the specific disease and its severity, but may include medications that suppress the immune system and plasmapheresis.

C3a is one of the proteins formed by the cleavage of complement component 3; the other is C3b. C3a is a 77 residue ... C3 convertase activity is also regulated without C3b inactivation, through complement control proteins, including decay- ... 12th European Meeting on Complement in Human Disease12th European Meeting on CHD12th European Meeting on Complement in Human ... to form C3b(H2O)Bb, or fluid-phase C3-convertase. This complex has the ability to catalyze the formation of C3a and C3b after ...

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

This newly bound C3b recruits more B, D and P activity and greatly amplifies the complement activation. When complement is ... Polymorphisms of complement component 3, complement factor B, and complement factor I, as well as deletion of complement factor ... The complement system, also known as complement cascade, is a part of the immune system that enhances (complements) the ability ... Three biochemical pathways activate the complement system: the classical complement pathway, the alternative complement pathway ...

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

Jokiranta TS, Westin J, Nilsson UR, Nilsson B, Hellwage J, Löfås S, Gordon DL, Ekdahl KN, Meri S (Mar 2001). "Complement C3b ... Complement component 3, often simply called C3, is a protein of the immune system. It plays a central role in the complement ... "Entrez Gene: C3 complement component 3". Sahu A, Lambris JD (Apr 2001). "Structure and biology of complement protein C3, a ... "Structure of C3b in complex with CRIg gives insights into regulation of complement activation". Nature. 444 (7116): 217-20. ...

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

... is produced when complement factor I cleaves C3b. Complement receptors on white blood cells are able to bind iC3b, so iC3b ... Unlike intact C3b, iC3b cannot associate with factor B, thus preventing amplification of the complement cascade through the ... Complement factor I can further cleave iC3b into a protein fragment known as C3d. Robbins Basic Pathology 8th ed 2007. R Cotran ... iC3b is a protein fragment that is part of the complement system, a component of the vertebrate immune system. ...

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

It recognizes iC3b (inactivated C3b) deposited on microbial surfaces. complement system immunoglobulin Helmy K, Katschke K, ... Complement receptor of the immunoglobulin family is a protein expressed in Kupffer cells. It is a critical receptor for the ... a macrophage complement receptor required for phagocytosis of circulating pathogens". Cell. 124 (5): 915-27. doi:10.1016/j.cell ...

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

1987). "A complement receptor locus: genes encoding C3b/C4b receptor and C3d/Epstein-Barr virus receptor map to 1q32". J. ... CR2 is involved in the complement system. It binds to iC3b (inactive derivative of C3b), C3dg, or C3d. B cells express CR2 ... Complement receptor type 2 (CR2), also known as complement C3d receptor, Epstein-Barr virus receptor, and CD21 (cluster of ... homology with the receptor for fragments C3b and C4b of the third and fourth components of complement". Proc. Natl. Acad. Sci. ...

https://en.wikipedia.org/wiki/Complement_receptor_2

Since C3b is free and abundant in the plasma, it can bind to either a host cell or a pathogen surface. To prevent complement ... Factor I requires a C3b-binding protein cofactor such as complement factor H, CR1, or Membrane Cofactor of Proteolysis (MCP or ... Pangburn MK, Schreiber RD, Müller-Eberhard HJ (July 1977). "Human complement C3b inactivator: isolation, characterization, and ... C3b)2BbP or C4b2a3b from the classical pathway), the complement system follows the same path regardless of the means of ...

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

... also cleaves IgG and complement component C3b, inhibiting phagocytosis. The full length of mature staphylokinase ...

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

These receptors recognise targets coated in C3b, C4b and C3bi from plasma complement. The extracellular domain of the receptors ... Recognition by complement receptors is not enough to cause internalisation without additional signals. In macrophages, the CR1 ... Complement coated targets are internalised by 'sinking' into the phagocyte membrane, without any protrusions. Mannose and other ... Among these are receptors that recognise the Fc part of bound IgG antibodies, deposited complement or receptors, that recognise ...

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

Opsonins include Mfge8, Gas6, Protein S, antibodies and complement factors C1q and C3b. Phagoptosis has multiple functions ... Pathogenic cells such as bacteria can be opsonised by antibodies or complement factors, enabling their phagocytosis and ...

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

Microbes may activate the complement system directly and complement component C3b bind to microbes. After C3b is degraded into ... Frank K, Atkinson JP (2001). "Complement system." In Austen KF, Frank K, Atkinson JP, Cantor H. eds. Samter's Immunologic ... Co-stimulation for B cells is provided alternatively by complement receptors. ... B cells express complement receptor CR2 (CD21) to bind to iC3b, C3dg, or C3d. This additional binding makes the B cells 100- to ...

https://en.wikipedia.org/wiki/Co-stimulation

This protein is also a receptor for the complement component 3 fragments C3b and iC3b. Alternate splicing results in multiple ... a macrophage complement receptor required for phagocytosis of circulating pathogens". Cell. 124 (5): 915-27. doi:10.1016/j.cell ...

https://en.wikipedia.org/wiki/V-set_and_immunoglobulin_domain_containing_4

They bear membrane receptors for opsonins, such as IgG and the fragment C3b of complement. They express LCAs (leucocyte common ...

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

"Structures of C3b in Complex with Factors B and D Give Insight into Complement Convertase Formation". Science. 330 (6012): 1816 ... This protein is part of the oldest part of the immune system that is present in the human body, the complement system. Using ... Among his findings are the molecular mechanisms that underlie key steps in the human immune defense by the complement system, ... Hadders, M. A.; Beringer, D. X.; Gros, P. (2007). "Structure of C8 -MACPF Reveals Mechanism of Membrane Attack in Complement ...

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

The oxidative stress damages the structure and function of erythrocytes, in particular RBC-complement 3b (C3b) receptors. ...

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

"Staphylococcus aureus clumping factor A binds to complement regulator factor I and increases factor I cleavage of C3b". The ... ClfA also has been shown to bind to complement regulator I protein. It is responsible for the clumping of blood plasma observed ...

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

"C3b deposition during activation of the alternative complement pathway and the effect of deposition on the activating surface ... C3b has different binding site for C3bINA, β1H, factor B and properdin. Binding β1H to C3b increases C3bINA binding, while ... Properdin also promotes association of C3b with Factor B and thus it inhibits the Factor H mediated cleavage of C3b by Factor I ... plasmin or even a bacterial enzyme leads to formation of C3a and C3b fragments. C3b, the larger fragment, becomes covalently ...

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

The active subunit Bb is a serine protease that associates with C3b to form the alternative pathway C3 convertase. Bb is ... Complement factor B is a protein that in humans is encoded by the CFB gene. This gene encodes complement factor B, a component ... "Entrez Gene: CFB complement factor B". Ambrus JL, Peters MG, Fauci AS, Brown EJ (March 1990). "The Ba fragment of complement ... Christie DL, Gagnon J (January 1983). "Amino acid sequence of the Bb fragment from complement Factor B. Sequence of the major ...

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

In lieu of the membrane attack complex, complement proteins (particularly C3b and C4b) are deposited on red blood cells. This ... Binding of antibodies to red blood cells activates the classical pathway of the complement system. If the complement response ... Jaffe, C J; Atkinson, J P; Frank, M M (1976-10-01). "The role of complement in the clearance of cold agglutinin-sensitized ... Detection of antibodies (cold or warm) and /or complement system on RBC from the patient is a direct Coombs antiglobulin test. ...

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

The S-layer prevents complement-mediated bacterial killing by impairing the binding of C3b to the surface of the bacteria. The ... Aside from complement-mediated mechanisms, C. fetus has also evolved variation in its S-layer proteins (SLPs) of the S-layer to ... Additionally, Cfv has long LPS side chains (O-antigens) that may resist complement-mediated bacterial killing. ...

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

The complement system is used to enhance the effect of antibodies and phagocytic cells, which engulf and destroy other cells. ... Microfilariae block this pathway by cleaving C3b-an important protein in this process-to form iC3b. iC3b cannot go on to ... "Onchocerca volvulus microfilariae avoid complement attack by direct binding of factor H". The Journal of Infectious Diseases. ...

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

... , also known as C3b/C4b inactivator, is a protein that in humans is encoded by the CFI gene. Complement ... Loss of function mutations in the Complement Factor I gene lead to low levels of factor I which results in increased complement ... Whaley K (March 1980). "Biosynthesis of the complement components and the regulatory proteins of the alternative complement ... that regulates complement activation by cleaving cell-bound or fluid phase C3b and C4b. It is a soluble glycoprotein that ...

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

DAF regulates the complement system on the cell surface. It recognizes C4b and C3b fragments that are created during activation ... Complement decay-accelerating factor, also known as CD55 or DAF, is a protein that, in humans, is encoded by the CD55 gene. ... DAF contains four complement control protein (CCP) repeats with a single N-linked glycan positioned between CCP1 and CCP2. CCP2 ... Binding of DAF to human HIV-1 when the virons are budding from the surface of infected cells protects HIV-1 from complement ...

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

... or the complement component C3b. These types of antibodies and complement are immune substances called opsonizers, molecules ... When the spleen is no longer present (asplenia), IgG and C3b are still bound to bacteria, but they cannot be removed from the ... So humoral immunity in forms of IgG and complement proteins is the human immune system's response against bacterial capsules. ...

https://en.wikipedia.org/wiki/Overwhelming_post-splenectomy_infection

Porins are also recognized by TLR2, they bind complement factors (C3b, C4b, factor H, and C4bp (complement factor 4b-binding ... fHbp protects meningococci from complement-mediated death in human serum experiments, but has also been shown to protect ... Porins are also an important factor for complement inhibition for both pathogenic and commensal species. Porins are important ... and complement deficiency. The incubation period is short, from 2 to 10 days. In susceptible individuals, N. meningitidis may ...

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

... cleaving most C3 molecules in the serum into C3a and C3b fragments, which depletes the amount of intact C3. C3 deficiency makes ... Complement 3 deficiency is a genetic condition affecting complement component 3 (C3). People can suffer from either primary or ... C3 is the most abundant complement component and is a particularly important complement component because there are three ways ... Complement component 3 (C3) is a protein involved in both the innate and adaptive immune response. C3 is one of over 30 ...

https://en.wikipedia.org/wiki/Complement_3_deficiency

... or complement mediated. They then looked at the complement factors and immunoglobulin deposits to identify the underlying cause ... encounters conformational change that leads to C3 convertase breaking C3 into C3a and C3b. C3a, C5a, IL-8 are all chemotactic ... Inactive and active complement proteins that split fragments are found in the glomeruli. There are currently drugs available ... There are no current clinical trials for DPGN happening.[citation needed] Activating complement pathways plays a large role in ...

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

SpeB degrades immunoglobulins and cytokines, as well as through cleavage of C3b, inhibiting recruitment of phagocytic cells and ... the complement activation pathway. This results in decreased inflammation and neutrophil levels around the site of infection, ...

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

... aureus protein Sbi acts as a complement inhibitor and forms a tripartite complex with host complement Factor H and C3b". PLOS ... sbi protein interferes with the host's innate immune response by binding Factor H, Complement component 3 and IgG. Protein A ... June 2008). "Interaction of human complement with Sbi, a staphylococcal immunoglobulin-binding protein: indications of a novel ... mechanism of complement evasion by Staphylococcus aureus". J. Biol. Chem. 283 (25): 17579-17593. doi:10.1074/jbc.M800265200. ...

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

Complement proteins involved in innate opsonization include C4b, C3b and iC3b. In the alternative pathway of complement ... C1q association eventually leads to the recruitment of complement C4b and C3b, both of which are recognized by complement ... In both cases C1q activates complement, resulting in the cells being marked for phagocytosis by C3b and C4b. C1q is an ... C3b can spontaneously bind to pathogen surfaces through the alternative complement pathway. Furthermore, pentraxins can ...

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

... binds to complement protein C3 and its activation fragment C3b with high affinity, thereby regulating the ... Patients with PNH have greater and uninhibited complement activity, which may leads to intravascular (inside blood vessels) or ... Pegcetacoplan is the first treatment for paroxysmal nocturnal hemoglobinuria that binds to and inhibits complement protein C3. ... cleavage of C3 and the generation of downstream effectors of complement activation. Pegcetacoplan is indicated to treat adults ...

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

C3 is cleaved into its a and b subunits, and C3b binds the convertase. These together are called the C5 convertase. Similarly ... Complement receptors, collectins, ficolins, pentraxins such as serum amyloid and C-reactive protein, lipid transferases, ... Once bound to the ligands MBL and Ficolin oligomers recruit MASP1 and MASP2 and initiate the lectin pathway of complement ... "/"self turned nonself" type pathogen pattern are also identified and destroyed (e.g. by complement fixation or other cytotoxic ...

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

... complement c3 MeSH D12.776.124.486.274.250.250 - complement c3a MeSH D12.776.124.486.274.250.260 - complement c3b MeSH D12.776. ... complement c3b inactivator proteins MeSH D12.776.124.486.274.920.325.200 - complement factor h MeSH D12.776.124.486.274.920. ... complement c1 MeSH D12.776.124.486.274.050.270 - complement c1q MeSH D12.776.124.486.274.050.280 - complement c1r MeSH D12.776. ... complement c2 MeSH D12.776.124.486.274.150.500 - complement c2a MeSH D12.776.124.486.274.150.750 - complement c2b MeSH D12.776. ...

https://en.wikipedia.org/wiki/List_of_MeSH_codes_(D12.776.124)

2000). "Functional properties of complement factor H-related proteins FHR-3 and FHR-4: binding to the C3d region of C3b and ... Complement factor H-related protein 4 is a protein that in humans is encoded by the CFHR4 gene. GRCh38: Ensembl release 89: ... "Entrez Gene: CFHR4 complement factor H-related 4". Hageman GS, Hancox LS, Taiber AJ, et al. (2007). "Extended Haplotypes in the ... Diaz-Guillen MA, Rodriguez de Cordoba S, Heine-Suner D (Jul 1999). "A radiation hybrid map of complement factor H and factor H- ...

https://en.wikipedia.org/wiki/CFHR4

... where the C3b-tagged immune complex is then destroyed. In both cases C3b interacts with the C3b receptor, complement receptor 1 ... C3b is the larger of two elements formed by the cleavage of complement component 3, and is considered an important part of the ... Furthermore, if C3b does bind to a host-cell surface, regulators of complement activity (RCAs), a group of genetically-, ... The key to the success of the complement system in clearing antigens is regulating the effects of C3b to pathogens alone and ...

https://en.wikipedia.org/wiki/C3b

Beeken WL, Northwood I, Beliveau C, Baigent G, Gump D (1987). "Eosinophils of human colonic mucosa: C3b and Fc gamma receptor ... complement complex (C5-C6-C7), interleukin 5, and histamine (though this has a narrow range of concentration). Harm resulting ...

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

... which activate the classical pathway of the complement system. The cascade begins to work from C1 to C3b through C4b, C3b being ... Because primate erythrocytes express complement receptor 1 (CR1) on their surface and having binding specificity to C4b, C3b, ... London: Mosby, ISBN 0-7234-2918-9. Frank K, Atkinson JP (2001). "Complement system." In Austen KF, Frank K, Atkinson JP, Cantor ... Bala Subramanian V, Liszewski MK, Atkinson JP (2000). "The complement system and autoimmunity." In Lahita RG, Chiorazzi N, ...

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

After an antigen-antibody reaction, the immune complexes can be subject to any of a number of responses, including complement ... Red blood cells carrying CR1-receptors on their surface may bind C3b-coated immune complexes and transport them to phagocytes, ...

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

... of complement components C3b and C4b by serum factor I, which protects the host cell from damage by complement. The protein ... The protein encoded by this gene is a type I membrane protein and is a regulatory part of the complement system. The encoded ... CD46 complement regulatory protein also known as CD46 (cluster of differentiation 46) and Membrane Cofactor Protein is a ... This gene is found in a cluster on chromosome 1q32 with other genes encoding structural components of the complement system. At ...

https://en.wikipedia.org/wiki/CD46

C3b and thus form the alternative pathway C5 convertase.CVFBb is a noncovalent association product of CVF3 and the complement ... First of all, C5 has to bind to C3b fragment. The capacity to bind C3b is a stable feature of component C5, as C5b also has ... Cell-bound C3 and C5 convertase differ in their C3b requirement. C3-convertase (C3bBb) need only one molecule of C3b to form, ... whereas two or more C3b are required for generation of C5 convertase (C3bBb). It means, when C3b is randomly distributed on the ...

https://en.wikipedia.org/wiki/C5-convertase

Complement+C4b-Binding+Protein at the US National Library of Medicine Medical Subject Headings (MeSH) v t e (Articles with ... It also has ability to bind C3b. C4BP accelerates decay of C3-convertase and is a cofactor for serine protease factor I which ... The genes coding for C4BP α-chain (C4BPA) and β-chain (C4BPB) are located in the regulators of complement activation (RCA) gene ... C4b-binding protein (C4BP) is a protein complex involved in the complement system where it acts as inhibitor. C4BP has an ...

https://en.wikipedia.org/wiki/C4b-binding_protein

C3b and C5) to avoid opsonisation. It can also recruit complement regulators such as Factor H, C4b-binding protein, factor H- ... It also secretes proteases to degrade complement proteins such as C3. It can bind to thrombin that decreases the fibrin ... They also bind to several human proteins such as complement proteins, thrombin, fibrinogen, and plasminogen using surface ...

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

CD11c, also known as Integrin, alpha X (complement component 3 receptor 4 subunit) (ITGAX), is a gene that encodes for CD11c . ... This protein combines with the beta 2 chain (ITGB2) to form a leukocyte-specific integrin referred to as inactivated-C3b (iC3b ... "Entrez Gene: ITGAX integrin, alpha X (complement component 3 receptor 4 subunit)". Dyer KD, Garcia-Crespo KE, Killoran KE, ... and in the phagocytosis of complement coated particles. CD11c is a type I transmembrane protein found at high levels on most ...

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

Bliska JB, Falkow S (1992). "Bacterial resistance to complement killing mediated by the Ail protein of Yersinia enterocolitica ... "Role of the YadA protein in prevention of opsonization of Yersinia enterocolitica by C3b molecules". Infect. Immun. 61 (8): ... named Ail also bestows attachment and invasive abilities upon Yersiniae while interfering with the binding of complement on the ...

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

... such as when C3b binds to C3-convertase, or they can facilitate the formation of the Complement membrane attack complex (MAC) ... Should the microbe be coated with opsonising antibodies or C3b complement, the co-stimulation of endocytic PRR and opsonin ... complex also creates byproducts like C3b and C4b which are important components for the efficient function of the complement ... As well as endocytic PRRs, phagocytes furthermore express opsonin receptors such as Fc receptor and complement receptor 1 (CR1 ...

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

All three pathways converge at a step in which complement protein C3 is cleaved into proteins C3a and C3b, which results in a ... Complement component 4A Complement component 4B HLA A1-B8-DR3-DQ2 haplotype Complement system Complement deficiency Sekar A, ... Complement component 4 (C4), in humans, is a protein involved in the intricate complement system, originating from the human ... Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ...

https://en.wikipedia.org/wiki/Complement_component_4

September 2009). "Complement protease MASP-1 activates human endothelial cells: PAR4 activation is a link between complement ... C2a and C4b are used to create C3 convertase, a complex that will then be able to cleave C3 into C3a and C3b. However, MASP-1 ... MASP-1 is a serine protease that functions as a component of the lectin pathway of complement activation. The complement ... "The role of MASP-1/3 in complement activation". In Lambris JD, Holers VM, Ricklin D (eds.). Complement Therapeutics. Advances ...

https://en.wikipedia.org/wiki/MASP1_(protein)

... is an abundant regulator of complement activation and protects host cells from self-attack by complement. Here we provide ... Structure of complement fragment C3b-factor H and implications for host protection by complement regulators Jin Wu 1 , You- ... Structure of complement fragment C3b-factor H and implications for host protection by complement regulators Jin Wu et al. Nat ... Structure of C3b in complex with FH domains CCP1-4. (a) Overall structure of the C3b-FH(1-4) complex. C3b is shown in ribbon ...

https://pubmed.ncbi.nlm.nih.gov/19503104

Influence of complement C3 amount on IgG responses in early life: immunization with C3b-conjugated antigen increases murine ... Complement component C3, which plays an important role in both the innate and adaptative immune response, is present at low ... Complemento C3b/imunologia Imunoglobulina G/sangue Ovalbumina/imunologia Fatores Etários Animais Animais Recém-Nascidos Células ... conjugation of antigen to C3b significantly enhances antibody response elicited in 1-week-old mice--although it does not ...

https://pesquisa.bvsalud.org/saudepublica/resource/pt/mdl-15530677

Complement profiling of the patient showed decreased C3 and FB levels, with elevated levels of the terminal membrane attack ... Complement profiling of the patient showed decreased C3 and FB levels, with elevated levels of the terminal membrane attack ... Complement components analysis using specific immunoassays was performed on frozen plasma samples from the patient and mother. ... Complement components analysis using specific immunoassays and Western blotting was performed on frozen plasma samples from the ...

https://www.frontiersin.org/articles/10.3389/fimmu.2021.608604/full?utm_source=S-TWT&utm_medium=SNET&utm_campaign=ECO_FIMMU_XXXXXXXX_auto-dlvrit

The C3 gene provides instructions for making a protein called complement component 3 (or C3). Learn about this gene and related ... One of these pieces, called C3b, interacts with several other proteins on the surface of cells to trigger the complement ... This protein plays a key role in a part of the bodys immune response known as the complement system. The complement system is ... The C3 protein is essential for turning on (activating) the complement system. The presence of foreign invaders triggers the C3 ...

https://medlineplus.gov/genetics/gene/c3/

Access to the complement factor B scissile bond is facilitated by association of factor B with C3b protein. / Hourcade, Dennis ... Access to the complement factor B scissile bond is facilitated by association of factor B with C3b protein. Journal of ... Access to the complement factor B scissile bond is facilitated by association of factor B with C3b protein. ... title = "Access to the complement factor B scissile bond is facilitated by association of factor B with C3b protein", ...

https://profiles.wustl.edu/en/publications/access-to-the-complement-factor-b-scissile-bond-is-facilitated-by

... lytic pathway of complement by blocking the activation of the complement protein C5 and shows remarkable clinical benefits in ... certain complement-mediated diseases. However, several reports suggest that activation of C5 is not always completely ... depended on the strength of the complement activator and the resulting surface density of the complement activation product C3b ... Eculizumab inhibits the terminal, lytic pathway of complement by blocking the activation of the complement protein C5 and shows ...

https://pubmed.ncbi.nlm.nih.gov/28028023/

keywords = "C3b, Complement, Ulcerative colitis, iC3b/C3dg",. author = "T. Ueki and M. Mizuno and T. Uesu and T. Kiso and J. ... Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis ( ... Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis ( ... Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis ( ...

https://okayama.elsevierpure.com/en/publications/distribution-of-activated-complement-c3b-and-its-degraded-fragmen

... complement C3 (human). Find diseases associated with this biological target and compounds tested against it in bioassay ... complement component 3. complement component C3a. complement component C3b. epididymis secretory sperm binding protein Li 62p. ... Complement C3b contributes to Escherichia coli-induced platelet aggregation in human whole blood. Title: Complement C3b ... NTR_complement_C3; NTR/C345C domain, complement C3 subfamily; The NTR domain found in complement C3 is also known as the C345C ...

https://www.ncbi.nlm.nih.gov/gene?term=(C3%5BGene%20Name%5D)%20AND%209606%5BTaxonomy%20ID%5D

7. Complement C3b contributes to. Landsem A; Emblem Å; Lau C; Christiansen D; Gerogianni A; Karlsen BO; Mollnes TE; Nilsson PH ... 4. Platelet-borne complement proteins and their role in platelet-bacteria interactions.. Arbesu I; Bucsaiova M; Fischer MB; ...

https://pubmedhh.nlm.nih.gov/biomarkers/search.php?id=26669970&mod=related&page=1&outid=&proj=

Here, we show that complement-coordinated elimination of synapses participated in NPSLE in MRL/lpr mice, a lupus-prone murine ... Generally, complement cascade products of C3b, C5b, C4b are involved in opsonization for pathogens. And evidence suggests that ... 3d) and the classical complement pathway (KEGG term the complement and coagulation cascades, Fig. 2c). In the above category ... Nayak, A., Pednekar, L., Reid, K. B. & Kishore, U. Complement and non-complement activating functions of C1q: A prototypical ...

https://www.nature.com/articles/s41392-021-00867-y?error=cookies_not_supported&code=f7102891-991f-4604-b654-36cb68223e5f

The binding of NFa to C3b,Bb stabilizes the complex, preventing degradation by its normal inactivators, resulting in complement ... Adipocytes produce adipsin, which is identical to complement factor D and is responsible for activating the preconvertase C3b, ... The classic and alternate pathway convertases cause C3 activation, forming C3a and C3b. C3b is an opsonin itself, and C3 ... arising as a result of alternate complement activation or mutations in the complement-regulating proteins. C3NeF is commonly ...

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

Interactions between human complement components factor H, factor I and C3b. Biochem J. 1997 Sep 1. 326 ( Pt 2):553-61. [QxMD ... 21] Such rare variants have been described in the complement factor H (CFH), complement factor I (CFI), complement factor 9 (C9 ... 11] as well as other genes: factor B (BF)/complement component 2 (C2), [11, 12] complement component 3 (C3), [13, 14] and ... The Functional Effect of Rare Variants in Complement Genes on C3b Degradation in Patients With Age-Related Macular Degeneration ...

https://www.medscape.com/answers/1940442-168528/what-is-the-role-of-genetic-testing-in-the-management-of-age-related-macular-degeneration-amd

C3, complement C3. * Synonyms AHUS5, ARMD9, ASP, C3a, C3b, CPAMD1, HEL-S-62p ... J:5960 Da Silva FP, et al., Murine complement component 3: genetic variation and linkage to H-2. Proc Natl Acad Sci U S A. 1978 ... Human Disease Modeled: complement component 3 deficiency. Allelic Composition. Genetic Background. Reference. Phenotypes. ... Helicobacter pylori initiates successful gastric colonization by utilizing L-lactate to promote complement resistance. Nat ...

https://www.informatics.jax.org/marker/MGI:88227

complement C3b/C4b receptor 1 like. IAGP. ClinVar Annotator: match by term: Inflammatory bowel disease. ClinVar. PMID:28492532 ... complement C3b/C4b receptor 1 (Knops blood group). IAGP. ClinVar Annotator: match by term: Inflammatory bowel disease. ClinVar ... complement C3d receptor 2. IAGP. ClinVar Annotator: match by term: Inflammatory bowel disease. ClinVar. PMID:28492532. NCBI chr ... complement component 4 binding protein beta. IAGP. ClinVar Annotator: match by term: Inflammatory bowel disease. ClinVar. PMID: ...

https://rgd.mcw.edu/rgdweb/ontology/annot.html?acc_id=HP:0004386&species=Human

Pegcetacoplan acts proximally in the complement cascade controlling both C3b-mediated EVH and terminal complement-mediated IVH. ... Pegcetacoplan binds to complement protein C3 and its activation fragment C3b, thereby regulating the cleavage of C3 and the ... Control Arm = supportive care (excluding complement inhibitors). † The following terms were combined:. Infections include: acne ... Control Arm = supportive care (excluding complement inhibitors). † Patients who crossed over from the control arm group to the ...

https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=c23d89e9-b00b-4520-e053-2995a90a95af&type=display

Complement Component 3. *Complement Component C3a. *Complement Component C3b. *Epididymis Secretory Sperm Binding Protein Li ... From NCBI Gene: Complement component C3 plays a central role in the activation of complement system. Its activation is required ... for both classical and alternative complement activation pathways. The encoded preproprotein is proteolytically processed to ...

https://edrn.nci.nih.gov/data-and-resources/biomarkers/c3/

A Complement C3-Specific Nanobody for Modulation of the Alternative Cascade Identifies the C-Terminal Domain of C3b as ... Nanobody-mediated complement activation to kill HIV-infected cells. Research output: Contribution to journal/Conference ...

https://pure.au.dk/portal/en/persons/heidi-gytz-olesen

COMPLEMENT C3D; C3e; C3f; and C3g.. Entry Term(s). C3b Complement C3bi Complement 3b Complement Component 3b Inactivated C3b ... Complement C3b. Previous Indexing. Complement (1968-1974). Complement 3 (1975-1977). See Also. Receptors, Complement 3b. Public ... Complement C3a [D12.776.124.486.274.250.250] * Complement C3b [D12.776.124.486.274.250.260] * Complement C3c [D12.776.124.486. ... antag: consider COMPLEMENT C3B INACTIVATOR PROTEINS. Scope Note. The larger fragment generated from the cleavage of COMPLEMENT ...

https://meshb.nlm.nih.gov/record/ui?ui=D003179

This inhibits deposition of the host complement factor C3b and thus, complement-mediated opsonophagocytosis. Surface proteins ...

https://microbewiki.kenyon.edu/index.php?title=Streptococcus_agalactiae&action=edit&oldid=12956

C3b and iC3b. However, C4d did not bind to classic complement receptors. In monocytes, C4d exerted a dose-dependent inhibition ... Complement regulation leads to the generation of complement split products such as complement component (C)4d, a marker for ... Both receptors, expressed on monocytes, macrophages and dendritic cells, also interacted with complement split products C3d, ... Ig-like transcript 4 as a cellular receptor for soluble complement fragment C4d", published in „FASEB Journal" (IF 5.5).. ...

https://www.meduniwien.ac.at/hp/en/cepii/news/singleview/?tx_ttnews%5Btt_news%5D=4434&cHash=81dc0264531a72c2d8da346c3b3bc420

CD35, also known as CR1, binds C3b, iC3b, C4b, and iC4b. CD21/CD35 is primarily expressed on B lymphocytes, mast cells, ... complement receptor 2) and C3d receptor, binds C3d and iC3b. It is also a receptor of Epstein-Barr virus. ... CD21, also known as CR2 (complement receptor 2) and C3d receptor, binds C3d and iC3b. It is also a receptor of Epstein-Barr ... CD21 binds C3d, iC3b, and EBV; CD35 binds C3b, iC3b, C4b, and iC4b. Cell Type B cells, Dendritic cells Biology Area Cell ...

https://www.biolegend.com/fr-fr/products/pe-dazzle-594-anti-mouse-cd21-cd35-cr2-cr1-antibody-19453

Claudia Kemper, aims to understand the unexpected roles of complement proteins in the regula ... The Laboratory for Complement and Inflammation Research, led by Dr. ... which binds the complement activation fragment C3b) are critical checkpoints in human T cell lineage commitment and control ... Complement and Inflammation Research. The Laboratory for Complement and Inflammation Research, led by Dr. Claudia Kemper, aims ...

https://www.nhlbi.nih.gov/science/complement-and-inflammation-research

the protein crystal structure of complement component C3b reported in Nature 2006 and the corresponding structure factors and ... the protein crystal structure of vaccinia virus complement control protein (VCP) in complex with heparin reported in PNAS 2004 ...

https://grants.nih.gov/grants/guide/notice-files/NOT-OD-18-173.html

Pegcetacoplan intravitreal (Syfovre) binds to complement protein C3 and its activation fragment C3b, thereby regulating ... Early deposition of complement components C3 and C5 in the retina, suggest a contributing role of complement in AMD. It is ... Complement factor H variant increases the risk of age-related macular degeneration. Science. 2005 Apr 15. 308(5720):419-21. [ ... Complement factor H polymorphism and age-related macular degeneration. Science. 2005 Apr 15. 308(5720):421-4. [QxMD MEDLINE ...

https://emedicine.medscape.com/article/1226030-treatment

Avoid being bound by opsonization proteins like C3b.. C. Avoid triggering the complement system. ...

https://www.pearson.com/channels/microbiology/learn/jason/ch-24-principles-of-disease/1-hide-within-host-cells

Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b ... Breaking down the complement system: a review and update on novel therapies. Curr Opin Nephrol Hypertens. 2017 03; 26(2):123- ... Cutting Edge: Neutrophil Complement Receptor Signaling Is Required for BAFF-Dependent Humoral Responses in Mice. J Immunol. ... "Receptors, Complement" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical ...

https://connects.catalyst.harvard.edu/Profiles/display/Concept/Receptors,%20Complement

https://ori.hhs.gov/case-summary-murthy-krishna-hm

Properdin is a serum glycoprotein that up-regulates the alternative pathway of complement by stabilizing the C3b-Bb complex. It ... Properdin lacking TSR4 is unable to stabilize the C3b-Bb complex but is able to bind C3b and sulfatide, and shows the presence ... Properdin without TSR3 is able to stabilize the C3b-Bb complex, to bind C3b and sulfatide, and forms dimers, trimers, and ... Crystal Structure of human Complement Component C6. 3vdj. Crystal structure of circumsporozoite protein aTSR domain, R32 native ...

https://smart.embl.de/smart/do_annotation.pl?DOMAIN=TSP1&START=631&END=692&E_VALUE=1.85e-2&TYPE=SMART&BLAST=RWETSSWSECSRTCGEGHQFRIVRCWKMLSPGFDSSVYSDLCEATEAVRPEERKTCRNPACG

These data indicate that complement activation, or the presence of elements of the complement pathway, may inhibit the efficacy ... It would also be important to observe changes in the levels of complement and wound healing activation at baseline and over ... The complement C3a receptor contributes to melanoma tumorigenesis by inhibiting neutrophil and CD4+ T cell responses ... The PSEA analysis indicated that the serum of PD-1 resistant patients is characterized by acute phase, complement, and wound ...

https://aacrjournals.org/cancerimmunolres/article/6/1/79/468811/A-Serum-Protein-Signature-Associated-with-Outcome

Atypical hemolytic uremic syndrome (aHUS) is mostly attributed to dysregulation of the alternative complement pathway (ACP) secondary to disease-causing variants in complement components or regulatory proteins. (frontiersin.org)
To date, about two thirds of patients with aHUS carry identifiable mutations or likely-pathogenic risk variants in genes encoding complement pathway proteins ( 2 - 5 ). (frontiersin.org)
The complement system is a group of proteins that work together to destroy foreign invaders (such as bacteria and viruses), trigger inflammation, and remove debris from cells and tissues. (medlineplus.gov)
One of these pieces, called C3b, interacts with several other proteins on the surface of cells to trigger the complement system's response. (medlineplus.gov)
We examined the distribution of activated (C3b) and degraded fragments (iC3b/ C3dg) of C3, terminal complement complex (TCC), and complement regulatory proteins in normal and diseased colonic mucosa including UC and other types of colitis using immunohistochemical techniques at the level of light and electron microscopy. (elsevierpure.com)
4. Platelet-borne complement proteins and their role in platelet-bacteria interactions. (nih.gov)
The Laboratory for Complement and Inflammation Research, led by Dr. Claudia Kemper, aims to understand the unexpected roles of complement proteins in the regulation of key basic processes of the cell in health and disease. (nih.gov)
Avoid being bound by opsonization proteins like C3b. (pearson.com)
Description: The complement component proteins, C2, C3, C4 and C5, are potent anaphylatoxins that are released during complement activation. (wlsolutions.be)
Special Complements Research Reagents are products that are used for the analysis of the complement system, a part of the immune system that consists of a series of proteins that can be activated by various stimuli. (immunoconceptindia.co)
These kits allow for the analysis of activation of key proteins and specific pathways of the complement system in serum, plasma, and other biological fluids. (immunoconceptindia.co)
Most of those papers focused on immune cells, and we're part of the consortium of people that published those papers to show that actually cells express their own complement proteins. (nih.gov)

While C3b and iC3b/C3dg staining was negligible in the normal mucosa, iC3b/C3dg and, to a lesser extent, C3b were deposited in UC mucosa along the epithelial basement membrane. (elsevierpure.com)
Immunoelectron microscopy showed that C3b and iC3b/C3dg were distributed mainly along the epithelial basement membrane and the underlying connective tissue in a granular, studded manner, and weakly present along the basolateral surface of epithelial cells. (elsevierpure.com)
CD21, also known as CR2 (complement receptor 2) and C3d receptor, binds C3d and iC3b. (biolegend.com)
It is identical with CR-3, the receptor for the iC3b fragment of the third complement component. (nih.gov)

Here we provide insight into the regulatory activity of FH by solving the crystal structure of the first four domains of FH in complex with its target, complement fragment C3b. (nih.gov)
The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE . (nih.gov)
Dr. Johannes Hofer was selected MedUni Vienna Researcher of the Month, August 2017, for the work „Ig-like transcript 4 as a cellular receptor for soluble complement fragment C4d", published in „FASEB Journal" (IF 5.5). (meduniwien.ac.at)
Recent work from Dr. Kemper's lab, however, has highlighted an equally profound impact of complement on adaptive immunity through direct regulation of CD4+ T cells: signals mediated by T cell-expressed anaphylatoxin receptor C3aR and the complement regulator CD46 (which binds the complement activation fragment C3b) are critical checkpoints in human T cell lineage commitment and control initiation and resolution of inflammatory Th1 responses. (nih.gov)
C4a is a protein fragment from the cleavage of complement protein C4, along with C4b. (quidel.com)

While loss-of-function mutations are commonly implicated in genes encoding regulatory complement components, including complement Factor H ( CFH ), complement Factor I ( CFI ) and membrane cofactor protein (MCP, CD46 ), gain-of-function mutations are usually associated with complement Factor B ( CFB ) and C3 ( 6 - 8 ). (frontiersin.org)
The C3 gene provides instructions for making a protein called complement component 3 (or C3). (medlineplus.gov)
This protein plays a key role in a part of the body's immune response known as the complement system. (medlineplus.gov)
The C3 protein is essential for turning on (activating) the complement system. (medlineplus.gov)
This genetic change is described as a "gain-of-function" mutation because it leads to an altered version of the protein that overactivates the complement system. (medlineplus.gov)
These mutations are described as "loss-of-function" because the abnormal or missing C3 protein prevents normal activation of the complement system. (medlineplus.gov)
Eculizumab inhibits the terminal, lytic pathway of complement by blocking the activation of the complement protein C5 and shows remarkable clinical benefits in certain complement-mediated diseases. (nih.gov)
Complement protein C3a enhances adaptive immune responses towards FVIII products. (nih.gov)
The protein encoded by this gene is a type I membrane protein and is a regulatory part of the complement system. (antikoerper-online.de)
The encoded protein has cofactor activity for inactivation of complement components C3b and C4b by serum factor I, which protects the host cell from damage by complement. (antikoerper-online.de)
A rabbit antiserum raised against human complement C3a protein. (quidel.com)
C3a, along with C3b, is a cleavage product of complement protein C3. (quidel.com)
A goat antiserum raised against human complement Factor P protein. (quidel.com)
Among identified virulence factors is the attachment invasion locus protein, Ail, that is required to protect Y. pestis from serum complement in all mammals tested except mice. (cdc.gov)

Most forms of aHUS are associated with dysregulation of the alternative complement pathway (ACP), resulting in complement-mediated endothelial cell injury, with ensuing end-organ tissue damage ( 1 , 2 ). (frontiersin.org)
Factor B is a zymogen that carries the catalytic site of the complement alternative pathway C3 convertase. (wustl.edu)
The degree of such residual lytic activity depended on the strength of the complement activator and the resulting surface density of the complement activation product C3b, which autoamplifies via the alternative pathway (AP) amplification loop. (nih.gov)
The importance of AP-produced C3b clusters for C5 activation in the presence of eculizumab was corroborated by the finding that residual hemolysis after forceful activation of the classical pathway could be reduced by blocking the AP. (nih.gov)
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)
The classic and alternate pathway convertases cause C3 activation, forming C3a and C3b. (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)
[ 3 ] The existence of multiple, complement-related AMD risk alleles has lent further support to this theory and has shed light on the role of uncontrolled alternative complement pathway activation in this disease. (medscape.com)
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. (nih.gov)
Properdin is a serum glycoprotein that up-regulates the alternative pathway of complement by stabilizing the C3b-Bb complex. (embl.de)
An Alternative Complement Pathway, Rat, Assay ELISA Kit is a type of assay kit that can measure the activity of the alternative complement pathway in rat serum or plasma samples. (immunoconceptindia.co)
A Classical Complement Pathway, Mouse, Assay ELISA Kit is a type of ELISA kit that can measure the activity of the classical complement pathway in mouse serum or plasma samples. (immunoconceptindia.co)
Factor D is unique to the Alternative Complement Pathway. (quidel.com)

Complement component C3, which plays an important role in both the innate and adaptative immune response , is present at low level in human infants . (bvsalud.org)
The third component of complement (C3) is central to both the classical and alternative pathways in complement activation. (elsevierpure.com)
Complement component C3 plays a central role in the activation of complement system. (nih.gov)
Complement component 3 protects human bronchial epithelial cells from cigarette smoke-induced oxidative stress and prevents incessant apoptosis. (nih.gov)
From NCBI Gene: Complement component C3 plays a central role in the activation of complement system. (nih.gov)
Complement regulation leads to the generation of complement split products such as complement component (C)4d, a marker for disease activity in autoimmune syndromes or antibody-mediated allograft rejection. (meduniwien.ac.at)
The anti-complement component consists of murine monoclonal IgG anti-C3d-antibody reactive with C3b and C3d-coated red blood cells. (bio-rad.com)

it also serves as a cofactor for the factor-1 mediated cleavage and inactivation of C3b. (medscape.com)

IH -Card AHG Anti-IgG,-C3d consists of six microtubes containing a gel impregnated with polyspecific Anti-Human Globulin (AHG) containing a blend of rabbit anti-IgG and murine monoclonal anti-complement. (bio-rad.com)

However, C4d did not bind to classic complement receptors. (meduniwien.ac.at)
Receptors, Complement" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
This graph shows the total number of publications written about "Receptors, Complement" by people in Harvard Catalyst Profiles by year, and whether "Receptors, Complement" was a major or minor topic of these publication. (harvard.edu)
Below are the most recent publications written about "Receptors, Complement" by people in Profiles. (harvard.edu)
Untangling Fc and complement receptors to kill tumors. (harvard.edu)

Influence of complement C3 amount on IgG responses in early life: immunization with C3b-conjugated antigen increases murine neonatal antibody responses. (bvsalud.org)

Implication of platelets and complement C3 as link between innate immunity and tubulointerstitial injury in renal vasculitis with MPO-ANCA seropositivity. (nih.gov)

The structure indicated that FH destabilizes the C3 convertase by competition and electrostatic repulsion and that FH enables proteolytic degradation of C3b by providing a binding platform for protease factor I while stabilizing the overall domain arrangement of C3b. (nih.gov)

Here, we show that complement-coordinated elimination of synapses participated in NPSLE in MRL/lpr mice, a lupus-prone murine model. (nature.com)

Complement is generally well appreciated as a serum-effective system and critical arm of innate immunity required for the detection and removal of invading pathogens. (nih.gov)

C3d is a terminal degradation product of C3 that plays an important role in modulation of the adaptive immune response through the interaction with complement receptor type 2 (CR2). (wlsolutions.be)

Our results offer general models for complement regulation and provide structural explanations for disease-related mutations in the genes encoding both FH and C3b. (nih.gov)
Our laboratory aims at understanding the unexpected roles of complement in the regulation of key basic processes of the cell in health and disease. (nih.gov)
Dynamic regulation of B cell complement signaling is integral to germinal center responses. (harvard.edu)

We show that at high C3b densities required for binding and activation of C5, both inhibitors reduce but do not abolish this interaction. (nih.gov)
The decrease of C5 binding to C3b clusters in the presence of C5 inhibitors correlated with the levels of residual hemolysis. (nih.gov)

C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS . (nih.gov)

The normal complement system consists of the classic and alternative pathways. (medscape.com)
The company's complement portfolio now consists of several wholly-owned drug candidates at various stages of discovery for dry AMD. (yahoo.com)
Our complement portfolio consists of several proteases that regulate the complement cascade including CB 2782-PEG, a C3 degrader for the potential treatment of dry AMD, improved CFI protease CB 4332 for patients with deficiencies in CFI including dry AMD, and proteases from our ProTUNE™ C3b/C4b degrader and ImmunoTUNE™ C3a/C5a degrader platforms designed to target other disorders of the complement or inflammatory pathways. (yahoo.com)

Factor H (FH) is an abundant regulator of complement activation and protects host cells from self-attack by complement. (nih.gov)
In conjunction with genetic predisposition, acquired autoantibodies against Factor H (FH) have been implicated in the pathogenesis of aHUS in approximately 10% of cases, and are mostly attributed to genomic rearrangements or deletions in CFH / CFHR1/CFHR3/CFHR4 genes within the regulators of complement activation gene cluster ( 9 , 10 ). (frontiersin.org)
We propose that when factor B first associates with C3b, it bears two intact Arg 234 salt bridges. (wustl.edu)
The common coding variant Y402H in the complement factor H ( CFH ) gene was the first identified. (medscape.com)
[ 21 ] Such rare variants have been described in the complement factor H ( CFH ), complement factor I ( CFI ), complement factor 9 ( C9 ), and complement factor 3 ( C3) genes. (medscape.com)
Received Rare Pediatric Disease Designation for CB 4332, an enhanced Complement Factor I ("CFI") for the treatment of CFI Deficiency. (yahoo.com)

Several genes not involved in the complement cascade have also been implicated. (medscape.com)

Its activation is required for both classical and alternative complement activation pathways. (nih.gov)

It probably recognizes the R-G-D peptide in C3b. (nih.gov)

Complement components deposited rapidly on the Y. pestis surface as measured by immunofluorescent microscopy. (cdc.gov)

This process must be carefully regulated so the complement system targets only unwanted materials and does not damage the body's healthy cells. (medlineplus.gov)
Rare genetic variants in the complement system have also been found to play an important role in AMD. (medscape.com)
Avoid triggering the complement system. (pearson.com)
The complex functioning of the complement system in xenotransplantation. (harvard.edu)
Breaking down the complement system: a review and update on novel therapies. (harvard.edu)
That's called complement, and the reason that is called complement is because this is a really ancient system that was discovered a very long time ago that was supposed to complement the rest of the immune system. (nih.gov)
Now around 10 years ago, [in] 2013, there were papers that were being produced that were showing that this complement system is not just restricted to the blood, but that other cells produce it. (nih.gov)

SC5b-9 is the soluble version of the terminal complement complex (TCC). (quidel.com)

Complement profiling of the patient showed decreased C3 and FB levels, with elevated levels of the terminal membrane attack complex, while his healthy heterozygous mother showed intermediate levels of C3 consumption. (frontiersin.org)

They utilize immune/tissue cells from healthy donors, from patients with complement deficiencies, from patients with T cell-driven autoimmune disease and from patients with deviations in novel 'complosome'-regulated pathways for gene and miRNA arrays, epigenetic landscape evaluation, and proteomic and metabolomic assessments. (nih.gov)

Properdin "nicked" in TSR5 is unable to bind C3b but retains its overall structure and its ability to bind sulfatide. (embl.de)
Properdin lacking TSR4 is unable to stabilize the C3b-Bb complex but is able to bind C3b and sulfatide, and shows the presence of monomers and dimers in an electron microscope. (embl.de)
Properdin without TSR3 is able to stabilize the C3b-Bb complex, to bind C3b and sulfatide, and forms dimers, trimers, and tetramers. (embl.de)

Yersinia pestis Δail Mutants Are Not Susceptible to Human Complement Bactericidal Activity in the Flea. (cdc.gov)
Caucasica 1146 conferred resistance to human complement when expressed in the Y. pestis KIM6(+) ail mutant. (cdc.gov)

Complement components analysis using specific immunoassays was performed on frozen plasma samples from the patient and mother. (frontiersin.org)
Further, they have discovered that activation of the key complement components C3 and C5 is not confined to the extracellular space but occurs intracellulary (the 'Complosome') and that intracellular C3 and C5 activation fundamentally dictates the magnitude of Th1-mediated inflammation. (nih.gov)
Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b components of complement. (harvard.edu)

Binding to these sites increases the affinity of CFH for C3b, which, in turn, increases the ability of CFH to inhibit complement's effects. (medscape.com)

The removal of TSR5 prevents C3b and sulfatide binding. (embl.de)

Integrin ITGAM/ITGB2 is implicated in various adhesive interactions of monocytes, macrophages and granulocytes as well as in mediating the uptake of complement-coated particles. (nih.gov)

Consequently, lack of autocrine complement activation by T cells results in deficient Th1 responses and recurrent infections, while uncontrolled intracellular C3 and/or C5 activation contributes to hyperactive Th1 responses observed in autoimmunity (rheumatoid arthritis, CAPS) and can be normalised pharmacologically by inhibiting intracellular complement activity. (nih.gov)

The N-linked carbohydrate of properdin is not required for oligomerization or stabilization of the C3b-Bb complex. (embl.de)
The results implicate TSR5 in both C3b and sulfatide binding, and suggest that TSR4 may also be involved in stabilization of the C3b-Bb complex. (embl.de)

The central goal of Dr. Kemper's research programme is therefore to define the functional roles and regulative mechanisms of intracellular/autocrine complement and assess their biological relevance with an eye on delivering druggable targets in these pathways to therapeutically intervene in (autoimmune) diseases. (nih.gov)

The decrease was due primarily to a decrease in hemophilia-related costs, complement-related costs, personnel-related costs, and stock-based compensation expense. (yahoo.com)

FH interacted with multiple domains of C3b, covering a large, extended surface area. (nih.gov)
Ail reduced the amount of active C3b on the Y. pestis surface. (cdc.gov)

Cutting Edge: Neutrophil Complement Receptor Signaling Is Required for BAFF-Dependent Humoral Responses in Mice. (harvard.edu)

Association of Complement C3 With Incident Type 2 Diabetes and the Mediating Role of BMI: A 10-Year Follow-Up Study. (nih.gov)

Thus, complement plays unexpectedly a fundamental role in basic processes of the cell and understanding these novel functions will deliver critical new knowledge about cell biology in health and disease. (nih.gov)

This is important because circulating complement that's made by the liver is great if you have a blood-borne infection, but inside a tissue, let's say within your skin or something, that complement can't reach that site, so it's advantageous for local cells to be able to make their own. (nih.gov)

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Mutations of the type A domain of complement factor B that promote high-affinity C3b-binding. (1/656)

Capsular sialic acid limits C5a production on type III group B streptococci. (2/656)

Amplification of the antibody response by C3b complexed to antigen through an ester link. (3/656)

A novel glycosylphosphatidyl inositol-anchored protein on human leukocytes: a possible role for regulation of neutrophil adherence and migration. (4/656)

Binding of soluble immune complexes to Raji lymphocytes. Role of receptors for complement components, C1q and C3-C3b. (5/656)

Complement activation and increased systemic and pulmonary vascular resistance indices during infusion of postoperatively drained untreated blood. (6/656)

Complement activation and expression of membrane regulators in the middle ear mucosa in otitis media with effusion. (7/656)

Pneumococcal surface protein A inhibits complement activation by Streptococcus pneumoniae. (8/656)

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