Complement c4b. 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.

Immunohistochemical analysis of arterial wall cellular infiltration in Buerger's disease (endarteritis obliterans). (1/363)

PURPOSE: The diagnosis of Buerger's disease has depended on clinical symptoms and angiographic findings, whereas pathologic findings are considered to be of secondary importance. Arteries from patients with Buerger's tissue were analyzed histologically, including immunophenotyping of the infiltrating cells, to elucidate the nature of Buerger's disease as a vasculitis. METHODS: Thirty-three specimens from nine patients, in whom Buerger's disease was diagnosed on the basis of our clinical and angiographic criteria between 1980 and 1995 at Nagoya University Hospital, were studied. Immunohistochemical studies were performed on paraffin-embedded tissue with a labeled streptoavidin-biotin method. RESULTS: The general architecture of vessel walls was well preserved regardless of the stage of disease, and cell infiltration was observed mainly in the thrombus and the intima. Among infiltrating cells, CD3(+) T cells greatly outnumbered CD20(+) B cells. CD68(+) macrophages or S-100(+) dendritic cells were detected, especially in the intima during acute and subacute stages. All cases except one showed infiltration by the human leukocyte antigen-D region (HLA-DR) antigen-bearing macrophages and dendritic cells in the intima. Immunoglobulins G, A, and M (IgG, IgA, IgM) and complement factors 3d and 4c (C3d, C4c) were deposited along the internal elastic lamina. CONCLUSION: Buerger's disease is strictly an endarteritis that is introduced by T-cell mediated cellular immunity and by B-cell mediated humoral immunity associated with activation of macrophages or dendritic cells in the intima. (+info)

Deficiency of human complement protein C4 due to identical frameshift mutations in the C4A and C4B genes. (2/363)

The complement protein C4, encoded by two genes (C4A and C4B) on chromosome 6p, is the most polymorphic among the MHC III gene products. We investigated the molecular basis of C4 deficiency in a Finnish woman with systemic lupus erythematosus. C4-specific mRNA was present at low concentrations in C4-deficient (C4D) patient fibroblasts, but no pro-C4 protein was detected. This defect in C4 expression was specific in that synthesis of two other complement proteins was normal. Analysis of genomic DNA showed that the proposita had both deleted and nonexpressed C4 genes. Each of her nonexpressed genes, a C4A null gene inherited from the mother, a C4A null gene, and a C4B null gene inherited from the father, all contained an identical 2-bp insertion (TC) after nucleotide 5880 in exon 29, providing the first confirmatory proof of the C4B pseudogene. This mutation has been previously found only in C4A null genes. Although the exon 29/30 junction is spliced accurately, this frameshift mutation generates a premature stop at codon 3 in exon 30. These truncated C4A and C4B gene products were confirmed through RT-PCR and sequence analysis. Among the possible genetic mechanisms that produce identical mutations is both genes, the most likely is a mutation in C4A followed by a gene conversion to generate the mutated C4B allele. (+info)

Interaction between protein S and complement C4b-binding protein (C4BP). Affinity studies using chimeras containing c4bp beta-chain short consensus repeats. (3/363)

Human C4b-binding protein (C4BP) is a regulator of the complement system and plays an important role in the regulation of the anticoagulant protein C pathway. C4BP can bind anticoagulant protein S, resulting in a decreased cofactor function of protein S for activated protein C. C4BP is a multimeric protein containing several identical alpha-chains and a single beta-chain (C4BPbeta), each chain being composed of short consensus repeats (SCRs). Previous studies have localized the protein S binding site to the NH2-terminal SCR (SCR-1) of C4BPbeta. To further localize the protein S binding site, we constructed chimeras containing C4BPbeta SCR-1, SCR-2, SCR-3, SCR-1+2, SCR-1+3, and SCR-2+3 fused to tissue-type plasminogen activator. Binding assays of protein S with these chimeras indicated that SCR-2 contributes to the interaction of protein S with SCR-1, since the affinity of protein S for SCR-1+2 was up to 5-fold higher compared with SCR-1 and SCR-1+3. Using an assay that measures protein S cofactor activity, we showed that cofactor activity was decreased due to binding to constructs that contain SCR-1. SCR-1+2 inhibited more potently than SCR-1 and SCR-1+3. SCR-3 had no additional effect on SCR-1, and therefore the effect of SCR-2 was specific. In conclusion, beta-chain SCR-2 contributes to the interaction of C4BP with protein S. (+info)

Consumption of C4b-binding protein (C4BP) during in vivo activation of the classical complement pathway. (4/363)

C4BP has a central role in regulating the classical complement (C') pathway, but it is still uncertain whether or not it is consumed during in vivo complement activation. Attempts to demonstrate changes in C4BP plasma levels in systemic lupus erythematosus and essential mixed cryoglobulinaemia have failed, probably due to up-regulation of this protein during the inflammatory reaction. We have studied one patient with severe post-transfusion complement-mediated anaphylaxis (CMA), and 67 patients with hereditary C1 inhibitor deficiency (hereditary angioedema (HAE)). The first of these two conditions is characterized by the absence of systemic inflammatory reaction and the second by acute and chronic activation of the C' classical pathway. C4BP, C4BP-C4b complex, and soluble terminal C' complex (sC5b-9) were measured in the patients' plasmas by ELISA techniques and C3a and C4a by radioimmunoassays. In CMA, 15 min after the transfusion, there was a massive C' activation, with increases in C4a, C3a, sC5b-9, C4BP-C4b complexes and decreases in C4, C3 and C4BP. All parameters reverted to preinfusion values within 24 h. Depletion of C4 was correlated with that of C4BP. In patients with HAE, the median value of C4BP (83% range 54-165) was significantly lower (P < 0.0001) than in normal controls (99% range 70-159), with no difference between patients in remission or during acute attacks. C4BP-C4b complexes could not be detected in HAE patients. The results of this study indicate that C4BP is consumed in vivo during acute, and possibly during chronic activation of the C' classical pathway, and that this protein, after interaction with C4b, not longer circulates in plasma. (+info)

Some anticardiolipin antibodies recognize a combination of phospholipids with thrombin-modified antithrombin, complement C4b-binding protein, and lipopolysaccharide binding protein. (5/363)

The standard enzyme-linked immunosorbent assay (ELISA) for anticardiolipin antibodies (ACA) detects a heterogenous group of antibodies against cardiolipin on its own, beta2-glycoprotein I (beta2GPI), and, potentially, other phospholipid-binding plasma proteins from bovine or human origin. In an attempt to identify new proteic targets of ACA, we selected 6 patients who possessed cofactor-dependent ACA but no antibody to human or bovine beta2GPI detectable in the beta2GPI-ELISA. Three of these samples proved to recognize beta2GPI in combination with cardiolipin, but not beta2GPI directly immobilized on gamma-irradiated polystyrene or agarose beads. In the other cases, the component required for ACA binding was purified from adult bovine serum or plasma by means of ammonium sulfate precipitation and chromatography on Phenyl-Sepharose, diethyl aminoethyl (DEAE)-cellulose, heparin-Ultrogel, and Sephacryl S-300 columns. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis coupled to N-terminal amino acid microsequencing identified the cofactors of patients no. 4, 5, and 6 ACA as lipopolysaccharide binding protein (LBP), complement C4b-binding protein (C4BP), and the thrombin-antithrombin (AT) complex, respectively. Adsorption of each of these cofactor preparations with cardiolipin liposomes led to suppression of ACA reactivity, concomitant with the loss of bands from SDS gels corresponding to sequenced material. Bacterial lipopolysaccharide (which forms high-affinity complexes with LBP) specifically neutralized the cofactor activity of the LBP preparation in a concentration-dependent manner. Bovine serum and plasma, as well as the C4BP preparation, optimally supported the binding of a rabbit anti-C4BP antiserum to immobilized cardiolipin. The binding of a rabbit anti-AT antiserum to solid-phase cardiolipin was sustained by the thrombin-AT preparation and bovine serum, but neither by bovine plasma nor by native AT, thus reproducing the behavior of patient no. 6 ACA. Taking advantage of the restricted recognition by the latter ACA of a cofactor from bovine origin appearing upon clotting, we studied the generation of such activity in human plasma supplemented with bovine AT or bovine prothrombin before clotting. In these conditions, patient no. 6 antibody binding to cardiolipin required the addition of bovine AT, whereas addition of bovine prothrombin alone was ineffective. We therefore concluded that those ACA targeted bovine AT once it has been modified/cleaved by thrombin. These findings underline the wide heterogeneity of ACA and the links that may exist between various coagulation pathways, inflammation and the complement system. (+info)

A cluster of positively charged amino acids in the C4BP alpha-chain is crucial for C4b binding and factor I cofactor function. (6/363)

C4b-binding protein (C4BP) is a regulator of the classical complement pathway, acting as a cofactor to factor I in the degradation of C4b. Computer modeling and structural analysis predicted a cluster of positively charged amino acids at the interface between complement control protein modules 1 and 2 of the C4BP alpha-chain to be involved in C4b binding. Three C4BP mutants, R39Q, R64Q/R66Q, and R39Q/R64Q/R66Q, were expressed and assayed for their ability to bind C4b and to function as factor I cofactors. The apparent affinities of R39Q, R64Q/R66Q, and R39Q/R64Q/R66Q for immobilized C4b were 15-, 50-, and 140-fold lower, respectively, than that of recombinant wild type C4BP. The C4b binding site demonstrated herein was also found to be a specific heparin binding site. In C4b degradation, the mutants demonstrated decreased ability to serve as factor I cofactors. In particular, the R39Q/R64Q/R66Q mutant was inefficient as cofactor for cleavage of the Arg937-Thr938 peptide bond in C4b. In contrast, the factor I mediated cleavage of Arg1317-Asn1318 bond was less affected by the C4BP mutations. In conclusion, we identify a cluster of amino acids that is part of a C4b binding site involved in the regulation of the complement system. (+info)

Analysis of human C4A and C4B binding to an immune complex in serum. (7/363)

Previous studies using isolated complement proteins have shown that more C4A than C4B binds to certain types of immune complexes. However, the in vivo binding of the C4 isoforms to an immune complex has not been investigated in detail and may differ from events when measured with the isolated proteins. We report here the binding of C4A and C4B to an immune complex of bovine serum albumin (BSA) anti-BSA as it occurs in serum. We found that when using the isolated C4 proteins more C4A than C4B bound to the complex, but in serum similar amounts of C4A and C4B were found to bind. Furthermore, these results were not explainable by a difference in activity between isoforms. In an attempt to explain these results a number of unexpected observations were noted. First C4A, but not C4B, bound specifically to a yet unidentified 38-kD serum protein. Second, when both covalent and non-covalent binding was assessed, we found that as serum concentration increased there followed a concomitant decrease in covalent binding and C4B was more affected than C4A. The potential biological significance of these findings is discussed. (+info)

Upregulation of ICAM-1 on cardiomyocytes in jeopardized human myocardium during infarction. (8/363)

OBJECTIVE: Impaired perfusion of the myocardium induces a local inflammatory response. In animal models, there is ample evidence that polymorphonuclear leucocytes (PMNs) infiltrating infarcted myocardium contribute significantly to infarct size. METHODS: To explore a possible role for PMNs in the tissue damage of human myocardial infarction, we investigated localization of intercellular adhesion molecule-1 (ICAM-1) and CD66b (previously clustered as CD67), a marker of degranulation of human PMNs, in relation to deposition of complement in tissue specimens of infarcted and healthy parts of the heart obtained from 20 patients, who had died following acute myocardial infarction. RESULTS: ICAM-1 was transiently expressed by endothelium and for a longer period (few days) on myofibers of infarcted myocardium. This expression only occurred in parts that stained positive for complement. PMN infiltration exclusively occurred in areas with ICAM-1 expression, but not every ICAM-1-positive area contained PMN infiltrates. CD66b was found in PMNs but was also fixed to the plasma membrane of myofibers that stained positive for complement and ICAM-1. CONCLUSION: These findings indicate that, in infarcted human myocardium, PMNs are degranulated, possibly upon interaction with ICAM-1 and activated complement. (+info)

C4b and C3bi from plasma complement. The extracellular domain of the receptors contains a lectin-like complement-binding domain ... 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

"Importance of the alpha 3-fragment of complement C4 for the binding with C4b-binding protein". FEBS Letters. 271 (1-2): 131-6. ... Complement component 4 Complement component 4B HLA A1-B8-DR3-DQ2 haplotype Complement system Complement deficiency ... Complement C4-A is a protein that in humans is encoded by the C4A gene. This gene encodes the acidic form of complement factor ... "Structural basis of the polymorphism of human complement components C4A and C4B: gene size, reactivity and antigenicity". The ...

https://en.wikipedia.org/wiki/C4A

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

... duttonii acquire complement regulators C4b-binding protein and factor H". Infection and Immunity. 74 (7): 4157-63. doi:10.1128/ ...

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

The C1 complex (complement component 1, C1) is a protein complex involved in the complement system. It is the first component ... Active C1s splits C4 and then C2, producing C4a, C4b, C2a and C2b. The classical pathway C3-convertase (C4bC2b complex) is ... 2001). "The complement system and innate immunity". Immunobiology: The Immune System in Health and Disease. New York: Garland ... The antibodies IgM or certain subclasses of IgG complexed with antigens are able to initiate the complement system: a single ...

https://en.wikipedia.org/wiki/C1_complex

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 may protect HIV-1 from complement ...

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

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

DAF protects host cells from damage by autologous complement. DAF acts on C2b and Bb and dissociates them rapidly from C4b and ... C4b-binding protein inhibits the haemolytic function of cell-bound C4b. C4b-binding protein and C3b inactivator control the C3 ... complement receptor 1 (CR1), C4b-binding protein and Factor H. Convertase assembly is suppressed by the proteolytic cleavage of ... Cleavage of complement C3 by a free floating convertase, thrombin, plasmin or even a bacterial enzyme leads to formation of C3a ...

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

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 ... Opsonins of the innate immune system largely comprise complement proteins, though interaction between complement proteins and ...

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

In the circulation, Protein S exists in two forms: a free form and a complex form bound to complement protein C4b-binding ... Protein S also binds to the nascent complement complex C5,6,7 and prevents this complex from inserting into a membrane. This ... Dahlbäck B (2007). "The tale of protein S and C4b-binding protein, a story of affection". Thromb. Haemost. 98 (1): 90-6. doi: ... Griffin JH, Gruber A, Fernández JA (1992). "Reevaluation of total, free, and bound protein S and C4b-binding protein levels in ...

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

C3, C4A, C4B, C4B-1, C5, FBLN1, FBLN2 Allergy Anaphylatoxin receptors Anaphylaxis Complement system Inflammation Immune system ... that are produced as part of the activation of the complement system. Complement components C3, C4 and C5 are large ... Gennaro R, Simonic T, Negri A, Mottola C, Secchi C, Ronchi S, Romeo D (February 1986). "C5a fragment of bovine complement. ... C3a works with C5a to activate mast cells, recruit antibody, complement and phagocytic cells and increase fluid in the tissue, ...

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

"Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes ... Yang Z, Qu X, Yu CY (August 2001). "Features of the two gene pairs RD-SKI2W and DOM3Z-RP1 located between complement component ... are present between complement component genes factor B and C4 in the class III region of the HLA". Genomics. 53 (3): 338-47. ... are present between complement component genes factor B and C4 in the class III region of the HLA". Genomics. 53 (3): 338-47. ...

https://en.wikipedia.org/wiki/SKIV2L

"Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes ... Cite journal requires ,journal= (help) Yu CY (1991). "The complete exon-intron structure of a human complement component C4A ... 1996). "Complete sequence of the complement C4 gene from the HLA-A1, B8, C4AQ0, C4B1, DR3 haplotype". Immunogenetics. 43 (4): ... 1998). "Four ubiquitously expressed genes, RD (D6S45)-SKI2W (SKIV2L)-DOM3Z-RP1 (D6S60E), are present between complement ...

https://en.wikipedia.org/wiki/STK19

Because primate erythrocytes express complement receptor 1 (CR1) on their surface and having binding specificity to C4b, C3b, ... which activate the classical pathway of the complement system. The cascade begins to work from C1 to C3b through C4b, C3b being ... 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

... 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

... in the major histocompatibility complex III close to the Complement component 4 genes C4A and C4B, the Tenascin X gene TNXB and ... In the chicken and quail, there is only a single CYP21 gene, which locus is located between complement component C4 and TNX ... Sweeten TL, Odell DW, Odell JD, Torres AR (January 2008). "C4B null alleles are not associated with genetic polymorphisms in ... Yu CY (1999). "Molecular genetics of the human MHC complement gene cluster". Experimental and Clinical Immunogenetics. 15 (4): ...

https://en.wikipedia.org/wiki/21-Hydroxylase

2005). "Interaction between complement regulators and Streptococcus pyogenes: binding of C4b-binding protein and factor H/ ... "Entrez Gene: CFHR1 complement factor H-related 1". Zipfel PF, Skerka C (1994). "Complement factor H and related proteins: an ... Complement factor H-related protein 1 is a protein that in humans is encoded by the CFHR1 gene. GRCh38: Ensembl release 89: ... 2000). "Complement factor H: sequence analysis of 221 kb of human genomic DNA containing the entire fH, fHR-1 and fHR-3 genes ...

https://en.wikipedia.org/wiki/CFHR1

... the MASP protein functions to cleave the blood protein C4 into C4a and C4b. The C4b fragments can then bind to the surface of ... The complement system can be activated through three pathways: the classical pathway, the alternative pathway, and the lectin ... The subsequent complement cascade catalyzed by C3-convertase results in creating a membrane attack complex, which causes lysis ... In order to activate the complement system when MBL binds to its target (for example, mannose on the surface of a bacterium), ...

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

The classical pathway C5 convertase is composed of the fragments of complement proteins, C4b, C2a produced by cleavage mediated ... The complement component C5 can be also activated by fluid phase C5 convertase. C5 is activated by CVFBb in the presence of ... The target of C5 convertase is complement protein C5. C5 is a two-chain (α, β) plasma glycoprotein (Mr = 196,000). C5 and C3 ... In these respects, the mode of action of C5 is completely analogous to that of the other components of complement. The C5 step ...

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

It can also recruit complement regulators such as Factor H, C4b-binding protein, factor H-like binding protein, and vitronectin ... 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

... 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 ... or they can facilitate the formation of the Complement membrane attack complex (MAC) by being deposited on the cell surface of ... Should the microbe be coated with opsonising antibodies or C3b complement, the co-stimulation of endocytic PRR and opsonin ...

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

Besides complement particles C1q and C3b which help to opsonize the apoptotic cells, also thrombospondin, pentraxins (C- ... Among soluble inhibitors there are factor H, C1 inhibitor, C4b-binding protein, factor I, S protein or clusterin, the membrane- ... Non-apoptotic cells also express complement inhibitors, preventing the assembly of C3 convertase or the lytic pore. ... components of complement pathways (e.g. C1q, C3b) and other molecules found in extracellular space. Collectins (e.g. mannose- ...

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

Protein S circulates in human plasma in two forms: approximately 60 percent is bound to complement component C4b β-chain while ...

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

Complement receptor type 1 (C3b/C4b receptor) (Antigen CD35) belongs to the Knops blood group system and is associated with Kn( ... Complement decay-accelerating factor (Antigen CD55) belongs to the Cromer blood group system and is associated with Cr(a), Dr(a ... Complement components may activate B cells through CD21. CD21 is part of a large signal-transduction complex that also involves ... Sushi domains exist in a wide variety of complement and adhesion proteins. The structure is known for this domain; it is based ...

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

MASP-2 is activated to cleave complement components C4 and C2 into C4a, C4b, C2a, and C2b. MASP1 (protein) Mannan-binding ... MASP-2 is involved in the complement system. MASP-2 is very similar to the C1s molecule, of the classical complement pathway, ... The Ra-reactive factor (RARF) is a complement-dependent bactericidal factor that binds to the Ra and R2 polysaccharides ... Petersen SV, Thiel S, Jensenius JC (2001). "The mannan-binding lectin pathway of complement activation: biology and disease ...

https://en.wikipedia.org/wiki/MASP2_(protein)

... and demonstration of an absolute requirement for the serum protein beta1H for cleavage of C3b and C4b in solution". The Journal ... there are several different kinds of regulatory proteins that disrupt the complement activation process: *Complement Receptor 1 ... Complement Factor H can inhibit the formation of the C3 convertase by competing with factor B for binding to C3b;[1] accelerate ... "Inhibition of the alternative complement pathway by antisense oligonucleotides targeting complement factor B improves lupus ...

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

Together, MBL, C4b and C2a are known as the C3 convertase. C3 is cleaved into its a and b subunits, and C3b binds the ... 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 ... binding the C4b subunit and releasing C4a into the bloodstream; similarly, binding of C2 causes release of C2b. ...

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

In the classical pathway, C4 binds to Ig-associated C1q and C1r2s2 enzyme cleaves C4 to C4b and 4a. C4b binds to C1q, antigen- ... 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

C1q mediates the classical pathway by activating the C1 complex, which cleaves C4 and C2 into smaller fragments (C4a, C4b, C2a ... 12th European Meeting on Complement in Human Disease12th European Meeting on CHD12th European Meeting on Complement in Human ... C3a is one of the proteins formed by the cleavage of complement component 3; the other is C3b. C3a is a 77 residue ... Anaphylatoxins are small complement peptides that induce proinflammatory responses in tissues. C3a is primarily regarded for ...

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

... (C4BP) is a protein complex involved in the complement system where it acts as inhibitor. C4BP has an ... Complement+C4b-Binding+Protein at the US National Library of Medicine Medical Subject Headings (MeSH) v t e. ... C4BP accelerates decay of C3-convertase and is a cofactor for serine protease factor I which cleaves C4b and C3b. C4BP binds ... A number of bacterial and fungal pathogens capture human C4BP and use it to prevent binding of C4b, which allows them to ...

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

July 2008). "Autoimmune-associated HLA-B8-DR3 haplotypes in Asian Indians are unique in C4 complement gene copy numbers and HSP ... C4B C4BS CYP21 DR Loci HLA-DRB3 *0101 DR52 HLA-DR *0301 DR3 ... Complement component 4 *Complement component 4A. *Complement ...

https://en.wikipedia.org/wiki/HLA_A1-B8-DR3-DQ2

Zipfel, P. F., Hallström, T., & Riesbeck, K. (2013). Human complement control and complement evasion by pathogenic microbes- ... C4a ja C4b. C2a ja C4b kombineeruvad ning moodustub C3-konvertaas C4bC2a. Sama konvertaasi moodustumine on omane ka ... 1,0 1,1 1,2 1,3 Rus, H., Cudrici, C., & Niculescu, F. (2005). The role of the complement system in innate immunity. Immunologic ... 7,0 7,1 Lambris, J. D., Ricklin, D., & Geisbrecht, B. V. (2008). Complement evasion by human pathogens. Nature Reviews. ...

https://et.m.wikipedia.org/wiki/Komplemendisüsteem

... (EC 3.4.21.42, C1 esterase, activated complement C1s, complement C overbar 1r, C1s) is a protein ... complement activation, lectin pathway. • complement activation. • regulation of complement activation. Sources:Amigo / QuickGO ... complement activation, classical pathway. • immune system process. • innate immune response. • ... Sim RB (1981). "The human complement system serine proteases C1r and C1s and their proenzymes". Methods in Enzymology. 80 Pt C ...

https://en.wikipedia.org/wiki/Complement_component_1s

In the classical pathway, C4 binds to Ig-associated C1q and C1r2s2 enzyme cleaves C4 to C4b and 4a. C4b binds to C1q, antigen- ... complement factor B, and complement factor I, as well as deletion of complement factor H-related 3 and complement factor H- ... Complement deficiencyEdit. Main article: Complement deficiency. It is thought that the complement system might play a role in ... Three biochemical pathways activate the complement system: the classical complement pathway, the alternative complement pathway ...

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

Media related to Complement membrane attack complex at Wikimedia Commons. *Complement+Membrane+Attack+Complex at the US ... The membrane attack complex (MAC) or terminal complement complex (TCC) is a structure typically formed on the surface of ... Reid K. B. M., The complement system, in: B. D. Hames and D. M. Glover (eds.), Molecular Immunology, Oxford: IRL Press, 1988, ... MAC is composed of a complex of four complement proteins (C5b, C6, C7, and C8) that bind to the outer surface of the plasma ...

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

C4b jî li rûyê hokara nexweşiyê de tê girêdan. Girêdana C4b çêkirina C3 konvertazê hander dike. Piştî çêkirina C3 konvertazê ... a b https://www.britannica.com/science/complement-immune-system-component *↑ a b c d e f g h i OpenStax, Microbiology, openstax ... Sîstema temamker an jî sîstema tewawker (bi îngilîzî: complement system)[1] beşek ji sîstema bergiriya giştî ye. Sîstema ... Piştê girêdana MBL, proteîna C4 a nav xwînê tê perçekirin, ji C4ê C4a û C4b çê dibin. ...

https://ku.wikipedia.org/wiki/Sîstema_temamker

... is a member of the immunoglobulin superfamily, with a structure related to the putative primordial form of the family. As members of the immunoglobulin superfamily play fundamental roles in intercellular recognition involved in various immunologic phenomena, differentiation, and development, basigin is thought also to play a role in intercellular recognition (Miyauchi et al., 1991; Kanekura et al., 1991).[9][10] It has a variety of functions. In addition to its metalloproteinase-inducing ability, basigin also regulates several distinct functions, such as spermatogenesis, expression of the monocarboxylate transporter and the responsiveness of lymphocytes.[6] Basigin is a type I integral membrane receptor that has many ligands, including the cyclophilin (CyP) proteins Cyp-A and CyP-B and certain integrins.[11][12][13] It is expressed by many cell types, including epithelial cells, endothelial cells and leukocytes. The human basigin protein contains 269 amino acids that form two heavily ...

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

... na C4b pa se veže molekula C2, kar odkrije mesto za delovanje C1s, ki razcepi C2 na C2a in C2b. Fragmenta C2b ter C4b se vežeta ... Označujemo jih z veliko črko C (kratica za complement) in številko. Ko signal sproži spremembo enega od začetnih proencimov v ... Začetni element te poti je molekula C3b, ki je homologna molekuli C4b (tako po strukturi kot po funkciji). Ta se veže z ... Ti cepita najprej molekulo C4 na podenoti C4a in C4b; C4a oddifundira, ...

https://sl.wikipedia.org/wiki/Sistem_komplementa

... , also known as C3b/C4b inactivator, is a protein that in humans is encoded by the CFI gene. Complement ... either C3b or C4b) and a cofactor protein (Factor H, C4b-binding protein, complement receptor 1, and membrane cofactor protein ... 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 ...

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

... complement c4 MeSH D12.776.124.486.274.350.250 - complement c4a MeSH D12.776.124.486.274.350.260 - complement c4b MeSH D12.776. ... complement factor i MeSH D12.776.124.486.274.920.662 - complement c4b-binding protein MeSH D12.776.124.486.274.930 - complement ... 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)

The C1 complement complex binds to these antibodies resulting in its activation via cross proteolysis. This activated C1 ... or a C5 convertase when bound to C4b and C2b (C4b2b3b complex) or when an additional C3b molecule binds to the C3bBb complex ( ... C3b is the larger of two elements formed by the cleavage of complement component 3, and is considered an important part of the ... 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

It is thought that cleavage of C2 by C1s, while bound to C4b, results in a conformational rotation of C2b whereas the released ... Complement C2 is a protein that in humans is encoded by the C2 gene. The protein encoded by this gene is part of the classical ... "Entrez Gene: C2 complement component 2". Krishnan V, Xu Y, Macon K, Volanakis JE, Narayana SV (2009). "The structure of C2b, a ... Johnson CA, Densen P, Hurford RK, Colten HR, Wetsel RA (May 1992). "Type I human complement C2 deficiency. A 28-base pair gene ...

https://en.wikipedia.org/wiki/Complement_component_2

Complement C4 beta chain. A, D [auth B]. 656. Homo sapiens. Mutation(s): 0 Gene Names: C4B, CO4, CPAMD3, C4B_2. ... During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered ... During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered ... Moreover, C4b provides a platform for assembly of the proteolytically active convertases that mediate downstream complement ...

https://www.rcsb.org/structure/4XAM

complement c4a*complement c3b*complement c3d*complement factor i*complement c1q*complement c4*complement membrane attack ... complement c4b. Summary. Summary: The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound ... complement factor b*complement receptors*complement factor h*cd55 antigens*mannose binding lectin*complement c2* ... C4B products*C4A products*C3 products*factor I products*CR1 products*C4BPA products*C4B_2 products*COLEC11 products*C4b ...

http://www.labome.org/topics/and/proteins/blood/immunoproteins/complement/complement/complement-c4b-53963.html

Complement C4b RNAi. Tested Reactivity: Hu. Validated: RNAi, RNAi SP. Backed by our 100% Guarantee. ... Blogs on Complement C4b. There are no specific blogs for Complement C4b, but you can read our latest blog posts. ... Reviews for Complement C4b RNAi (H00000721-R01) (0) There are no reviews for Complement C4b RNAi (H00000721-R01). By submitting ... Diseases for Complement C4b RNAi (H00000721-R01). Discover more about diseases related to Complement C4b RNAi (H00000721-R01). ...

https://www.novusbio.com/products/complement-c4b-rnai_h00000721-r01

Mouse Monoclonal Anti-Complement C4b/d Antibody (SPM545) [PerCP]. Acute Humoral Rejection Marker. Validated: ICC/IF, IHC-Fr, ... Additional Complement C4b/d Products. Complement C4b/d NBP2-34421PCP * Complement C4b/d Antibodies ... Home » Complement C4b/d » Complement C4b/d Antibodies » Complement C4b/d Antibody (SPM545) [PerCP] ... Blogs on Complement C4b/d. There are no specific blogs for Complement C4b/d, but you can read our latest blog posts. ...

https://www.novusbio.com/products/complement-c4b-d-antibody-spm545_nbp2-34421pcp

Visualization of human C4b-binding protein and its complexes with vitamin K-dependent protein S and complement protein C4b. ... Binding of human complement component C4b-binding protein (C4BP) to Streptococcus pyogenes involves the C4b-binding site. J. ... In some experiments, unlabeled C4b (300 ng) was used instead of biotinylated C4b, and Western blot of C4b fragments was ... C4b-binding protein. In The complement facts book. Morley B. J., M. J. Walport Academic Press, London, p. 161-167. ...

https://www.jimmunol.org/content/187/1/424?ijkey=f022e8007e1f3acfeaf6be0e0fafbdd0b57ff430&keytype2=tf_ipsecsha

... and γ-chains complement component. - Find MSDS or SDS, a COA, data sheets and more information. ... Complement C4b, Human, is a native, 193 kDa glycoprotein composed of the modified C4 α-chain (α) and intact β- ... and γ-chains complement component.. More,, Complement C4b, Human, is a native, 193 kDa glycoprotein composed of the modified C4 ... Native, human C4b complement component. Cleavage of the C4 α-chain at peptide bond 77 by activated C1 enzyme results in the ...

https://www.emdmillipore.com/PR/en/product/Complement-C4b-Human,EMD_BIO-204897

C4b-binding protein), a 570-kDa serum protein that inhibits the classical pathway of complement activation. Molecular analysis ... When bound to streptococcal cells, C4BP retained its ability to act as a cofactor in the degradation of C4b by factor I. These ... Ig-binding surface proteins of Streptococcus pyogenes also bind human C4b-binding protein (C4BP), a regulatory component of the ... Ig-binding surface proteins of Streptococcus pyogenes also bind human C4b-binding protein (C4BP), a regulatory component of the ...

https://www.jimmunol.org/content/154/1/375?ijkey=565c7905e6f0daea6f10382036d2dc2fd3b6ccee&keytype2=tf_ipsecsha

Hydrolysis, Protein Conformation, Receptors, Complement : chemistry, Complement : genetics, Complement : isolation & ... C4b-binding protein (C4BP), an important inhibitor of complement activation, has a unique spider-like shape. It is composed of ... C4b-binding protein (C4BP), an important inhibitor of complement activation, has a unique spider-like shape. It is composed of ... Complement : chemistry,Complement : genetics,Complement : isolation & purification,Recombinant Proteins : chemistry,Recombinant ...

https://lup.lub.lu.se/search/publication/109552

The Hyphal and Yeast Forms of Candida albicans Bind the Complement Regulator C4b-Binding Protein. T. Meri, A. M. Blom, A. ... The Hyphal and Yeast Forms of Candida albicans Bind the Complement Regulator C4b-Binding Protein ... The Hyphal and Yeast Forms of Candida albicans Bind the Complement Regulator C4b-Binding Protein ... The Hyphal and Yeast Forms of Candida albicans Bind the Complement Regulator C4b-Binding Protein ...

https://iai.asm.org/content/72/11/6633/figures-only

The Complement Regulator C4b-Binding Protein (C4BP) Interacts with both the C4c and C4dg Subfragments of the Parent C4b Ligand ...

https://www.infona.pl/resource/bwmeta1.element.acs-doi-10_1021_bi700248q

You need info about Human Complement fragment 4b (C4b) ELISA Kit or any other Gentaur produtct? Contact us on Live Chat Our ... Human (Homo sapiens) C4b elisa. Shipping, handling and storage. The kit is shipped on ice packs. Upon receiving it store the ... Detects Human (Homo sapiens) C4b; Additional information. ...

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Synonyms: Complement Component 4b, Complement Component IVb, C4b, CIVb, Acidic C4, Acidic Complement C4, Basic C4, C3 and PZP- ... Human Complement C4b Antibody. Post date. June 29, 2017. Post last updated dateUpdated Post read time. 24 sec read Post author ... Product Name: Human Complement C4b Antibody. Description: Purified antibody validated for specificity and sensitivity.. CAS NO ... Product Name: Human Complement C4b AntibodyDescription: Purified antibody validated for specificity and sensitivity.CAS NO: ...

https://www.emlinhibitor.com/2017/06/29/Human-Complement-C4b-Antibody/

Compound page for L00080: Complement component C4b. Top page for Compound List ...

http://ezcatdb.cbrc.jp/EzCatDB/Compound/data/L00080.html

The fourth component of complement (C4) is crucial to the activation of the classical complement pathway, a key defense against ... The two isotypes of C4, C4A and C4B, have very different in vitro activities. An increased incidence of total C4B deficiency ... C4B deficiency: a risk factor for bacteremia with encapsulated organisms.. Bishof NA1, Welch TR, Beischel LS. ... 2% of race-matched controls, P = .02). In black patients, however, there was no difference in incidence of C4B deficiency ...

https://www.ncbi.nlm.nih.gov/pubmed/2355198?dopt=Abstract

Hydralazine binds covalently to complement component-C4: Different reactivity of C4A AND C4B Gene-Products ... Sim, Edith and Law, Sai-Kit A. (1985) Hydralazine binds covalently to complement component-C4: Different reactivity of C4A AND ... C4B Gene-Products. FEBS letters, 184(2), pp. 323-327. ISSN (print) 0014-5793 ...

http://eprints.kingston.ac.uk/19436/

C4b-binding protein (C4BP) is a potent soluble inhibitor of the classical and lectin pathways of complement. This large (500 ... Functions of human complement inhibitor C4b-binding protein in relation to its structure. ... Considering the destructive potential of the complement cascade, it is no surprise that there are several complement inhibitors ... function relationships have yielded new understanding of the interactions between C4BP and the activated complement factors C4b ...

http://psjd.icm.edu.pl/psjd/element/bwmeta1.element.element-from-psjc-1da43f29-9a91-3b96-8a86-8b6f28c24015

Ausgesuchte Qualitäts-Hersteller für C4B Antikörper. Hier bestellen. ... Monoklonale und polyklonale C4B Antikörper für viele Methoden. ... basic complement C4 , complement C4-B , complement C4B1a , ... anti-C4B (C4B) Antikörper. Bezeichnung:. anti-Complement Component 4B Antikörper (C4B). Auf www.antikoerper-online.de finden ... Am meisten referenzierte anti-C4B Antikörper. Show all anti-Complement Component 4B (C4B) Antikörper with Pubmed References. * ...

https://www.antikoerper-online.de/komplementsystem-pathway-11/c4b-antibody-29425/

Compare C4B ELISA Kits and find the right product on antibodies-online.com. ... Order C4B ELISA Kits for many Reactivities. Chicken, Cow, Dog and more. ... complement C4-B , complement C4B1a , complement component 4A , complement component 4B , complement component 4B (Chido blood ... Browse our C4B (C4B) ELISA Kits. Full name:. Complement Component 4B ELISA Kits (C4B). On www.antibodies-online.com are 49 ...

http://www.antibodies-online.com/complement-system-pathway-11/c4b-elisa-kit-29426/

complement C3b/C4b receptor 1 (Knops blood group). Enable Javascript to view the expand/collapse boxes.. Open All Close All ... This gene is a member of the receptors of complement activation (RCA) family and is located in the cluster RCA region of ... Membrane immune adherence receptor that plays a critical role in the capture and clearance of complement-opsonized pathogens by ... The protein mediates cellular binding to particles and immune complexes that have activated complement. Decreases in expression ...

https://ghr.nlm.nih.gov/gene/CR1

C4 binding protein binds C4, which accelerates its rate of dissociation from C2a and makes C4b more susceptible to proteolysis ... encoded search term (Complement-Related Disorders) and Complement-Related Disorders What to Read Next on Medscape. Related ... Table 3. Proteins of the Human Complement (C) System, Lectin Pathway *Table 4. Proteins of the Human Complement (C) System, C3 ... Table 1. Proteins of the Human Complement (C) System, Classical Pathway* *Table 2. Proteins of the Human Complement (C) System ...

https://emedicine.medscape.com/article/136368-overview

Of the 8 plasma membrane receptors for complement, only deficiencies of CR3 and CR4 due to CD18 deficiency have been described ... The complement system exerts many of its effects through complement receptors (CRs). ... C3b/C4b. RBC, polymorphonuclear cell, macrophage, B cell, follicular dendritic cell. Immune adherence, phagocytosis ... encoded search term (Pediatric Complement Receptor Deficiency) and Pediatric Complement Receptor Deficiency What to Read Next ...

https://emedicine.medscape.com/article/886248-workup

Carrying no copies of C4B significantly increases the risk of cCSC, whereas carrying three C4B copies is protective. These ... findings reinforce the hypothesis of a possible involvement of the complement system in the pa … ... This study showed that copy numbers of C4B are significantly associated with cCSC. ... Diseases associated with the low copy number of the C4B gene encoding C4, the fourth component of complement. Szilágyi A, Fust ...

https://phgkb.cdc.gov/PHGKB/phgHome.action?action=forward&dbsource=huge&id=117467

Recombinant Human Complement C4-B Protein Proteins A ... Recombinant Human Complement C4-B Protein 200μg enQuireBio™ ... enQuireBio™ Recombinant Human Complement C4-B Protein A DNA sequence encoding the Homo sapiens (Human) Complement C4-B, was ...

https://www.fishersci.fi/shop/products/recombinant-human-complement-c4-b-protein-1/16006970

Insights into IgM-mediated complement activation based on in situ structures of IgM-C1-C4b June 26, 2019 ... Insights into IgM-mediated complement activation based on in situ structures of IgM-C1-C4b ... C1s then enzymatically cleaves C4 to form C4b (cyan) and initiate the complement cascade. The results indicate a surface ... Researchers in the Sharp lab solved the structures of IgM antibodies with multiple components of the immune complement system, ...

https://ccb.lumc.nl/news/insights-into-igm-mediated-complement-activation-based-on-in-situ-structures-of-igm-c1-c4b-103

Complement receptors CR1 and CR2 are active in the immune response and autoimmune diseases. The susceptibility and severity of ... A method and a package for identifying single nucleotide polymorphisms in complement receptor is useful in identifying ... autoimmune disease is determined by genotyping or phenotyping an individual for complement receptor. ... The resulting C3b/C4b coded complexes are ligands for the C3b/C4b receptor on human peripheral blood cells. The C3b/C4b ...

http://www.google.com/patents/US6664052?dq=6,073,142

RESULTS Patients and healthy control subjects differed at both the C4A (P , 0.00001) and C4B (P , 0.0005) loci. The C4 null ... Polymorphism of Complement C4 and Susceptibility to IDDM and Microvascular Complications. Karl Lhotta, Martin Auinger, Florian ... Polymorphism of Complement C4 and Susceptibility to IDDM and Microvascular Complications. Karl Lhotta, Martin Auinger, Florian ... Polymorphism of Complement C4 and Susceptibility to IDDM and Microvascular Complications Message Subject (Your Name) has ...

https://care.diabetesjournals.org/content/19/1/53

Home » Publications » THE ALFA7BETA0 ISOFORM OF THE COMPLEMENT REGULATOR C4B-BINDING PROTEIN INDUCES A SEMIMATURE, ANTI- ... THE ALFA7BETA0 ISOFORM OF THE COMPLEMENT REGULATOR C4B-BINDING PROTEIN INDUCES A SEMIMATURE, ANTI-INFLAMMATORY STATE IN ... THE ALFA7BETA0 ISOFORM OF THE COMPLEMENT REGULATOR C4B-BINDING PROTEIN INDUCES A SEMIMATURE, ANTI-INFLAMMATORY STATE IN ...

https://www.iibb.csic.es/ca/publications/alfa7beta0-isoform-complement-regulator-c4b-binding-protein-induces-semimature-anti

Binding of Complement Inhibitor C4b-binding Protein to a Highly Virulent Streptococcus pyogenes M1 Strain Is Mediated by ... Binding of Complement Inhibitor C4b-binding Protein to a Highly Virulent Streptococcus pyogenes M1 Strain Is Mediated by ... uses exclusively protein H to bind the complement inhibitor C4b-binding protein (C4BP). We found a strong correlation between ... Furthermore, C4b deposited from serum onto AP1 bacterial surfaces was processed into C4c/C4d fragments, which did not occur on ...

https://www.jpt.com/literature/Binding-of-Complement-Inhibitor-C4b-binding-Protein-to-a-Highly-Virulent-Streptococcus-pyogenes-M1-Strain-Is-Mediated-by-Protein-H-and-Enhances-Adhesion-to-and-Invasion-of-Endothelial-Cells/

... regulated antigen 1 of Candida albicans binds the human complement inhibitor C4b-binding protein and mediates fungal complement ... regulated antigen 1 of Candida albicans binds the human complement inhibitor C4b-binding protein and mediates fungal complement ... Candida albicans binds and utilizes human complement inhibitors, such as C4b-binding protein (C4BP), Factor H, and FHL-1 for ... Pra1, via binding to C4BP, mediates human complement control, thereby favoring the immune and complement evasion of C. albicans ...

https://www.leibniz-hki.de/en/management-publication-details.html?publication=235

Animals; Cell Line, Tumor; CHO Cells; Complement C3b; Complement C4b; Complement Factor I; Complement Membrane Attack Complex; ... we found that CSMD1 inhibits complement by promoting factor I-mediated C4b/C3b degradation and inhibition of MAC assembly at ... The novel complement inhibitor human CUB and Sushi multiple domains 1 (CSMD1) protein promotes factor I-mediated degradation of ... The novel complement inhibitor human CUB and Sushi multiple domains 1 (CSMD1) protein promotes factor I-mediated degradation of ...

http://orca-mwe.cf.ac.uk/76409/

Kirjavainen V, Jarva H, Biedzka Sarek M, Blom A, Skurnik M, Meri S. Yersinia enterocolitica serum resistance proteins YadA and ail bind the complement regulator C4b-binding protein. (labome.org)
Ig-binding surface proteins of Streptococcus pyogenes also bind human C4b-binding protein (C4BP), a regulatory component of the complement system. (jimmunol.org)
Additionally we are shipping C4B Antibodies (135) and C4B Proteins (22) and many more products for this protein. (antibodies-online.com)
Yet, the C4 protein derives from a simple two-locus allelic model, the C4A-C4B genes, that allows for an abundant variation in the levels of their respective proteins within a population. (wikipedia.org)
More specifically, the two proteins, Ch and Rg, function together as a medium for interaction between the Ab-Ag complex and other complement components. (wikipedia.org)
The complement system as understood today is a multimolecular system composed of more than 32 proteins and consisting of serum proteins, serosal proteins, and cell membrane receptors that bind to complement fragments. (medscape.com)
The complement system consists of 7 serum and 9 membrane regulatory proteins, 1 serosal regulatory protein, and 8 cell membrane receptors that bind complement fragments. (medscape.com)
The complement system involves a group of proteins that play a role in host defense against infection. (google.com)
The inflammatory response is triggered by way of the cascade, in which low molecular weight peptides are cleaved from complement proteins. (google.com)
The attachment of complement proteins, C3b/C4b to microbial membranes or immune complexes, a process commonly known as opsonization, facilitates the binding of opsonized material to cell receptors. (google.com)
Inhibits these pathways by cleaving three peptide bonds in the alpha-chain of C3b and two bonds in the alpha-chain of C4b thereby inactivating these proteins. (uniprot.org)
The latter group of genetically and structurally unrelated proteins has been collectively referred to as "complement regulator-acquiring surface proteins" and consists of CspA, CspZ, ErpA, ErpC, ErpP, and the as yet unidentified protein p43. (frontiersin.org)
The complement consists of at least 35 or more plasma proteins and cell surface receptors/regulators, which can be activated by three pathways: classical (CP), lectin (LP), and alternative (AP). (frontiersin.org)
Here we demonstrated that the deposition of complement proteins from adult serum prevented the invasion of E. coli into human brain microvascular endothelial cells, whereas the invasion of GBS was enhanced. (biomedsearch.com)
We also examined the effect of the deposited complement proteins on phagocytosis using THP-1 cells and THP-1 cells differentiated into macrophages. (biomedsearch.com)
We further demonstrate that the inhibitory effect of complement proteins is the result of the bound complement inhibitors C4b-binding protein, in the case of E. coli, and Factor H, in the case of GBS. (biomedsearch.com)
Complement regulator-acquiring surface proteins of Borrelia burgdorferi: a new protein family involved in complement resistance. (nih.gov)
The Classical pathway of activation of the complement system is a group of blood proteins that mediate the specific antibody response. (wikipathways.org)
C3 and C4, mainly produced by the liver, are the major plasma proteins of the immune system complement pathways. (thermofisher.com)
Host cells are protected from complement activation by regulatory proteins that inactivate C3b deposited on their surface ( 12 , 13 ). (pnas.org)
Four of the significant differentially expressed proteins (lipopolysaccharide binding protein, fibrinogen β chain, α‑1 antitrypsin, and complement factor H) were validated by western blotting. (spandidos-publications.com)
The regulators of complement activation gene cluster encodes a group of proteins that have evolved to control the amplification of complement at the critical step of C3 activation. (sigmaaldrich.com)
VCP contains 4 short consensus repeat domains (SCR) that are also present in eukaryotic complement regulatory proteins ( 9 ). (asm.org)
Thus, the poxvirus complement control proteins might be attractive therapeutic targets to treat poxvirus infections. (asm.org)
To date, most, if not all, of the serum proteins that constitute the complement system have been identified and their activities characterized. (springer.com)
Binds complement components C3B and C4B with cofactor activity for the I-dependent cleavage of these proteins. (biolegend.com)
Results After short-term ERT (4-12 months), the levels of 15 plasma proteins involved in inflammation, oxidative and ischaemic injury, or complement activation were reduced significantly. (bmj.com)
The gene variants are a member of the complement system, a cascade of proteins that help antibodies and phagocytic cells remove damaged cells of a person's own body, as well as an infection defense that promotes inflammation and attacks pathogens. (uab.edu)
For the complement proteins that are encoded by the genes for C4 and for complement component 3, or C3, both C4 protein and its effector C3 protein were present at greater levels in men than in women in cerebrospinal fluid and blood plasma among adults ages 20-50. (uab.edu)
Because the alternative complement pathway has many features in common with the classical complement pathway, and because many proteins of that pathway function in a manner analogous to proteins of the classical pathway, we studied the role of the C1-INH in inhibition of the alternative complement pathway. (rupress.org)
Allele frequencies of 3 genes (C4A, C4B, and C3) encoding proteins of the complement system were determined by electrophoresis and immunofixation. (ahajournals.org)
Jun 10, 2002 (CIDRAP News) The smallpox virus has a protein that inhibits the human complement system far more effectively than does its counterpart protein in the closely related vaccinia virus, used in smallpox vaccine, according to researchers who compared the two proteins. (umn.edu)
Human complement components C3b and C4b then were incubated with SPICE, VCP, and other complement regulatory proteins. (umn.edu)
Because erythrocytes are lysed in the presence of an increasing amount of complement, the test was done by individually placing the two proteins, along with sheep or rabbit erythrocytes, in blood serum samples from the four species and then measuring the extent of hemolysis. (umn.edu)
The complement system consists of a number of small proteins found in the blood, in general synthesized by the liver , and normally circulating as inactive precursors ( pro-proteins ). (wikipedia.org)
Over 30 proteins and protein fragments make up the complement system, including serum proteins , and cell membrane receptors . (wikipedia.org)
Most of the proteins and glycoproteins that constitute the complement system are synthesized by hepatocytes . (wikipedia.org)
The decreased expression of complement regulatory proteins (CRP) seems to play an important role in RA activity, and is associated with worsening of the clinical symptoms. (scielo.br)
rheumatoid arthritis, complement system proteins, complement activation. (scielo.br)
The complement system (CS) is composed of receptors and regulators bound to the cell membrane and different plasma proteins that interact with cells and mediators of the immune system ( Figure 1 ). (scielo.br)
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. (quidel.com)
Depleted sera are well suited for the detection and quantitation of hemolytically active complement proteins. (quidel.com)

Complement component C4 is a central protein in the classical and lectin pathways within the complement system. (rcsb.org)
Meri T, Blom A, Hartmann A, Lenk D, Meri S, Zipfel P. The hyphal and yeast forms of Candida albicans bind the complement regulator C4b-binding protein. (labome.org)
Dengue, West Nile, or yellow fever virus NS1 directly associated with C4b binding protein (C4BP), a complement regulatory plasma protein that attenuates the classical and lectin pathways. (jimmunol.org)
C4b binding protein (C4BP) is the primary fluid-phase regulator of the CP and lectin pathways. (jimmunol.org)
Here we report a novel interaction between S. pyogenes and the human immune system, the ability of most S. pyogenes strains to bind human C4BP (C4b-binding protein), a 570-kDa serum protein that inhibits the classical pathway of complement activation. (jimmunol.org)
Structural requirements for the intracellular subunit polymerization of the complement inhibitor C4b-binding protein. (lu.se)
C4b-binding protein (C4BP), an important inhibitor of complement activation, has a unique spider-like shape. (lu.se)
article{5be1f4a6-d9f6-43e4-84be-f1c903a8b6fe, abstract = {C4b-binding protein (C4BP), an important inhibitor of complement activation, has a unique spider-like shape. (lu.se)
C4b-binding protein (C4BP) is a potent soluble inhibitor of the classical and lectin pathways of complement. (edu.pl)
Both types of subunit are almost exclusively composed of complement control protein (CCP) domains. (edu.pl)
Zusätzlich bieten wir Ihnen C4B Kits (50) und C4B Proteine (22) und viele weitere Produktgruppen zu diesem Protein an. (antikoerper-online.de)
The presence of high C4A and C4B copy numbers in AD patients could explain the increased C4 protein expression observed in AD patients, thus highlighting a possible role for C4A and C4B copy number variations in the risk of developing AD. (antikoerper-online.de)
The structural basis for inhibition of the classical and lectin complement pathways by S. aureus extracellular adherence protein binding to C4b has been presented. (antikoerper-online.de)
The protein mediates cellular binding to particles and immune complexes that have activated complement. (nih.gov)
Complement component 4 (C4), in humans, is a protein involved in the intricate complement system, originating from the human leukocyte antigen (HLA) system. (wikipedia.org)
Using protein variants visualized by electrophoresis, the four structural genes were located between HLA-B and HLA-D. More specifically, they verified the proposed molecular map in which the gene order went from factor B, C4B, C4A, and C2 with C2 nearest to HLA-B. In another study, Law et al. (wikipedia.org)
Streptococcus pyogenes AP1, a strain of the highly virulent M1 serotype, uses exclusively protein H to bind the complement inhibitor C4b-binding protein (C4BP). (jpt.com)
We found a strong correlation between the ability of AP1 and its isogenic mutants lacking protein H to inhibit opsonization with complement C3b and binding of C4BP. (jpt.com)
C4BP bound to immobilized protein H or AP1 bacteria retained its cofactor activity for degradation of (125)I-C4b. (jpt.com)
The pH-regulated antigen 1 of Candida albicans binds the human complement inhibitor C4b-binding protein and mediates fungal complement evasion. (leibniz-hki.de)
Luo S, Blom AM, Rupp S, Hipler UC, Hube B, Skerka C, Zipfel PF (2011) The pH-regulated antigen 1 of Candida albicans binds the human complement inhibitor C4b-binding protein and mediates fungal complement evasion. (leibniz-hki.de)
Candida albicans binds and utilizes human complement inhibitors, such as C4b-binding protein (C4BP), Factor H, and FHL-1 for immune evasion. (leibniz-hki.de)
The Pra1 binding domains within C4BP were localized to the complement control protein domain 4 (CCP4), CCP7, and CCP8. (leibniz-hki.de)
CUB and Sushi multiple domains 1 (CSMD1) is a transmembrane protein containing 15 consecutive complement control protein (CCP) domains, which are characteristic for complement inhibitors. (cf.ac.uk)
In all functional assays performed, well-characterized complement inhibitors were used as positive controls, whereas Coxsackie adenovirus receptor, a protein with no effect on complement, was a negative control. (cf.ac.uk)
Escudero- Esparza, A., Kalchishkova, N., Kurbasic, E., Jiang, W. G., Blom, A.M. The novel complement inhibitor human CUB and Sushi multiple domains 1 (CSMD1) protein promotes factor I-mediated degradation of C4b and C3b and inhibits the membrane attack complex assembly. (cf.ac.uk)
Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated strongly with predisposition to atypical haemolytic uraemic syndrome (aHUS). (csic.es)
C4b-binding protein (C4BP), a major regulator of the classical pathway of complement activation, also has capacity to regulate the alternative pathway. (csic.es)
C4A isotype is responsible for effective binding to form amide bonds with immune aggregates or protein antigens, while C4B isotype catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens. (abcam.com)
Complement component 4 is a protein involved in the complement system . (thefullwiki.org)
To counteract these opsonization effects, E. coli and GBS bind to the complement regulators C4 binding protein and Factor H, respectively. (biomedsearch.com)
CFI (Complement Factor I) is a Protein Coding gene. (genecards.org)
Responsible for cleaving the alpha-chains of C4b and C3b in the presence of the cofactors C4-binding protein and factor H respectively. (genecards.org)
Binding of the complement inhibitor C4b-binding protein to Lyme disease Borreliae. (nih.gov)
C4BPA (Complement Component 4 Binding Protein Alpha) is a Protein Coding gene. (genecards.org)
S206P protein was expressed on the cell surface but had a reduced ability to prevent complement activation, consistent with its reduced C3b binding and cofactor activity. (pnas.org)
Mutations have been reported in the complement regulatory protein factor H in both sporadic ( n = 9) and familial ( n = 8 families) HUS ( 3 - 7 ) with mutations identified in 10-20% of cases studied. (pnas.org)
Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. (jci.org)
Antigen standard for complement component 4 binding protein, beta (C4BPB), transcript variant 3 is a lysate prepared from HEK293T cells transiently transfected with a TrueORF gene-carrying pCMV plasmid and then lysed in RIPA Buffer. (creativebiomart.net)
Publications] Matsuguchi Tetsuya: 'Interleukin-6 and tumor necrosis factor-alpha fully activate liver-specific gene expression of C4b-binding protein. (nii.ac.jp)
Publications] Aso Teijiro: 'Genomic organization of the α chain of the human C4b-binding protein. (nii.ac.jp)
Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. (asm.org)
The vaccinia virus complement control protein (VCP) is secreted by infected cells and has been shown to inhibit complement activation through interactions with C3b/C4b. (asm.org)
The vaccinia virus complement control protein (VCP) is a 35-kDa protein that is encoded by the C3L gene and secreted by cells infected with vaccinia virus ( 7 , 8 ). (asm.org)
Complement receptor type 1 (CR1 or CD35) is a peripheral glycosylated membrane protein that regulates the complement activation in the control of immune responses. (intechopen.com)
CD46 is a transmembrane protein that is known as a complement membrane cofactor protein, MCP, and measles virus receptor. (biolegend.com)
Complement system - CD46 MCP Introduction of CD46 MCP CD46 complement also known as membrane cofactor protein MCP is a type 1 transmembrane glycoprotein which in humans is encoded by the CD46 gene. (authorstream.com)
Thus, differences in complement protein levels in men and women occur mostly during the reproductive years, ages 20-50. (uab.edu)
The researchers say sex differences in complement protein levels may help explain the larger effects of C4 alleles in men, the greater risk of women for lupus and Sjögren's, and the greater vulnerability of men for schizophrenia. (uab.edu)
Complement 1 inhibitor (C1-INH) * is a critically important protein that controls activation of multiple plasma mediator pathways ( 1 ). (rupress.org)
They compared this with its homologue in the vaccinia virus vaccinia virus complement control protein, or VCP. (umn.edu)
The fact that SPICE functions better against human complement quantitatively and qualitatively demonstrates that variola exhibits human preference at the protein level, a concept previously suggested, but not shown," the report states. (umn.edu)
We report the structure of suramin, in complex with the heparin-binding site of vaccinia virus complement control protein (VCP), which interacts with heparin in a geometrically similar manner to many FGFs. (proteopedia.org)
Structural basis for antagonism by suramin of heparin binding to vaccinia complement protein. (proteopedia.org)
Isaacs SN, Kotwal GJ, Moss B. Vaccinia virus complement-control protein prevents antibody-dependent complement-enhanced neutralization of infectivity and contributes to virulence. (proteopedia.org)
Cell surface expression of the vaccinia virus complement control protein is mediated by interaction with the viral A56 protein and protects infected cells from complement attack. (proteopedia.org)
CFHR5 (Complement Factor H-Related protein 5) is able to bind to act as a cofactor for factor I, has decay accelerating activity and is able to bind preferentially to C3b at host surfaces. (wikipedia.org)
Complement receptor type 1 (CR1 or CD35) is a multiple modular protein that mediates the immune adherence phenomenon, a fundamental event for destroying microbes and initiating an immunological response. (rcsb.org)
The structure of the principal C3b/C4b binding site (residues 901-1095) of CR1 is reported, revealing three complement control protein modules (modules 15-17) in an extended head-to-tail arrangement with flexibility at the 16-17 junction. (rcsb.org)
ab222866 Human Complement C4-Binding Protein ELISA Kit is designed for the quantitative measurement of Complement C4-Binding Protein in plasma, serum, urine, milk, saliva, cerebrospinal fluid (CSF), and cell culture samples. (abcam.com)
The kit employs a quantitative sandwich enzyme immunoassay technique that measures human Complement C4-Binding Protein (C4BP) in less than 4 hours. (abcam.com)
Complement component C4-binding protein (C4BP) regulates the complement system by accelerating the decay of the complement component C3 convertase and by acting as a cofactor to the serine protease factor I in the degradation of C4b. (abcam.com)
The major form of C4BP is composed of seven identical 70-kDa alpha chains, each containing a binding site for the complement protein C4b, and a unique 45 kDa beta chain which contains a binding site for the vitamin K-dependent protein S. C4BP was overexpressed in the synovial membranes of patients with rheumatoid arthritis. (abcam.com)
Each complement protein has been tested for functional purity in standard hemolytic assays and for biochemical purity by SDS-polyacrylamide gel electrophoresis. (quidel.com)
The concentration of each complement protein, except for Factor D and C3a, is approximately 1.0 mg/mL. (quidel.com)
Except for the C3-dpl, C3/C4-dpl and the C4-deficient guinea pig sera, a specific complement protein has been removed immunochemically from each depleted human serum reagent. (quidel.com)

Binding of C4bp could help Y. enterocolitica to evade complement-mediated clearance in the human host. (labome.org)
Soluble NS1 recruited C4BP to inactivate C4b in solution and on the plasma membrane. (jimmunol.org)
Mapping studies revealed that the interaction sites of NS1 on C4BP partially overlap with the C4b binding sites. (jimmunol.org)
When bound to streptococcal cells, C4BP retained its ability to act as a cofactor in the degradation of C4b by factor I. These results indicate that many strains of S. pyogenes interfere with the classical pathway of complement activation by binding C4BP to the bacterial cell surface. (jimmunol.org)
Inhibition of binding of C4BP to C. albicans cells with FHL-1, factor H, and C4BP (A) and with C4b, heparin, and BSA (B). C. albicans hyphal forms (10 9 /assay) were used in direct binding assays. (asm.org)
Furthermore, C4b deposited from serum onto AP1 bacterial surfaces was processed into C4c/C4d fragments, which did not occur on strains unable to bind C4BP. (jpt.com)
C4BP bound to Pra1 maintains complement-inhibitory activity. (leibniz-hki.de)
C4BP captured by C. albicans from human serum inhibits C4b and C3b surface deposition and also maintains cofactor activity. (leibniz-hki.de)
Pra1, via binding to C4BP, mediates human complement control, thereby favoring the immune and complement evasion of C. albicans. (leibniz-hki.de)
A polyclonal antibody specific for human complement C4BP has been pre-coated onto a 96-well microplate with removable strips. (abcam.com)
Complement C4BP in standards and samples is sandwiched by the immobilized antibody and biotinylated polyclonal antibody specific for complement C4BP, which is recognized by a streptavidin-peroxidase conjugate. (abcam.com)

Complement is active in immune defenses, especially antibody mediated events by way of the "classical pathway. (google.com)
Complement response to an invasion by a foreign particle can also embody an antibody independent mechanism which is known as the "alternative pathway. (google.com)
A Complement C4 specific antibody has been precoated onto 96-well plates and blocked. (abcam.com)
Standards or test samples are added to the wells and subsequently a Complement C4 specific biotinylated detection antibody is added and then followed by washing with wash buffer. (abcam.com)
However, it should be kept in mind that apart from the classical antibody-mediated route of complement activation, C4 can also be activated via an alternative, antibody-independent mechanism, the 'mannan-binding lectin' pathway. (thefullwiki.org)
Immune evasion of Borrelia burgdorferi: insufficient killing of the pathogens by complement and antibody. (nih.gov)
The following product was used in this experiment: Complement Polyclonal Antibody from Thermo Fisher Scientific, catalog # RAHU-C. (thermofisher.com)
Complement C3b may be an opsonin for antigen-antibody complexes which helps prevent damage from the formation of large, insoluble immune aggregates. (sigmaaldrich.com)
Subsequent binding of the antibody to complement C1q subunits of C1 result in catalytically active C1s subunits. (sigmaaldrich.com)
Pharmacology and Biological Efficacy of a Recombinant, Humanized, Single-Chain Antibody CS Complement Inhibitor in Patients Undergoing Coronary Artery Bypass Graft Surgery With Cardiopulmonary Bypass, Circulation, 100:2499-2506 (1999). (freepatentsonline.com)
VCP inhibits the antibody-dependent, complement-enhanced neutralization of vaccinia virus virions ( 3 ). (asm.org)
Lé vy 2017 Because of the importance in the regulation of complement activation control of pathogens entry and activation of T Cell Immunity CD46 has become a promising target for therapeutic antibody exploration and clinical trial. (authorstream.com)
The antibody reacts with C4, C4b and C4c, but does not react with the C4d fragment. (agilent.com)
Crossed immunoelectrophoresis: Only reactivity with C4 complement and its C4c-containing fragments is observed when using unconjugated antibody corresponding to 40 µL F 0169 per square cm gel area against 2 µL human plasma. (agilent.com)
The classical complement pathway typically requires antigen-antibody complexes for activation (specific immune response), whereas the alternative pathway can be activated by spontaneous C3 hydrolysis, foreign material, pathogens, or damaged cells. (wikipedia.org)

It binds as a cofactor to C3b/C4b inactivator (C3bINA), which then hydrolyzes the complement fragment C4b. (genecards.org)
Alpha chain binds C4b. (genecards.org)
When an IgG1 anti-fHbp MAb binds to sparsely exposed fHbp on the bacterial surface, there appears to be insufficient complement activation for bacteriolysis unless fH binding also is inhibited. (asm.org)
VCP inhibits activation of complement, binds C4b and C3b, acts as a cofactor in the enzymatic inactivation of C4b and C3b by factor I, prevents the formation of the classical and alternative pathway C3 convertases, and accelerates their decay ( 6 , 12 , 15 , 18 ). (asm.org)
CD46 binds complement components C3b and C4b and has been reported to play a role in T cell regulation. (biolegend.com)
Binds C3b and C4b. (proteopedia.org)
CD21, also known as CR2 (complement receptor 2) and C3d receptor, binds C3d and iC3b. (biolegend.com)
[3] Complement factor H preferentially binds to vertebrate cells (because of affinity for sialic acid residues), allowing preferential protection of host (as opposed to bacterial) cells from complement-mediated damage. (wikipedia.org)

Our results revealed a novel complement inhibitor for the classical and lectin pathways. (cf.ac.uk)
Transgenic Expression of a Soluble Complement Inhibitor Protects Against Renal Disease and Promotes Survival in MAU/pr Mice, J. Immunol. (freepatentsonline.com)
A recombinant soluble chimeric complement inhibitor composed of human CD46 and COSS reduces acute cardiac tissue injury in models of pig-to-human heart transplantation, Transplantation, 69:2282-2289 (2000). (freepatentsonline.com)
We studied complement 1 inhibitor (C1-INH) as an inhibitor of the alternative complement pathway. (rupress.org)
Recently, it has been shown to be an inhibitor of the mannan-binding lectin pathway of complement activation, inhibiting mannan-binding lectin-associated serine proteases (MASPs) in that pathway ( 10 ). (rupress.org)
The research team, led by Ariella M. Rosengard of the University of Pittsburgh, molecularly engineered and analyzed what they call "smallpox inhibitor of complement enzymes," or SPICE. (umn.edu)
Variola virus immune evasion design: expression of a highly efficient inhibitor of human complement. (umn.edu)

Low complement C4B gene copy number predicts short-term mortality after acute myocardial infarction. (labome.org)
results suggest that the C4B gene number associates positively with inflammation in patients with PIBD. (antikoerper-online.de)
Multiple copies of the C4B gene may thus aggravate the IBD-associated dysbiosis through escalated complement reactivity towards the microbiota. (antikoerper-online.de)
Increased transcription of the complement C4 gene in the Rag1 (show RAG1 ELISA Kits )(-/-) intestine. (antibodies-online.com)
This gene encodes the basic form of complement factor 4, part of the classical activation pathway. (antibodies-online.com)
This gene is a member of the receptors of complement activation (RCA) family and is located in the 'cluster RCA' region of chromosome 1. (nih.gov)
Chronic central serous chorioretinopathy (cCSC) has recently been associated to variants in the complement factor H gene. (cdc.gov)
To further investigate the role of the complement system in cCSC, the genomic copy number variations in the complement component 4 gene (C4) were studied. (cdc.gov)
This gene encodes a serine proteinase that is essential for regulating the complement cascade. (genecards.org)
Defects in this gene cause complement factor I deficiency, an autosomal recessive disease associated with a susceptibility to pyogenic infections. (genecards.org)
The genes encoding both alpha and beta chains are located adjacent to each other on human chromosome 1 in the regulator of complement activation gene cluster. (genecards.org)
They noted associations near the C4 gene, which encodes for complement component 4. (nih.gov)
The gene encoding MCP is in the cluster of complement-related genes on chromosome 1q32. (pnas.org)
Now complement gene variants apparently play a contributing role in the diseases systemic lupus erythematosus, Sjögren's syndrome and schizophrenia. (uab.edu)
The complement receptor 1 (CR1) gene encodes a transmembrane glycoprotein that functions in the innate immune system. (alzforum.org)

We propose an overall molecular model for the classical pathway C5 convertase in complex with C5, suggesting that C3b increases the affinity for the substrate by inducing conformational changes in C4b rather than a direct interaction with C5. (rcsb.org)
In the first phase, a series of specific interactions leads to formation of intrinsic complement proteinase, termed C3 convertase. (medscape.com)
Depending on the nature of complement activators, the classic pathway, the alternative pathway, or the more recently discovered lectin pathway is activated predominantly to produce C3 convertase. (medscape.com)
When bound to microorganisms, the MBL complex activates the complement components C4 and C2, thereby generating the C3 convertase and leading to opsonisation by the deposition of C4b and C3b fragments. (nih.gov)
Further degradation of C4b by C1 into the inactive fragments C4c and C4d blocks the generation of C3 convertase. (abcam.com)
In fact, several T. cruzi molecules are known to interfere in the initiation of all three pathways and in the assembly of C3 convertase, a key step in the activation of complement. (frontiersin.org)
Moreover, T. cruzi promotes secretion of plasma membrane-derived vesicles from host cells, which prevent the activity of C3 convertase C4b2a and thereby may hinder complement. (frontiersin.org)
This heterodimer can cleave and inactivate the complement components C4b and C3b, and it prevents the assembly of the C3 and C5 convertase enzymes. (genecards.org)
Activated cleavage products C2A and C4B combine to form C3 convertase, which cleaves C3. (wikipathways.org)
It also accelerates the degradation of the C4bC2a complex (C3 convertase) by dissociating the complement fragment C2a. (genecards.org)
The two activated C1s subunits are then able to catalyze the assembly of the C3 convertase (complement C4b2a) from complements C2 and C4. (sigmaaldrich.com)
C4c interacts with complement C1 and complement C2 to form complement C3 convertase of the classic activation pathway. (cellsciences.com)
C2a, a serine protease, then combines with complement factor C4b to generate the C3 or C5 convertase. (uniprot.org)
After the creation of C5 convertase (either as (C3b) 2 BbP or C4b2a3b from the classical pathway), the complement system follows the same path regardless of the means of activation (alternative, classical, or lectin). (wikipedia.org)
The formation of a C3 convertase can also be prevented when a plasma protease called complement factor I cleaves C3b into its inactive form, iC3b. (wikipedia.org)

In the assay described here, the specific C4b-depositing capacity of the MBL pathway was determined by incubating serum diluted in buffer containing 1 M NaCl in mannan-coated microtiter wells before the addition of purified C4. (nih.gov)
When 100 normal serum samples were analysed we found that the MBL level correlated with the amount of C4b deposited on the mannan-coated surface. (nih.gov)
The assay permits for the determination of MBL complex activity in serum and plasma samples and may thus be used to evaluate the clinical implications of complement activation via this pathway. (nih.gov)
Nonetheless, the deposition of complement components on these two bacteria from neonatal serum and their effect on the host cell interaction is unclear. (biomedsearch.com)
Complement-mediated serum sensitivity among spirochetes that cause Lyme disease. (nih.gov)
Complement evasion by Borrelia burgdorferi: serum-resistant strains promote C3b inactivation. (nih.gov)
Measurements of serum complement components C3 and C4 are useful in the diagnosis and monitoring of immune complex disease. (thermofisher.com)
The complement system is a complex cascade involving proteolytic cleavage of serum glycoproteins often activated by cell receptors. (sigmaaldrich.com)
Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. (jci.org)
Reduced levels of components of the classic pathway (Complements C1, C2, C4, C3) are common after such activation, Systemic lupus erythematosus, acute serum sickness and conditions associated with circulating immune complexes. (cellsciences.com)
While some fHbp-specific monoclonal antibodies (MAbs) block binding of fH to fHbp, the stoichiometry of blocking in the presence of high serum concentrations of fH and its effect on complement-mediated bactericidal activity are unknown. (asm.org)
Complement was first described as a heat-labile component in serum with bactericidal activity. (springer.com)
C4c complement isolated from human serum. (agilent.com)
C1-INH prevented lysis, induced by the alternative complement pathway, of paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes in human serum. (rupress.org)

Monitoring patients with the C1q assay, which detects antibodies that fix complement, offers a minimally invasive means of identifying patients at risk for transplant glomerulopathy and graft loss. (labome.org)
05). The results of our study suggest that anti-beta2GPI antibodies may play a role in GMT formation, and this process might involve complement activation. (labome.org)
On www.antibodies-online.com are 49 Complement Component 4B (C4B) ELISA Kits from 10 different suppliers available. (antibodies-online.com)
Researchers in the Sharp lab solved the structures of IgM antibodies with multiple components of the immune complement system, revealing insights into immune system activation. (lumc.nl)
IgM antibodies protect us against infections and mediate clearance of cellular debris by activating the immune complement system upon binding to cell-surface antigens. (lumc.nl)
were able to image activation of the immune system complement cascade by IgM antibodies. (lumc.nl)
C4d is the degradation product of the activated complement factor C4, a component of the classical complement cascade which is typically initiated by binding of antibodies to specific target molecules. (thefullwiki.org)
Among these are receptors that recognise the Fc part of bound IgG antibodies, deposited complement or receptors, that recognise other opsonins of cell or plasma origin. (wikipedia.org)
The complement system is a biochemical cascade that helps, or complements, the ability of antibodies to clear pathogens from an organism. (wikipathways.org)
While all three MAbs elicited similar C1q-dependent C4b deposition on live bacteria (classical complement pathway), only those antibodies that inhibited binding of fH to fHbp (JAR 3 and JAR 5) had bactericidal activity with human complement. (asm.org)
In preclinical studies with mice, antibodies elicited by fHbp vaccines bound to the bacterial surface, activated complement-mediated bactericidal activity directly ( 8 , 16 , 17 , 33 , 47 ), and inhibited binding of fH to fHbp ( 8 , 30 , 47 ). (asm.org)
To elucidate which SCR domains are involved in abolishing complement-enhanced neutralization of vaccinia virus virions, we generated and characterized a panel of mouse monoclonal antibodies (MAbs) raised against VCP. (asm.org)
Complement Components and Antibodies. (rupress.org)
The complement system is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promotes inflammation, and attacks the pathogen's cell membrane . (wikipedia.org)
The complement system can be recruited and brought into action by antibodies generated by the adaptive immune system . (wikipedia.org)
In the early 20th century, this controversy was resolved when it became understood that complement can act in combination with specific antibodies, or on its own in a non-specific way. (wikipedia.org)

Moreover, C4b provides a platform for assembly of the proteolytically active convertases that mediate downstream complement activation by cleavage of C3 and C5. (rcsb.org)
Our results provide the molecular details of the rearrangement accompanying C4 cleavage and suggest intramolecular flexibility of C4b. (rcsb.org)
Previous work has defined an immune evasion role of flavivirus NS1 in limiting complement activation by forming a complex with C1s and C4 to promote cleavage of C4 to C4b. (jimmunol.org)
Each complement activation pathway is initiated by a distinct set of recognition molecules and converges at the cleavage of C3 to C3a and C3b. (jimmunol.org)
Cleavage of the C4 α-chain at peptide bond 77 by activated C1 enzyme results in the production of C4a (M.W. 8,758) and C4b (M.W. 193,000) fragments. (emdmillipore.com)
Acts also in the inhibition of spontaneous complement activation by impairing the formation and function of the alternative and classical pathway C3/C5 convertases, and by serving as a cofactor for the cleavage by factor I of C3b to iC3b, C3c and C3d,g, and of C4b to C4c and C4d (PubMed:2972794, PubMed:8175757). (nih.gov)
Inactivates complement subcomponents C3b, iC3b and C4b by proteolytic cleavage. (uniprot.org)
In the alternate pathway complement C3 undergoes spontaneous cleavage resulting in complement B binding to C3b. (sigmaaldrich.com)
Regulator of Complement Activation CD46 primarily functions as a cofactor for complement factor I in mediating cleavage of C3b. (authorstream.com)
Also it participates in the cleavage of C4b resulting in the formation of C4c and C4d. (authorstream.com)

Expression of the complement anaphylatoxin C3a and C5a receptors on bronchial epithelial and smooth muscle cells in models of sepsis and asthma. (medscape.com)
Structure, function and cellular expression of complement anaphylatoxin receptors. (medscape.com)
Complement receptors CR1 and CR2 are active in the immune response and autoimmune diseases. (google.com)
Neutrophils phagocytose mainly via the Fcγ receptors and complement receptors 1 and 3. (wikipedia.org)
Macrophages initiate phagocytosis by mannose receptors, scavenger receptors, Fcγ receptors and complement receptors 1, 3 and 4. (wikipedia.org)
These receptors recognise targets coated in C3b, C4b and C3bi from plasma complement. (wikipedia.org)
The extracellular domain of the receptors contains a lectin-like complement-binding domain. (wikipedia.org)
Recognition by complement receptors is not enough to cause internalisation without additional signals. (wikipedia.org)
This report describes receptors for C4b on human peripheral B lymphocytes. (rupress.org)
The simultaneous presence of C3b and C4b receptors on the same lymphocytes was demonstrated by the formation of mixed rosettes consisting of the lymphocytes, EAC14 and EAC1423. (rupress.org)
Binding of EAC14 intermediates to receptors on human lymphocytes and erythrocytes could be inhibited by equal amounts of soluble C3b or C4b, suggesting the presence of a single receptor for both ligands on those cells. (rupress.org)
In contrast, the results of the rosette assay with Raji cells, cultured human lymphoblastoid cells, EAC14 and EAC1423 suggested that the receptors for C4b and C3b are distinct entities, since Raji cells formed rosettes with EAC1423, but not with EAC14. (rupress.org)
In this chapter, the structure and function of the complement receptors on the macrophage and related cells are described. (springer.com)

The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. (labome.org)
In this study, we demonstrate a second mechanism, also involving C4 and its active fragment C4b, by which NS1 antagonizes complement activation. (jimmunol.org)
You need info about Human Complement fragment 4b (C4b) ELISA Kit or any other Gentaur produtct? (gentaurshop.com)
Furthermore, by expressing a soluble 1721 CCP fragment of CSMD1, we found that CSMD1 inhibits complement by promoting factor I-mediated C4b/C3b degradation and inhibition of MAC assembly at the level of C7. (cf.ac.uk)
Segregation analysis mapped the recombination to a region 3' to the unique 6.4-kb TaqI restriction fragment of the maternal C4B locus. (jci.org)

Considering the destructive potential of the complement cascade, it is no surprise that there are several complement inhibitors present in blood and expressed on virtually all cells of the body to protect self tissue. (edu.pl)
Complement inhibitors are being studied as potential therapeutics for immune diseases and Alzheimer's. (sigmaaldrich.com)
Complement receptor 1 (CR1) is the most versatile of these inhibitors with both receptor and regulatory functions. (sigmaaldrich.com)
The invention relates to complement inhibitors that inhibit both the classical and alternative complement pathways. (freepatentsonline.com)
In particular, the invention relates to complement inhibitors derived from the salivary glands of haematophagous arthropods that inhibit both the classical and alternative complement pathways. (freepatentsonline.com)
The invention also relates to the use of the complement inhibitors in the treatment and prevention of diseases. (freepatentsonline.com)
Derivation of RNA aptamer inhibitors of human complement C5, Immunopharmacology, 42:219-230 (1999). (freepatentsonline.com)
Endothelial Targeting and Enhanced Antiinflammatory Effects of Complement Inhibitors Possessing Sialyl Lewisx Moieties, J. Immunol. (freepatentsonline.com)
These anti-VCP MAbs may have clinical significance as therapeutic inhibitors of VCP's complement control activity and may also offer a novel approach to managing vaccinia virus vaccine complications that occur from smallpox vaccination. (asm.org)

In addition, surface bound C4b has opsonic and immune adherence activities which are mediated via binding to the CR1 (CD35) complement receptor which is found on a variety of inflammatory cells. (emdmillipore.com)
CD35) on epithelial cells: A model for understanding complement-mediated damage in the kidney. (sigmaaldrich.com)
CD35 (CR1, Complement Receptor 1) is a cell membrane-bound, monomeric glycoprotein and its primary function is to serve as the cellular receptor for C3b and C4b, the most important components of the complement system leading to clearance of foreign macromolecules. (thermofisher.com)
CD35 is involved in the processing of immune complexes, promoting of binding and phagocytosis of C3b complexes and inhibition of complement activation. (thermofisher.com)

The complement system functions as an interactive sequence, with one reaction leading to another in the form of a cascade. (medscape.com)
C1s then enzymatically cleaves C4 to form C4b (cyan) and initiate the complement cascade. (lumc.nl)
As part of the body's natural defenses, the complement system operates as a biological cascade in which one component activates successive components. (google.com)
C4 is part of the complement cascade, an immune system pathway that eliminates pathogens and cellular debris. (nih.gov)
These findings, along with evidence from other studies, suggested to the researchers that C4 might work with other components of the classical complement cascade to promote synaptic pruning. (nih.gov)
Ischaemic infarction may also cause initiation of the complement cascade. (sigmaaldrich.com)
The end result of this complement activation or complement fixation cascade is stimulation of phagocytes to clear foreign and damaged material, inflammation to attract additional phagocytes, and activation of the cell-killing membrane attack complex . (wikipedia.org)
Bioinformatics analyses indicated that DEPs in both the EOPE and LOPE groups were associated with abnormalities in the activation of the coagulation cascade and complement system as well as with lipid metabolism. (peerj.com)
The pathogenesis of EOPE and LOPE appeared to be associated with coagulation cascade activation, lipid metabolism, and complement activation. (peerj.com)

Data indicate complement C3 (show C3 ELISA Kits ) deposition on peanut extract (PE) was abolished in immunoglobulin- and C4-deficient sera. (antibodies-online.com)
Like factor H it inhibits complement activation by regulating C3b deposition on targets. (pnas.org)
We propose that this localized deposition of complement fragments aids in the fusion process between the spermatozoa and egg, in a role akin to that of complement in immune adherence. (jci.org)

This MAb is specific to Complement 4d (C4d) and it reacts with the secreted as well as cell-bound C4d.C4d is a degradation product of the activated complement factor C4b. (novusbio.com)
Following activation and degradation of the C4 molecule, thio-ester groups are exposed, which allow transient, covalent binding of the degradation product Complement 4d to endothelial cell surfaces and extracellular matrix components of vascular basement membranes near the sites of C4 activation. (novusbio.com)
The presence of these cofactors on healthy cells allows degradation of deposited C3b by CFI in order to prevent undesired complement activation, while in apoptotic cells or microbes, the absence of such cofactors leads to C3b-mediated complement activation and subsequent opsonization. (uniprot.org)
Derived from proteolytic degradation of complement C4, C4a anaphylatoxin is a mediator of local inflammatory process. (abcam.com)

The complement system plays a pivotal protective role in the innate immune response to many pathogens including flaviviruses. (jimmunol.org)
The complement system is a key component of the early innate immune response to pathogens. (jimmunol.org)
Membrane immune adherence receptor that plays a critical role in the capture and clearance of complement-opsonized pathogens by erythrocytes and monocytes/macrophages (PubMed:2963069). (nih.gov)
To survive and establish a persistent infection in the human host, pathogens must evade the first line of host defense by counteracting complement as an essential part of innate immunity. (frontiersin.org)
The complement system is part of the body's immune system to fight pathogens and remove cell debris. (uab.edu)
The alternative pathway is one of three complement pathways that opsonize and kill pathogens. (wikipedia.org)

CD46) is a widely expressed transmembrane complement regulator. (pnas.org)
Our studies underscore the potential importance of CR1 on an epithelial cell population as both an intrinsic complement regulator and an immune adherence receptor. (sigmaaldrich.com)

Among them, β-actin (ACTB), inactivated complement C3b (iC3b), and C4B were elevated significantly in pre-ERT Fabry disease plasma compared with control plasma. (bmj.com)

Inhibition of binding of fH to the bacterial surface would be expected to increase susceptibility of the bacteria to complement-mediated bacteriolysis. (asm.org)
Combined Inhibition of Apoptosis and Complement Improves Neural Graft Survival of Embryonic Rat and Porcine Mesencephalon in the Rat Brain, Exp. (freepatentsonline.com)
IgM rheumatoid factor and the inhibition of covalent binding of C4b to IgG in immune complexes, Clin. (freepatentsonline.com)
Effects of Complement Inhibition with Soluble Complement Receptor-1 on Vascular Injury and Inflammation during Renal Allograft Rejection in the Rat, Am. J. Pathol. (freepatentsonline.com)

Beyond its lytic capacity, complement protects against viral infections by priming adaptive B and T cell responses, triggering leukocyte chemotaxis through the release of anaphylatoxins (C3a and C5a),and opsonizing viruses for phagocytosis and destruction by macrophages (reviewed in Refs. (jimmunol.org)
Once activated, several relevant complement functions are generated which include opsonization and phagocytosis of particles or microorganisms and cell lysis. (frontiersin.org)
The ingestion mediated by the mannose receptor is distinct in molecular mechanisms from Fcγ receptor or complement receptor mediated phagocytosis. (wikipedia.org)

Classical Complement Pathway Component C1q: Purification of Human C1q, Isolation of C1q Collagen-Like and Globular Head Fragments and Production of Recombinant C1q-Derivatives. (springer.com)
Component C2 which is part of the classical pathway of the complement system is cleaved by activated factor C1 into two fragments: C2b and C2a. (uniprot.org)

The deposited C4b and C3b were progressively cleaved with a t½ of ∼ 30 min to C4d and C3d, respectively, by CR1-dependent cofactor activity. (sigmaaldrich.com)

Through experiments involving restriction mapping, nucleotide sequence analysis, and hybridization with C4A and C4B, they found that the genes are actually fairly similar though they have their differences. (wikipedia.org)
In the same year, studies relatedly identified a 98 kb region of the chromosome the four class III genes (that express C4A, C4B, C2, and factor B) are closely linked, which does not allow for cross-overs to occur. (wikipedia.org)
We first described factor H mutations ( 4 ) after a linkage study in three families that mapped HUS to a 26-centiMorgan region of chromosome 1 (1q32) containing a cluster of complement related genes, including factor H. However, we identified a factor H mutation in only one of the three families used in this linkage study. (pnas.org)
The genes which are now known to be important in predisposing towards lupus are the DR genes, the complement genes, the X chromosome and race. (lupusuk.org.uk)
The fourth component of complement (C4) is encoded by two closely linked genes (C4A and C4B) within the MHC. (jci.org)
Previously we have found a highly significant association between the morbidity and mortality of myocardial infarction and C4B*Q0, the silent allele of 1 of the 2 genes encoding C4, a component of the complement system. (ahajournals.org)

Complement C5a, like C3a is an anaphylatoxin, and is a chemotactic attractant for induction of neutrophilic release of antimicrobial proteases and oxygen radicals. (sigmaaldrich.com)

C4A and C4B copy numbers were analyzed in 197 cCSC patients and 303 healthy controls by using a Taqman copy number determination assay. (cdc.gov)
Therefore, in a generally applicable complement activation assay specific for the MBL pathway, the activity of the classical pathway must be inhibited. (nih.gov)
Abcam's Complement C4 Human in vitro ELISA (Enzyme-Linked Immunosorbent Assay) kit is designed for the quantitative measurement of Complement C4 levels in urine, milk, saliva, CSF and cell culture supernatants. (abcam.com)
The seven remaining MAbs did not alter VCP function in the complement neutralization assay and recognized VCP bound to C3b/C4b. (asm.org)

Difference in the clustering of complement receptor type 1 (CR1) on polymorphonuclear leukocytes and erythrocytes: effect on immune adherence. (medscape.com)
Wakabayashi M, Ohi H, Tamano M, Onda K, Fujita T, Tomino Y. Acquired loss of erythrocyte complement receptor type 1 in patients with diabetic nephropathy undergoing hemodialysis. (medscape.com)

C4b-specific features revealed by our structural studies are probably involved in the assembly of the classical pathway C3/C5 convertases and C4b binding to regulators. (rcsb.org)
In regard to complement resistance, Borrelia utilize a plethora of immune evasion strategies involves capturing of host-derived complement regulators, terminating complement activation as well as shedding of cell-destroying complement complexes to manipulate and to expeditiously inhibit human complement. (frontiersin.org)
Effects of complement regulators bound to Escherichia coli K1 and Group B Streptococcus on the interaction with host cells. (biomedsearch.com)
Opportunities for new therapies based on the natural regulators of complement activation. (wikipathways.org)

Once bound to the target surface, C4b becomes an essential non-enzymatic subunit of the classical pathway C3 cleaving enzyme (C4b,C2a). (emdmillipore.com)
Together with factor I, it degrades C3b and C4b bound to the cell surface ( 20 - 25 ). (pnas.org)

In addition to the complement components, CD46 has been shown to interact with moesin, c-Src, tetraspanin 4, c-Yes, and integrin β1. (biolegend.com)
CD46 is widely expressed in host tissue such as brain kidney skin reproductive eye thyroid liver and synovium where it acts as an inhibitory complement receptor to play the critical role in self-protection from the destructive action of autologous complement. (authorstream.com)

Several studies in rodents suggest that the alternative pathway of the complement system plays a pivotal role in renal ischemia-reperfusion injury. (nih.gov)
The alternative pathway of the complement system is an innate component of the immune system 's natural defense against infections. (wikipedia.org)

C4b can bind CR1 . (thefullwiki.org)
In contrast to KAF-treated C3b, KAF-treated C4b did not bind to B lymphocytes, indicating that these cells lack a receptor for C4d. (rupress.org)

In conclusion, we demonstrated the activation and a pathogenic role of classical and lectin pathways of complement in a swine model of ischemia-reperfusion-induced renal damage. (nih.gov)

This C4/C2 cleaving activity is shared with the C1 complex of the classical pathway of complement activation. (nih.gov)
Controls the classical pathway of complement activation. (genecards.org)

C4B deficiency: a risk factor for bacteremia with encapsulated organisms. (nih.gov)
An increased incidence of total C4B deficiency was found in white patients with Streptococcus pneumoniae, Haemophilus influenzae, or Neisseria meningitidis infection (14% of bacteremic children vs. 2% of race-matched controls, P = .02). (nih.gov)
In black patients, however, there was no difference in incidence of C4B deficiency between bacteremic patients and race-matched controls (7% and 5%, respectively, P greater than .5). (nih.gov)
These data suggest that, at least in whites, total C4B deficiency is a risk factor for invasive disease with these three encapsulated organisms. (nih.gov)
Diseases associated with CFI include Complement Factor I Deficiency and Hemolytic Uremic Syndrome, Atypical 3 . (genecards.org)
Systemic lupus erythematosus is often associated with congenital complement C4 deficiency. (cellsciences.com)
Although the risk of lupus in patients with complement deficiency is high, C1q deficiency and C2 deficiency is extremely rare, with less than 100 patients with each being described in the world literature. (lupusuk.org.uk)
In addition, any patients with C4a deficiency are likely to have both copies of C4b, so true C4 deficiency is extremely rare. (lupusuk.org.uk)

It inhibits complement activation at the yeast surface and, in addition, mediates adhesion of C. albicans to host endothelial cells. (labome.org)

A complex of complements C5b,C6, C7, and C8 mediates the polymerization of up to eighteen C9 molecules into a tube-like membrane attack complex that is inserted into the plasma membrane of an unwanted organism such as of gram-negative bacteria and viral infected cells. (sigmaaldrich.com)
Protection of hDAF-transgenic porcine endothelial cells against activation by human complement: role of the membrane attack complex, Xenotransplantation, 9:97-105 (2002). (freepatentsonline.com)

Trypsin-like serine protease that plays an essential role in regulating the immune response by controlling all complement pathways. (uniprot.org)

The fourth component of complement (C4) is crucial to the activation of the classical complement pathway, a key defense against invading microorganisms. (nih.gov)
Complements C3a and C4b are opsonins that bridge phagocytes to microorganisms. (sigmaaldrich.com)
The complement system as a major part of innate immunity is the first line of defense against invading microorganisms. (epfl.ch)

The increased mortality of C4(-/-) or Factor B (show CFB ELISA Kits )(-/-) mice indicates that these two pathways of complement activation are required for survival in mousepox. (antibodies-online.com)
VCP_VACCW ] Serves to protect the virus against complement attack by inhibiting both classical and alternative pathways of complement activation. (proteopedia.org)

Complement Systems: Methods and Protocols is composed of 32 individual chapters that describe a variety of protocols to purify and analyze the activity of the individual complement components or pathways. (springer.com)
Complement, the first line of defence in the host, acts on these bacteria to opsonize with various components of complement for subsequent presentation to phagocytes. (biomedsearch.com)
Complement components C6, C7, C8 and C9. (ebi.ac.uk)
This hypothesis is based on the observation that complement components are important in the clearance of material from apoptotic or necrotic cells. (lupusuk.org.uk)

Together, these studies further define the immune evasion potential of NS1 in reducing the functional capacity of C4 in complement activation and control of flavivirus infection. (jimmunol.org)
This review focuses on the current knowledge of immune evasion mechanisms exhibited by Lyme disease spirochetes and highlights the role of complement-interfering, infection-associated molecules playing an important part in these processes. (frontiersin.org)
While attempting to decipher the molecular mechanisms of complement evasion, distinct complement-interfering and -inhibiting molecules of B. burgdorferi s.s. (frontiersin.org)

A DNA sequence encoding the Homo sapiens (Human) Complement C4-B, was expressed in the hosts and tags indicated. (fishersci.fi)

Complement C4b, Human, is a native, 193 kDa glycoprotein composed of the modified C4 α-chain (α') and intact β- and γ-chains complement component. (emdmillipore.com)
Glycoprotein (DAF or CD55 , regulates complement fractions C3 and C5, attached to the membrane by GPI). (wikidoc.org)

Ehrlich introduced the term "complement" as part of his larger theory of the immune system. (wikipedia.org)
Ehrlich, therefore, named this heat-labile component "complement," because it is something in the blood that "complements" the cells of the immune system. (wikipedia.org)
Quidel MicroVue Products are a well-established name in Immune System Monitoring, assays for the assessment of complement activation, as well as biochemical bone markers. (quidel.com)

Mediates the binding by these cells of particles and immune complexes that have activated complement to eliminate them from the circulation (PubMed:2963069). (nih.gov)
The results indicate a surface trigger that activates complement and contributes to differentiating between silent removal of targeted host cells versus raising inflammatory responses to invading microbes. (lumc.nl)
Taken together, these results suggest that E. coli and GBS utilize contrasting mechanisms of complement-mediated interactions with their target cells for successful establishment of disease. (biomedsearch.com)
Other deleterious effects of complement activation include, degranulation of neutrophils, basophils and mast cells, unwanted release of the neutrophil products elastase and oxygen radicals, and extracorporeal blood circulation. (sigmaaldrich.com)
In addition, we speculate that this "targeted and restricted" form of complement activation on host cells is a common strategy to handle modified self. (jci.org)
This in vivo effect is likely due in part to enhanced complement-mediated neutralization of virus lacking expression of VCP ( 3 ) as well as the recruitment of inflammatory cells to areas of active infection ( 13 ). (asm.org)
Therefore, the purpose of SPICE may be to create a microenvironment around variola-infected cells to protect them from complement-mediated attack while they serve as a site of viral replication. (umn.edu)

The extracellular domain is composed of four complement control modules that house the sites for complement regulation. (pnas.org)

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Immunohistochemical analysis of arterial wall cellular infiltration in Buerger's disease (endarteritis obliterans). (1/363)

Deficiency of human complement protein C4 due to identical frameshift mutations in the C4A and C4B genes. (2/363)

Interaction between protein S and complement C4b-binding protein (C4BP). Affinity studies using chimeras containing c4bp beta-chain short consensus repeats. (3/363)

Consumption of C4b-binding protein (C4BP) during in vivo activation of the classical complement pathway. (4/363)

Some anticardiolipin antibodies recognize a combination of phospholipids with thrombin-modified antithrombin, complement C4b-binding protein, and lipopolysaccharide binding protein. (5/363)

A cluster of positively charged amino acids in the C4BP alpha-chain is crucial for C4b binding and factor I cofactor function. (6/363)

Analysis of human C4A and C4B binding to an immune complex in serum. (7/363)

Upregulation of ICAM-1 on cardiomyocytes in jeopardized human myocardium during infarction. (8/363)

Complement C3

Complement C4

Complement C4a

Complement C3a

Complement C1q

Complement C5a

Complement Activation

Complement C4b

Complement C5

Complement C3b

Complement System Proteins

Complement C6

Complement C3c

Complement C3d

Complement C2

Complement C9

Receptors, Complement

Complement C1s

Complement Membrane Attack Complex

Complement C1r

Complement Inactivator Proteins

Complement C7

Complement C3-C5 Convertases

Complement Factor B

Complement Pathway, Alternative

Complement Pathway, Classical

Complement C8

Complement C1

Receptors, Complement 3b

Complement Factor H

Complement C5b

Complement C2a

Receptor, Anaphylatoxin C5a

Complement Activating Enzymes

Complement Inactivating Agents

Complement Hemolytic Activity Assay

Complement C1 Inactivator Proteins

Receptors, Complement 3d

Anaphylatoxins

Complement Fixation Tests

Complement Factor D

Complement Factor I

Complement C4b-Binding Protein

Complement C3b Inactivator Proteins

Antigens, CD55

Complement C3-C5 Convertases, Classical Pathway

Complement C2b

Antigens, CD59

Cobra Venoms

Antigen-Antibody Complex

Steroid 21-Hydroxylase

Complement C3-C5 Convertases, Alternative Pathway

Complement C1 Inhibitor Protein

Immunoglobulin G

Hemolysis

Complement C3 Convertase, Alternative Pathway

Complement C5 Convertase, Classical Pathway

Molecular Sequence Data

Complement C3 Convertase, Classical Pathway

Antigens, CD46

Opsonin Proteins

Blood Proteins

Lupus Erythematosus, Systemic

Complement C5 Convertase, Alternative Pathway

Phagocytosis

Amino Acid Sequence

Complement Pathway, Mannose-Binding Lectin

Properdin

Complement C5a, des-Arginine

Mice, Inbred C57BL

Macrophage-1 Antigen

Protein Binding

Neutrophils

Base Sequence

Kidney Glomerulus

Serum

Glomerulonephritis, Membranoproliferative

Immunoglobulin M

Schistosoma

Genetic Complementation Test