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 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 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.
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).
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).
The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.
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.
Immunoglobulins produced in response to VIRAL ANTIGENS.
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.
Antibodies produced by a single clone of cells.
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.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
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.
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 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.
The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.
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).
Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.
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.
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.
Compounds that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host.
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.
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 proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.
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 measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.
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.
Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.
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.
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.
Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
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.
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.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A 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.
Sites on an antigen that interact with specific antibodies.
Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.
Antibodies reactive with HIV ANTIGENS.
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.
Immunoglobulins induced by antigens specific for tumors other than the normally occurring HISTOCOMPATIBILITY ANTIGENS.
Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.
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.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
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)
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.
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.
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 measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
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.
Immunoglobulins produced in a response to FUNGAL ANTIGENS.
The processes triggered by interactions of ANTIBODIES with their ANTIGENS.
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Established cell cultures that have the potential to propagate indefinitely.
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).
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
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.
Proteins prepared by recombinant DNA technology.
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.
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.
Antibodies, often monoclonal, in which the two antigen-binding sites are specific for separate ANTIGENIC DETERMINANTS. They are artificial antibodies produced by chemical crosslinking, fusion of HYBRIDOMA cells, or by molecular genetic techniques. They function as the main mediators of targeted cellular cytotoxicity and have been shown to be efficient in the targeting of drugs, toxins, radiolabeled haptens, and effector cells to diseased tissue, primarily tumors.
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.
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.
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 are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Antibodies that inhibit the reaction between ANTIGEN and other antibodies or sensitized T-LYMPHOCYTES (e.g., antibodies of the IMMUNOGLOBULIN G class that compete with IGE antibodies for antigen, thereby blocking an allergic response). Blocking antibodies that bind tumors and prevent destruction of tumor cells by CYTOTOXIC T-LYMPHOCYTES have also been called enhancing antibodies. (Rosen et al., Dictionary of Immunology, 1989)
A form of antibodies consisting only of the variable regions of the heavy and light chains (FV FRAGMENTS), connected by a small linker peptide. They are less immunogenic than complete immunoglobulin and thus have potential therapeutic use.
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).
Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
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.
Antibodies elicited in a different species from which the antigen originated. These antibodies are directed against a wide variety of interspecies-specific antigens, the best known of which are Forssman, Hanganutziu-Deicher (H-D), and Paul-Bunnell (P-B). Incidence of antibodies to these antigens--i.e., the phenomenon of heterophile antibody response--is useful in the serodiagnosis, pathogenesis, and prognosis of infection and latent infectious states as well as in cancer classification.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
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.
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 sum of the weight of all the atoms in a molecule.
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.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Antibodies that can catalyze a wide variety of chemical reactions. They are characterized by high substrate specificity and share many mechanistic features with enzymes.
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
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 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.
Antibodies from non-human species whose protein sequences have been modified to make them nearly identical with human antibodies. If the constant region and part of the variable region are replaced, they are called humanized. If only the constant region is modified they are called chimeric. INN names for humanized antibodies end in -zumab.
Substances that are recognized by the immune system and induce an immune reaction.
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.
Cells artificially created by fusion of activated lymphocytes with neoplastic cells. The resulting hybrid cells are cloned and produce pure MONOCLONAL ANTIBODIES or T-cell products, identical to those produced by the immunologically competent parent cell.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
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.
Elements of limited time intervals, contributing to particular results or situations.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.
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.
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
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.
Substances elaborated by bacteria that have antigenic activity.
The clear portion of BLOOD that is left after BLOOD COAGULATION to remove BLOOD CELLS and clotting proteins.
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.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
Methods used for studying the interactions of antibodies with specific regions of protein antigens. Important applications of epitope mapping are found within the area of immunochemistry.
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).
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.
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.
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.
Autoantibodies directed against phospholipids. These antibodies are characteristically found in patients with systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC;), ANTIPHOSPHOLIPID SYNDROME; related autoimmune diseases, some non-autoimmune diseases, and also in healthy individuals.
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
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.
Transfer of immunity from immunized to non-immune host by administration of serum antibodies, or transplantation of lymphocytes (ADOPTIVE TRANSFER).
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.)
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 parts of a macromolecule that directly participate in its specific combination with another molecule.
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).
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.
Glycoproteins found on the membrane or surface of cells.
The rate dynamics in chemical or physical systems.
Partial immunoglobulin molecules resulting from selective cleavage by proteolytic enzymes or generated through PROTEIN ENGINEERING techniques.
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.
Proteins found in any species of bacterium.
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.
A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.
Substances elaborated by viruses that have antigenic activity.
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
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.
Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
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.
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.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
A 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.
Transport proteins that carry specific substances in the blood or across cell membranes.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
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.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
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.
Techniques used to demonstrate or measure an immune response, and to identify or measure antigens using antibodies.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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.
Thickening of the walls of small ARTERIES or ARTERIOLES due to cell proliferation or HYALINE deposition.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Antibodies from an individual that react with ISOANTIGENS of another individual of the same species.
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).
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.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The phenomenon of antibody-mediated target cell destruction by non-sensitized effector cells. The identity of the target cell varies, but it must possess surface IMMUNOGLOBULIN G whose Fc portion is intact. The effector cell is a "killer" cell possessing Fc receptors. It may be a lymphocyte lacking conventional B- or T-cell markers, or a monocyte, macrophage, or polynuclear leukocyte, depending on the identity of the target cell. The reaction is complement-independent.
A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.
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.
An encapsulated lymphatic organ through which venous blood filters.
Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.
Techniques for removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody.
The classes of immunoglobulins found in any species of animal. In man there are nine classes that migrate in five different groups in electrophoresis; they each consist of two light and two heavy protein chains, and each group has distinguishing structural and functional properties.
Small antigenic determinants capable of eliciting an immune response only when coupled to a carrier. Haptens bind to antibodies but by themselves cannot elicit an antibody response.
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.
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.
Autoantibodies directed against cytoplasmic constituents of POLYMORPHONUCLEAR LEUKOCYTES and/or MONOCYTES. They are used as specific markers for GRANULOMATOSIS WITH POLYANGIITIS and other diseases, though their pathophysiological role is not clear. ANCA are routinely detected by indirect immunofluorescence with three different patterns: c-ANCA (cytoplasmic), p-ANCA (perinuclear), and atypical ANCA.
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).
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.
Unique genetically-controlled determinants present on ANTIBODIES whose specificity is limited to a single group of proteins (e.g., another antibody molecule or an individual myeloma protein). The idiotype appears to represent the antigenicity of the antigen-binding site of the antibody and to be genetically codetermined with it. The idiotypic determinants have been precisely located to the IMMUNOGLOBULIN VARIABLE REGION of both immunoglobin polypeptide chains.
Polysaccharides found in bacteria and in capsules thereof.
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.
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)
The 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).
EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.
C3a - the other fragment C3 is cleaved into along with C3b Liszewski, M. Kathryn; Atkinson, John P. (2015-06-10). "Complement ... The C1 complement complex binds to these antibodies resulting in its activation via cross proteolysis. This activated C1 ... In such cases treatment with the complement-inhibitory anti-C5 monoclonal antibody, eculizumab, is found to be highly effective ... C3b is the larger of two elements formed by the cleavage of complement component 3, and is considered an important part of the ...
C3a, C5a, IL-8 are all chemotactic factors of the activated complement system. Part of their role is to recruit ... It has been proposed that if fluorescently tagged antibodies were used to target different split products of the complement ... Usually the deposition of immune-complexes (antigen-antibody complex) that activates the complement system are involved. The ... Immune complexes can be visualized by staining with fluorescent antibodies directed against immunoglobulins or complement, ...
Cleavage of complement C3 by a free floating convertase, thrombin, plasmin or even a bacterial enzyme leads to formation of C3a ... Thus it can form covalent amide or ester linkages with the plasma membrane of the pathogen and any associated antibodies, where ... DAF protects host cells from damage by autologous complement. DAF acts on C2b and Bb and dissociates them rapidly from C4b and ... attached to the microbial surface or to the antibody molecules through the thioester domain at the site of complement ...
Isohemagglutinins also activate the complement cascade via C3a and C5a, which then promote inflammatory cytokine release from ... Antibodies against A and B blood groups (isohemagglutinins) present in the recipient's blood destroy the donor red blood cells ... The donor and recipient blood can be re-tested with a type, crossmatch, and antibody screen to determine the cause of the ... The reaction is triggered by pre-formed host antibodies destroying donor red blood cells. AHTR typically occurs when there is ...
Antibodies are produced against the RBCs, which leads to complement activation. Complement fragments, such as C3a, C4a and C5a ... Cases may also arise with complement alone or with IgA, IgM or a combination of these three antibody classes and complement. ... Cold-type AIHA usually reacts with antisera to complement and occasionally to the above antibodies. This is the case in both ... Warm-type AIHA shows a positive reaction with antisera to IgG antibodies with or without complement activation. ...
C3a works with C5a to activate mast cells, recruit antibody, complement and phagocytic cells and increase fluid in the tissue, ... C3a, C4a and C5a) that are produced as part of the activation of the complement system. Complement components C3, C4 and C5 are ... coded for by a single exon within the complement protein gene. The C3a, C4a and C5a components are referred to as ... This term is reserved only for fragments of the complement system. C3, C4A, C4B, C4B-1, C5, FBLN1, FBLN2 Allergy Anaphylatoxin ...
Activation of complement primarily results in cleavage of soluble complement proteins forming C5a and C3a, which activate ... If the animal/patient was previously sensitized (has circulating antibody), an Arthus reaction occurs. Typical of most ... An Arthus reaction is a local vasculitis associated with deposition of immune complexes and activation of complement. Immune ... Type III hypersensitivity reactions are immune complex-mediated, and involve the deposition of antigen/antibody complexes ...
C3a and C5a, proteins produced from the complement system, attract neutrophils to the vessels. Once activated, neutrophils then ... The immune system senses these altered proteins as foreign and produces antibodies in efforts to eliminate them from the body. ... A similar process occurs with infectious agents, such as bacteria, in which antibodies target microbial components. The ... immune complexes deposit in vessel walls leading to activation of the complement system. ...
... also known as complement cascade, is a part of the immune system that enhances (complements) the ability of antibodies and ... Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ... Polymorphisms of complement component 3, complement factor B, and complement factor I, as well as deletion of complement factor ... Three biochemical pathways activate the complement system: the classical complement pathway, the alternative complement pathway ...
... recognizes the Fc region of IgM or IgG antibodies bound to a pathogen. C1q mediates the classical pathway by activating the C1 ... C3a is one of the proteins formed by the cleavage of complement component 3; the other is C3b. C3a is a 77 residue ... C3a molecules induce responses through the GPCR C3a receptor. Like other anaphylatoxins, C3a is regulated by cleavage of its ... C3a has a regulatory process and a structure homologous to complement component C5a, with which it shares 36% of its sequence ...
The complement system is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells ... Complement Peptide C5a, C4a, and C3a Receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ... 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 ...
Arribas J, Arizti P, Castaño JG (1994). "Antibodies against the C2 COOH-terminal region discriminate the active and latent ... 1996). "Molecular cloning and characterization of the human anaphylatoxin C3a receptor". J. Biol. Chem. 271 (34): 20231-4. doi: ... Complement component 5 is involved in the complement system. It is cleaved into C5a and C5b: C5a plays an important role in ... Complement component 5 is the fifth component of complement, which plays an important role in inflammatory and cell killing ...
The cause of damage is as a result of the action of cleaved complement anaphylotoxins C3a and C5a, which, respectively, mediate ... Because of the nature of the antibody aggregation, tissues that are associated with blood filtration at considerable osmotic ... Type III hypersensitivity occurs when there is accumulation of immune complexes (antigen-antibody complexes) that have not been ... are far more capable of interacting with complement; these medium-sized complexes, formed in the slight excess of antigen, are ...
Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ... C5a has been identified as a key mediator of neutrophil dysfunction in sepsis, with antibody blockade of C5a improving outcomes ... Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ... C5a is a protein fragment released from cleavage of complement component C5 by protease C5-convertase into C5a and C5b ...
C3a / C3b / iC3b C5 - C5a C3-convertase C5-convertase Late stage Membrane attack complex (MAC) C6 C7 C8 C9 Complement pathway ... Antibodies Kinds of antibodies Monoclonal antibodies Polyclonal antibodies Autoantibody Microantibody Neutralizing antibody ... system Complement system Classical complement pathway Mannan-binding lectin pathway Alternate complement pathway Complement ... Complement receptor of the immunoglobulin family) Anaphylatoxin receptors C3a receptor C5a receptor (CD88) C5AR2 Fc receptor Fc ...
All three pathways converge at a step in which complement protein C3 is cleaved into proteins C3a and C3b, which results in a ... Biochemically, they also found that C4A reacted more steadily with an antibody's amino acid side chains and antigens that are ... Complement component 4A Complement component 4B HLA A1-B8-DR3-DQ2 haplotype Complement system Complement deficiency Sekar A, ... Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ...
Plasma derived complement C3b and antibodies that exude into the inflamed tissue during the vascular phase bind to and coat the ... A variety of molecules behave as chemoattractants, for example, C3a or C5, and cause the leukocytes to move along a chemotactic ... This exuded tissue fluid contains various antimicrobial mediators from the plasma such as complement, lysozyme, antibodies, ... These include the complement system activated by bacteria and the coagulation and fibrinolysis systems activated by necrosis, e ...
Complement peptide C5a, C4a, and C3a receptors". Pharmacological Reviews. 65 (1): 500-43. doi:10.1124/pr.111.005223. PMID ... Werfel T, Zwirner J, Oppermann M, Sieber A, Begemann G, Drommer W, Kapp A, Götze O (August 1996). "CD88 antibodies specifically ... The C5a receptor also known as complement component 5a receptor 1 (C5AR1) or CD88 (Cluster of Differentiation 88) is a G ... Complement component 5a for binding mechanism GRCh38: Ensembl release 89: ENSG00000197405 - Ensembl, May 2017 GRCm38: Ensembl ...
For targets to be recognized, they must be coated in opsonins-a process known as antibody opsonization. They can internalize ... Neutrophils have a variety of specific receptors, including ones for complement, cytokines like interleukins and IFN-γ, ... C3a, C5a, and Leukotriene B4, which these cells use to direct the path of their migration. ...
Anafilatoksin (C3a, C5a) • Angiotenzin (1, 2) • Apelin • Bombezin (BRS3, GRPR, NMBR) • Bradikinin (B1, B2) • Hemokin • ... Sengeløv H (1996). "Complement receptors in neutrophils.". Crit. Rev. Immunol. 15 (2): 107-31. PMID 8573284. ... 1996). "CD88 antibodies specifically bind to C5aR on dermal CD117+ and CD14+ cells and react with a desmosomal antigen in human ... 1996). "Molecular cloning and characterization of the human anaphylatoxin C3a receptor.". J. Biol. Chem. 271 (34): 20231-4. ...
... complement c3 MeSH D12.776.124.486.274.250.250 - complement c3a MeSH D12.776.124.486.274.250.260 - complement c3b MeSH D12.776. ... antibodies MeSH D12.776.124.486.485.114.071 - antibodies, anti-idiotypic MeSH D12.776.124.486.485.114.089 - antibodies, ... complement c3a MeSH D12.776.124.486.274.024.260 - complement c4a MeSH D12.776.124.486.274.024.270 - complement c5a MeSH D12.776 ... 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 components C5a and C3a which are chemotactic factors formed during the activation of the host's blood complement ... promotes B cell lymphocytes to differentiate into antibody secreting cells; inhibits innate lymphoid cells from releasing pro- ... "The specialized proresolving mediator 17-HDHA enhances the antibody-mediated immune response against influenza virus: a new ...
His work also confirmed that an anaphylatoxin molecule of complement activation "C3a" enhances intestinal stem cell expansion, ... but CD4 and CD8 negative T cells are expanded in patients with SLE and provide help to B cells to produce anti-DNA antibodies. ... Tsokos established the role of complement activation in tissue injury and regeneration. His findings demonstrated for the first ... deposition of C4d and C5b-9 in human subjects of trauma and patients with severe trauma maintain high deposition of complement ...
"Europium-Labeled Synthetic C3a Protein as a Novel Fluorescent Probe for Human Complement C3a Receptor" (PDF). Bioconjugate ... Specifically labelled dystrophin with Tb labelled monoclonal antibodies labeled were used. Traditional virus diagnostic ... β2-adrenergic receptor and C3a receptor. The emitted photons from excited lanthanides are detected by highly sensitive devices ...
... can cleave multiple C3 proteins into C3a and C3b. The complex is believed to be unstable until it binds properdin, a serum ... Antibodies. *Antibody *Monoclonal antibodies. *Polyclonal antibodies. *Autoantibody. *Microantibody. *Polyclonal B cell ... 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 ...
It is hoped that by developing antibodies to the parasite ligand for Basigin, Rh5, a better vaccine for malaria might be found. ... Complement receptors. *CR1. *CR2. *CR3. *CR4. *CD11b/CD11c/CD18. *Anaphylatoxin *C3a. *C5a ... Berditchevski F, Chang S, Bodorova J, Hemler M (1997). "Generation of monoclonal antibodies to integrin-associated proteins. ... Berditchevski F, Chang S, Bodorova J, Hemler ME (1997). "Generation of monoclonal antibodies to integrin-associated proteins. ...
Decay accelerating factor (DAF/CD55), a regulatory protein of the complement cascade, interacts with the first and second EGF- ... antibody treatment but not gene targeting curtails granulocyte migration". Journal of Immunology. 181 (9): 6574-83. doi:10.4049 ... CD97 antibodies and lack of CD97 or CD55 in mice reduced synovial inflammation and joint damage in collagen- and K/BxN serum ... "CD97 antibody depletes granulocytes in mice under conditions of acute inflammation via a Fc receptor-dependent mechanism". ...
For targets to be recognized, they must be coated in opsonins-a process known as antibody opsonization.[15] They can ... Neutrophils have a variety of specific receptors, including ones for complement, cytokines like interleukins and IFN-γ, ... C3a, C5a, and Leukotriene B4, which these cells use to direct the path of their migration. ...
Mouse Monoclonal Anti-Complement C3a Antibody (K13/16-5.7) [Alexa Fluor® 405]. Validated: WB, ELISA, ICC/IF, IHC, IHC-P. Tested ... Home » Complement C3a » Complement C3a Antibodies » Complement C3a Antibody (K13/16-5.7) [Alexa Fluor® 405] ... PTMs for Complement C3a Antibody (NBP1-05122AF405). Learn more about PTMs related to Complement C3a Antibody (NBP1-05122AF405). ... Reviews for Complement C3a Antibody (NBP1-05122AF405) (0) There are no reviews for Complement C3a Antibody (NBP1-05122AF405). ...
... expressing myeloperoxidase and complement C3a and C5a as markers of renal involvement in antineutrophil cytoplasmic antibody - ... expressing myeloperoxidase and complement C3a and C5a as markers of renal involvement in antineutrophil cytoplasmic antibody - ... expressing myeloperoxidase and complement C3a and C5a as markers of renal involvement in antineutrophil cytoplasmic antibody - ... expressing myeloperoxidase and complement C3a and C5a as markers of renal involvement in antineutrophil cytoplasmic antibody - ...
C3a des-Arg Antibody (clone 2991) for WB/Western LS-C140007 ... C3a des-Arg Antibodies. Anti-Complement C3a / C3a des-Arg ... About Complement C3a / C3a des-Arg. Description:. C3a is one of the proteins formed by the cleavage of complement component 3; ... Antibody:. Mouse Monoclonal [clone 2991] (IgG1) to Human Complement C3a / C3a des-Arg. ... Antibody:. Mouse Monoclonal [clone 2991] (IgG1) to Human Complement C3a / C3a des-Arg. ...
Evaluation of C3a receptor expression on human leukocytes by the use of novel monoclonal antibodies. Immunology 97: 166. ... Complement peptides C3a- and C5a-induced mediator release from dissociated human skin mast cells. J. Invest. Dermatol. 102: 803 ... Expression of the Complement Anaphylatoxin C3a and C5a Receptors on Bronchial Epithelial and Smooth Muscle Cells in Models of ... Expression of the Complement Anaphylatoxin C3a and C5a Receptors on Bronchial Epithelial and Smooth Muscle Cells in Models of ...
C5a antibodies (2 μg) compared with isotype control antibodies (E) or with C3a receptor antagonist or C5a receptor antagonist ( ... complement components 3/5;. C3a/5a,. bioactive fragments of C3/5;. C3aR/5aR,. Cea/5a receptors;. RPE,. retinal pigmented ... Drusen complement components C3a and C5a promote choroidal neovascularization. Miho Nozaki, Brian J. Raisler, Eiji Sakurai, J. ... Drusen complement components C3a and C5a promote choroidal neovascularization. Miho Nozaki, Brian J. Raisler, Eiji Sakurai, J. ...
Novus offers a wide range of antibodies for immunohistochemistry on paraffin sections. View our catalog of IHC-P products plus ... Primary Antibodies (2). clear. Protein/Target. *. Complement C3a (1). *. Peptide YY (1) ... IHC (Paraffin section) Antibodies - Support (IHC-P). Immunohistochemistry (IHC) is a common in vitro staining technique that ... Specific antibodies are applied to the fixed tissue and typically visualized using either immunofluorescent (IF) or chromogenic ...
13 antibodies to C3a Receptor and validated for use in 4 applications (Immunohistochemistry, Flow Cytometry, Western Blot, ... C3a anaphylatoxin chemotactic receptor; C3a receptor; C3AR; complement component 3 receptor 1 ... C3a Receptor Antibodies C3AR1 is a receptor for the chemotactic and inflammatory peptide anaphylatoxin C3a. The receptor ... Custom Antibody Service. Searching for an antibody we dont offer? We make custom antibodies for specific targets, species and ...
... complement component 3) for IA, WB. Anti-C3/C3a mAb (GTX11874) is tested in Human samples. 100% Ab-Assurance. ... antibody ASP antibody C3 antibody C3a anaphylatoxin antibody C3a antibody C3b antibody Complement C3 antibody Complement C3 ... antibody Complement component 3 antibody Complement component C3 antibody Complement factor 3 antibody CPAMD 1 antibody CPAMD1 ... This antibody reacts with the C-terminus of C3a. It reacts with intact C3 as with C3a. ...
Complement factor, especially C3, C5, C3a, or C5a. TF or thrombin. Complement regulatory protein, especially CD46, CD55, CD59, ... CEACAM5 antibodies, EGP-1 (e.g., RS-7)+ILGF antibodies, CEACAM5+EGFR antibodies. Such antibodies need not only be used in ... anti-Flk-1 antibodies, anti-Flt-1 antibodies and peptides, anti-Kras antibodies, anti-cMET antibodies, anti-MIF (macrophage ... J. Cancer 46: 310 (1990). In another embodiment, an antibody may be a human monoclonal antibody. Such antibodies are obtained ...
The "C" in C3a and C4a stands for complement. Complement proteins work with antibodies to destroy pathogens. They activate ... Role of C3a and C4a Complement Proteins in Chronic Lyme Disease​ August 12, 2014 in Science/Research by Ginger Savely, DNP ... The C3a complement protein level was normal in the AIDS patients, the healthy patients and the chronic Lyme patients. So, ... Patients often ask if there are other medical conditions that may lower or raise the C3a and/or C4a. Both of these complement ...
complement component C3a binding. IDA. 17070910. GO:0001851. complement component C3b binding. IDA. 17070910. ... Antibody Products. * LifeSpan BioSciences PHB / Prohibitin Monoclonal Antibody and PHB / Prohibitin Antibody ... Creative Biolabs Recombinant Mouse anti-Human PHB Monoclonal antibody (EML637) and Mouse Anti-PHB Recombinant Antibody (5H7) ... View all R&D Systems PHB (Prohibitin) Primary Antibodies*Human Prohibitin Antibody (AF3470) ...
C3a des Arg Monoclonal Antibody, Unconjugated, Clone 2991 from Abcam,Mouse monoclonal [2991] to C3a / C3a des Arg ( SwissProtID ... Mouse Anti-Human Complement factor B Monoclonal Antibody, Unconjugated, Clone 9B6 from AntibodyShop A/S. 11. Mouse Anti-Human ... Mouse Anti-C3a / C3a des Arg Monoclonal Antibody, Unconjugated, Clone 2991 from Abcam. ... Mouse monoclonal [2991] to C3a / C3a des Arg (Abpromise for all tested applications).. SwissProtID: P01024. ...
Pexelizumab, an anti-C5 complement antibody, as adjunctive therapy to primary percutaneous coronary intervention in acute ... Regulation by complement C3a and C5a anaphylatoxins of cytokine production in human umbilical vein endothelial cells. FASEB J. ... Complement c3a and c5a induce different signal transduction cascades in endothelial cells. J. Immunol. 169: 2102-2110. ... C3a powerfully increased P-selectin expression and reduced TM on the HMEC-1 surface, indicating a major role for C3a as a ...
Complement Proteins offered by Sigma-alderich online.The complement system is a complex cascade involving proteolytic cleavage ... Complements C3a and C4a promote phagocyte chemotaxis. Complement C3b may be an opsonin for antigen-antibody complexes which ... The Whole Complement Classical Pathway Assay. Antibody Sensitization of Sheep Red Blood Cells. Plasma & Blood Protein Resource ... Complement C5a, like C3a is an anaphylatoxin, and is a chemotactic attractant for induction of neutrophilic release of ...
The complement system is an important part of the humoral response in innate immunity, consisting of three different pathways. ... C3a is a protein of 74 amino acids. C3a itself is very short-lived and in serum is cleaved rapidly into the more stable C3a- ... Primary Antibodies. Catalog No.. Host. Iso.. Clone. Pres.. React.. Applications. TA308855. Complement C3 antibody. Not ... Rabbit Polyclonal antibody to Complement C3 (complement component 3). Rabbit. IgG. Aff - Purified. Hu, Ms. ICC/IF, P, WB. 0.1 ...
Antibody- and complement-mediated neurodegeneration. Antibodies can induce neurodegeneration through two mechanisms, antibody- ... Complement anaphylatoxin C3a is selectively protective against NMDA-induced neuronal cell death. Neuroreport. 2001;12(2):289- ... v) B cells produce antibodies that bind to myelin sheaths and may promote complement-mediated damage (C′). (vi) IFN-γ ... CDC is a function of the complement system that kills without the involvement of antibodies or cells. Three pathways of ...
... antibodies also contribute to allograft injury. Insertion of the MAC into the EC results in EC activation. C3a and C5a mediate ... The use of antibody to complement protein C5 for salvage treatment of severe antibody-mediated rejection. Am J Transplant. 2009 ... Complement and antibody-mediated transplant injury. Donor reactive anti-HLA antibodies are generally accepted as pathogenic ... Complement-binding anti-HLA antibodies and kidney-allograft survival. N Engl J Med. 2013;369(13):1215-1226.. View this article ...
... which is one of the mechanisms for eliminating tumor cells by therapeutic antibodies. C3a, which contributes to the ... Unbroken lines connect complement proteins to their functions in tumor growth. Broken lines connect complement proteins to ... Unbroken lines connect complement proteins to functions which inhibit tumor growth, whereas broken lines connect complement ... Complement effectors generated during activation contribute to various mechanisms that limit tumor growth. The complement ...
Type II Hypersensitivity is antibody and complement dependent mechanism of killing.. Uses IgG, complement, targeting cell ... 3. Activation of complement releases inflammatory mediators, C5a, C3a and C4a. C5a also induces mast-cell degranulation. ... Fc receptors on mast cells can be detected by the IgE antibody. Mast cells have a lot of Fc receptors that recognise IgE ... 2. Fc receptors on NK cells recognise bound antibody.. 3. Crosslinking of Fc receptors signals the NK cell to kill the target ...
C3a is an anaphylatoxin that triggers a response by stimulating inflammatory cells to release histamine, enzymes, cytokines and ... using monoclonal anti-C3a antibodies to capture C3a on the 96-well ELISA plate, and a second enzyme-linked anti-C3a antibody ... C3a. C3a is a one of the peptides (complement split products) formed by the cleavage of complement component 3. C3a is an ... is a sensitive and specific competitive inhibition in vitro assay that utilizes 125-iodine labeled C3a and anti-C3a antibodies ...
Here you may find a number of matched pair antibodies as well as related products for adrenal and pancreatic research topics. ... anti-Complement C3a (desArg) antibody (ABIN2688487). Mouse. Monoclonal. M81625. Human. anti-Complement C3a (desArg) antibody ( ... C3a and C3a (desArg). anti-Complement D antibody (ABIN2688486). Mouse. Monoclonal. M81610. Human. anti-Complement D antibody ( ... Excellent antibody pair to detect Complement D in sandwich immunoassays. anti-Complement H antibody (ABIN2688489). Mouse. ...
Role of C3a receptors, C5a receptors, and complement protein C6 deficiency in collagen antibody-induced arthritis in mice. ...
ICs trigger complement activation and generate inflammatory mediators such as C3a and C5a anaphylotoxins. Complement opsonized ... Antibodies present in the ICs by bind to activating or inhibitory Fc receptors (FcRs), which trigger effector function and ... Complement opsonized ICs interact and regulate B-cell responses. ICs activate macrophages and produce proinflammatory cytokines ... Elevated levels of ICs opsonized by complement activation by-products are present during viral infections such as H1N1, HIV, ...
The byproducts of complement activation (e.g., C3a and C5a) act as chemokines resulting in inflammatory cell infiltration and ... They tested antibodies for their capacity to fix C1q complement and compared them to regular IgG antibody detection and found a ... Antibodies can also mediate injury via complement independent mechanisms such as antibody-cell-dependent cytotoxicity (ADCC). ... antibodies or a mix of weak and strong complement fixing HLA antibodies respectively, but had no difference in AMR or graft ...
This antibody reacts with Human samples. Supplied as 1 mL unpurified antibody. ... Nordic Anti-Complement Polyclonal, Catalog # RAHU-C. Tested in Immunoelectrophoresis (IE) applications. ... Complement C4 beta chain; Complement C4 gamma chain; Complement C4-A; Complement C4-A alpha chain; complement component C3a; ... Complement C3; Complement C3 alpha chain; Complement C3 beta chain; Complement C3b alpha chain; Complement C3c alpha chain ...
C3a Receptor Rabbit anti-Human, Polyclonal, Invitrogen 100 µL; Unconjugated ... This polyclonal antibody was raised in Rabbit against C3AR / C3a Receptor. This antibody is unconjugated. This antibody is ... Fusion protein corresponding to a region derived from internal residues of human complement component 3a receptor 1. ... The antibody detects endogenous levels of total C3a Receptor protein.. ...
C3a - the other fragment C3 is cleaved into along with C3b Liszewski, M. Kathryn; Atkinson, John P. (2015-06-10). "Complement ... The C1 complement complex binds to these antibodies resulting in its activation via cross proteolysis. This activated C1 ... In such cases treatment with the complement-inhibitory anti-C5 monoclonal antibody, eculizumab, is found to be highly effective ... C3b is the larger of two elements formed by the cleavage of complement component 3, and is considered an important part of the ...
COMPLEMENT LEVELS IN SEPTIC PRIMATES TREATED WITH ANTI-C5A ANTIBODIES JOURNAL OF SURGICAL RESEARCH HANGEN, D. H., Stevens, J. H ... The antibody to human C5a was thus shown to be cross-reactive with primate C5a and was specific since C3a and C4a levels were ... Complement levels were measured in primates made septic by Escherichia coli infusions. Anti-human C5a antibodies were ... such as antineutrophil cytoplasmic antibodies, antinuclear antibodies, and antiglomerular basement membrane antibodies, may ...
COMPLEMENT LEVELS IN SEPTIC PRIMATES TREATED WITH ANTI-C5A ANTIBODIES JOURNAL OF SURGICAL RESEARCH HANGEN, D. H., Stevens, J. H ... The antibody to human C5a was thus shown to be cross-reactive with primate C5a and was specific since C3a and C4a levels were ... Complement levels were measured in primates made septic by Escherichia coli infusions. Anti-human C5a antibodies were ... such as antineutrophil cytoplasmic antibodies, antinuclear antibodies, and antiglomerular basement membrane antibodies, may ...
Anti-Mast Cell Tryptase antibody [AA1] (ab2378) has been cited in 39 publications. References for Human, Mouse, Rat, AGMk in ... Lohman RJ et al. Exploiting a novel conformational switch to control innate immunity mediated by complement protein C3a. Nat ... Primary antibodies. Secondary antibodies. ELISA and Matched Antibody Pair Kits. Cell and tissue imaging tools. Cellular and ... Anti-Mast Cell Tryptase antibody [AA1] (ab2378). Mouse monoclonal Mast Cell Tryptase antibody [AA1]. Validated in WB, ELISA, ...
  • Both in patients with AMD and in a recently described mouse model of AMD, early subretinal pigmented epithelium deposition of complement components C3 and C5 occurs, suggesting a contributing role for these inflammatory proteins in the development of AMD. (pnas.org)
  • Complement proteins work with antibodies to destroy pathogens. (publichealthalert.org)
  • There are about 30 of these complement proteins that circulate in the bloodstream making up complement "cascades", so called because activation of one protein initiates activation of the next, etc. (publichealthalert.org)
  • Search, Find and Buy Antibodies, ELISA Kits and Proteins. (antibodies-online.com)
  • Inter-species cross-reactivity is a normal feature of antibodies to plasma proteins, since homologous proteins of different species frequently share antigenic determinants. (thermofisher.com)
  • C3 and C4, mainly produced by the liver, are the major plasma proteins of the immune system complement pathways. (thermofisher.com)
  • Previous studies have suggested that complement proteins can contribute to the immune surveillance of malignant tumors. (nih.gov)
  • However, a very recent study has indicated that complement proteins can also promote tumor growth. (nih.gov)
  • Unbroken lines connect complement proteins to functions which inhibit tumor growth, whereas broken lines connect complement proteins to functions that can currently only be hypothetically linked to inhibition of tumor growth. (nih.gov)
  • Some complement proteins can accelerate tumor growth. (nih.gov)
  • In addition, tumor cells are protected from co attack by membrane complement regulatory proteins (mCRPs) and soluble complement inhibitors, secreted in the tumor microenvironment, such as factor H (fH) and factor I (fI). (nih.gov)
  • Unbroken lines connect complement proteins to their functions in tumor growth. (nih.gov)
  • Furthermore, if C3b does bind to a host-cell surface, regulators of complement activity (RCAs), a group of genetically-, structurally-, and functionally-related proteins, inactivate the complement component. (wikipedia.org)
  • Cedarlane offers numerous formats of reagent complement as well as an extensive range of recombinant proteins and antibodies. (cedarlanelabs.com)
  • The complement system consists of a number of small proteins that are synthesized by the liver, and circulate in the blood as inactive precursors. (wikipedia.org)
  • Over 30 proteins and protein fragments make up the complement system, including serum proteins, and cell membrane receptors. (wikipedia.org)
  • Lectin pathway) Most of the proteins and glycoproteins that constitute the complement system are synthesized by hepatocytes. (wikipedia.org)
  • Growing evidence suggests that complement proteins not only serve as mediators of innate immune defense against foreign pathogens but can also modulate diverse developmental processes, such as cell survival, growth, and differentiation in various tissues ( 1 , 2 ). (rupress.org)
  • 1 Recent work demonstrates that defects in regulation of the alternative pathway of complement are major risk factors for developing atypical HUS (aHUS), and mutations in numerous complement proteins have been identified in these patients. (asnjournals.org)
  • 2 - 5 Even in patients with mutations in complement regulatory proteins, however, the disease is episodic and is frequently triggered by a clinical illness or stressor. (asnjournals.org)
  • 8 , 9 Although complement proteins can be detected on the surface of microparticles released from apoptotic and injured cells, 10 less is known regarding whether microparticles from specific cell types themselves can cause complement activation. (asnjournals.org)
  • Because endothelial cells are in contact with complement proteins in the plasma, the release of complement-activating microparticles by endothelial cells could have a profound effect on intravascular complement activation. (asnjournals.org)
  • and immunohistochemistry utilized to detect expression of complement regulatory proteins, expression, CD46/Crry and CD55, in lung tissue. (iupui.edu)
  • The complement system consist of a complex family of proteins and receptors which are found in the circulation, in tissues and other body-fluids. (linscottsdirectory.com)
  • Complement activation proceeds in a sequential fashion through the proteolytic cleavage of a series of proteins leading to the generation of activated products that mediate various biological activities through their interaction with specific cellular receptors and other serum proteins The three pathways, designated classical, lectin and alternative pathway, converge at a central component into a final common pathway. (linscottsdirectory.com)
  • The complement pathway includes more than 30 component proteins, regulators and receptors, which work together to fight infection and to clear toxic material. (biomedcentral.com)
  • Further, Double-stranded RNA-dependent protein kinase (PKR), 2', 5'-oligoadenylate synthetase (2'- 5' OAS), and adenosine deaminase acting on RNA (ADAR), known as effector proteins, complement the function of PRRs. (intechopen.com)
  • Viruses encode homologs of complement regulatory proteins that are secreted and block complement activation and neutralization of virus particles. (intechopen.com)
  • Lysozyme, some milk proteins, such as alpha lactalbumin, and low molecular-weight ligands, such as citrates and phosphates, are known to have high affinity binding sites for calcium (4), and may therefore act as inhibitors of complement indirectly, by chelating the divalent ions required for complement activation. (mcmaster.ca)
  • The complement system consists of a number of small proteins found in the blood, normally circulating as inactive zymogens . (wikidoc.org)
  • Human complement 5a (C5a) is an enzymatically generated glycoprotein that belongs to a family of structurally and functionally related proteins known as anaphylatoxins. (rndsystems.com)
  • Fragments resulting from proteolytic cleavage of complement proteins are designated with lower-case-letter suffixes, e.g. (thefreedictionary.com)
  • C3a and C5a, proteins produced from the complement system, attract neutrophils to the vessels. (wikipedia.org)
  • The immune system senses these altered proteins as foreign and produces antibodies in efforts to eliminate them from the body. (wikipedia.org)
  • Most of the proteins and glycoproteins that constitute the complement system are synthesized by hepatocytes . (wikipedia.org)
  • Purified antigens might have contaminants, or might not contain the full complement of native proteins. (bmj.com)
  • Deposition of complement proteins on the bacteria was monitored by Western blotting. (asm.org)
  • The complement system is a series of proteins that act in a defined sequence (Fig. 1 ) to promote immune clearance by opsonizing or killing microorganisms and augmenting the inflammatory response. (asm.org)
  • The nonactivated complement proteins are indicated above and to the right of the wide arrows, and the arrows pointing from them show the product that is released during activation. (asm.org)
  • To elucidate the molecular basis for complement resistance by BrkA, in this study we have attempted to determine which step in the complement cascade is affected by BrkA by monitoring the deposition of complement proteins on the surface of strains either expressing or not expressing BrkA. (asm.org)
  • However, few drugs directly target complement proteins, and none targets the C3a receptor, in part because of the complexity of the complement system. (ucr.edu)
  • Human complement receptor 1 (CR1, CD35) is a single chain transmembrane glycoprotein of molecular weight 160 kd to 250 kd (depending on allotype) and is a member of the regulators of complement activators (RCA) family of proteins that prevent excessive complement activation by inhibiting key enzymes, C3 and C5 convertases of the 3 complement pathways, namely the classical, alternative, and lectin. (bloodjournal.org)
  • conversely, higher levels of complement proteins were detected in plasma from patients than those in healthy subjects. (biomedcentral.com)
  • Our iTRAQ proteome study identified decreased and increased levels of 31 and 2 complement and complement-related proteins, respectively, in lung cancer tissues, of which the reduced levels of 10 components were further confirmed using quantitative RT-PCR and western blotting. (biomedcentral.com)
  • Complement activation in myasthenia gravis (MG) may damage muscle endplate and complement regulatory proteins such as decay-accelerating factor (DAF) or CD55 may be protective. (pubmedcentralcanada.ca)
  • Innate complement control mechanisms include complement regulatory proteins expressed on all serum-exposed cells, each of which intervenes at key points in the cascade, thereby protecting cell membranes against autologous complement damage. (pubmedcentralcanada.ca)
  • 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)
  • 5 More than 30 proteins act synergically to provide host defense against cells, microorganisms, and tissues identified as abnormal by a specific antibody. (scielo.br)
  • Western blot: 1) 0.1 µg of purified Human C3 protein, and 2) 10 µg of normal Human serum proteins was stained with ARG10707 anti-Complement C3 (alpha chain, anaphylatoxin) antibody [6B1] at 1:5000 dilution. (arigobio.com)
  • Type III hypersensitivity reactions occur when IgG and IgM antibodies bind to soluble proteins rather than cell surface molecules as in type II hypersensitivity reactions forming immune complexes that can deposit in tissues, leading to complement activation, inflammation, neutrophil influx and mast cell degranulation. (musicmarkup.info)
  • C3a is a 77 residue peptide that binds to the C3a receptor (C3aR) a class A G protein-coupled receptor. (lsbio.com)
  • C3AR1 is a receptor for the chemotactic and inflammatory peptide anaphylatoxin C3a. (thermofisher.com)
  • Complement opsonized ICs deposit at vascular sites, trigger proinflammatory response by releasing cytokines via Fc-receptor and/or complement receptor engagement. (frontiersin.org)
  • The C3b cleavage product iC3b binds to tumor cells and through the interaction with complement receptor 3 (CD11b/CD18) on mononuclear phagocytes and natural killer (NK) cells enhances antibody-dependent cellular cytotoxicity (ADCC). (nih.gov)
  • In both cases C3b interacts with the C3b receptor, complement receptor 1 on phagocytic cells, such as macrophages and neutrophils, allowing for engulfment of the pathogen. (wikipedia.org)
  • Furthermore, host cells express p33 (globular C1q receptor) on the surface, which binds C1q, and prevents it from initiating complement activation. (wikipedia.org)
  • The antibody detects endogenous levels of total C3a Receptor protein. (fishersci.com)
  • This polyclonal antibody was raised in Rabbit against C3AR / C3a Receptor. (fishersci.com)
  • This antibody is useful for testing in the following assays: IHC-P. The specificity of this antibody has been described as follows: Human C3a Receptor. (fishersci.com)
  • Scientists at the Georg-August-University produced different monoclonal antibodies directed against the C3a-Receptor which binds to one of the fragments of activated complement factor C3. (innovations-report.com)
  • The plasma levels of clusterin, soluble complement receptor 2 (sCR2) and CRP were determined using commercially available enzyme-linked immunosorbent assay (ELISA)-compatible antibody pairs (clusterin and CRP from R&D systems (Abingdon, UK) (cat# DY5874 and DY1707) and sCR2 from Sino Biological (Beijing, China) (cat# SEKA10811)) and protocols were followed as described by the manufacturers. (biomedcentral.com)
  • The plasma levels of soluble complement receptor 1 (sCR1), C1-inhibitor (C1inh), C5, C9 and C1q were determined using optimised antibody pairs in sandwich ELISAs developed in-house. (biomedcentral.com)
  • The team, which included Dimitrios Morikis , professor of bioengineering at the University of California, Riverside's Bourns College of Engineering , started by creating a dynamic three-dimensional map of the structure of a protein called the C3a receptor, which sits on the surface of human cells and plays a critical role in regulating a branch of the immune system called the complement system. (ucr.edu)
  • This ability to design peptides of a desired shape, allowed them to target the C3a receptor in precise ways. (ucr.edu)
  • Morikis and his graduate students Chris Kieslich and Li Zhang provided the collaborators 3D structures, derived from molecular dynamics simulations, of the naturally occurring peptide that normally regulates the C3a receptor in human cells. (ucr.edu)
  • In the present study, we have assessed the ability of a human recombinant soluble form of complement receptor 1 (sCR1) to inhibit complement-mediated RBC destruction in vitro and in vivo. (bloodjournal.org)
  • Complement C5a neuroprotects through regulation of GluR2 receptor subunit. (biomedcentral.com)
  • The protein encoded by this gene is an orphan G protein-coupled receptor for C3a. (genecards.org)
  • Binding of C3a by the encoded receptor activates chemotaxis, granule enzyme release, superoxide anion production, and bacterial opsonization. (genecards.org)
  • C3AR1 (Complement C3a Receptor 1) is a Protein Coding gene. (genecards.org)
  • Gene Ontology (GO) annotations related to this gene include G protein-coupled receptor activity and complement component C3a receptor activity . (genecards.org)
  • Finally, fragmentation of C3b leads to formation of C3bi, which is bound by complement receptor (CR)3, a phagocytic receptor expressed on the surface of neutrophils (reviewed in [27] ). (prolekare.cz)
  • 1 , 2 Although IgG1-acetylcholine receptor (AChR) complexes can modulate AChRs by cross-linking and accelerating degradation as well as functionally blocking AChRs, it is the activation of complement through successive stimulation of C3 and C5 convertase that ultimately results in a membrane attack complex with lysis of the post-synaptic muscle endplate. (pubmedcentralcanada.ca)
  • 1 , 3 , 5 Animal models became resistant to the induction of EAMG when circulating complement was either depleted by cobra venom toxin or functionally inhibited by the administration of a monoclonal C5 antibody or soluble C1 receptor. (pubmedcentralcanada.ca)
  • The methods involve administration of a complement inhibitor to inhibit C5a receptor signaling in the tumorigenic or pre-tumorigenic tissue. (justia.com)
  • The complement system is an important part of the humoral response in innate immunity, consisting of three different pathways. (acris-antibodies.com)
  • The third complement component, C3, is central to the classical, alternative and lectin pathways of complement activation. (acris-antibodies.com)
  • Its activation is required for both classical and alternative complement activation pathways. (genetex.com)
  • All three pathways merge through at common intersection, complement C3. (sigmaaldrich.com)
  • In this topic we will highlight the new pathways by which ICs and complement synergism with other lymphocyte signals drive autoimmunity and also discuss their role in transplant rejection. (frontiersin.org)
  • The complement system can be activated through several distinctive pathways. (nih.gov)
  • Three biochemical pathways activate the complement system: the classical complement pathway, the alternative complement pathway, and the lectin pathway. (wikipedia.org)
  • Activation of the complement system via three pathways. (els.net)
  • These new antibody mediated arthritis models have proven to be very useful for studies involved in understanding the molecular pathways of the induction of arthritis in joints. (biomedcentral.com)
  • The classical complement pathway typically requires antibodies for activation (specific immune response), while the alternative and mannose-binding lectin pathways can be activated by C3 hydrolysis or antigens without the presence of antibodies (non-specific immune response). (wikidoc.org)
  • In all three pathways, a C3-convertase cleaves and activates component C3 , creating C3a and C3b and causing a cascade of further cleavage and activation events. (wikidoc.org)
  • The classical and alternative complement pathways. (wikidoc.org)
  • The complement system is activated through three enzyme cascades, the classical, lectin, and alternative pathways, which converge at the step involving cleavage of C3 to C3a and C3b. (arvojournals.org)
  • Both the classical and alternative pathways of complement activation are represented, although details are given only for the classical pathway. (asm.org)
  • An important gene associated with C6 Deficiency is C6 (Complement C6), and among its related pathways/superpathways are Innate Immune System and IL-17 Family Signaling Pathways . (malacards.org)
  • Among its related pathways are Complement and coagulation cascades and A-beta Pathways: Uptake and Degradation . (genecards.org)
  • Its processing by C3 convertase is the central reaction in both classical and alternative complement pathways. (arigobio.com)
  • The complement component system is important for the identification and clearance of foreign pathogens that involves both classical, alternative and mannose-binding lectin pathways. (justia.com)
  • Complement component 3 (C3) is central to the activation of all pathways, is critical to the cleavage and subsequent activation of the potent chemoattractant, complement component C5a (C5a), and is responsible for mediating the inflammatory response during infection (Carroll, 2008 , Vaccine 26S: 128-133). (justia.com)
  • Mouse monoclonal [2991] to C3a / C3a des Arg ( Abpromise for all tested applications). (bio-medicine.org)
  • Mouse monoclonal Mast Cell Tryptase antibody [AA1]. (abcam.com)
  • Connexin 32 antibody LS-C14536 is an unconjugated mouse monoclonal antibody to Connexin 32 (GJB1 / CX32) from human, mouse and rat. (lsbio.com)
  • C3 is the most abundant protein of the complement system with serum protein levels of about 1.3 mg/ml. (acris-antibodies.com)
  • The complement system is a complex cascade involving proteolytic cleavage of serum glycoproteins often activated by cell receptors. (sigmaaldrich.com)
  • Measurements of serum complement components C3 and C4 are useful in the diagnosis and monitoring of immune complex disease. (thermofisher.com)
  • 76 : 29738 Improved capillary electrophoresis method for the analysis of carbohydrate-deficient transferrin in human serum, avoiding interference by complement C3. (genetex.com)
  • Those receptors, which we now call "antibodies", were called by Ehrlich "amboceptors" to emphasise their bifunctional binding capacity: They recognise and bind to a specific antigen, but they also recognise and bind to the heat-labile antimicrobial component of fresh serum. (wikipedia.org)
  • Prepared from serum that has been shown by certified tests to be negative for HBsAg and for antibodies to HIV and HCV. (emdmillipore.com)
  • We found that sCD46 expression was significantly increased in the serum and blister fluids of BP patients and correlated with the levels of anti-BP180 NC16A antibody and C3a. (sigmaaldrich.com)
  • Methods: Serum anti-col(V) antibodies were measured in asthma patients, and immunohistochemistry utilized to detect interstitial col(V) in fatal asthma. (iupui.edu)
  • Disease mechanisms and gene regions studied using the two antibody-induced arthritis mouse models (collagen antibody-induced arthritis and serum transfer-induced arthritis) are compared and discussed for their relevance in RA pathogenesis. (biomedcentral.com)
  • In a model of polymicrobial infection, S. aureus in elevated glucose conditions depleted C3 from serum resulting in decreased complement-mediated killing of E. coli . (biomedcentral.com)
  • We advise to include in your study your own reference sample for 100% complement activity and negative control (eg non-preserved activated serum) to determine the level of activation of your samples. (linscottsdirectory.com)
  • a term originally used to refer to the heat-labile factor in serum that causes immune cytolysis (lysis of antibody-coated cells). (thefreedictionary.com)
  • Ehrlich's term for the thermolabile substance, normally present in serum, that is destructive to certain bacteria and other cells sensitized by a specific complement-fixing antibody. (thefreedictionary.com)
  • In vitro assays using human serum as a source of complement were used, and the C3 split product iC3b was measured by enzyme immunoassay. (arvojournals.org)
  • Although often overlooked as a defense of the respiratory tract, complement levels in this location are normally 10 to 20% of that found in serum and increase during inflammation ( 21 ). (asm.org)
  • The presence of autoantibodies, such as rheumatoid factor (RF) and citrullinated peptide antibody in the serum, provides an autoimmune character to the disease. (scielo.br)
  • This body of literature, to be reviewed herein, suggests that complement components produced by the liver as well as by kidney cells and immune cells play crucial roles as pathogenic mediators of transplant rejection in animals and humans. (jci.org)
  • Complement C3b may be an opsonin for antigen-antibody complexes which helps prevent damage from the formation of large, insoluble immune aggregates. (sigmaaldrich.com)
  • Complement inhibitors are being studied as potential therapeutics for immune diseases and Alzheimer's. (sigmaaldrich.com)
  • C3a, which contributes to the mobilization of hematopoietic progenitor cells, probably contributes to tumor immune surveillance. (nih.gov)
  • C3b is the larger of two elements formed by the cleavage of complement component 3, and is considered an important part of the innate immune system. (wikipedia.org)
  • C3b is potent in opsonization: tagging pathogens, immune complexes (antigen-antibody), and apoptotic cells for phagocytosis. (wikipedia.org)
  • Additionally, C3b molecules can attach to the Fc regions of antigen-bound antibodies leading to phagocytosis or movement to the liver, where the C3b-tagged immune complex is then destroyed. (wikipedia.org)
  • The complement system, also known as complement cascade, 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, promote inflammation, and attack the pathogen's cell membrane. (wikipedia.org)
  • The complement system can, however, be recruited and brought into action by antibodies generated by the adaptive immune system. (wikipedia.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)
  • citation needed] Complement triggers the following immune functions: Membrane attack - by rupturing cell wall of bacteria. (wikipedia.org)
  • The classical complement pathway typically requires antigen-antibody complexes for activation (specific immune response), whereas the alternative pathway can be activated by spontaneous complement component 3 (C3) hydrolysis, foreign material, pathogens, or damaged cells. (wikipedia.org)
  • The complement system is a key component of the innate immune system that is involved in eliminating unwanted self and nonself material via cellular and humoral mechanisms. (els.net)
  • Complement receptors and Fc receptors, expressed on effector cells, have a synergistic role in antibody‐mediated immune modulation and antigen clearance. (els.net)
  • The complement system plays an important role in innate immunity inducing liver diseases as well as signaling immune cell activation in local inflammation regulating immunomodulatory effects such as liver damage and/or liver regeneration. (hindawi.com)
  • In ALF, extensive liver injury can be caused by a variety of molecules of the innate immune system, and the complement system plays an important role in this process [ 9 , 10 ]. (hindawi.com)
  • These data indicate that C3a and C5a, two potent inflammatory mediators of the innate immune response, contribute essentially to the early priming stages of hepatocyte regeneration. (rupress.org)
  • The contributions of antibodies to the disease are initiated by their direct binding to their respective antigens and involve immune complex formation, deposition, and activation of complement and Fc receptors (FcRs). (biomedcentral.com)
  • The term "complement" was introduced by Paul Ehrlich in the late 1890s, as part of his larger theory of the immune system. (wikidoc.org)
  • In general, immune complexes deposit in vessel walls leading to activation of the complement system. (wikipedia.org)
  • Antigen-antibody complexes on the surface of a microorganism can activate the classical pathway of complement, a part of the acquired immune system (Fig. 1 ), by providing a binding site for C1. (asm.org)
  • Complement is also part of the innate immune defenses and provides a defense against pathogens that have not previously infected the host by recognizing repeating structures such as lipopolysaccharide (LPS) found on the surface of bacteria. (asm.org)
  • However, an acquired immune response can lead to killing of the bacteria by activating the antibody-dependent classical pathway. (asm.org)
  • The regulation of the complement system - so called because it complements the body's central system of immune cells and antibodies - is thought to be a possible route to controlling over-active or mistaken immune responses that cause damage. (ucr.edu)
  • In some cases complement activity can help downplay immune responses while in other cases it can stoke even stronger reactions. (ucr.edu)
  • Collectively, our data highlight a potential use of CR1-based inhibitors for prevention of complement-dependent immune hemolysis. (bloodjournal.org)
  • The complement system is an important mediator of the host immune response to infection and tissue damage, but may cause substantial injury when activated inappropriately. (bloodjournal.org)
  • In immune destruction of red blood cells (RBCs), complement plays a critical role, being involved in both intravascular and extravascular hemolysis. (bloodjournal.org)
  • Indeed, as many as 50% of patients with immune hemolytic diseases have both IgG and complement on their red cells. (bloodjournal.org)
  • 4 Because of the contribution of complement in RBC destruction, we have taken the approach of activation using recombinant complement inhibitory molecules to block complement-mediated immune hemolysis, and thereby prevent some of its associated life-threatening effects. (bloodjournal.org)
  • The complement system is an essential effector of the humoral and cellular immunity involved in cytolysis and immune inflammatory responses. (biomedcentral.com)
  • As a functional bridge between innate and adaptive immunity, the complement system plays critical roles in tumour progression and immune responses. (biomedcentral.com)
  • Immune complex reactions are caused by immunoglobulin antibody reacting directly with tissue antigens (usually basement membrane antigens) or by antibody reacting with soluble antigen in the blood to form soluble antigen-antibody complexes that deposit in tissues. (asmscience.org)
  • These organs are susceptible to anti-basement membrane antibody attack and deposition of immune complexes. (asmscience.org)
  • Antibody (usually IgG) reacts with soluble antigens to produce soluble circulating immune complexes or with basement membranes (such as renal glomerular basement membrane). (asmscience.org)
  • Complement is a highly conserved pathway of the innate immune system, and its role in the first line of defense against pathogens is widely appreciated. (asm.org)
  • There are four types of hypersensitivity reactions [ 6 , 7 ]: Type I: immediate hypersensitivity Type II: cytotoxic or antibody-dependent hypersensitivity Type III: immune complex disease Type IV: delayed-type hypersensitivity Type I hypersensitivity is the most common type of hypersensitivity reaction. (musicmarkup.info)
  • The innate immune system is a type of immunity that has many functions in the body including the induction of cytokine production for the recruitment of immune cells to sites of infection, identification of foreign pathogens to induce an immune response, and the activation of the complement component system. (justia.com)
  • The complement component system is a biochemical cascade involved in both the innate immune system and the activation of the adaptive immune system. (justia.com)
  • The complement system helps defend the host by initiating inflammatory and immunological responses and by promoting the cell lysis and death of invading microorganisms (reviewed in Ref. 2 ). (jimmunol.org)
  • C3a is a mediator of local inflammatory processes. (acris-antibodies.com)
  • C3a is involved in inflammatory reactions seen in gram-negative bacterial sepsis, trauma, ischemic heart disease, post-dialysis syndrome and a variety of autoimmune diseases. (acris-antibodies.com)
  • ICs trigger complement activation and generate inflammatory mediators such as C3a and C5a anaphylotoxins. (frontiersin.org)
  • C3a is an anaphylatoxin that triggers a response by stimulating inflammatory cells to release histamine, enzymes, cytokines and other mediators. (nationaljewish.org)
  • The complement anaphylatoxin C5a is a potent inflammatory mediator. (asnjournals.org)
  • As such, NovelMed's antibodies are active against multiple inflammatory-mediated diseases, in orphan and non-orphan categories, where the complement system plays a pathogenetic role. (biotech-now.org)
  • Secondly, NovelMed's antibodies act proximal to the generation of negative products such as C3a, C3b and C5a which cause extravascular hemolysis and activate inflammatory cytokines. (biotech-now.org)
  • Complement is an important part of innate immunity and plays a key role in inflammatory processes. (biomedcentral.com)
  • C3a and C35 act as potent chemotactic factors, promoting the infiltration of pro-inflammatory cells. (wikipathways.org)
  • Among the conditions potentially treatable through complement regulation is reperfusion injury, which occurs when blood flow is temporarily cut off to some part of the body, as in a heart attack or stroke, and then an inflammatory response develops when the blood returns. (ucr.edu)
  • further we showed that mice genetically deficient of complement component C5 revealed a higher susceptibility to KA neurodegeneration [ 11 , 12 ] suggesting that in addition to their pro-inflammatory mechanisms, specific complement components may also mediate neuroprotection. (biomedcentral.com)
  • The Arthus reaction is a dermal inflammatory response caused by the reaction of precipitating antibody with antigen placed in the skin. (asmscience.org)
  • Antibody-antigen complexes cause activation of complement with formation of inflammatory (phlogistic) complement fragments. (asmscience.org)
  • Derived from proteolytic degradation of complement C3, C3a anaphylatoxin is a mediator of local inflammatory process. (arigobio.com)
  • Inflammatory diseases (inflammatory bowel disease, ulcerative colitis, Crohn's disease) of the intestine are associated with an increased risk of developing colon cancer in humans and studies have shown that complement component C3 is elevated in patients with these diseases (Lundgren et al. (justia.com)
  • Emerging evidence over the past 15 years supports the concept that the complement cascade, traditionally considered a component of innate immunity, unexpectedly regulates kidney IR injury, T cell and humoral alloimmunity that underlie transplant rejection, and progressive kidney injury that results in late graft failure. (jci.org)
  • Exploiting a novel conformational switch to control innate immunity mediated by complement protein C3a. (abcam.com)
  • Links between the complement system, an arm of innate immunity, and age-related macular degeneration (AMD) have been provided by analyses of the composition of the extracellular deposits that form subretinally as drusen 1 2 3 4 and by molecular genetic studies. (arvojournals.org)
  • Primary Antibodies are guaranteed for 1 year from date of receipt. (novusbio.com)
  • The classical pathway is initiated by binding of C1q to antibody complexes, whereas the alternative and lectin pathway are activated in an antibody-independent fashion through the interaction of complement components with respectively specific carbohydrate groups and lipopolysaccharides (LPS) on the surface of foreign pathogens. (linscottsdirectory.com)
  • The classical pathway is activated mainly by antigen-antibody complexes (IgG or IgM mostly) starting with C1q, C1r, C1s, C4 and C2, and eventually leading to the activation of C3 by cleavage into C3a and C3b. (mcmaster.ca)
  • Generation of multiple fluid-phase C3b:plasma protein complexes during complement activation: possible implications in C3 glomerulopathies. (rndsystems.com)
  • The classical pathway is primarily activated by the binding of C1 to antigen-antibody complexes containing the immunoglobulins IgM or IgG. (thefreedictionary.com)
  • In general, the classical pathway of complement is activated by antigen-antibody complexes and C-reactive protein (CRP), whereas the alternative pathway is activated through direct contact with foreign particles or cells. (arvojournals.org)
  • The mouse reactivity of this antibody is based on mouse IHC-P testing and may be not suitable for mouse WB assay. (genetex.com)
  • C3a and C5a mediate these effects by binding to their specific receptors, C3aR and C5aR, respectively. (jimmunol.org)
  • We also show that genetic ablation of receptors for C3a or C5a reduces VEGF expression, leukocyte recruitment, and CNV formation after laser injury, and that antibody-mediated neutralization of C3a or C5a or pharmacological blockade of their receptors also reduces CNV. (pnas.org)
  • The data support the need for further efficacy testing of targeting complement and/or its receptors to improve kidney transplant outcome in humans. (jci.org)
  • Antibodies present in the ICs by bind to activating or inhibitory Fc receptors (FcRs), which trigger effector function and regulate cellular responses. (frontiersin.org)
  • We have antibodies to complement components, regulators and receptors which are offered in a variety of formats including purified and conjugates to biotin, FITC, PE, APC and horseradish peroxidase. (cedarlanelabs.com)
  • Baumann U and Schmidt RE (2001) The role of Fc receptors and complement in autoimmunity. (els.net)
  • Ravetch JV and Clynes RA (1998) Divergent roles for Fc receptors and complement in vivo. (els.net)
  • C3 inhibition could simultaneously block C3a and C5a generation, as well as intrapulmonary C3 activation and IL-6 release from alveolar macrophages, or other cells that express C3a receptors (C3aRs) and/or C5a receptors (C5aRs), thereby ameliorating lung injury. (nature.com)
  • Activation products of the complement cascade contain neo-epitopes that are not present in the individual native components. (acris-antibodies.com)
  • Monoclonal antibodies detecting neo-epitopes have been used for direct quantification of activation at different steps in the complement cascade. (acris-antibodies.com)
  • Emerging evidence over the last decade unexpectedly identified the complement cascade as a common thread in this process. (jci.org)
  • Ischaemic infarction may also cause initiation of the complement cascade. (sigmaaldrich.com)
  • The alternate pathway does not require the action of antibodies to inititate the cascade, but is initiated by foreign cell surface components. (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)
  • Following the complement cascade, C5b with C6-C9 forms the "membrane attack complex" (MAC), capable of lysing infected cells and pathogens [ 17 , 18 ]. (hindawi.com)
  • The ELISA contains a positive control which can be used as process control to ensure that the classical complement cascade has run completely. (linscottsdirectory.com)
  • The complement system is a biochemical cascade which helps clear pathogens from an organism. (wikidoc.org)
  • Activated B cells lead to plasma cell formation followed by IgG antibodies and the complement cascade pathway in acute antibody-mediated rejection (AMR) and chronic AMR with C3 being the therapeutic target. (wikipathways.org)
  • In this study we characterized the step in the complement cascade where BrkA acts, using three strains: a wild-type strain, a strain containing an insertional disruption of brkA , and a strain containing two copies of the brkA locus. (asm.org)
  • Activation of complement cascade via the antibody-mediated classical pathway can initiate red blood cell (RBC) destruction, causing transfusion reactions and hemolytic anemia. (bloodjournal.org)
  • Activation of the complement cascade results in the release of several anaphylatoxins, notable being C3a and C5a, leading to inflammation. (biomedcentral.com)
  • One of the earliest events in the complement cascade is the conversion of C3 to C3a and C3b, the latter typically binds to one or more acceptor molecules on the pathogen surface. (asm.org)
  • Immunohistochemistry (IHC) is a common in vitro staining technique that uses antibodies to identify specific protein antigens within thinly sliced tissue samples. (novusbio.com)
  • The classical pathway is initiated by the binding of antibodies to cell surface antigens. (sigmaaldrich.com)
  • The key to the success of the complement system in clearing antigens is regulating the effects of C3b to pathogens alone and not healthy, host cells. (wikipedia.org)
  • Classical Complement Pathway) Phagocytosis - by opsonizing antigens. (wikipedia.org)
  • the violent reaction is produced by the neutralization of antigens by the antibodies. (thefreedictionary.com)
  • in immunity, antibodies circulate in the blood and neutralize antigens without producing a violent reaction. (thefreedictionary.com)
  • The classical pathway is triggered by activation of the C1-complex (which consists of one molecule C1q and two molecules C1r and C1s), either by C1q's binding to antibodies from classes M and G, complexed with antigens , or by its binding C1q to the surface of the pathogen. (wikidoc.org)
  • 2 Generally, in the presence of a potent, complement-binding antibody and large numbers of closely situated red cell antigens, complement activation can proceed to completion, resulting in intravascular hemolysis. (bloodjournal.org)
  • Human and experimental glomerulonephritis may also be initiated by antibodies to glomerular basement membrane (anti-GBM) or to antigens on epithelial cells. (asmscience.org)
  • When activated by foreign antigens, B cells undergo proliferation and differentiate into antibody-secreting plasma cells or memory B cells see Figure 2. (musicmarkup.info)
  • Upon activation of the complement system, cleavage of the third and fifth components of the complement system (C3 and C5, respectively) generates the peptides C3a and C5a, both of which are potent anaphylatoxins (reviewed in Ref. 3 ). (jimmunol.org)
  • C3a, one of the three complement-derived anaphylatoxins, expresses a wide variety of biological activities which include smooth muscle contraction, platelet and neutrophil activation and aggregation, skin wheal and flare, and immunoregulatory reactions. (emdmillipore.com)
  • During the activation, components known as anaphylatoxins (C3a and C5a) are released which may directly cause bronchoconstriction with respiratory impairment, and vasodilation with hypotension or shock. (thefreedictionary.com)
  • Complement activation also results in the formation of many biologically active complement fragments that act as anaphylatoxins, opsonins, or chemotactic factors. (thefreedictionary.com)
  • 1 The pathobiologic effects of complement are mediated directly by the formation of the cytolytic membrane attack complex (C5b-9), and indirectly by the generation of anaphylatoxins C3a and C5a. (bloodjournal.org)
  • 2004 . Novel monoclonal antibodies against C3 interfering with complement activation: description of fine specificity and applications to various immunoassays. (acris-antibodies.com)
  • No test or test panel can currently perform all these tasks because increases in specificity usually lead to reciprocal decreases in sensitivity, and because some of the clinical features of SLE are not antibody mediated. (bmj.com)
  • Our findings displayed low levels of C3a in plasma samples with high frequency of C3a, C5a, and C5b/9 deposition in liver parenchyma. (hindawi.com)
  • A recent preprint study reported that lung biopsy samples from patients with severe COVID-19 showed widespread complement activation, characterized by C3a generation and C3-fragment deposition 6 . (nature.com)
  • Direct immunofluorescence was negative for immunoglobulin and complement deposition. (mdedge.com)
  • A decrease in deposition on the bacteria of C4, C3, and C9 corresponded with decreased complement sensitivity. (asm.org)
  • Following transfusion of human group O RBCs into mice lacking detectable pre-existing antibodies against the transfused RBCs, systemic coadministration of 10 mg/kg sCR1, a dose well tolerated in human subjects for prevention of tissue injury, completely inhibited the in vivo clearance of the transfused RBCs and surface C3 deposition in the first hour after transfusion, correlating with the half-life of sCR1 in the circulation. (bloodjournal.org)
  • Treatment with sCR1 increased the survival of transfused human group A RBCs in the circulation of mice with pre-existing anti-A for 2 hours after transfusion by 50%, reduced intravascular hemolysis, and lowered the levels of complement deposition (C3 and C4), but not immunoglobulin G (IgG) or IgM, on the transfused cells by 100-fold. (bloodjournal.org)
  • In turn, surface bound C3 convertase promotes accelerated cleavage of C3 into C3a and C3b, thereby promoting opsonization by amplifying C3b deposition through ester bond formation with hydroxyl groups present on the bacterial surface. (prolekare.cz)
  • complement deposition has been observed at the muscle endplate of human subjects with MG and in experimental allergic MG (EAMG). (pubmedcentralcanada.ca)
  • Those resembling erythema nodosum (EN) show small vessel vasculitis and perivascular lymphocytic and mononuclear cell infiltration and fibrin deposition in the vessel wall, while the punched out ulcers are characterized by a leucocytoclastic vasculitis (neutrophil infiltrate) with fibrinoid necrosis. (angelfire.com)
  • The following product was used in this experiment: Complement Polyclonal Antibody from Thermo Fisher Scientific, catalog # RAHU-C. (thermofisher.com)
  • The set provides primary anti-Histidine Decarboxylase rabbit polyclonal antibody and secondary rabbit IgG HRP antibody for western blot. (progen.com)
  • In the current study, we utilized either C3 polyclonal or C3b monoclonal antibodies in a far-Western technique followed by mass spectroscopy to identify the C3b acceptor molecule(s) on the P. aeruginosa surface. (asm.org)
  • Detection limit for recombinant GST tagged C3 is approximately 1ng/ml as a capture antibody. (acris-antibodies.com)
  • We screened for antibodies against activated factor XII (FXIIa) using phage display and demonstrated that recombinant fully human antibody 3F7 binds into the FXIIa enzymatic pocket. (sciencemag.org)
  • In ELISAs, this antibody does not cross-react with recombinant human (rh) Complement Component C3a, rh alpha 2‑macroglobulin, recombinant mouse (rm) Complement Component C5a, or rmComplement Component C5d. (rndsystems.com)
  • The anti-Histidine Decarboxylase antibody is raised against recombinant rat HDC. (progen.com)
  • The agent-polymer-peptide complex may be delivered to target cells by, for example, a pre-targeting technique utilizing bispecific or multispecific antibodies or fragments, having at least one binding arm that recognizes the hapten and at least a second binding arm that binds specifically to a disease or pathogen associated antigen, such as a tumor associated antigen. (freepatentsonline.com)
  • It has been shown to be a chemoattractant for eosinophils, and the form C3a desArg is also known as ASP (Acylation Stimulating Protein), a peptide that participates in fatty acid metabolism. (nationaljewish.org)
  • The C3 convertase enzymes of either complement activation pathway will cleave the C3 α-chain at peptide bond 77 resulting in the production and release of the C3a peptide. (emdmillipore.com)
  • A peptide (C3a) derived from the encoded protein has antimicrobial activity, so people with C3 deficiency are susceptible to bacterial infection. (arigobio.com)
  • See our complete line of Immunohistochemistry Reagents including antigen retrieval solutions, blocking agents ABC Detection Kits and polymers, biotinylated secondary antibodies, substrates and more. (lsbio.com)
  • Donor-reactive T cells and anti-HLA antibodies are established mediators of transplant injury and must be controlled by appropriate immunosuppression. (jci.org)
  • Through these mediators C3a can induce changes in the vascular permeability and local blood flow. (nationaljewish.org)
  • The antigen-antibody interaction leads to increased cell-membrane permeability, with influx of calcium and release of either preformed or newly formed pharmacologic mediators from the granules. (thefreedictionary.com)
  • The functional role of C3a was documented by data showing that glomerular fibrin(ogen), platelet clumps, and TM loss were markedly decreased in HUS mice receiving C3aR antagonist. (jimmunol.org)
  • Also, these drugs will not affect the C3a-C3aR axis. (nature.com)
  • The C1 complement complex binds to these antibodies resulting in its activation via cross proteolysis. (wikipedia.org)
  • Another mechanism for induction of anaphylaxis in humans occurs when antigen binds to preformed IgG antibody and complement components interact with the antigen-antibody complex. (thefreedictionary.com)
  • The monoclonal antibodies binds strongly and cleanly to a band at about 115 kDa which represents the intact α subunit of C3 and various proteolytic bands at approximately 68 and 48 kDa. (arigobio.com)
  • Here we provide evidence that bioactive fragments of these complement components (C3a and C5a) are present in drusen of patients with AMD, and that C3a and C5a induce VEGF expression in vitro and in vivo . (pnas.org)
  • 4 - 6 The relevance of alternative complement pathway activation to human AAV is supported by immunohistochemical demonstration of alternative complement pathway components at sites of AAV 7 , 8 and by correlation of plasma alternative complement pathway activation fragments with AAV disease activity. (asnjournals.org)
  • Fragments C3a, C4a, and C5a (anaphylatoxin) cause constriction of vascular endothelium (increased vascular permeability). (asmscience.org)
  • Recent discoveries indicate that this dualism in the role of inflammation in cancer is mirrored by the effects of the complement system on this disease process. (nih.gov)
  • Alternative Complement Pathway) Inflammation - by attracting macrophages and neutrophils. (wikipedia.org)
  • The cowpox virus (CPV) complement inhibitor, termed inflammation modulatory protein (IMP), blocks immunopathological tissue damage at the site of infection, presumably by inhibiting production of the macrophage chemo attractant factors C3a and C5a. (intechopen.com)
  • Importantly, treatment of patients with an anti-C5a antibody led to immediate clinical improvement, as measured by increased lung oxygenation and decreased systemic inflammation 6 . (nature.com)
  • These events in the setting of complement dysregulation could contribute to the chronic inflammation that underlies AMD pathogenesis. (arvojournals.org)
  • They also plan to explore more generally the dual role of C3a in inflammation, with an eye toward developing further drug candidates. (ucr.edu)
  • NovelMed's antibodies differ from other complement inhibitors in several ways. (biotech-now.org)
  • Proximal complement inhibitors (which target C3 or its upstream activators) could be more effective, but these are still in clinical development, and none has yet been approved, although limited data from phase II clinical trials are available. (nature.com)
  • In the search for mechanisms linking complement activation and thrombosis, we found that exuberant complement activation in response to Stx generated an increased amount of C3a that caused further endothelial P-selectin expression, thrombomodulin (TM) loss, and thrombus formation. (jimmunol.org)
  • Here, we describe our current understanding of the role of complement in tumor development and progression. (nih.gov)
  • Our aim is to evaluate the role of complement components in acute liver failure (ALF) caused by viral hepatitis, involving virus-induced ALF in human subjects using peripheral blood, samples of liver tissues, and ex vivo assays. (hindawi.com)
  • However, the role of complement was difficult to assess because the mice were C5-deficient and the whole blood-killing assays used heparin, which inhibits complement activation [ 21 ]. (biomedcentral.com)
  • An important caveat is that, although complement activation has been associated with the pathophysiology of ARDS caused by various underlying diseases 5 , clinical data on the role of complement activation in the development of SARS-CoV-2-associated ARDS are scarce. (nature.com)
  • The role of complement in antibody-mediated rejection in kidney transplantation. (wikipathways.org)
  • One potential mechanism by which the lung can protect itself from infection is through in situ activation of the complement system (reviewed in Ref. 1 ). (jimmunol.org)
  • C3a is an anaphylatoxin released during activation of the complement system. (genecards.org)
  • Complement component C3 plays a central role in the activation of complement system. (genetex.com)
  • In 1899, Paul Ehrlich renamed the heat-sensitive component "complement. (wikipedia.org)
  • A major component of this response is the complement system. (linscottsdirectory.com)
  • Detects human Complement Component C5/C5a in ELISAs. (rndsystems.com)
  • In sandwich immunoassays, detects human Complement Component C5a by itself or in the context of Complement Component C5. (rndsystems.com)
  • A recent study of SARS-CoV, which is closely related to SARS-CoV-2, found that activation of complement component C3 exacerbates disease in SARS-CoV-associated ARDS 4 . (nature.com)
  • H13 recognizes human complement component C3a alpha, present also on native C3. (progen.com)
  • 71 Complement component 6 deficiency: A rare defect of the complement classical pathway associated with susceptibility to severe recurrent infections, predominantly by Neisseria gonorrhoeae or Neisseria meningitidis. (malacards.org)
  • C6 Deficiency, also known as complement component 6 deficiency , is related to meningitis and oculocutaneous albinism , and has symptoms including abnormality of metabolism/homeostasis , complement deficiency and recurrent meningococcal disease . (malacards.org)
  • Diseases associated with C3AR1 include Hemolytic Uremic Syndrome, Atypical 1 and Complement Component 3 Deficiency . (genecards.org)
  • The complement component 3 (C3) cleavage product C3b is generated continuously at a low level. (prolekare.cz)
  • Outsource the entire localization process without having to worry about finding and characterizing target specific antibodies, sourcing and validating difficult-to-find tissues, and having the ability to interpret the resulting immunostaining in relation to complex human pathologies. (lsbio.com)
  • Specific antibodies are applied to the fixed tissue and typically visualized using either immunofluorescent (IF) or chromogenic reporters. (novusbio.com)
  • It occurs due to preformed donor specific antibodies (DSA) present in high titers and presents as graft failure that can occur within minutes (but sometimes may be delayed for a few days) after transplantation [ 1 ]. (hindawi.com)
  • 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)
  • Both C3a and C5a can induce chemotaxis of eosinophils ( 25 ) and mast cells ( 26 , 27 ). (jimmunol.org)
  • Complements C3a and C4a promote phagocyte chemotaxis. (sigmaaldrich.com)
  • Transplant rejection originally considered as cell mediated response, now has shown to involve humoral response and complement system. (frontiersin.org)
  • Crawford K and Alper CA (2000) Genetics of the complement system. (els.net)
  • 1998) The Human Complement System in Health and Disease New York, NY: Marcel Dekker, Inc. (els.net)
  • In summary, our data suggest that the complement system may be involved in liver dysfunction in viral-induced acute liver failure cases using ex vivo assays. (hindawi.com)
  • Nevertheless, the function of the complement system is associated with processes of development, degeneration, and regeneration of multiple organs [ 12 - 14 ]. (hindawi.com)
  • Here, we assessed the toxicological effects of the complement system in the peripheral blood of patients during acute liver failure. (hindawi.com)
  • 11 Because of the association of CsA with renal toxicity, vascular injury, and aHUS, we examined whether exposure of endothelial cells to CsA could induce the release of microparticles, and we examined whether microparticles from CsA-exposed endothelial cells activate the complement system within the kidney. (asnjournals.org)
  • these studies provide new insight into the role of the host defense complement system in controlling bacterial pathogens in hyperglycemic environments. (biomedcentral.com)
  • The impact of hyperglycemia on the complement system remains unclear. (biomedcentral.com)
  • NovelMed has developed a portfolio of fully humanized monoclonal antibodies that selectively target only the disease-associated Complement System. (biotech-now.org)
  • Complement deficiencies or other defects in the complement system can easily be screened by running an assay for each pathway in parallel or separately. (linscottsdirectory.com)
  • Under certain conditions, the complement system can be unfavorable to the host leading to e.g. autoimmune diseases and infections. (linscottsdirectory.com)
  • One of the major non-speific humoral deffense mechanisms of the body for combating and clearing the infectious agents is complement system [ 14 , 15 , 16 ]. (intechopen.com)
  • Its interaction with the Complement system (Cp) system has so far been found to be indirect, by an inhibition of PMN response towards complement derived chemotaxins. (mcmaster.ca)
  • The early components of the complement system bind to the antibody molecule, leading to activation of other complement components. (thefreedictionary.com)
  • Here, we urge immunologists and clinicians to consider the potential of targeting the complement system in these patients. (nature.com)
  • Other common conditions affected by the complement system are rheumatoid arthritis and sepsis. (ucr.edu)
  • The complement system is thought to be involved in the pathogenesis of numerous neurological diseases. (biomedcentral.com)
  • The clinical and experimental evidences for complement-cancer relationships are solid, whereas an epidemiological study reporting the imbalance of complement system in patients is still lacking. (biomedcentral.com)
  • The opposite associations between the levels of complement and complement-related components in lung cancer tissues and plasma from patients that have been repeatedly reported by independent publications may indicate the prevalence of an imbalance in the complement system of lung cancer patients. (biomedcentral.com)
  • Consistent with the conflicting roles of the complement system in tumour formation, the levels of complement components in plasma and cancer tissues from patients with lung cancer seem to be paradoxical. (biomedcentral.com)
  • The complement system in systemic autoimmune disease. (mdedge.com)
  • In several models of autoimmune diseases, the overactivation of the complement system (CS) is the cause of disease exacerbation. (scielo.br)
  • The interactions of complement C3 with bacteria in elevated glucose were assayed for complement activation to opsonic forms, phagocytosis and bacterial killing. (biomedcentral.com)
  • Activation of complement can directly result in the lysis of invading bacteria or opsonization of infectious particles for efficient phagocytosis by macrophages and polymorphonuclear leukocytes. (rupress.org)
  • Different assays detect particular antibody properties, which are often quite different, and the clinical importance of this for pathogenesis or diagnosis is rarely fully understood. (bmj.com)
  • Kupffer cells and other macrophage cell types help clear complement-coated pathogens. (wikidoc.org)
  • Complement resistance is common among respiratory pathogens. (asm.org)
  • Furthermore, IgM is a potent complement activator. (rupress.org)
  • Factor B-deficient mice after Stx2/LPS exhibited less thrombocytopenia and were protected against glomerular abnormalities and renal function impairment, indicating the involvement of complement activation via the alternative pathway in the glomerular thrombotic process in HUS mice. (jimmunol.org)
  • Complement influences renal graft viability and transplant out come. (frontiersin.org)
  • Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. (asnjournals.org)
  • These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. (asnjournals.org)
  • Non-HLA antibodies to immunogenic epitopes predict the evolution of chronic renal allograft injury. (wikipathways.org)
  • Antibody response to horse gamma-globulin in recipients of renal allografts: relationship with transplant crises and transplant survival. (mdedge.com)
  • Elevated levels of ICs opsonized by complement activation by-products are present during viral infections such as H1N1, HIV, Hepatitis C, autoimmunity, and malignancies as well as during acute humoral rejection. (frontiersin.org)
  • Immunodiffusion (ID) detects high affinity antibodies, immunofluorescence (IIF) moderate and high affinity antibodies, and enzyme linked immunosorbent assay (ELISA) low and high affinity antibodies. (bmj.com)
  • Complement activation was monitored by enzyme-linked immunosorbent assay (ELISA) or Western blotting. (asm.org)
  • The presence of the complement-derived anaphylatoxin peptides, C3a and C5a, in the lung can induce respiratory distress characterized by contraction of the smooth muscle walls in bronchioles and pulmonary arteries and aggregation of platelets and leukocytes in pulmonary vessels. (jimmunol.org)
  • Complement factors C3a, C5a and C4 can induce vasodilatation, increased capillary permeability, and expression of leukocyte adhesion molecules. (sigmaaldrich.com)
  • 6 , 7 Complement activation on the cell membrane can induce cells to release microparticles. (asnjournals.org)
  • Anti-AChR antibodies of the isotype immunoglobulin G (IgG) can be found in the blood stream of 89-90% of autoimmune generalized MG patients (Zweiman & Levinson, 1992). (davidson.edu)
  • C3 antibody [C3], C-term detects C3 protein at cytoplasm in mouse brain by immunohistochemical analysis. (genetex.com)
  • C3 antibody [C3], C-term detects C3 protein at cytoplasm by immunofluorescent analysis. (genetex.com)
  • The antibody also detects nuclear actin isoforms. (progen.com)
  • Specific for human C3, C3a and C3a (desArg) and does not cross-react with C4a or C5a. (novusbio.com)
  • Therefore, measurement of C3a-desArg allows reliable conclusions about the level of complement activation in the test samples. (acris-antibodies.com)
  • 1 Eyelid closure during sleep results in increases in proinflammatory cytokines, complement activation products, and matrix metalloproteinases in the tears within the conjunctival sac. (arvojournals.org)
  • Test your therapeutic antibodies in immunohistochemistry against a broad panel of normal frozen human tissue types in order to determine potential unintended binding. (lsbio.com)
  • The human C3a and C5a peptides are 77 and 74 aa in length, respectively, and have a carboxyl-terminal Arg residue that is important for biological activity. (jimmunol.org)
  • Immunoperoxidase of monoclonal antibody to C3 on formalin-fixed paraffin-embedded human salivary gland. (acris-antibodies.com)
  • Lane 1 : Complement C3 isolated from Human plasma. (acris-antibodies.com)
  • Formalin-Fixed, Paraffin-Embedded Human Placenta tissue stained with Complement C3c Antibody Cat. (acris-antibodies.com)
  • Formalin-Fixed, Paraffin-Embedded Human skin biopsy (4 μm) from lesion of the early pemphigus vulgaris (without blister formation), stained with anti-C3d antibody (DB 106) shows strong positive intraepidermal intercellular immunostaining. (acris-antibodies.com)
  • Human plasma (30 μg) was separated by 7.5% SDS-PAGE, and the membrane was blotted with C3 antibody [C3], C-term (GTX101316) diluted at 1:10000. (genetex.com)
  • 191 (4) : 1827-34 Human skin mast cells express complement factors C3 and C5. (genetex.com)
  • In a manner that requires activation of the alternative complement pathway, passive transfer of antibodies to mouse MPO (anti-MPO) induces a mouse model of ANCA NCGN that closely mimics human disease. (asnjournals.org)
  • 1 , 2 Injection of anti-MPO antibodies into mice causes NCGN and vasculitis, closely mimicking human AAV. (asnjournals.org)
  • Human neutrophils activated by human ANCA release factors that activate the alternative complement pathway. (asnjournals.org)
  • We also found that CD46 knockdown in HaCaT human keratinocytes enhanced autoantibody-mediated complement activation. (sigmaaldrich.com)
  • Using paired co-cultures of human normal QSG-7701 hepatocytes with lung cancer cells (A549, LTEP-α-2 or NCI-H1703) or human normal bronchial epithelial (HBE) cells, we examined the effects of lung cancer cells on complement synthesis and secretion in QSG-7701 hepatocytes. (biomedcentral.com)
  • 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)
  • Various whole cell extracts (30 μg) were separated by 5% SDS-PAGE, and the membrane was blotted with C3 antibody (GTX101316) diluted at 1:20000. (genetex.com)
  • These complement components form the final membrane attack complex (MAC). (thefreedictionary.com)
  • Complement activation is tightly regulated at the cell membrane and within body fluids with an important fluid phase-negative regulator, CFH. (arvojournals.org)
  • However, in older lesions, 2-5 days old, IgG and complement (C3) were found in the basement membrane in almost all of the sixteen biopsies from patients with minor aphthous ulcers. (angelfire.com)
  • The collaborators were able to create peptides that blocked activity of C3a (antagonists) and others that stimulated it (agonists) with unprecedented potency and precision. (ucr.edu)
  • Using a portion of the structures as a flexible templates, Floudas and graduate students Meghan Bellows-Peterson and Ho Ki Fung designed new peptides that were predicted either to enhance or block C3a. (ucr.edu)
  • 5 , 6 ANCA-activated neutrophils activate the alternative complement pathway. (asnjournals.org)
  • One of the most common forms of IHC uses tissues that are fixed with paraformaldehyde and then embedded in paraffin (IHC-P). However, because this preparation can mask the epitope that the antibody needs to detect, it is often recommended to perform antigen retrieval methods on paraffin embedded tissues. (novusbio.com)
  • Using publicly available databases, we jointly compared the levels of complement components in plasma and lung cancer tissues. (biomedcentral.com)
  • With iTRAQ proteomics, quantitative RT-PCR and western blotting, we analysed the differences in complement levels in lung cancer tissues and normal control tissues. (biomedcentral.com)
  • The possible mechanism of the imbalance may be associated not only with the decreased complement levels in lung cancer tissues but also the concurrent lung cancer tissue-induced increase in hepatocyte complement synthesis and plasma secretion in patients. (biomedcentral.com)
  • And the imbalance should be accompanied by a suppression of complement-dependent immunity in lung cancer tissues coupled with a burden of complement immunity in the circulation of patients. (biomedcentral.com)
  • Although hyperacute (i.e., preformed antibody-mediated) rejection has been recognized since the 1960s, the role of antibodies in other forms of rejection was not clear until new diagnostic methods became available. (hindawi.com)
  • The identification of these AMRs has become easier with the development of C4d-staining in biopsies and improved methods of antibody detection. (hindawi.com)
  • Methods of using the combination for treating an individual having a complement-mediated disease or condition which involves excessive or uncontrolled activation of C5, or for enhancing the clearance of C5 from plasma in an individual, are also provided. (patents.com)
  • Importantly, the methods for detecting these antibodies are not specified by the ARA, and this article aims to highlight the fact that the particular assay used will crucially influence the interpretation of the test (table 2). (bmj.com)
  • The present invention provides a combination of two or more isolated or purified anti-C5 antibodies, wherein the isolated or purified anti-C5 antibodies bind to an epitope within the beta chain or alpha chain of C5 and wherein the isolated or purified anti-C5 antibodies to be combined do not compete with each other for binding to the epitope. (patents.com)
  • 5. The combination according to any one of claims 1 to 4, wherein one or more of the isolated or purified anti-C5 antibodies bind to the same epitope as any one of reference antibodies described in Table 2. (patents.com)
  • 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)
  • This activated C1 complex cleaves C4 and C2 forming a C4bC2b complex that covalently bonds to the surface of the microbe and functions as a C3 convertase, binding and cleaving C3 into C3a and C3b. (wikipedia.org)
  • A generalized or localized tissue reaction occurring within minutes of an antigen-antibody reaction. (thefreedictionary.com)
  • Histopathology in these patients is again related to endothelial injury mediated by antibodies but is less severe than that seen in hyperacute rejections. (hindawi.com)
  • We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. (asnjournals.org)
  • Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. (asnjournals.org)
  • Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. (asnjournals.org)
  • We hypothesized that injury of endothelial cells induces the release of complement-activating microparticles into the circulation. (asnjournals.org)
  • Antibody PAL-E shows a distinct positive staining of endothelial cells in all brain tumors (astrocytoma, oligodendroglioma, meningioma, medulloblastoma, ependymoma). (progen.com)
  • CD46, a crucial complement regulatory protein in the complement activation, has been reported to be involved in several autoimmune diseases. (sigmaaldrich.com)
  • Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. (asnjournals.org)
  • 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)
  • Anaphylaxis in humans is most often the result of the interaction of specific IgE antibody fixed to mast cells and antigen. (thefreedictionary.com)
  • Both C3a and C5a have anaphylatoxin activity, directly triggering degranulation of mast cells as well as increasing vascular permeability and smooth muscle contraction. (wikidoc.org)
  • IL-17 is key to anti-col(V) immunity, and regulates complement activation. (iupui.edu)
  • 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)