Biomaterial Database

Human anti-idiotypic antibody responses to autoantibody against the alternative pathway C3 convertase. 1990

R E Spitzer, and A E Stitzel, and G C Tsokos

Department of Pediatrics, State University of New York, Health Science Center, Syracuse 13210.

Anti-idiotypic antibodies to autoantibody against the alternative pathway C3 convertase (C3NeF) were isolated and purified from normal human serum as well as from serum from six patients with membrano-proliferative glomerulonephritis (MPGN). All preparations of anti-id antibody blocked C3NeF deposition on EC3bBb as well as C3NeF stabilization of EC3bBb functional activity. The Ka of these ant-id antibodies for C3NeF was 10(9) liters/mol which is comparable to the Ka of C3NeF for its antigen. In addition, 90% of anti-id antibody isolated from patients with MPGN and 20% isolated from normal individuals resembled Bb and bound to C3b as well as to antibody specific for the Bb portion of Factor B. These anti-id antibodies also resembled C3b and bound to antibody specific for the C3c portion of C3b. Immunization of rabbits with this latter form of anti-id antibody led to the production of functionally active C3NeF. These data indicate that C3NeF anti-idiotypic antibodies exist in two distinct forms, with and without internal imagery of C3bBb, and can occur in both normal individuals and patients with MPGN.

UI	MeSH Term	Description	Entries
D003166	Complement Activating Enzymes	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.	Activating Enzymes, Complement,Enzymes, Complement Activating
D003170	Complement Pathway, Alternative	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.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D003178	Complement C3 Nephritic Factor	An IgG autoantibody against the ALTERNATIVE PATHWAY C3 CONVERTASE, found in serum of patients with MESANGIOCAPILLARY GLOMERULONEPHRITIS. The binding of this autoantibody to C3bBb stabilizes the enzyme thus reduces the actions of C3b inactivators (COMPLEMENT FACTOR H; COMPLEMENT FACTOR I). This abnormally stabilized enzyme induces a continuous COMPLEMENT ACTIVATION and generation of C3b thereby promoting the assembly of MEMBRANE ATTACK COMPLEX and cytolysis.	C3 NeF,C3 NeF IgG Autoantibodies,C3 NeF IgG Autoantibody,C3NeF IgG Autoantibodies,C3NeF IgG Autoantibody,C 3 Nephritic Factor,C3 Nephritic Factor,Complement 3 Nephritic Factor,Autoantibody, C3NeF IgG,IgG Autoantibody, C3NeF
D003179	Complement C3b	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.	C3b Complement,C3bi,Complement 3b,Complement Component 3b,Inactivated C3b,iC3b,C3b, Complement,C3b, Inactivated,Complement, C3b,Component 3b, Complement
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000888	Antibodies, Anti-Idiotypic	Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.	Anti-Antibodies,Anti-Idiotype Antibodies,Antibodies, Internal Image,Antigamma Globulin Antibodies,Antiglobulins,Anti Antibodies,Anti-gamma Globulin Antibodies,Anti Idiotype Antibodies,Anti gamma Globulin Antibodies,Anti-Idiotypic Antibodies,Antibodies, Anti,Antibodies, Anti Idiotypic,Antibodies, Anti-Idiotype,Antibodies, Anti-gamma Globulin,Antibodies, Antigamma Globulin,Globulin Antibodies, Anti-gamma,Globulin Antibodies, Antigamma,Image Antibodies, Internal,Internal Image Antibodies
D000915	Antibody Affinity	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.	Affinity, Antibody,Antibody Avidity,Avidity, Antibody,Affinities, Antibody,Antibody Affinities,Antibody Avidities,Avidities, Antibody
D001323	Autoantibodies	Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.	Autoantibody
D001666	Binding Sites, Antibody	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.	Antibody Binding Sites,Paratopes,Antibody Binding Site,Binding Site, Antibody,Paratope
D015432	Glomerulonephritis, Membranoproliferative	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.	C3G Complement 3 Glomerulopathy,Complement 3 Glomerulopathies,Complement 3 Glomerulopathy,Glomerulonephritis, Mesangiocapillary,MPGN Membranoproliferative Glomerulonephritis,Membranoproliferative Glomerulonephritis,Mesangiocapillary Glomerulonephritis,DDD MPGNII,Dense Deposit Disease,Glomerulonephritis, Hypocomplementemic,MPGNII,Membranoproliferative Glomerulonephritis Type II,Membranoproliferative Glomerulonephritis, Type I,Membranoproliferative Glomerulonephritis, Type II,Membranoproliferative Glomerulonephritis, Type III,Mesangiocapillary Glomerulonephritis, Type I,Mesangiocapillary Glomerulonephritis, Type II,Subendothelial Membranoproliferative Glomerulonephritis,Type II MPGN,DDD MPGNIIs,Glomerulonephritides, MPGN Membranoproliferative,Glomerulonephritides, Membranoproliferative,Glomerulonephritis, MPGN Membranoproliferative,Glomerulopathies, Complement 3,Glomerulopathy, Complement 3,Hypocomplementemic Glomerulonephritides,Hypocomplementemic Glomerulonephritis,MPGN Membranoproliferative Glomerulonephritides,MPGN, Type II,MPGNII, DDD,MPGNIIs,Membranoproliferative Glomerulonephritides,Membranoproliferative Glomerulonephritides, MPGN,Membranoproliferative Glomerulonephritis, MPGN,Membranoproliferative Glomerulonephritis, Subendothelial,Mesangiocapillary Glomerulonephritides,Type II MPGNs