title: Idiotype profile of an immune response. II. Reversal of the relative dominance of major and minor cross-reactive idiotypes in arsonate-specific T-independent responses.
abstract: Two different cross-reactive idiotype (CRI) groups are distinguishable in the Ab response of A/J mice to the p-azobenzenearsonate (ABA) hapten: CRIA and CRIm. These two groups showed distinct patterns of relative dominance in the ensuing response depending on whether the inducing Ag was a T cell-dependent (TD) form of ABA, such as ABA-KLH or ABA-CGG, or a T-independent type 1 (TI-1) form, such as ABA-Brucella abortus or ABA-lipopolysaccharide (LPS), and on whether the response was elicited in vivo or in vitro. The CRI+ component of primary in vivo plaque-forming cell (PFC) responses to TD ABA Ags was largely (greater than 90%) CRIA+ as was, to a slightly lesser extent (greater than 75%) the CRI+ portion of secondary or hyperimmune serum Ab or PFC responses to the same Ags. In contrast, in vivo primary and hyperimmune PFC responses to ABA-Bru or ABA-LPS showed a significantly lower CRIA/CRI ratio, averaging 0.5-0.6, with some individual mice giving figures as low as 0.2, indicating predominance of CRIm over CRIA. Serological analysis of hyperimmune anti-ABA Abs from a group of 5 A/J mice immunized with ABA-Bru gave a figure of less than 0.5 for the CRIA/CRI ratio. The most striking disparity from the TD pattern was seen in primary in vitro PFC responses to the TI ABA Ags; here ratios of less than 0.2 were generally seen. Since T cell removal did not alter the Id pattern in the TI responses, CRIA-specific Ts cells do not account for the weak expression of CRIA in such responses. We propose a model that explains these results on the basis of differential expression of IdX dominance by two distinct B cell subpopulations--equatable to the Lyb-5+ and Lyb-5- B cell subsets--along with differential relative activation of these subsets in different types of responses. Examination of anti-ABA PFC responses of F1 progeny of CBA/N and A/J mice to ABA-Bru lends support to this hypothesis since CRIA expression was significantly lower in mice with the xid defect.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology; D000955:Antigens, T-Independent / Q000008:administration & dosage*; D001391:Azo Compounds / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002004:Brucella Vaccine / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes; D005260:Female; D005799:Genes, Dominant; D006433:Hemocyanins; D006462:Hemolytic Plaque Technique; D007130:Immunoglobulin Idiotypes / Q000235:genetics* / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008808:Mice, Inbred CBA; D051381:Rats; D012729:Sex Chromosome Aberrations / Q000235:genetics / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D010132:p-Azobenzenearsonate / Q000276:immunology*
chemical_list: D000941:Antigens; D000955:Antigens, T-Independent; D001391:Azo Compounds; D002004:Brucella Vaccine; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D008070:Lipopolysaccharides; D010132:p-Azobenzenearsonate; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin