Fine specificity of cloned insulin-specific T cell hybridomas: evidence supporting a role for tertiary conformation.
Two groups of cloned insulin-specific T cell hybridomas were derived from the fusion of (BALB/c X A/J)F1 T cells with the BW5147 tumor line. Group I responded only to the immunogen pork insulin and failed to respond to rat insulin, which differs only at amino acids A4 and B3. The second group of T cell hybridomas exhibited a broader pattern of reactivity to heterologous insulins because they could be stimulated with the B chain-identical pork, beef, sheep, and human insulins, as well as by isolated oxidized B chain. These hybridomas, however, displayed a much greater reactivity to pork insulin than to beef insulin or to the oxidized B chain. Comparison of the reactivity profiles of these two groups of hybridomas with the three-dimensional structure of the insulin molecule strongly suggested that group I cells were recognizing an immunogenic moiety composed of residues A4 and/or B3 in association with A chain loop determinants and that group II hybrids recognized a moiety composed of the amino acid sequence of the B chain and the A chain loop. Both groups of hybrids were restricted to the high-responder I-Ad allele but could be distinguished by their pattern of alloreactivity. We were unable to show any effect of a panel of monoclonal anti-insulin antibodies on the induction of interleukin 2 secretion by these hybridomas or to demonstrate the presence of idiotypic determinants on these T hybrids by using a panel of anti-idiotypic reagents raised against the monoclonal anti-insulin antibodies.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D002417:Cattle; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007328:Insulin / Q000276:immunology*; D007376:Interleukin-2 / Q000096:biosynthesis; D046911:Macromolecular Substances; D051379:Mice; D008805:Mice, Inbred A; D008815:Mice, Inbred Strains; D011487:Protein Conformation; D051381:Rats; D012756:Sheep; D013045:Species Specificity; D013552:Swine; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007130:Immunoglobulin Idiotypes; D007328:Insulin; D007376:Interleukin-2; D046911:Macromolecular Substances