title: Receptor specificity of Ia-restricted T lymphoblasts activated against trinitrobenzene sulfonate-coupled spleen cells: recognition of distinct trinitrophenyl and Ia moieties.
abstract: The receptor specificity of H-2-restricted T lymphoblasts activated against trinitrobenzene sulfonate (TNBS)-coupled spleen cells was examined using an antigen binding assay. A population of Lyt-1+,2-T lymphoblasts acquired syngeneic Ia determinants during 4 days of primary culture with hapten-coupled stimulator cells. Syngeneic Ia was not reexpressed after trypsin treatment of the T cells, but was found after incubation with soluble Ia shed from lipopolysaccharide-activated blasts. Self-Ia binding was specific in that Lyt-1+,2- but not Lyt-1-,2+ cells acquired the antigen, and in that self-Ia bound more effectively than allogeneic Ia material. To determine the relationship of self-Ia binding to the recognition of foreign antigen, the binding of trinitrophenyl (TNP)-coupled plasma membrane vesicles by TNP-specific T cells was studied. TNP-vesicle binding occurred via TNP and H-2(Ia) molecules on the vesicles in that binding was inhibited with antibodies against TNP or H-2(Ia) molecules but not non-major histocompatibility complex (e.g., Ly-6.2) molecules on the vesicles. Complete inhibition of TNP-vesicle binding by an Iak-restricted TNP-specific T-cell line occurred with soluble TNP-lysine, but not an unrelated hapten, N-iodoacetyl-N-(5-sulfonic-1-naphthyl)ethylenediamine (I-AED)-cysteine. Conversely, I-AED-cysteine, but not TNP-lysine, inhibited binding of I-AED-coupled B6 vesicles by B6 anti-I-AED T cells. Significant, but weak inhibition of TNP-vesicle binding by the anti-TNP line was observed with glycoprotein preparations containing partially purified self-Ia molecules. However, inhibition was specific for I-Ak molecules, in that inhibition was lost after removal of I-Ak molecules from the glycoprotein preparation, and very little inhibition occurred with soluble glycoproteins prepared from thymocytes which contained very little Ia material or from LPS blasts of an unrelated H-2 haplotype. These results suggest a recognition model in which TNP and Ia determinants are recognized by neighboring receptor combining sites.
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000276:immunology; D001667:Binding, Competitive; D000939:Epitopes; D005260:Female; D006241:Haptens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D009578:Nitrobenzenes / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D014302:Trinitrobenzenesulfonic Acid / Q000276:immunology* / Q000378:metabolism
chemical_list: D000950:Antigens, Ly; D000939:Epitopes; D006241:Haptens; D000949:Histocompatibility Antigens Class II; D009578:Nitrobenzenes; D011948:Receptors, Antigen, T-Cell; D014302:Trinitrobenzenesulfonic Acid