title: The specificity of T lymphocyte responses to chemically defined antigens.
abstract: A system is described that allows the definition of T cell receptor specificity with some precision. It involves immunization of guinea pigs with hapten coupled to mycobacteria. The T cells of such animals respond to many but not all carriers modified by that hapten. Such T cells recognize neither hapten nor carrier alone, but rather determinants involving both the hapten and the carrier. No evidence for hapten-specific T cells was found. A model of the antigen binding site of the T cell receptor emerged from these experiments. According to this model, the T cell receptor consists of a single site of relatively large extent involving multiple subsites which are of low and roughly equal affinity. Thus, the haptenic group is not immunodominant for T cells as it is for B cells and for anti-hapten antibody. This suggests that the antigen binding receptor on T cells differs in some fundamental way from that on B cells. It is proposed that antigen recognition by T cells is mediated by an immunoglobulin heavy chain variable region that is not paired with an immunoglobulin light chain variable region.
mesh_terms: D000818:Animals; D000941:Antigens / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D001666:Binding Sites, Antibody; D002464:Cell Migration Inhibition; D004140:Dinitrophenols / Q000008:administration & dosage / Q000276:immunology; D000939:Epitopes; D006168:Guinea Pigs; D006241:Haptens / Q000008:administration & dosage; D007111:Immunity, Cellular; D007114:Immunization; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D008954:Models, Biological; D009169:Mycobacterium tuberculosis / Q000276:immunology; D009592:Nitrohydroxyiodophenylacetate / Q000008:administration & dosage / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D004140:Dinitrophenols; D000939:Epitopes; D006241:Haptens; D009592:Nitrohydroxyiodophenylacetate