title: Requirement for the coexpression of T3 and the T cell antigen receptor on a malignant human T cell line.
abstract: The association between T3 and the T cell antigen receptor was examined using the T3 bearing T cell leukemic line Jurkat. A monoclonal antibody, C305, was produced, which reacted with idiotypic-like determinants expressed on Jurkat. The molecule with which this antibody reacted was a disulfide-linked heterodimer of 90 kD, composed of polypeptides of 42 and 54 kD. Thus, C305 reacted with a molecule with characteristics of the putative T cell antigen receptor described by others. A series of mutants of Jurkat, induced with ethyl methane sulfonate or radiation, was selected for T3 or antigen receptor negativity. In every instance, there was a concomitant loss of both T3 and the antigen receptor as assessed by quantitative absorption, indirect immunofluorescence, and antibody plus complement-mediated cytotoxicity. The absence of antigen receptor molecules was confirmed on diagonal gels, excluding the possibility that conformational changes of the antigen receptor on such T3-negative mutants were responsible for the failure of such mutants to react with C305. Moreover, in a mutant that expressed a marked decrease in the level of T3 expression, there was a comparable decrease in the expression of antigen receptor determinants. These results suggest that there is an obligate requirement for the coexpression of T3 and the T cell antigen receptor. Furthermore, attempts to activate such mutants with the lectin phytohemagglutinin suggested that the expression of T3 and/or the antigen receptor was required for activation of these cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D002460:Cell Line; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000235:genetics; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D011948:Receptors, Antigen, T-Cell