Both a monoclonal antibody and antisera specific for determinants unique to individual cloned helper T cell lines can substitute for antigen and antigen-presenting cells in the activation of T cells.
Two antisera and a monoclonal antibody raised in BALB.K mice against cloned, major histocompatibility complex (MHC)-restricted, antigen-specific helper T cell lines are described. These antibodies are specific for individual cloned T cell lines and are potent inducers of T cell proliferation. The induction of T cell proliferation by these antibodies requires the presence of an adherent accessory cell. There is no H-2 restriction between this accessory cell and the cloned T cell, nor is this antibody-induced proliferation blocked by a monoclonal anti-Fc receptor antibody. The requirement for an accessory cell, however, is eliminated in the presence of an IL-1- or IL-2-rich supernatant. Thus this system allows the analysis of helper T cell activation with only a single cell type present. Anti-T cell sera also induce T cell-dependent B cell proliferation and immunoglobulin secretion. The induction of T cell-dependent B cell activation by these sera does not require H-2-matched T cells and B cells. The specificity of these antibodies and their ability to stimulate cloned helper T cells in the absence of antigen and antigen-presenting cells strongly suggest that these antibodies are directed against antigen and/or Ia recognition sites on the T cell.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000502:physiology*; D000921:Antibody-Producing Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology; D000961:Antilymphocyte Serum / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000235:genetics; D007375:Interleukin-1 / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000494:pharmacology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000941:Antigens; D000961:Antilymphocyte Serum; D000939:Epitopes; D007375:Interleukin-1; D007376:Interleukin-2; D008934:Mitogens