title: Anti-T3 antibody both activates and inhibits the cytotoxic activity of human T cell clones.
abstract: The present report outlines results using several approaches to investigate the effects of antibodies against cell surface molecules on human cytotoxic T lymphocyte (CTL) recognition. First, when interactions between CTL and targets are perturbed by antibody immobilized on the surface of the incubation vessel, anti-T3 antibody was unique in its ability to inhibit at least 10 times more efficiently than when present in solution. Second, anti-T3 antibody at sufficiently high concentrations inhibits lectin-dependent cellular cytotoxicity as well as allospecific cytotoxicity. Third, murine hybridomas expressing anti-T3 antibody induce their own lysis by human CTL clones; but hybridomas bearing antibodies of other specificities are not lysed in a similar manner. We have exploited this anti-T3 triggered lysis of the OKT3 hybridoma as a model system in which to study T cell recognition. Such lysis is susceptible to inhibition not only by anti-T3 but also by anti-LFA-1 antibody; however, conjugate formation between the anti-T3 hybridoma and CTL is not easily inhibited by anti-LFA-1. These data, which are discussed in the context of results from other laboratories, are consistent with a model in which CTL triggering can be induced by interaction of the antigen specific receptor (Ti) with its physiologic ligand, antigen plus MHC, or interaction of the T3 complex with a surrogate ligand, anti-T3/anti-Ti. However, they raise questions regarding the role which LFA-1 plays in CTL recognition.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D037102:Lectins / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D037102:Lectins; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell