title: Two distinct mechanisms regulate the in vivo generation of cytotoxic T cells.
abstract: Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D006241:Haptens / Q000276:immunology; D007116:Immunization, Passive; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014301:Trinitrobenzenes / Q000276:immunology; D010132:p-Azobenzenearsonate / Q000276:immunology
chemical_list: D000950:Antigens, Ly; D006241:Haptens; D014301:Trinitrobenzenes; D003208:Concanavalin A; D010132:p-Azobenzenearsonate