title: Concanavalin A-mediated in vitro activation of a secondary cytotoxic T-cell response in virus-primed splenocytes.
abstract: In a recent report it was shown that what appeared to be secondary cytotoxic T cells could be obtained from lymphocytic choriomeningitis virus (LCMV)-primed splenocytes after stimulation in vitro with the non-specific T cell mitogen concanavalin A (Con A). The present experiments attempt to characterize further these effector cells and, in particular, to establish whether the Con A-activated cytotoxic effectors are qualitatively different from the secondary cytotoxic T cells induced by restimulation with the homologous antigen. It was found that: (1) in vitro activation with Con A could be obtained with populations harvested between 13 days (the earliest tested) and at least 300 days after priming; (2) cytotoxicity was independent of the presence of carried-over Con A in the cytotoxicity assay; (3) cytotoxicity was dependent on close association between activated T cells and target cells, since no evidence was found to indicate a role for other cell types or soluble (cytotoxic or arming) factors; (4) cytotoxicity was specific with regard to both virus and 'self'. By comparison with previous data on LCMV-induced cytotoxic T cells, it is concluded that Con A induces the generation of cytotoxic T cells from LCMV-primed splenocytes, which, by the criteria used, are indistinguishable from virus-induced secondary cytotoxic T cells. The implications of these findings are discussed.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D003208:Concanavalin A / Q000494:pharmacology*; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005260:Female; D008213:Lymphocyte Activation / Q000187:drug effects*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D008297:Male; D051379:Mice; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000939:Epitopes; D003208:Concanavalin A