title: Induction of CTL responses to alloantigens by a Db-specific T helper clone.
abstract: A T cell helper clone was derived 2 yr ago from a mixed lymphocyte culture. This clone, referred to as clone 9, was propagated in interleukin 2 (IL 2)-containing medium in the presence of irradiated stimulator and irradiated syngeneic spleen cells. Clone 9 was of H-2d origin and was found to be Thy-1+ and Lyt-1-2-. Clone 9, as well as supernatant factor(s) derived from it, were able to enhance the primary cytotoxic responses of Db responder cells to alloantigens. Furthermore, clone 9 cells or its factor(s) were only active when added during the first 24 hr of a 5-day culture period. When a low stimulator cell dose (10(4) cells per 0.2 ml culture) was used, it was possible to demonstrate that clone 9 also required a source of irradiated allogeneic splenic accessory cells to exert its helper action. Under these conditions, clone 9 or its factor(s) could also synergize with IL 2-containing medium in mounting cytotoxic responses to alloantigens. Synergy between IL 2-containing medium and clone 9 or its factor(s) was observed only when Db responder cells were used. The helper activity in clone 9 supernatant was also specifically absorbed out by Con A-stimulated Db spleen cell blasts. Preincubation with clone 9 supernatant for 1 hr at room temperature also led to enhanced cytotoxic responses of Db responder cells to alloantigens. Clone 9 supernatant was also found to be devoid of detectable IL 2 activity. Thus, clone 9 or its helper factor(s) appear to exert its helper activity by an early interaction with Db cytotoxic T lymphocyte precursors (CTL-P).
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000235:genetics; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes; D006183:H-2 Antigens / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D007376:Interleukin-2 / Q000502:physiology; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008806:Mice, Inbred AKR; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D051381:Rats; D011919:Rats, Inbred Strains; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D007376:Interleukin-2; D007519:Isoantigens