title: Accessory cell function in the Con A response: role of Ia-positive and Ia-negative accessory cells.
abstract: We have examined the role of Ia-positive and Ia-negative accessory cells (AC) and soluble factors in Con A-stimulated murine T cell activation. Supernatant fluids containing interleukin 1 (IL 1) derived from the P388D1 macrophage cell line and from a lipopolysaccharide (LPS)-stimulated macrophage hybridoma provided only partial reconstitution of the response of purified T cells (18 to 27%). The complete reconstitution obtained with gamma-irradiated spleen cells or LPS-activated B cells was inhibited by approximately 60 to 77% when anti-Ia antibody was included in the culture. Despite this apparent involvement of Ia+ spleen AC, Ia-negative L cell AC could also reconstitute the response of both Class I-restricted Lyt-2+ T cells and Class II-restricted L3T4+ T cells. When the Ia-negative AC were employed, the L3T4 antigen on L3T4+ T cells played a critical role because addition of anti-L3T4 antibody to the culture inhibited the response by 85 to 90%. In contrast, anti-L3T4 did not inhibit the response in the presence of spleen AC. These results suggest that the molecules involved in T cell-AC interactions may vary depending on the AC source. Moreover, at least one of the putative target ligands for L3T4 presumably is not Ia, because anti-L3T4 inhibited T cell stimulation when Ia-negative AC were used.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D000938:Antigen-Presenting Cells / Q000145:classification / Q000276:immunology / Q000502:physiology*; D000954:Antigens, Surface / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology; D007739:L Cells / Q000276:immunology; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D016169:Lymphocyte Function-Associated Antigen-1; D003208:Concanavalin A