title: The mode of recognition of tumor antigens by noncytolytic-type antitumor T cells: role of antigen-presenting cells and their surface class I and class II H-2 molecules.
abstract: The present study investigated the role of antigen-presenting cells (APC) in the activation of noncytolytic T cells against tumor antigens. The noncytolytic-type T cells exerted their antitumor effect by producing gamma-interferon (IFN-gamma) and by activating macrophages as the ultimate effectors. The production of IFN-gamma by these noncytolytic T cells following the stimulation with tumor cells required the participation of Ia+ APC, since the depletion of APC from cultures of tumor-immunized spleen cells resulted in almost complete inhibition of the IFN-gamma production. Both L3T4+ and Lyt-2+ subsets of T cells were capable of producing IFN-gamma, and the requirement of APC for the production of IFN-gamma was the case irrespective of whether noncytolytic T cells were of L3T4+ or Lyt-2+ phenotype. More importantly, it was demonstrated that the production of IFN-gamma by L3T4+ and Lyt-2+ T cells was inhibited by addition of the respective anti-class II and anti-class I H-2 antibody to cultures. These results indicate that antitumor L3T4+ or Lyt-2+ noncytolytic T cells are activated for the IFN-gamma production by recognizing tumor antigens in the context of self-class II or -class I H-2 molecules on APC.
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D005354:Fibrosarcoma / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D008114:Liver Neoplasms, Experimental / Q000276:immunology; D008262:Macrophage Activation; D051379:Mice; D008809:Mice, Inbred C3H; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D006183:H-2 Antigens; D007371:Interferon-gamma