title: Molecular signals in antigen presentation. II. Activation of cytolytic cells in vitro after ultraviolet radiation or combined gamma and ultraviolet radiation treatment of antigen-presenting cells.
abstract: Murine low-density spleen cells have potent antigen-presenting ability in a hapten-specific cytolytic T lymphocyte (CTL) system using the hapten azobenzenearsonate (ABA). Exposure of these cells to 0.33 KJ/m2 of ultraviolet radiation (UVR) after coupling to hapten results in markedly inhibited antigen-presenting function that can be substantially corrected or bypassed by interleukin 1 (IL 1). These results have been interpreted to reflect an inhibition of Lyt-1+ T cell activation by UVR-treated APC. Treatment of these cells sequentially with 1500 rad of gamma-radiation (GR) prior to hapten coupling, followed by 0.33 KJ/m2 of UVR radiation after coupling, results in an antigen-presenting defect only minimally improved by IL 1. However, partially purified interleukin 2 (IL 2) can completely bypass or correct this defect. Thus, combined GR and UVR induces a different or more profound defect in APC function when compared to UVR alone. However, these cells do provide a signal(s) other than hapten necessary for CTL activation because ABA-coupled high density spleen cells do not activate CTL cells, even with the addition of IL 2. Fluorescence-activated cell sorter analysis demonstrates that exposure of these low density spleen cells to GR or UVR results in decreased I-A antigen expression at 24 hr than either alone. The addition of nonhapten-coupled low-density APC partially reconstitutes the ability of combined GR/UVR-treated LD-APC to present antigen, and this effect is enhanced by the administration of exogenous IL 1. This occurs despite a lack of significant accessory cell activity by the LD-APC for the ABA hapten, and indicates that combined GR/UVR-treatment of APC is not functionally equivalent to completely removing them.
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology* / Q000528:radiation effects; D001391:Azo Compounds / Q000276:immunology*; D002470:Cell Survival / Q000528:radiation effects; D005260:Female; D005434:Flow Cytometry; D006241:Haptens / Q000276:immunology; D007111:Immunity, Cellular / Q000528:radiation effects; D007165:Immunosuppression Therapy; D007375:Interleukin-1 / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation / Q000528:radiation effects; D051379:Mice; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D010132:p-Azobenzenearsonate / Q000276:immunology*
chemical_list: D000941:Antigens; D001391:Azo Compounds; D006241:Haptens; D007375:Interleukin-1; D007376:Interleukin-2; D010132:p-Azobenzenearsonate