title: Inhibitory effect of tumor-bearing state on the generation of in vivo protective immune T cells in a syngeneic murine tumor system.
abstract: Tumor-specific immunity mediated by thymus-derived lymphocytes (T cells) was established in C3H/He mice against syngeneic X5563 plasmacytoma. Splenic T cells from mice, which exhibited resistance to tumor challenge, revealed a potent in vivo tumor-neutralizing activity as well as in vitro cytotoxicity. In contrast, spleen cells from mice 7 days after tumor cell inoculation (7-day tumor-bearing mice) exhibited no protective activity when assayed by in vivo tumor-neutralization test, whereas these cells exhibited almost comparable in vitro cytotoxic activity to that from the tumor-resistant mice. Any suppressor cell activity was not detected in 7-day tumor-bearing animals. While a slight in vivo protective activity was observed in the spleen cells from 14-day tumor-bearing mice, this activity was still significantly weaker than that of spleen cells from mice similarly inoculated with tumor 14 days before but whose tumor had been removed 7 days before the assay. The development of in vivo protective immunity in tumor-resected mice was suppressed by intravenous inoculation with 7000 R X-irradiated tumor cells. These results indicate that in vitro reactivity of immune T lymphocyte population is not always correlated with in vivo protective immunity, but there is a substantial decrease in in vivo immune capability of T cells from tumor-bearing animals, and that this suppression may be ascribed to the presence of a large amount of tumor-associated transplantation antigens rather than to suppressor cell activity.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000008:administration & dosage / Q000528:radiation effects; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005260:Female; D007111:Immunity, Cellular; D007156:Immunologic Memory; D066298:In Vitro Techniques; D008212:Lymphocyte Depletion; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D009374:Neoplasms, Experimental / Q000276:immunology; D010954:Plasmacytoma / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D000951:Antigens, Neoplasm; D000939:Epitopes