| Abstract: | The total count, spontaneous proliferation and proliferative response of thymic and spleen T-cells in mixed lymphocyte culture and Con A-induced suppressor activity do not reveal significant disorders in 10-14-month A/Sn and C3H/He mice with spontaneous mammary tumors (weight under 2-3 g). However, these indices are quite different in varying age (2, 6, 12 month) A/Sn mice and C57Bl/6 mice with low rates of spontaneous tumors. The analysis of thymus-dependent immunity changes observed with age shows that relatively intensive migration of nonmature thymocytes, T-suppressor precursors is noted in mice with high cancer incidence. This phenomenon is considered to be one of major mechanisms regulating immune response in spontaneous-carcinogenesis. |
