IMPAIRMENT OF HOST VS GRAFT REACTION IN PREGNANT MICE .1. SUPPRESSION OF CYTOTOXIC T-CELL GENERATION IN LYMPH-NODES DRAINING UTERUS

Abstract

The fetus resulting from an allogeneic (interstrain) mating represents a type of graft that is not rejected by the mother. The maternal immune system seems to recognize and to react to the presence of the fetus in a number of ways. One manifestation is significant enlargement of the lymph nodes that drain the uterus (DLN) of pregnant rodents. The DLN lymphocytes of mice were tested for reactivity to paternal H-2 alloantigens after interstrain mating. The DLN lymphoid cells obtained from pregnant mice killed fewer newborn F1 recipients in a graft vs. host mortality assay, and generated less cytotoxic T [thymus-derived] cell activity against paternal H-2 antigens in vivo and in vitro. In vitro mixing experiments demonstrated the presence of a cell-associated suppressor activity in the DLN of pregnant mice. This suppressor proved resistant to treatment with mitomycin C, and appeared in the DLN early in pregnancy.