The effect of intrauterinely injected lymphocytes prepared from sensitized or non-sensitized guinea-pigs on the ultrastructure of rat fetal membranes (visceral yolk sac).

The susceptibility of rat fetal membranes (visceral yolk sac) to cell-mediated immunity was studied electron microscopically at day 19 of pregnancy. For this purpose guinea-pigs were sensitized to rat placental antigens and the activated lymphocytes were injected intrauterinely. Simultaneously, the effect of lymphocytes from non-sensitized guinea-pigs was examined on the rat yolk sac. Lymphocytes from sensitized guinea-pigs revealed a clear cytotoxic effect on the visceral yolk sac, but the degree of cell destruction showed marked differences from one epithelial cell to the other. Furthermore, the yolk sac regionally displayed great differences in the intensity of immune cytolysis...