IMMUNIZATION WITH A SYNGENEIC REGRESSOR TUMOR CAUSES RESORPTION IN ALLO-PREGNANT MICE

The purpose of our studies is to establish experimental systems in which one can deliberately disrupt the apparent maternal tolerance toward the semiallogeneic fetuses. Bases on the hypothesis that immunization against tumor-associated antigens may lead to a subsequent immune response directed against cross-reacting fetal antigens, we have immunized C57BL/6J female mice with a syngeneic regressor tumor. Mice were subsequently mated to B6D2F1, DBA/2, CBA/J or C57BL/6J males. We show that a high proportion of embryos sired by either B6D2F1 or DBA/2 males undergo resorption whereas those engendered by CBA/J or C57BL/6J males remain fully protected.