Modulatory effect of prostaglandin E2 on the immune response in mice, with special reference to anti-sperm immunity

The intraperitoneal administration of prostaglandin E2 (PgE2) considerably delayed the rejection of allogeneic skin grafts, both in the primary (first set) and secondary (second set) reaction, and inhibited the production of plaque-forming cells after antigenic stimulation with sheep red blood cells. In addition, the treatment of mice with PgE2 during their immunization with allogeneic epididymal spermatozoa resulted in a markedly slower rejection of the following skin grafts from the donor's strain in comparison with the animals injected with spermatozoa only. Evidence was also found concerning the immunosuppressive effect of PgE2 on the humoral immune response against sperm antigens. The possible immunoregulatory role of PgE2 in the natural immune tolerance to sperm antigens is discussed.