abstract
- Mechanisms that explain failure of rejection of the antigenic fetus by the mother appear to lie at the fetomaternal interface. Successful pregnancies have been correlated with the presence of decidua-associated suppressor cells. Supernatants from these cells were tested for their ability to suppress the proliferation of interleukin 2-dependent cells and were also subjected to high-performance liquid chromatography. Decidual supernatant was found to have peak suppressive activity at two molecular weights (43,000 and 21,000 daltons). The activity of decidual supernatant was directed specifically at interleukin 2-dependent cells and interfered with interleukin 2 action. The importance of this mechanism in graft rejection is well known. Decidual supernatant may thus prevent fetal allograft rejection by preventing the maternal cytotoxic effectors from receiving the interleukin 2-dependent help that they need to proliferate and remain actively cytolytic.