The immunosuppressive contribution of prostaglandin components of human semen and their ability to elevate cyclic adenosine monophosphate levels in peripheral blood mononuclear cells.

We have compared the ability of fractions from seminal plasma to suppress lymphocyte proliferation and examined the effects of these fractions in raising intracellular cyclic adenosine monophosphate (cAMP) in the same preparations of peripheral blood mononuclear cells. Human seminal plasma is very effective at raising cAMP but seminal plasma stripped by C-18 reverse phase columns is inactive. Both prostaglandin E (PGE) and 19-hydroxy PGE contribute to the elevation of cAMP and a combination of these two prostaglandins is as effective as whole seminal plasma in raising cAMP but not as effective in inhibiting lymphoproliferation. These results suggest that human seminal plasma prostaglandins act through the EP2 receptor to inhibit T cell and NK cell function and thus attenuate both the cellular and humoral actions of the female's immune system.