PGI2 and PGD2 effects on cyclic AMP and human T-cell mitogenesis

The effects of PGI2, PGD2, and PGF2 alpha on human peripheral blood lymphocytes (HPBL) cyclic AMP levels and their response to a T cell mitogen (PHA) were investigated. It was determined that although PGI2, PGD2, and PGE2 all elevate intracellular levels of cyclic AMP in HPBL, only PGD2 and PGE2 exert potent suppression of PHA-induced lymphocyte proliferation. It is suggested that the instability of PGI2 in aqueous solution is at least partially responsible for its relative inability to maintain elevated levels of cyclic AMP and concomitant suppression of mitogenesis. PGD2 was found to exert an effect very similar to PGE2, both in terms of cyclic AMP elevation and suppression of T cell mitogenesis.