SOME MECHANISMS INVOLVED IN THE PROSTAGLANDIN-E2 IMMUNOSUPPRESSIVE EFFECT IN (CBAXC57BL)F1 MICE INVIVO

The cellular mechanisms involved in the immunosuppressive effect of prostaglandin E2 (PGE2) multiple injections into (CBA X C57Bl)F1 mice in vivo have been studied. PGE2 injection increases the induction of specific T-suppressors. In addition, there is a decrease in macrophage phagocytic activity and in the phagocytosis index, apparently mediated by Fcγ receptors (FcγR) and not by the macrophage complement receptor (C3R). The induction of antibody synthesis by using "immune" macrophages injected into a syngeneic recipient results in considerable decrease in the accumulation of antibody-forming cells if the macrophage donor has been pretreated with exogenous PGE2 in comparison with untreated controls. These cellular mechanisms are possibly one part of the diverse way in which PGE2 exerts an immunosuppressive effect in vivo and contributes to humoral immune response suppression. © 1990.