Effect of PGE sub(2) on thymocyte proliferation induced by Con A or IL-4 + PMA

Prostaglandin E sub(2) (PGE sub(2)) is known to inhibit peripheral T-lymphocyte and thymocyte proliferation activated by antigens, mitogens or anti-CD3 antibodies. In this study, we have investigated, the effect of PGE sub(2) on thymocyte proliferation induced by the combination of IL-4 plus PMA. PGE sub(2) inhibits the proliferation of thymocytes activated by ConA, whatever the culture period; in contrast PGE sub(2) shifts the kinetics of thymocyte proliferation after stimulation by IL-4 plus PMA, but does not sustain the proliferation beyond day 3. The results suggest that PGE sub(2) can regulate thymocyte proliferation differently according to the activation pathway and the thymic subpopulations.