Human choriogonadotropin (hCG) and placental lactogen (hPL) inhibit interleukin-2 (IL-2) and increase interleukin-1 beta (IL-1 beta), -6 (IL-6) and tumor necrosis factor (TNF-alpha) expression in monocyte cell cultures.

The effect of the human trophoblast hormones chorionic gonadotropin (hCG) and placental lactogen (hPL) on the expression of cytokines in peripheral blood mononuclear cell cultures was followed under a variety of culture conditions, (a) phytohemagglutinin stimulated cells (PHA-MSC), (b) allogenic mixed cells (AMC) and (c) spontaneously proliferating cells (SPC). A dose dependent enhanced release of IL-6, IL-1 beta and TNF-alpha by hCG and hPL was observed under all culture conditions. However, an inhibitory effect on the IL-2 release was seen in PHA-MSC by hPL and in AMC by hPL and hCG. The role of the suppression of IL-2 production/release on cytotoxicity towards trophoblast is discussed. These results suggest a sensitive, dose dependent hormonal control of the modulation of the immune response during pregnancy and strengthen the concept of a distinct regulation of monocytes and lymphocyte subpopulation by trophoblast hormones.