CONSTITUTIVE SECRETION OF INTERLEUKIN-6 BY HUMAN DECIDUAL STROMAL CELLS IN CULTURE - REGULATORY EFFECT OF PROGESTERONE

PROBLEM: Although several studies have demonstrated that decidual stro mal cells (DSC) can secrete cytokines in culture, none of these studie s documented the purity of the cultures. Since other cells of the deci dua, such as macrophages and epithelial cells, also produce cytokines, it is important to ensure purity of the culture so that cytokine prod uction can be ascribed with confidence to DSC. METHOD: DSC from early human pregnancies were highly purified and maintained in culture. Basa l secretion by these cells of IL-6, together with other cytokines cons idered critical for pregnancy (IL-1 beta, TNF alpha and IFN gamma), wa s measured with immunological techniques. RESULTS: We found that DSC i n culture produce insignificant quantities of IL-1 beta, TNF alpha and IFN gamma, but appreciable amounts of IL-6. The production of this la ter cytokine was, however, inhibited by the effect of progesterone. CO NCLUSIONS: Basal production of IL-6 by DSC may be involved in physiolo gical functions at the maternal-fetal interface. Nevertheless, the sec retion of this cytokine is regulated by progesterone, probably to prev ent excessive production of this cytokine from triggering an inflammat ory response that might compromise pregnancy.