Preferential production of prostaglandin D2 by lipopolysaccharide stimulated human choriodecidual explants

It has been postulated that the progression of a pregnancy to term is, in part, the result of a relative maternal Th2 immunological state. Prostaglandins (PG) are critical mediators throughout pregnancy. Recent studies have demonstrated that one PG, PGD2, may be a mediator of a Th2 immunological state. To date, very little is known about the factors that regulate of PGD2 production by human gestational tissues. Placentae were collected from women undergoing Caesarean sections at term. Amnion was separated from the choriodecidua and choriodecidual explants established. Explants were allowed to equilibrate overnight in media containing 10% fetal calf serum. The following day, media were replaced with serum free media and then after an additional 24-h, media were collected and the wet weight of the tissues determined. Production rates of PGs were determined using radioimmunoassays. At all concentrations tested, LPS significantly enhanced PGD2 production by human choriodecidual explants compared to PGE2 and PGF2alpha production. Neutralization of TNF-alpha and IL-10 further increased the production of LPS stimulated PGD2 production. We suggest that a novel stimulatory pathway that drives the production of PGD2 has been uncovered.