Decidual cytokines and complications of pregnancy

Abstract

uterine-draining lymphnodesbefore the implantation, and moved to the uterus after implantation. When a seminal vesicle-removed DBA/2 male mouse mated with a BALB/c female mouse, PA-Treg did not increase in the uterinedraining lymph nodes, suggesting that seminal plasma might play an important role in the induction of PA-Treg at the feto-maternal interface. Our recent data showed that seminal plasma-priming reduced the expression of MMCclass II and CD86 on uterine dendritic (u-DC) cells and enhanced the expression of B7-HC on u-DC cells, suggesting that seminal plasma might have induced the induction of tolerogenic DC in pregnant uterus. In human pregnancy, we have studied the population of CD4+Foxp3bright CD45RA−-functional Treg, CD4+Foxp3dimCD45RA+-naive Treg cells and CD4+Foxp3dim CD45RA−-activated T cells in the decidua of miscarriage cases. Functional Treg cells decreased and Foxp3+-activated T cells increased in the decidua ofmiscarriagewith normal chromosomal embryo. But these levels did not change in the decidua of miscarriage with abnormal chromosomal embryo, suggesting that decreased-functional Treg cells might induce miscarriage in humans. Samstein et al. reported that extrathymic Treg cells play a central role in the maintenance of allogeneic pregnancy in mice, but our data showed that Helios—extrathymic Treg cells constituted a minor population in human decidua and that these levels did not change in miscarriage with normal chromosomal embryo suggesting that thymic Treg cellsmight be important in the maintenance of pregnancy in humans.