Original Article Mouse endometrial stromal cells and progesterone inhibit the activation and regulate the differentiation and antibody secretion of mouse B cells

* Equal contributors. Received October 20, 2013; Accepted November 18, 2013; Epub December 15, 2013; Published January 1, 2014 Abstract: The regulation mechanism for the B cells in the female reproductive tract (FRT) is unclear now. The aim of this study was to analysis the effect of progesterone and mouse endometrium stromal cells (ESCs) on B cells and explore it roles in modulating B cells-mediated immune responses. We primary isolated mouse ESCs from endome- trium of BALB/c mice and B cells from spleen cells of BALB/c mice, and then constructed these two kind of cells co-culture system, and treated with or without progesterone. We found that both treatment with progesterone and co-culture with ESCs reduced the expression of co-stimulatory molecules CD80 and CD86 on mouse B cells from spleen cells. In addition, the expression of CD138 (syndecan-1) on B cells was increased after co-culture with ESCs, however, progesterone could partly reduce this effect. Unlike progesterone, ESCs alone promoted the proliferation and stimulated the secretion level of antibodies IgG and IgA of B cells. Our current results progesterone and ESCs could inhibit the activation of B cells through deceasing CD80 and CD86 expression, regulated the differentiation status of B cells by up-regulating the expression of CD138 together, and might further inhibit the antigen presenta- tion function of B cells, which is beneficial to the establishment of fertilization and pregnancy. In addition, ESCs also promoted the proliferation and antibody secretion, which might participate in the resisting infections during non pregnancy and pregnancy.