Sonic hedgehog (Shh) signaling is important in the growth and differentiation of many cell types and recently has been reported to play a role in T cell development in the thymus. This prompted us to investigate whether or not Shh contributes to the clonal expansion of peripheral CD4+ T cells. In this study, we demonstrate that Shh and other components of the signaling pathway patched, smoothened, and Gli1 (glioma-associated oncogene) are expressed in peripheral CD4+ T cells. The addition of the biologically active amino-terminal Shh peptide had no effect on resting CD4+ T cells, but significantly enhanced proliferation of anti-CD3/28 Ab-activated CD4+ T cells. This was not due to antiapoptotic effects, but by promoting entry of T cells into the S-G2 proliferative phase of the cell cycle. Neutralizing anti-Shh Ab reduced T cell proliferation by inhibiting cell transition into the S-G2 phase, suggesting that endogenously produced Shh plays a physiological role in the clonal expansion of T cells. Furthermore, we have observed a significant up-regulation of Shh and Gli1 (glioma-associated oncogene) mRNA in activated CD4+ T cells with or without addition of exogenous Shh, which corresponds with maximal CD4+ T cell proliferation, whereas bcl-2 was only up-regulated in activated cells in the presence of Shh. Our findings suggest that endogenously produced Shh may play a role in sustaining normal CD4+ T cell proliferation and exogenously added Shh enhances this response.

Sonic hedgehog (Shh) is important in the growth and differentiation of a variety of cell types, including the development of T cells in the thymus. This prompted us to investigate whether Shh signaling is a functional component of the physiological response of human mature CD4+ T cells following Ag recognition. In this study, we demonstrate that Shh and its receptor Patched (Ptc) are expressed on resting and activated human peripheral CD4+ T cells. In approximately one-half of the randomly selected, anonymous blood donors tested, exposure of anti-CD3/28 Ab-activated CD4+ T cells to the biologically active N-terminal Shh peptide increased the transcription of ptc, thereby demonstrating that Shh signaling had occurred. Furthermore, the addition of exogenous Shh amplified the production of IL-2, IFN-γ, and IL-10 by activated CD4+ T cells. The synthesis of IL-2 and IFN-γ, but not IL-10, by CD4+ T cells was down-regulated by the addition of neutralizing anti-Shh Ab. Cell surface expression of CD25 and CD69 on activated T cells was up-regulated by exogenous Shh, whereas in the presence of the neutralizing anti-Shh Ab expression it was reduced. Collectively, our findings demonstrate that Shh-mediated signaling is a physiological component of T cell responses, which acts to modulate CD4+ T cell effector function.

Context:The endometrium is a multicellular, steroid-responsive tissue that undergoes dynamic remodeling every menstrual cycle in preparation for implantation and, in absence of pregnancy, menstruation. Androgen receptors are present in the endometrium.Objective:The objective of the study was to investigate the impact of androgens on human endometrial stromal cells (hESC).Design:Bioinformatics was used to identify an androgen-regulated gene set and processes associated with their function. Regulation of target genes and impact of androgens on cell function were validated using primary hESC.Setting:The study was conducted at the University Research Institute.Patients:Endometrium was collected from women with regular menses; tissues were used for recovery of cells, total mRNA, or protein and for immunohistochemistry.Results:A new endometrial androgen target gene set (n = 15) was identified. Bioinformatics revealed 12 of these genes interacted in one pathway and identified an association with control of cell survival. Dynamic androgen-dependent changes in expression of the gene set were detected in hESC with nine significantly down-regulated at 2 and/or 8 h. Treatment of hESC with dihydrotestosterone reduced staurosporine-induced apoptosis and cell migration/proliferation.Conclusions:Rigorous in silico analysis resulted in identification of a group of androgen-regulated genes expressed in human endometrium. Pathway analysis and functional assays suggest androgen-dependent changes in gene expression may have a significant impact on stromal cell proliferation, migration, and survival. These data provide the platform for further studies on the role of circulatory or local androgens in the regulation of endometrial function and identify androgens as candidates in the pathogenesis of common endometrial disorders including polycystic ovarian syndrome, cancer, and endometriosis.