The functional regulation of endometrial stromal cells on Treg cells in the endometriotic milieu

The study investigate the functional regulation of endometrial stromal cells on Treg cells in the ectopic milieu.The endometrial stromal cells(ESC)were separated from the eutopic endometrium of patients with endometriosis,and Treg cells were sorted by density gradient centrifugation and MACS.The ESC,regulatory T cells(Treg cells)culture alone or co-culture was established,respectively,and the co-culture were then treated with recombinant human proinflammatory cytokines,IL-1βor TNF-α.The TGF-β1concentrations in culture supernatant were quantified by ELISA kits.The expression of CTLA-4and transcription factor Stat3,Stat6 and Foxp3were analyzed by FCM.The expression of CTLA-4and Foxp3 were up-regulated in Treg cells when co-cultured with ESC.The secretion of TGF-β1was increased significantly in Treg cells in co-culture with ESC,IL-1βor TNF-αhad no further role.The expression of Stat3 and Stat6were up-regulated in Treg cells when co-cultured with ESC,and both IL-1βand TNF-αhad further promoted Stat3 expression,but only IL-1βhad further promoted Stat6 expression in Treg.Our study suggested that the ESC from the eutopic endometrium could enhance the immune suppression of Treg cells,which is easy to form an immune tolerance milieu in the ectopic milieu in the pathogenesis of endometriosis.