Regulation of the expression of Th17 cells and regulatory T cells by IL-27 in patients with unexplained early recurrent miscarriage.

In normal pregnancy, tolerance of the maternal immune system with regard to the genetically incompatible fetus depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicating that altered immunity exists in unexplained recurrent miscarriage (RM) has been dominated by the Th1/Th2 hypothesis. Recently, the Th1/Th2 paradigm has been expanded into the Th1/Th2/Th17 and regulatory T cells paradigm. We recently demonstrated a prevalence of Th17 cells, an inverse relationship between Th17 cells and regulatory T cells and deregulation of Th17 cells by regulatory T cells in early pregnancy in unexplained RM patients. In this study, we investigated the expression of IL-27 and the role of the cytokine IL-27 in the regulation of Th17/Treg expression. Quantitative real-time RT-PCR and Western blot analyses were performed to evaluate IL-27 expression in deciduas from unexplained RM patients, spontaneous miscarriage (SM) patients and healthy women following elective abortion in the early stages of normal pregnancy (control). Regulation of IL-17, TGF-β and IL-10 expression in CD4(+) T cells in unexplained RM patients by IL-27 was assessed using enzyme-linked immunosorbent assay (ELISA). Expression of IL-27 was lower in deciduas of patients with unexplained RM compared with SM and control subjects. IL-27 inhibited IL-17 expression and enhanced IL-10 expression in a dose-dependent manner. IL-27 had no effect on TGF-β expression. IL-27 regulates the expression of IL-17 and IL-10, which are predominantly secreted by Th17 cells and regulatory T cells in unexplained RM patients.