CD4 and CD8 but not dn mucosa-associated invariant T cells foster the development of endometriosis: a pilot study

Abstract

Our study aims to demonstrate the relationship between Mucosa-associated invariant T (MAIT) cells and endometriosis. Case-control study. The study group comprised 32 patients with a diagnosis of endometriosis.18 women with only ovarian benign cysts or uterine leiomyoma who underwent laparoscopy were recruited as control group. Peritoneal fluid (PF) was collected during laparoscopy. Peripheral blood (PB) was obtained shortly before the surgery. We investigated MAIT cells and their different subpopulations in PB and PF from endometriosis (EMS) and control group (CG). MAIT cells were characterized as CD3+CD161+Vα7.2+ cells by flow cytometry. Next based on CD4 and CD8, the cells were divided into three subsets: CD8 MAIT cells, CD4/CD8-/- (double negative, DN) MAIT cells and CD4 MAIT cells. And IL-8, 12, 18, 17, MMP-9, INF-g from the peritoneal fluid and plasma were analyzed by ELISA kit. Our results revealed that there were enrichments of MAIT cells, especially CD4 and CD8 MAIT subset. Moreover, CD8 MAIT cells had a greater activation in EMS group as compared to the results from CG patients. In line with this data, EMS patients produced higher level of IL-8/12/17 as compared to these from controls. On the contrary, control patients exhibited a dramatic upregulation of DN MAIT cells, however, these DN MAIT cells from controls showed a higher expression of PD-1. At the end we performed the relevance analysis, and we discovered that the accumulation of PB MAIT cells correlated with elevated level of serum CA125 production. Our study suggests functional diversities of MAIT cells subsets in the development of endometriosis. CD4 and CD8 MAIT cells could be a promoter in endometriosis, whereas DN MAIT cells might be a protector for the host.