Involvement Of Mucosal-associated Invariant T Cells And Myeloid-derived Suppressor Cells In Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome（PCOS）is a kind of endocrine disease which is common in women of childbearing age.Many PCOS patients are accompanied by metabolic disorders.It has been reported that the frequency and function changes of various immune cells may be related to the occurrence and development of PCOS.The aim of this study is to explore the association of mucosal-associated invariant T（MAIT）cells and myeloid-derived suppressor cells（MDSCs）with PCOS.Methods: In this study,68 PCOS patients were recruited as the study group and 40 infertile women who received assisted reproductive technology because of male factors or fallopian tube factors were recruited as the control group.We collected the peripheral blood of participants during their follicular phase and extracted peripheral blood mononuclear cells by gradient centrifugation.The frequencies of MAIT cells and MDSCs were determined by flow cytometry after being stained with different monoclonal antibodies,and the concentrations of cytokines were determined by ELISA.Results: Compared to controls with normal metabolism,the frequency of MDSCs,CD8+MAIT cells and CD38+CD8+MAIT cells was significantly decreased in PCOS patients with normal metabolism.However,proportion of CD4+MAIT cells exhibited a noticeable increase.Similar results of CD8+MAIT,CD38+CD8+MAIT cells and reduced expression of interleukin 17 were observed in PCOS patients with metabolic dysfunction as compared to controls with metabolic disorders.PCOS patients with excessive testosterone levels displayed significantly decreased levels of CD8+MAIT,CD38+CD8+MAIT cells,MDSCs and Mo-MDSCs as compared to PCOS patients with normal testosterone concentrations.In the circulation of PCOS patients,MDSCs were positively correlated with MAIT cells.Overweight or obese PCOS patients showed a lower level and weaker activation of CD8+MAIT cells.On the contrary,they displayed an enrichment of CD4+MAIT cells.Negative correlations between the frequency of CD8+MAIT cells,CD38+CD8+MAIT cells and body mass index（BMI）were revealed.CD4+MAIT cells positively correlated with BMI.PCOS patients with glucose metabolic disorder displayed a remarkable dysregulation of MDSCs and Mo-MDSCs.Mo-MDSCs were found to be negatively related to the levels of 2 hour plasma glucose and HOMA-IR（homeostasis model assessment of insulin resistance）index.Conclusions: The frequency of CD8+MAIT cells,the main subset of MAIT cells,decreased significantly in the peripheral blood of overweight or obese PCOS patients,suggesting that the impairment of CD8+MAIT cells may be related to the occurrence of PCOS and lipid metabolism dysfunction.In the peripheral blood of PCOS patients,the frequency of MAIT cells decreased,and the effect of inducing the accumulation of MDSCs was weakened.The frequency of MDSCs of PCOS patients with glucose metabolism disorders showed a noticeable decrease,suggesting that the impairment of MDSCs may be related to the onset of PCOS and glucose metabolism disorders.