The roles of polymorphonuclear myeloid-derived suppressor cells in endometriosis.

Abstract Objectives This study aimed to determine the systemic and local proportions, focal localization, and characteristics of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in endometriosis. Study design Peripheral blood and peritoneal fluid were obtained from patients with a benign gynecologic condition (controls) or endometriosis. PMN-MDSCs were defined as CD33+HLA-DRlow/−CD14−CD15+ and monocytic (M)-MDSCs were defined as CD33+HLA-DRlow/−CD14+CD15−, and were identified using flowcytometry. Ovarian endometriotic tissues were obtained, and the expression of lectin-type oxidized low density lipoprotein receptor-1 (LOX1) as a marker of PMN-MDSCs, arginine 1 (Arg1), and matrix metalloproteinase 9 (MMP9) were detected using immunohistochemistry. Anti-Ly6G antibody was administered to endometriosis model mice, and the number and weight of the lesions were measured, and cell proliferations and apoptosis in the lesions were analyzed using Ki67 immunohistochemistry and TUNEL assay. Results In the peripheral blood, the proportion of PMN-MDSCs was significantly higher in endometriosis (3.20 vs 1.63 %, p Conclusions PMN-MDSCs may contribute to the pathogenesis of endometriosis via Arg1 and MMP9 expression.