Mannose receptor is highly expressed by peritoneal dendritic cells in endometriosis

OBJECTIVES: To characterize peritoneal dendritic cells (DCs) in endometriosis and to clarify their role in its etiology. DESIGN: Experimental. SETTING: University hospital. PATIENT(S): Sixty-three women (35 patients with endometriosis and 28 control women) who had undergone laparoscopic surgery. INTERVENTION(S): Peritoneal DCs from endometriosis and control samples were analyzed for the expression of cell surface markers. Monocyte-derived dendritic cells (Mo-DCs) were cultured with dead endometrial stromal cells (dESCs) to investigate changes in phagocytic activity and cytokine expression. MAIN OUTCOME MEASURE(S): Cell surface markers and cytokine expression and identification with the use of flow cytometry or reverse-transcription polymerase chain reaction (RT-PCR). Changes in cytokine expression and phagocytic activity of Mo-DCs cultured with dESCs and d-mannan were measured with the use of flow cytometry and RT-PCR. RESULT(S): The proportion of mannose receptor (MR)-positive myeloid DC type 1 was higher in endometriosis samples than in control samples. The blocking of MR reduced phagocytosis of dESCs by Mo-DCs. Mo-DCs cultured with dESCs expressed higher levels of interleukin (IL) 1β and IL-6 than control samples. CONCLUSION(S): Peritoneal DCs in endometriosis tissue express high levels of MR, which promotes phagocytosis of dead endometrial cells and thereby contributes to the etiology of endometriosis.