IL-2 and IL-27 synergistically promote growth and invasion of endometriotic stromal cells by maintaining the balance of IFN-γ and IL-10 in endometriosis

Immune cells and cytokines have important roles in the pathogenesis of endometriosis. However, the production and role of cytokines of T helper type 1 (Th1) and Th2 cells in the progress of endometriosis have remained to be fully elucidated. The present study reported that the interferon (IFN)-γ levels and the percentage of IFN-γ+CD4+ cells were significantly increased in the peritoneal fluid (PF) at the early stage and maintained at a higher level at the advanced stage of endometriosis; furthermore, interleukin (IL)-10 and IL-10+CD4+ cells were elevated in the advanced stage of endometriosis. In addition, IL-2 levels in the PF at the advanced stage of endometriosis were elevated and negatively associated with IFN-γ expression. In a co-culture system of ectopic endometrial stromal cells (ESCs) and macrophages, elevated IL-2 was observed, and treatment with cytokines IL-2 and transforming growth factor-β led to upregulation of the ratio of IL-2+ macrophages. IL-27-overexpressing ESCs and macrophages were able to induce a higher ratio of IL-10+CD4+ T cells. Blocking of IL-2 with anti-IL-2 neutralizing antibody led to upregulation of the ratio of IFN-γ+CD4+ T cells in the co-culture system in vitro. Recombinant human IL-10 and IFN-γ promoted the viability, invasiveness and transcription levels of matrix metalloproteinase (MMP)2, MMP9, and prostaglandin-endoperoxide synthase 2 of ESCs, particularly combined treatment with IL-10 and IFN-γ. These results suggest that IL-2 and IL-27 synergistically promote the growth and invasion of ESCs by modulating the balance of IFN-γ and IL-10 and contribute to the progress of endometriosis.