Effect of rIL-10on HLA-G Expression in Endometrial Cells of Patients with Adenomyosis

BackgroundAdenomyosis is characterized by diffusion growth of ectopic endometrial glands and stroma in myometrium. Adenomyosis often causes pain and infertility and the rate of early miscarriage in this disease is higher in patients with adenomyosis. According to the recent studies, although the quantity of macrophages, natural killer cells, and T cells increase significantly, the immune system in patients with adenomyosis fail to eliminate the ectopic endometrium. The pathogenesis of adenomyosis is not clearly, it is believed to be related to the occurrence and immune tolerance. Human leukocyte antigen-G (HLA-G) is a non-classical MHC (major histocompatibility complex, MHC) class Ib antigen, it was first found to be restrictively expressed by the fetal-maternal interface on the extravillous cytotrophoblast. This molecule has been related initially to the tolerogenic microenvironment at the fetomaternal interface, protecting the semi-allogeneic fetus from the maternal immune system. We summarize the HLA-G molecules immunomodulatory function in the establishment and maintenance of immune tolerance by inhibiting the functions of immunocompetent cells:they can induce apoptosis in CD8-positive T cells, inhibit CD4-positive T-and B-cell proliferation, control natural killer cell lytic activity and restrain dendritic cell maturation, while leading regulatory T cell proliferation. HLA-G antigens have been detected in pathologic conditions such as autoimmune and infective diseases, tumors and transplantation.The expression of HLA-G molecules in transplanted organs and/or in recipient plasma/serum samples has been associated with a diminished rejection rate. It has been found that HLA-G was expressed both in eutopic endometrial stromal cells and glandular epithelial cells in patients with adenomyosis.It is believed that the HLA-G expressed in ectopic endometrium could make the endometrium evade from surveillance of immune system by approaches mentioned above. And the endometrium which do not express HLA-G could be identified and eliminated by the immune system. Also according to early studies, many cytokines such as IL-10can induce HLA-G expression. IL-10R plays an important role. This study tries to explore the functional role of IL-10molecules in induce of HLA-G expression in stromal cells and glandular epithelial cells in patients with adenomyosis. Our previous study reported that the expression of IL-10in patients with adenomyosis was higher than patients with uterine myoma, and HLA-G is also expressed by glandular epithelial and stromal cells. It was also found that in patients with adenomyosis, IL-10R2exists in the epithelial cells and stromal cells of endometrium but IL-10R1only exist in the glandular epithelial cells, and levels of HLA-G expression in patients with adenomyosis could be correlated with potential immunimodulatory. This study was performed with the aims to evaluate the induction function of IL-10about HLA-G expression both in glandular epithelial and stromal cells.ObjectiveTo explore the change of expression of human leukocyte antigen-G(HLA-G) via interleukin-10(IL-10) induction in stromal cells and glandular epithelium cells of patients with adenomyosis.MethodsLaboratory study using the human endometrium stromal cells and glandular epithelium cells obtained from25patients with adenomyosis undergoing hysterectomy. Two cells were divided into three groups:Control group was cultured for72h in culture dish containing DMEM/F12supplemented with100IU/ml of penicillin,100IU/ml of streptomycin and10%heat-inactivated fetal bovine serum (FBS) at37℃in5%CO2in air. Intervention group A cultured24h as control group, except anti-IL-10R1and anti-IL-10R2were added to the media, then using20ng/ml IL-10to stimulate cells for48h. Intervention group B cultured24h as control group, then using20ng/ml IL-10to stimulate cells for48h. HLA-G protein expression in two cells via IL-10induction with Flow cytometry assay, Western blotting and Immunofluorescence. Quantitative analysis of HLA-G protein expression via IL-10induction, according to Student’s t-test.ResultsImmunocytochemistry microscopy showed that in stromal cells, a lower level of HLA-G is expressed in the IL-10intervention group than Non-intervention group and IL-10receptor blocked group. Results Flow cytometry analysis showed that the intensity of HLA-G expression of Non-intervention group and IL-10receptor blocked group was significantly higher than that in IL-10intervention group (p<0.05). But in glandular epithelial cells, the results of immunohistochemistry and Western blotting assay showed a higher level of HLA-G expression is observed in IL-10intervention group than Non-intervention group and IL-10receptor blocked group.ConclusionIn endometrial cells, IL-10involves in the expression of HLA-G through the IL-10receptor indirectly. IL-10receptor blockers have no effect on HLA-G expression. The expression of HLA-G becomes higher when stimulated by IL-10through IL-10receptorl in glandular epithelium cells, and HLA-G becomes lower in the stromal cells which only have the IL-10receptor2.