Changes of Th17/Tc17 and Th17/Treg cells in endometrial carcinoma

T helper 17 (Th17), T cytotoxic 17 (Tc17) and regulatory T (Treg) cells are important factors in the pathogenesis of inflammatory and autoimmune diseases. However, information concerning the roles of these cells in antitumor immunity or endometrial tumorigenesis remains limited. In this study, we aimed to describe the distribution of Th17, Tc17 and Treg cells in endometrial carcinoma patients, and elucidate the probable role of these effector T cells.

We assessed the expression of interleukin (IL)-17 and Foxp3 in the peripheral blood of endometrial carcinoma patients and healthy controls by flow cytometry to determine the relative numbers of Th17, Tc17 and Treg cells. Th17 cells and Tc17 cells were counted as percentages of the total number of CD3(+) T cells; Treg cells were counted as a percentage of the total number of CD4(+) T cells. We also evaluated Th17 and Tc17 cells in tumor tissue by immunohistochemical staining. IL-17 and IL-10, dominant products of these three cell types, were detected by using enzyme-linked immunosorbent assays.

The frequencies of Th17, Tc17 and Treg cells, as well as the serum level of IL-10, were significantly elevated in endometrial carcinoma patients compared to healthy controls. The Th17/Tc17 and Th17/Treg ratios were also observed to change significantly. However, there was no significant difference on the IL-17 levels in the serum. Additionally, immunohistochemistry performed on tumor tissues indicated that the amounts of Th17 and Tc17 increased in the cancer patients.

Our data suggests a probable involvement of Th17, Tc17 and Treg cells in the pathogenesis of endometrial carcinoma. Restoring the balance of these cells may help with the research and development of immunotherapies for endometrial carcinoma.