Herpesvirus entry mediator regulates the transduction of Tregs via STAT5/Foxp3 signaling pathway in ovarian cancer cells

The ratio of regulatory T cells (Treg) in peripheral blood of cancer patients has a closely correlation to the occurrence and development of ovarian cancer. In this study, our aim to explore the expression of herpesvirus entry mediator (HVEM) in ovarian cancer and its correlation with Tregs. The expression of HVEM in peripheral blood of ovarian cancer patients was detected by ELISA, and the ratio of CD4+ CD25 + Foxp3 positive Tregs cells was detected by flow cytometry. Ovarian cancer cell lines with high- and low-HVEM expression were constructed. CD4+ cells were co-cultured with ovarian cancer (OC) cells, and the expressions of IL-2 and TGF-β1 in the supernatant of cells were detected by ELISA, and western blot was used to detect the expressions of STAT5, p-STAT5, and Foxp3. The results indicated that the number of Treg cells in the peripheral blood of OC patients increased, and the expression of HVEM increased, the two have a certain correlation. At the same time, the overexpression of HVEM promoted the expression of cytokines IL-2 and TGF- β1, promoted the activation of STAT5 and the expression of Foxp3, leading to an increase in the positive rate of Treg, while the HVEM gene silence group was just the opposite. Our results showed that the expression of HVEM in OC cells has a positive regulation effect on Tregs through the STAT5/Foxp3 signaling pathway. To provide experimental basis and related mechanism for the clinical treatment of ovarian cancer.