Distribution and functions of T cells infiltrated in the ovarian cancer microenvironment

BackgroundThe role of T cells, innate-like lymphocytes with unrestrained MHC, in various malignancies has recently been extensively studied. However, there is limited research regarding T cells in ovarian cancer (OC) patients.MethodsHere, we investigated the distribution patterns of T cells and their main subsets in peripheral blood and tumor tissues among OC patients, benign ovarian tumor (BOT) patients, and age-matched healthy controls (HC) by flow cytometry, as well as the expression levels of IFN- and IL-17A secreted from T cells. Immunohistochemical staining was utilized to detect the numbers of T cells and their main subsets in different types of ovarian tumor tissues. Additionally, we also investigated chemotaxis effects on T cells, as well as their cytotoxic activity and proliferation.ResultsWe found that the percentages of T cells and V1 T cells were significantly higher in OC tissues than BOT tissues and normal (N) ovarian tissues, while there were no obvious differences in peripheral blood. Meanwhile, higher numbers of T cells and V1 T cells were observed in OC tissues, and were positively related to advanced clinicopathological features of OC patients. Further, the levels of IFN- secreted by T cells were relatively lower, while IL-17A was expressed at a high level in both the peripheral blood and tissues of OC patients. Chemotaxis assay revealed that supernatants derived from OC tissues possessed a stronger capacity to attract and recruit T cells. However, T cells sorted from OC tissues showed weakened cytotoxic activity against ovarian cancer cells, and T cells cocultured with OC tissue supernatants could effectively inhibit the proliferative activity of naive CD4(+) T cells.ConclusionsThese data suggested that T cells might have critical roles in OC progression and potential utilization in treatment approaches or prognosis prediction.