NLRC5 potentiates anti-tumor CD8+ T cells responses by activating interferon-ß in endometrial cancer.

ABSTRACT

OBJECTIVES: NLR family CARD domain containing 5 (NLRC5) could promote major histocompatibility complex class I (MHC-I)-dependent CD8+ T cell-mediated anticancer immunity. In this study, the immunosurveillance role and underlying mechanisms of NLRC5 in endometrial cancer (EC) were characterized. METHODS: CD8+ T cells were separated from healthy women's peripheral blood by using magnetic beads. The effect of NLRC5 and interferon-ß (IFN-ß) on immunosurveillance of EC were examined through a mouse tumor model and a CD8+ T cell-EC cell coculture system after NLRC5 overexpression and IFN-ß overexpression or depletion. The effect of NLRC5 on IFN-ß expression was examined with gain- and loss-of-function experiments. RESULTS: NLRC5 overexpression in the EC cell and CD8+ T cell coculture system inhibited EC cell proliferation and migration and promoted EC cell apoptosis and CD8+ T cell proliferation. In vivo, NLRC5 overexpression increased the proportion of CD8+ T cells and inhibited EC progression. Furthermore, IFN-ß overexpression in the EC cell and CD8+ T cell coculture system activated CD8+ T cell proliferation; however, genetic depletion of IFN-ß exerted the opposite effects. In addition, NLRC5 could negatively regulate IFN-ß expression in EC cells. Mechanistically, NLRC5 potentiated the antitumor responses of CD8+ T cells to EC by activating IFN-ß. CONCLUSIONS: Taken together, our findings demonstrated that NLRC5 potentiates anti-tumor CD8+ T cells responses by activating interferon-ß in EC, suggesting that genetically escalated NLRC5 and IFN-ß may act as potential candidates for the clinical translation of adjuvant immunotherapies to patients with EC.