NLRC5 potentiates anti-tumor CD8(+) T cells responses by activating interferon-β in endometrial cancer

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-β (IFN-β) 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-β overexpression or depletion. The effect of NLRC5 on IFN-β 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-β overexpression in the EC cell and CD8(+) T cell coculture system activated CD8(+) T cell proliferation; however, genetic depletion of IFN-β exerted the opposite effects. In addition, NLRC5 could negatively regulate IFN-β expression in EC cells. Mechanistically, NLRC5 potentiated the antitumor responses of CD8(+) T cells to EC by activating IFN-β. CONCLUSIONS: Taken together, our findings demonstrated that NLRC5 potentiates anti-tumor CD8(+) T cells responses by activating interferon-β in EC, suggesting that genetically escalated NLRC5 and IFN-β may act as potential candidates for the clinical translation of adjuvant immunotherapies to patients with EC.