Melanoma-intrinsic NR2F6 activity regulates anti-tumor immunity
Nuclear receptors (NRs) are implicated in the regulation of tumors and immune cells. We identify a tumor-intrinsic function of the orphan NR, NR2F6, regulating anti-tumor immunity. NR2F6 was selected from 48 candidate NRs, based on an expression pattern in melanoma patient specimens (i.e., IFN? signature) associated with positive responses to immunotherapy and favorable patient outcomes. Correspondingly, genetic ablation of NR2F6 in a mouse melanoma model conferred a more effective response to PD-1 therapy. NR2F6 loss in B16F10 and YUMM1.7 melanoma cells attenuated tumor development in immune-competent but not -incompetent mice via the increased abundance of effector and progenitor-exhausted CD8+ T cells. Inhibition of NACC1 and FKBP10, identified as NR2F6 effectors, phenocopied NR2F6 loss. Remarkably, inoculation of NR2F6 KO mice with NR2F6 KD melanoma cells further decreased tumor growth compared with NR2F6 WT mice. Tumor-intrinsic NR2F6 function complements its tumor-extrinsic role and justifies the development of novel anti-cancer therapies. Overall design: Gene expression comparisons of  NR2F6 KO and control in bulk tumors, MACS-sorted tumor cells, and cultured cells using RNA-seq.