YTHDF2-m6A-NF-kB axis controls anti-tumor immunity through regulating intratumoral Treg survival and function

N6-methyladenosine (m6A) in messenger RNA (mRNA) regulates immune cells in homeostasis and in response to infection and inflammation. The function of YTHDF2 in the tumor microenvironment (TME) in these contexts has not been explored. We discovered that loss of Ythdf2 in regulatory T (Treg) cells can reduce tumor growth in mice while maintaining peripheral homeostasis. In the tumor microenvironment, Ythdf2-deficient Treg cells have impaired function and poor survival. The elevated tumor necrosis factor (TNF) signaling in the TME grants the location-specific function of YTHDF2, which participates in the feedback regulation of NF-kB signaling by accelerating the degradation of m6A-modified, NF-kB negative regulators, Nlrc3, Nfkbie, and Traf3. TME-specific regulation of Treg by YTHDF2 points to YTHDF2 as a target for anti-cancer immunotherapy, where intratumoral Treg cells can be targeted to enhance antitumor immune response, while avoiding Treg cells in the periphery to minimize undesired inflammations. Overall design: We performed m6A RIP-seq to examine m6A marked transcripts