Nutrient-driven histone code determines exhausted CD8+ T cell fates

Exhausted T cells (TEX) in cancer and chronic viral infections undergo metabolic and epigenetic remodeling, impairing protective capabilities. However, the impact of nutrient metabolism on epigenetic modifications that control TEX differentiation remains unclear. Our study reveals that TEX cells shift from acetate to citrate metabolism by downregulating acetyl-CoA synthetase 2 (ACSS2) while maintaining ATP-citrate lyase (ACLY) activity. This metabolic switch increases citrate-dependent histone acetylation, mediated by histone acetyltransferase KAT2A-ACLY interactions, at TEX signature-genes while reducing acetate-dependent histone acetylation, dependent on p300-ACSS2 complexes, at effector and memory T cell genes. Nuclear ACSS2 overexpression or ACLY inhibition prevents TEX differentiation and enhances tumor-specific T cell responses. These findings unveil a nutrient-driven histone code governing CD8+ T cell differentiation, with implications for metabolic- and epigenetic-based T cell therapies Overall design: Gene expression profile at single cell level of tumor infiltrating immune cells in MC38 tumor model