Acetate promotes T cell effector function during glucose restriction [ATAC-seq]

Competition for nutrients like glucose can metabolically restrict T cells and contribute to their hyporesponsiveness during cancer. Metabolic adaptation to the surrounding microenvironment is therefore key for maintaining appropriate cell function. For instance, cancer cells use acetate as a substrate alternative to glucose to fuel metabolism and growth. Here we show that acetate rescued effector function in glucose-restricted CD8+ T cells. Mechanistically, acetate promoted histone acetylation and chromatin accessibility, and enhanced IFN-γ gene transcription and cytokine production in an acetyl-CoA synthetase (ACSS)-dependent manner. Ex vivo acetate treatment increased IFN-γ production by exhausted T cells, while reducing ACSS expression in T cells impaired IFN-γ production by tumor-infiltrating lymphocytes and tumor clearance. Thus, hyporesponsive T cells can be epigenetically remodeled and reactivated by acetate, suggesting that pathways regulating the use of substrates alternative to glucose could be therapeutically targeted to promote T cell function during cancer. ATAC-seq was performed on acute (24h) or prolonged (120h) glucose restriction (1mM) CD8+ T cells exposed or not to 5mM Acetate.