Autophagy Suppresses CD8+ T cell Anti-tumour Immunity

Here we demonstrate that inactivation of the essential autophagy genes, Atg5, Atg14, or Atg16L1 results in tumour rejection. Despite a significant reduction in the total number of CD8+ tumour infiltrating lymphocytes (TILs), loss of Atg5 causes a profound shift toward IFNg and TNF producing effector memory cells. Consistent with this, adoptive transfer with Atg5-/- T cells promotes tumour control. Mechanistically, CD8+ T cells lacking autophagy exhibit enhanced glucose metabolism resulting in global changes in histone trimethylation and increased transcriptional activation of effector target genes. Restricting glucose is sufficient to suppress autophagy-dependent increases in effector function and reverse alterations in histone trimethylation. These findings identify autophagy as a cell-autonomous negative regulator of CD8+ T cell anti-tumour immunity with implications on T cell-based immunotherapy. Overall design: Examination of two different histone modifications in CD8+ tumour-infiltrating lymphocytes from wild-type (WT) and Atg5-/- (KO) mice.