Mitochondrial Damage and the Road to Exhaustion.

Two recent studies published in Nature Immunology map out the link between dysregulated mitochondrial metabolism and terminal exhaustion of tumor-infiltrating T lymphocytes. Yu et al. (2020) and Vardhana et al. (2020) show that defective mitophagy or impaired oxidative phosphorylation triggers mitochondrial reactive oxygen species production, which in turn promotes a T cell exhaustion program, limiting T cell proliferation and self-renewal.