Metabolic plasticity and regulation of T cell exhaustion.

The metabolic reprogramming during T cell activation and differentiation affects T cell fate and immune responses. Cell metabolism may serve as the driving force that induces epigenetic modifications, contributing to regulating T cell differentiation. Persistent pathogen infection leads to T cell exhaustion, which is composed of two main subsets and with distinct metabolic characteristics. The progenitor exhausted T cells utilize mitochondrial fatty acid oxidation (FAO) and oxidative phosphorylation (OXPHOS) for energy, while terminally exhausted T cells mainly rely on glycolytic metabolism with impaired glycolysis and OXPHOS. Here, we compiled the latest research on how T cell metabolism defines differentiation, focusing on T cell exhaustion during chronic infections. In addition, metabolic-related factors including antigen stimulation signals strength, cytokines and epigenetics affecting T cell exhaustion were also reviewed. Furthermore, the intervention strategies on metabolism and epigenetics to reverse T cell exhaustion were discussed in detail, which may contribute to achieving the goal of prevention and treatment of T cell exhaustion.