ABSTRACT
T-cell exhaustion is characterized by the stepwise and progressive loss of T cell functions under conditions of antigen-persistence, which occurs following chronic infections and tumor outgrowth. Exhausted T cells present functional defects, express multiple inhibitory receptors and show reprogrammed transcriptional regulation. As T cell exhaustion is correlated to its dysfunction to control infections and tumors, exploring new strategies to target exhausted T cell may reverse this dysfunctional state and reinvigorate immune response. This study takes CD8+ T cell as an example, which acts as an important subset involved in exhaustion state, discuss current understanding of the properties of exhausted T cell and the mechanisms that promote and maintain this state, and reveal new therapeutic targets for chronic infection and cancer.