Abstract
Chimeric antigen receptors (CAR) are fusion proteins engineered from antigen recognition, signaling, and costimulatory domains that can be used to reprogram T cells to specifically target tumor cells expressing specific antigens. Current CAR-T cell technology utilizes the patient's own T cells to stably express CARs and has achieved exciting clinical success in the past few years. However, current CAR-T cell therapy still faces several challenges, including suboptimal persistence and potency, impaired trafficking to solid tumors, local immunosuppression within the tumor microenvironment and intrinsic toxicity associated with CAR-T cells. This review focuses on recent strategies to improve the clinical efficacy of CAR-T cell therapy and other exciting CAR approaches currently under investigation, including CAR natural killer (NK) and NKT cell therapies.