T cell exhaustion and challenges of CAR-T cell therapy for solid tumors

Abstract

 CD19-redirected chimeric antigen receptor (CAR) T cell therapy has achieved remarkable success in hematological malignancies. However, targeting solid tumor is still challenging. T cell exhaustion is one of the major barriers in tumor microenvironment of solid tumors. In this review, we summarize the multifaceted mechanisms of T cell exhaustion and describe a new insight of CAR T cell exhaustion characterized by a T to NK like transition. Furthermore, the strategies to overcome T cell exhaustion to improve the efficacy of CAR T cell therapy will be addressed.