Adaptive T cell immunotherapy in cancer

Impaired tumor-specific effector T cells contribute to tumor progression and unfavorable clinical outcomes. As a compensatoryT cell-dependent cancer immunoediting strategy, adoptive T cell therapy (ACT) has achieved encouraging therapeutic results,and this strategy is now on the center stage of cancer treatment and research. ACT involves the ex vivo stimulation and expansionof tumor-infiltrating lymphocytes (TILs) with inherent tumor reactivity or T cells that have been genetically modified to expressthe cognate chimeric antigen receptor or T cell receptor (CAR/TCR), followed by the passive transfer of these cells into alymphodepleted host. Primed T cells must provide highly efficient and long-lasting immune defense against transformed cellsduring ACT. Anin-depth understanding of the basic mechanisms of these living drugs can help us improve upon currentstrategies and design better next-generation T cell-based immunotherapies. From this perspective, we provide an overview ofcurrent developments in different ACT strategies, with a focus on frontier clinical trials that offer a proof of principle. Meanwhile,insights into the determinants of ACT are discussed, which will lead to more rational, potent and widespread applicationsin the future.