Adoptive immunotherapy for hematological malignancies: Current status and new insights in chimeric antigen receptor T cells

Hematological malignancies frequently express cancer-associated antigens that are shared with normal cells. Such tumor cells elude the host immune system because several T cells targeted against self-antigens are removed during thymic development, and those that persist are eliminated by a regulatory population of T cells. Chimeric antigen receptor-modified T cells (CAR-Ts) have emerged as a novel modality for tumor immunotherapy due to their powerful efficacy against tumor cells. These cells are created by transducing genes-coding fusion proteins of tumor antigen-recognition single-chain Fv connected to the intracellular signaling domains of T cell receptors, and are classed as first-, second- and third-generation, differing on the intracellular signaling domain number of T cell receptors. CAR-T treatment has emerged as a promising approach for patients with hematological malignancies, and there are several works reporting clinical trials of the use of CAR-modified T-cells in acute lymphoblastic leukemia, chronic lymphoblastic leukemia, multiple myeloma, lymphoma, and in acute myeloid leukemia by targeting different antigens. This review reports the history of adoptive immunotherapy using CAR-Ts, the CAR-T manufacturing process, and T cell therapies in development for hematological malignancies.