Chimeric antigen receptor natural killer cells: a promising antitumor immunotherapy

Abstract

Chimeric antigen receptor (CAR) T cells have been successfully used in adoptive cell therapy for malignancies. However, some obstacles, including side effects such as graft‐versus‐host disease and cytokine release syndrome, therapy resistance, limited sources, as well as high cost, limited the application of CAR T cells. Recently, CAR natural killer (NK) cells have been pursued as the effector cells for adoptive immunotherapy for their attractive merits of strong intrinsic antitumor activity and relatively mild side effects. Additionally, CAR NK cells can be available from various sources and do not require strict human leukocyte antigen matching, which suggests them as promising “off‐the‐shelf” products for clinical application. Although the use of CAR NK cells is restrained by the limited proliferation and impaired efficiency within the immunosuppressive tumor microenvironment, further investigation in optimizing CAR structure and combination therapies will overcome these challenges. This review will summarize the advancement of CAR NK cells, CAR NK cell manufacture, the clinical outcomes of CAR NK therapy, the challenges in the field, and prospective solutions. Besides, we will discuss the emerging application of other immune cells for CAR engineering. Collectively, this comprehensive review will provide a valuable and informative summary of current progress and evaluate challenges and future opportunities of CAR NK cells in tumor treatment.

Natural killer cells in cancer immunotherapy

“… 54 , 55 With the rapid development of chimeric antigen receptor T (CAR‐T) cell therapy, NK cell has gained attention as an alternative to T cell in the field of immune cell engineering because of its intrinsic cytotoxicity, high efficacy and controllable adverse effects. 56 The first CAR‐NK‐cell clinical trials (NCT00995137) started in 2009, recruited 14 patients under the age of 18 years. CAR‐T cells with chimeric activating receptor NKG2D were also reported.…”