Abstract
Natural killer (NK) cells are a unique subset of cytotoxic lymphocytes within the innate immune system. They play a pivotal role in antiviral and antitumor immunity. NK cell-based adoptive immunotherapy has advanced rapidly in recent years. Innovative approaches, such as autologous/haploidentical NK cell infusion, chimeric antigen receptor NK cells, and NK cell engagers, have emerged, demonstrating promising potential in the treatment of various diseases. Currently, enhancement strategies for NK cell therapy primarily focus on two key aspects: improving expansion efficiency and persistence, with a positive effect on the therapy's potency and cytotoxic efficacy. The present review systematically introduces the functional mechanisms of NK cells and their specialized functional subsets. This review discusses the progress and optimization methods of NK cell therapy and provides an outlook on future research directions.