Stem cell mitochondrial transfer rejuvenates CAR-NKT cell metabolism and antitumor activity

Abstract Chimeric antigen receptor–engineered natural killer T (CAR-NKT) cells have emerged as a promising cancer immunotherapy owing to their potent antitumor activity, efficient tissue homing, and capacity to remodel the immunosuppressive tumor microenvironment (TME). Although strategies such as cytokine engineering and checkpoint blockade have improved CAR-NKT cell function, approaches that enhance their metabolic fitness remain limited. Here, we rejuvenate CAR-NKT cell metabolism and antitumor activity through induced pluripotent stem cell–derived mitochondrial transfer (iPSC-MT). iPSC-MT markedly enhances mitochondrial activity and metabolic fitness in CAR-NKT cells, resulting in improved effector function, memory formation, and persistence while limiting exhaustion. CAR-NKT cells enhanced by iPSC-MT (CAR-NKTMito) exhibit superior cytotoxicity in vitro and robust antitumor efficacy in vivo across multiple xenograft mouse models, including human lymphoma, liver cancer, and ovarian cancer. Notably, CAR-NKTMito cells exhibit enhanced TME modulation through effective targeting of CD1d⁺ myeloid cells, outperforming conventional iPSC-MT-enhanced CAR-T cells. Together, these findings establish mitochondrial transfer as a powerful organelle-level metabolic reprogramming strategy to enhance CAR-NKT cell function and provide a new therapeutic paradigm for improving cellular immunotherapy against cancer.