CAR-NK cells with dual targeting of PD-L1 and MICA/B in human lung cancer H1299 cell tumor model

Abstract Background Chimeric antigen receptor (CAR) engineered natural killer (NK) cells have shown their efficacy and superiority against cancer and possess the potential to become off-the-shelf immunotherapy products. Nonetheless, some challenges associated with CAR-NK cells still exist including inhibitory receptor engagement, antigen escape, and inadequate activation. Methods Given this, based on the concept of synthetic biology, we rationally designed a novel dual-targeted CAR (dtCAR), primarily comprising PD-L1 nanoantibody (PD-L1Nb) and NKG2D as the ectodomain, transmembrane and cytoplasmic domains (CP) of CD28, and the CP of 41BB and CD3ζ. NK92 cells were engineered to express this third-generation of dtCAR. We then elucidated the role of dtCAR-modified NK92 cells against cancer cells in vitro and in vivo. Results In vitro , the dtCAR-NK92 cells could still retain the characteristics of parental NK cells and exhibit improved NK cell cytotoxicity and produce more cytokines than NK92 cells when they were co-cultured with human lung cancer H1299 cells. Notably, the dtCAR-NK92 cell therapy might elicit clearance of H1299 cells by pyroptosis. Additionally, dtCAR-NK92 cells could considerably inhibit tumor growth in the human lung cancer H1299 cell tumor model. Conclusions We confirmed that expression of dtCAR enhanced NK92-cell activation and killing in vitro and in vivo, which provides a novel immunotherapeutic strategy for using NK-tailored CAR-engineered NK92 cells to treat human lung cancer.