Developing enhanced immunotherapy using NKG2A knockout human pluripotent stem cell-derived NK cells

Cancer immunotherapy is gaining increasing attention. However, immune checkpoints are exploited by cancer cells to evade anti-tumor immunotherapy. Here, we knocked out NKG2A, an immune checkpoint expressed on natural killer (NK) cells, in human pluripotent stem cells (hPSCs) and differentiated these hPSCs into NK (PSC-NK) cells. We show that NKG2A knockout (KO) enhances the anti-tumor and anti-viral capabilities of PSC-NK cells. NKG2A KO endows PSC-NK cells with higher cytotoxicity against HLA-E-expressing glioblastoma (GBM) cells, leukemia cells, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected cells in vitro. The NKG2A KO PSC-NK cells also exerted potent anti-tumor activity in vivo, leading to substantially suppressed tumor progression and prolonged survival of tumor-bearing mice in a xenograft GBM mouse model. These findings underscore the potential of PSC-NK cells with immune checkpoint KO as a promising cell-based immunotherapy. The unlimited supply and ease of genetic engineering of hPSCs makes genetically engineered PSC-NK an attractive option for easily accessible "off-the-shelf" cancer immunotherapy.