Dual blockade of PD-1 and NKG2A prevents NK cell senescence and reprograms the immunosuppressive microenvironment in pancreatic cancer

Immune checkpoint blockade (ICB) shows limited efficacy in pancreatic ductal adenocarcinoma (PDAC). Here, we demonstrate that ICB-induced IFN-γ signaling upregulates H2-T23 on pancreatic tumor cells, which interacts with NKG2A on NK cells to induce NK cell senescence through activation of p38 MAPK and STAT1/3 pathways. This impairs NK cell cytotoxicity and restricts antitumor immunity. Dual blockade of PD-1 and NKG2A effectively prevents NK cell senescence, restores NK cell function, and enhances antitumor immunity. Mechanistically, the combination therapy promotes NK cell-derived CCL5 and facilitates CD8⁺ T cell recruitment in an NK cell-dependent manner, thereby activating both innate and adaptive immunity. Analysis of single-cell sequencing data across nine cancer types further revealed increased NK cell senescence after immunotherapy, suggesting a potentially common pan-cancer mechanism. These findings identify NK cell senescence as a key mechanism underlying immunotherapy resistance and support dual targeting of PD-1 and NKG2A as a promising therapeutic strategy for PDAC.