Dual checkpoint blockade of PD-1 and Tim-3 by engineered hybrid nanovesicles for enhanced cancer immunotherapy

T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) is an inhibitory receptor expressed on immune cells, and its co-expression with programmed cell death protein 1 (PD-1) is an established mechanism of immune exhaustion and resistance to checkpoint blockade. To overcome this, we developed PD-1/Tim-3-decorated nanovesicles (PD-1/Tim-3 NVs) for combination immunotherapy against colorectal cancer. These vesicles selectively engaged the ligands PD-L1 and Galectin-9. In mice bearing CT26 xenografts, PD-1/Tim-3 NVs suppressed tumor growth by 69.0%, remodeled the tumor microenvironment by enhancing CD8⁺ T cell infiltration and activation, and depleting immunosuppressive regulatory T cells. Our findings highlight the promising potential of simultaneous PD-1 and Tim-3 blockade for treating advanced tumors.