A combination of immunoadjuvant nanocomplexes and dendritic cell vaccines in the presence of immune checkpoint blockade for effective cancer immunotherapy

摘要

Nanovaccines are used as delivery platforms for antigens and adjuvants, which activate antigen-presenting cells (APCs) and enhance anticancer immune responses.1,2 Researchers have recently developed a self-assembled nanocomplex using a polysorbitol-co-PEI (PSPEI) polymer complexed with poly(I:C) (PIC). By binding to different surface proteins, this nanocomplex enhances the intracellular delivery of cargos and induces potent anticancer immune responses against melanoma cells.3 We have previously demonstrated that PD-1/PD-L1 blockade enhanced the efficacy of DC-based cancer immunotherapy.4,5 Moreover, the combination of nanomedicines and PD-L1 blockade has been reported to enhance CD8+ T cell activation and inhibit immunosuppressive cells within the tumor microenvironment.6 In the present study, we investigated the therapeutic efficacy of a combinatorial treatment comprising the immunoadjuvant nanocomplex PSPEI-PIC, a DC vaccine, and PD-L1 blockade in a murine colon cancer model.