Sulfonium-Stapled Peptides-Based Neoantigen Delivery System for Personalized Tumor Immunotherapy and Prevention

Neoantigen peptides hold great potential as vaccine candidates for tumor immunotherapy. However, due to the limitation of antigen cellular uptake and cross-presentation, the progress with neoantigen peptide-based vaccines has obviously lagged in clinical trials. Here, a stapling peptide-based nano-vaccine is developed, comprising a self-assembly nanoparticle driven by the nucleic acid adjuvant-antigen conjugate. This nano-vaccine stimulates a strong tumor-specific T cell response by activating antigen presentation and toll-like receptor signaling pathways. By markedly improving the efficiency of antigen/adjuvant co-delivery to the draining lymph nodes, the nano-vaccine leads to 100% tumor prevention for up to 11 months and without tumor recurrence, heralding the generation of long-term anti-tumor memory. Moreover, the injection of nano-vaccine with signal neoantigen eliminates the established MC-38 tumor (a cell line of murine carcinoma of the colon without exogenous OVA protein expression) in 40% of the mice by inducing potent cytotoxic T lymphocyte infiltration in the tumor microenvironment without substantial systemic toxicity. These findings represent that stapling peptide-based nano-vaccine may serve as a facile, general, and safe strategy to stimulate a strong anti-tumor immune response for the neoantigen peptide-based personalized tumor immunotherapy.