The employment of double-adjuvant nanoparticle to enhance immune responses for neoantigen vaccine

Cancer immunotherapy faces challenges in achieving durable antitumor immunity due to poor immunogenicity of tumor antigens and inadequate immune activation. In this study, we developed a self-assembling neoantigen nanoparticle vaccine (Neo-NV) integrating charge-modified Kirsten rat sarcoma viral oncogene homologue (KRAS) G12V-derived multi-epitope peptides with dual adjuvants—hydrophilic CpG oligonucleotides (ODNs) and hydrophobic R848. Neo-NV demonstrated enhanced antigen uptake by dendritic cells (DCs) in vitro, promoting DC maturation and M1 macrophage polarization, while stimulating robust neoantigen-specific CD8⁺ T cell responses. Additionally, Neo-NV enhanced the activation of antigen-specific T cells from human peripheral blood mononuclear cells (PBMCs) and their proliferation in immunodeficient NSG mice. Moreover, it significantly increased CD4⁺ and CD8⁺ T cell proliferation in the spleen and PBMCs of mice, while promoting the activation and aggregation of CD4⁺ and CD8⁺ T cells in the draining lymph nodes. In murine KRAS G12V melanoma models, Neo-NV significantly suppressed tumor growth and prolonged survival without systemic toxicity, as evidenced by stable body weight and normal hepatic/renal biomarkers. Mechanistically, Neo-NV enhanced tumor-infiltrating lymphocyte (TIL) activation and memory precursor T cell formation. This study establishes Neo-NV as a modular platform for personalized immunotherapy, highlighting the synergy of dual adjuvants and self-assembled nanoparticle in overcoming neoantigen immunogenicity barriers.