A facile approach to enhance antigen response for personalized cancer vaccination

Existing strategies to enhance peptide immunogenicity for cancer vaccination generally require direct peptide alteration, which beyond practical issues may impact peptide presentation and result in vaccine variability. Here, we report a simple adsorption approach using polyethyleneimine (PEI) in a mesoporous silica micro-rod (MSR) vaccine to enhance antigen immunogenicity. The MSR-PEI vaccine significantly enhanced host dendritic cell activation and T cell response over the existing MSR vaccine and bolus vaccine formulations. Impressively, a single injection of the MSR-PEI vaccine using an E7 peptide completely eradicated large established TC-1 tumors in ~80% of mice and generated immunological memory. When immunized with a pool of B16F10 or CT26 neoantigens, the MSR-PEI vaccine eradicated established lung metastases, controlled tumor growth and synergized with anti-CTLA4 therapy. Our findings using three independent tumor models suggest that the MSR-PEI vaccine approach may serve as a facile and powerful multi-antigen platform to enable robust personalized cancer vaccination.