A novel mRNA-based therapeutic vaccine elicits robust anti-tumor immunity against HPV-associated malignancies.

Background: Human papillomavirus (HPV) infection is strongly associated with multiple malignancies, primarily driven by the viral oncoproteins E6 and E7, which play a central role in HPV-induced malignant transformation. Although current prophylactic HPV vaccines have shown remarkable efficacy in preventing initial infections, there remains an urgent need for therapeutic vaccines targeting pre-existing HPV infections and HPV-associated malignancies. Methods: In this study, we developed TriStim-E6/E7, a novel HPV mRNA vaccine that combines E6/E7 antigens with three T cell co-stimulatory molecules (CD80, 4-1BBL, and CD70). The TriStim-E6/E7 mRNA was encapsulated in lipid nanoparticles (LNPs) and administered intramuscularly to mice, followed by analysis of cellular immunogenicity. The anti-tumor efficacy of TriStim-E6/E7 mRNA was evaluated using an HPV-positive TC-1 tumor model. Results: Administration of TriStim-E6/E7 mRNA elicited robust antigen-specific cellular immune responses and achieved complete regression of HPV-positive TC-1 tumors in a syngeneic mouse model. The vaccine also demonstrated durable immunoprotection, preventing tumor recurrence upon rechallenge. Through targeted T cell depletion experiments, we established that CD8 Conclusions: These findings collectively demonstrate the promising therapeutic potential of TriStim-E6/E7 mRNA for clinical translation against HPV-associated malignancies.