Nanoparticle vaccine based on the envelope protein domain III of Japanese encephalitis virus elicits robust protective immune responses in mice

Abstract

Aim: To develop a vaccine candidate for Japanese encephalitis virus (JEV), for which an effective and safe vaccine is urgently needed. Materials & methods: A vaccine candidate based on domain III of the JEV envelope protein and lumazine synthase (EDIII–LS) was prepared by coupling multivalent ED III to a self-assembling nanoparticle of LS through genetic fusion and self-assembly. Results: High enrichment of ED III was achieved based on the self-assembly of an EDIII–LS polymer. EDIII–LS strongly promoted dendritic cells’ internalization and presentation compared with ED III monomer. The cellular and humoral immune responses provoked by EDIII–LS were remarkably higher than those caused by ED III in mice, and conferred complete protection against JEV challenge. Conclusion: The study of ED III-based nanoparticles suggests an effective approach against JEV.