A Novel Recombinant Virus-Like Particles Displaying B and T Cell Epitopes of Japanese Encephalitis Virus Offers Protective Immunity in Mice and Guinea Pigs.

Virus-like particles (VLPs) are non-replicative vectors for the delivery of heterologous epitopes and are considered one of the most potent inducers of cellular and humoral immune responses in mice and guinea pigs. In the present study, VLP-JEVe was constructed by the insertion of six Japanese encephalitis virus (JEV) envelope protein epitopes into different surface loop regions of PPV VP2 by the substitution of specific amino acid sequences without altering the assembly of the virus; subsequently, the protective efficacy of this VLP-JEVe was evaluated against JEV challenge in mice and guinea pigs. Mice immunized with the VLP-JEVe antigen developed high titers of neutralizing antibodies and 100% protection against lethal JEV challenge. The neutralizing and hemagglutination inhibition (HI) antibody responses were also induced in guinea pigs vaccinated with VLP-JEVe. In addition, immunization with VLP-JEVe in mice induced effective neutralizing antibodies and protective immunity against PPV (porcine parvovirus) challenge in guinea pigs. These studies suggest that VLP-JEVe produced as described here could be a potential candidate for vaccine development.