Design and characterization of polytope construct with multiple B and TH epitopes of Japanese encephalitis virus.

Japanese encephalitis (JE) remains a major public health threat with vaccination as the only measure for its prevention. Epitope-based vaccination is a promising approach for achieving protective immunity and avoid immunopathology in Japanese encephalitis virus (JEV) infection due to flavivirus cross-reactivity. We have mapped B-cell epitopes from JEV envelope protein, responsible for elicitation of neutralizing antibodies. Incorporation of T helper (T(H)) epitopes, along with these, imparted protective immunity to the host. In the present study, based on in silico epitope selection we optimized and proposed a polytope DNA construct (P-JEV) consisting B-cell and T(H) epitopes from the JEV envelope (E) protein as well as non-structural protein-1 (NS1). The immunogenicity and protective efficacy of P-JEV was assessed by in vitro and in vivo experiments. The expressed P-JEV showed reactivity in in vitro assays with JEV monoclonal antibodies. Protective efficacy of P-JEV was assessed in BALB/c mice. Our findings indicate that P-JEV may be a candidate vaccine for the prevention of JEV infection.