West Nile virus (WNV) and Japanese encephalitis virus (JEV), the members of JEV serocomplex group are pathogens of global health concern. The co-circulation of these viruses poses challenges in effective diagnostics due to antigenic similarity between the E-
protein of these viruses. The present study aimed to design chimeric
peptides and study the immune response against the same.
B-cell epitopes were predicted on structural
proteins of WNV and JEV based on bioinformatics tools. The
peptides representing to these
B-cell epitopes were synthesized and subjected to ELISA. Two
peptides, one each from WNV (named WE147) and JEV (named JE40) E-
protein, showed virus-specific and strong reactivity to the immune mice sera and human clinical samples. The chimeric
peptides for WNV and JEV were constructed by synthesizing the
B-cell epitope of WNV (WE147) or JEV (JE40) with T-helper
epitope (JM17) separated by
diglycine spacer in between. The immune response generated against these chimeric
peptides was found to be specific to the respective
B-cell epitopes. The anti-
peptide sera showed virus-specific reactivity in ELISA and in immunofluorescence assay with no cross-reactivity. Also, the anti-
peptide sera could neutralize JE and WN viruses in an in vitro virus neutralization assay. The
B-cell epitopes identified in the present study may be used as diagnostic markers for differentiating between WN and JE
virus infections. The present study can form a basis for future design of
vaccines.