Background: Many epidemic outbreaks of Chikungunya fever (CHIKF) have been reported throughout the world including India after its reemergence in 2005. The immuno protective role of envelope proteins during Chikungunya virus (CHIKV) infection has been reported. With the aim of identifying the immunodominant epitopes within the envelope protein we investigated the detailed analysis of fine specificity of antibody response in different individuals during CHIKV infection.
Methods: The peptides corresponding to the full length of E1, E2 and E3 proteins of S27 strain of CHIKV were synthesized and their seroreactivity with CHIKV positive patients' sera collected from different epidemic regions of India was determined using indirect ELISA.
Results: The data analysis reveals many potent epitopes throughout the length of envelope E2 protein thus displaying it as the most promising antigen for diagnostic purpose. We found that the main IgG isotype response to envelope protein was predominantly of subclass IgG3. Interestingly, most of the epitopes were found to be conserved for detecting IgM, IgG and IgG3 antibody response.
Conclusions: Peptides E2P3, E2P7, E2P16 and E2P17 were revealed as the most immunodominant peptides that together can form the basis for designing an accurate, economical and easy to synthesize a peptide-based immunodiagnostic for CHIKV. This study provides new and important insight into the humoral response generated by CHIKV S27 strain during the early phase of infection.