Comprehensive mapping of common immunodominant epitopes in the eastern equine encephalitis virus E2 protein recognized by avian antibody responses.
Authors: Sun Encheng, Zhao Jing, Sun Liang, Xu Qingyuan, Yang Tao, Qin Yongli, Wang Wenshi, Wei Peng, Sun Jing, Wu Donglai
Journal: PloS one
Summary
# Editorial Summary: Immunodominant Epitopes in Eastern Equine Encephalitis Virus E2 Protein Eastern equine encephalitis virus (EEEV) poses a significant disease risk across both equine and avian populations, yet the specific antibody binding sites on its E2 surface protein—critical for developing robust diagnostic and vaccine strategies—have remained poorly characterised in birds. Sun and colleagues mapped the avian antibody response to EEEV E2 by immunising chickens and ducks with recombinant E2 protein, then screening their sera against 42 overlapping peptides spanning the entire protein sequence. They identified 12 and 13 distinct epitopes recognised by chicken and duck antibodies respectively, with six epitopes common to both species; notably, two of these common epitopes (amino acids 211–226 and 331–352) were conserved across all EEEV strains but absent from related alphaviruses, whilst three others (amino acids 11–26, 30–45 and 151–166) were unique to EEEV subtype I. For equine professionals involved in disease management, these findings offer a molecular foundation for developing more specific and sensitive serological tests to distinguish EEEV from other viral exposures, and provide a rational framework for designing peptide-based vaccines that could elicit protective immunity without the risks associated with whole-virus immunisation. The characterisation of these conserved yet EEEV-specific epitopes may ultimately enable faster field diagnosis and more targeted immunisation strategies in at-risk equine populations.
Read the full abstract on PubMed
Practical Takeaways
- •Understanding EEEV E2 protein epitopes supports development of more specific diagnostic tests to differentiate EEEV from other avian viral infections
- •Identified epitopes provide targets for rational vaccine design that could reduce EEEV infection rates in susceptible bird populations serving as viral reservoirs
- •Knowledge of cross-species antibody recognition patterns helps explain transmission dynamics between avian species and equine populations in endemic regions
Key Findings
- •Twelve and thirteen E2 protein peptide epitopes were recognized by chicken and duck antibody responses respectively following EEEV immunization
- •Six linear peptides were commonly recognized by both avian species, with epitopes at amino acids 211-226 and 331-352 conserved across EEEV antigenic complex
- •Five common epitopes were specific to EEEV and did not cross-react with Avian Influenza Virus or Duck Plague Virus antibodies