Antigenic mapping of African horse sickness virus

Journal: Equine Veterinary Journal

DOI: 10.1111/evj.14393 PubMed: 39599893Log in to save

Summary

# Editorial Summary: Antigenic Mapping of African Horse Sickness Virus The 2020 emergence of African horse sickness virus serotype 1 (AHSV-1) in Thailand and Malaysia represented a significant epidemiological shift, yet fundamental knowledge about this strain's antigenic characteristics remained limited—a gap that hampers both diagnostic development and vaccine strategies. Researchers generated three novel monoclonal antibodies (7D11, 10A9, and 9E7) against the VP2 outer capsid protein by expressing recombinant AHSV-1 VP2 in *Escherichia coli*, then validated their utility across immunofluorescence assay, Western blotting, and ELISA platforms. Using systematic protein truncation, two overlapping linear epitopes were identified within the VP2 sequence: the 670NEFDFE675 motif (recognised by 9E7) and the partially overlapping 670NEFDF674 sequence (recognised by both 7D11 and 10A9), with the longer epitope showing complete conservation across AHSV-1 isolates but substantial divergence from other serotypes. This serotype-specific antigenic signature offers a valuable diagnostic and research tool for distinguishing AHSV-1 from co-circulating serotypes without relying on serological cross-reactivity, which is virtually absent between AHSV types. For practitioners in endemic or at-risk regions, these findings support development of more targeted diagnostic assays and highlight the potential for serotype-specific immunological approaches—particularly relevant as AHSV-1 continues to pose an expanding geographical threat to equine populations.

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Practical Takeaways

•These monoclonal antibodies provide improved diagnostic tools for specific identification of AHSV-1 in clinical cases, which is critical given the recent emergence of AHSV-1 in Southeast Asia
•Serotype-specific epitope mapping may enable more precise diagnostic differentiation between AHSV serotypes in field conditions

Key Findings

•Three monoclonal antibodies (7D11, 10A9, 9E7) against AHSV-1 VP2 were successfully generated and validated for detection via IFA, WB, and ELISA
•Two overlapping linear epitopes (670NEFDFE675 and 670NEFDF674) were identified on AHSV-1 VP2 protein
•The 670NEFDFE675 motif is completely conserved within AHSV-1 but highly divergent across other AHSV serotypes

Conditions Studied

african horse sickness (ahs)ahsv-1 infection

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