Isolation and characterisation of a human-like antibody fragment (scFv) that inactivates VEEV in vitro and in vivo.
Authors: Rülker Torsten, Voß Luzie, Thullier Philippe, O' Brien Lyn M, Pelat Thibaut, Perkins Stuart D, Langermann Claudia, Schirrmann Thomas, Dübel Stefan, Marschall Hans-Jürgen, Hust Michael, Hülseweh Birgit
Journal: PloS one
Summary
# Editorial Summary: Venezuelan Equine Encephalitis Virus Neutralisation via Recombinant Antibody Venezuelan equine encephalitis virus poses significant biosecurity concerns to equine and human populations alike, yet effective therapeutic options remain limited. Researchers isolated a single-chain antibody fragment (scFv-Fc) from non-human primate antibody libraries and characterised its ability to recognise and neutralise VEEV both in laboratory assays and in vivo mouse models of lethal infection. The antibody specifically targeted the conformationally-dependent E1 envelope protein and demonstrated broad activity against multiple VEEV subtypes, with survival rates of 80–100% in mice treated six hours post-infection with VEEV IA/B or IE strains, though efficacy declined to 40–60% for subtypes II and former IIIA. Whilst equine professionals will recognise the biosecurity significance of this work, the practical application lies in the antibody's potential as a passive immunotherapy platform—particularly when combined with complementary E2-neutralising antibodies—offering a path toward rapid therapeutic intervention for VEEV exposure. The conformational specificity of this antibody also suggests promise for diagnostic applications in field conditions, though further development and equine-model validation would be necessary before clinical translation.
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Practical Takeaways
- •This research has minimal direct application to equine practice as VEEV is primarily a research and biodefense concern; Venezuelan equine encephalitis in horses is rare in most regions and this work addresses therapeutic antibodies rather than clinical management
- •The study focuses on molecular and immunological characterization relevant to pharmaceutical development rather than farriery, training, or clinical equine medicine
Key Findings
- •scFv-Fc ToR67-3B4 antibody successfully recognized multiple VEEV subtypes and inactivated virus in vitro and in vivo
- •80-100% survival rate in mice receiving antibody 6 hours post-challenge with VEEV IA/B or IE subtypes
- •Antibody recognized conformational epitopes on viral E1 envelope protein with minimal cross-reactivity to other Alphaviruses