An Equine Model for Vaccination against a Hepacivirus: Insights into Host Responses to E2 Recombinant Protein Vaccination and Subsequent Equine Hepacivirus Inoculation

Badenhorst, Marcha; Saalmüller, Armin; Daly, Janet M.; Ertl, Reinhard; Stadler, Maria; Puff, Christina; de le Roi, Madeleine; Baumgärtner, Wolfgang; Engelmann, Michael; Brandner, Sabine; Junge, Hannah K; Pratscher, Barbara; Volz, Asisa; Saunier, Bertrand; Krey, Thomas; Wittmann, Johannes; Heelemann, Steffen; Delarocque, Julien; Wagner, Bettina; Todt, Daniel; Steinmann, Eike; Cavalleri, Jessika-M V

Abstract

Equine hepacivirus (EqHV) is the closest known genetic homologue of hepatitis C virus. An effective prophylactic vaccine is currently not available for either of these hepaciviruses. The equine as potential surrogate model for hepacivirus vaccine studies was investigated, while equine host responses following vaccination with EqHV E2 recombinant protein and subsequent EqHV inoculation were elucidated. Four ponies received prime and booster vaccinations (recombinant protein, adjuvant) four weeks apart (day −55 and −27). Two control ponies received adjuvant only. Ponies were inoculated with EqHV RNA-positive plasma on day 0. Blood samples and liver biopsies were collected over 26 weeks (day −70 to +112). Serum analyses included detection of EqHV RNA, isotypes of E2-specific immunoglobulin G (IgG), nonstructural protein 3-specific IgG, haematology, serum biochemistry, and metabolomics. Liver tissue analyses included EqHV RNA detection, RNA sequencing, histopathology, immunohistochemistry, and fluorescent in situ hybridization. Al-though vaccination did not result in complete protective immunity against experimental EqHV inoculation, the majority of vaccinated ponies cleared the serum EqHV RNA earlier than the control ponies. The majority of vaccinated ponies appeared to recover from the EqHV-associated liver insult earlier than the control ponies. The equine model shows promise as a surrogate model for future hepacivirus vaccine research.

Citation

Badenhorst, M., Saalmüller, A., Daly, J. M., Ertl, R., Stadler, M., Puff, C., …Cavalleri, J. V. (2022). An Equine Model for Vaccination against a Hepacivirus: Insights into Host Responses to E2 Recombinant Protein Vaccination and Subsequent Equine Hepacivirus Inoculation. Viruses, 14(7), Article 1401. https://doi.org/10.3390/v14071401

• Journal Article Type: Article
• Acceptance Date: Jun 15, 2022
• Online Publication Date: Jun 27, 2022
• Publication Date: Jul 1, 2022
• Deposit Date: Jun 17, 2022
• Publicly Available Date: Jun 17, 2022
• Journal: Viruses
• Electronic ISSN: 1999-4915
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 7
• Article Number: 1401
• DOI: https://doi.org/10.3390/v14071401
• Keywords: Virology; Infectious Diseases
• Public URL: https://nottingham-repository.worktribe.com/output/8500467
• Publisher URL: https://www.mdpi.com/1999-4915/14/7/1401