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

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

*Corresponding author for this work

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.

Original languageEnglish
Article number1401
JournalViruses
Volume14
Issue number7
DOIs
Publication statusPublished - 07.2022

Research Areas and Centers

  • Academic Focus: Center for Infection and Inflammation Research (ZIEL)
  • Centers: Center for Structural and Cell Biology (CSCM/ZMSZ)

DFG Research Classification Scheme

  • 204-04 Virology

Coronavirus related work

  • Research on SARS-CoV-2 / COVID-19

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