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Updated: Aug 16, 2025
A Cell Culture Model for Producing High Titer Hepatitis E Virus Stocks
Published on: June 26, 2020
Targeting proteostasis of the HEV replicase to combat infection in preclinical models
Fei Zhang1, Ling-Dong Xu2, Qian Zhang1
1Department of Hepatobiliary and Pancreatic Surgery and Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China; MOE Laboratory of Biosystems Homeostasis & Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China.
Background & Aims:
Appropriate treatment options are lacking for hepatitis E virus (HEV)-infected pregnant women and immunocompromised individuals. Thus, we aimed to identify efficient anti-HEV drugs through high-throughput screening, validate them in vitro and in vivo (in a preclinical animal study), and elucidate their underlying antiviral mechanism of action.
Methods:
Using appropriate cellular and rodent HEV infection models, we studied a critical pathway for host-HEV interactions and performed a preclinical study of the corresponding antivirals, which target proteostasis of the HEV replicase.
Results:
We found 17 inhibitors that target HEV-HSP90 interactions by unbiased compound library screening on human hepatocytes harboring an HEV replicon. Inhibitors of HSP90 (iHSP90) markedly suppressed HEV replication with efficacy exceeding that of conventional antivirals (IFNα and ribavirin) in vitro. Mechanistically, iHSP90 treatment released the viral replicase ORF1 protein from the ORF1-HSP90 complex and triggered rapid ubiquitin/proteasome-mediated degradation of ORF1, resulting in abrogated HEV replication. Furthermore, a preclinical trial in a Mongolian gerbil HEV infection model showed this novel anti-HEV strategy to be safe, efficient, and able to prevent HEV-induced liver damage.
Conclusions:
In this study, we uncover a proteostatic pathway that is critical for host-HEV interactions and we provide a foundation from which to translate this new understanding of the HEV life cycle into clinically promising antivirals.
Impact And Implications:
Appropriate treatment options for hepatitis E virus (HEV)-infected pregnant women and immunocompromised patients are lacking; hence, there is an urgent need for safe and effective HEV-specific therapies. This study identified new antivirals (inhibitors of HSP90) that significantly limit HEV infection by targeting the viral replicase for degradation. Moreover, these anti-HEV drugs were validated in an HEV rodent model and were found to be safe and efficient for prevention of HEV-induced liver injury in preclinical experiments. Our findings substantially promote the understanding of HEV pathobiology and pave the way for antiviral development.
