Characterization of a cell culture system of persistent hepatitis E virus infection in the human HepaRG hepatic cell line

National audiencethan 2 000 cases of acute hepatitis in France every year resulting in majority from zoonotic infections associatedwith the consumption of raw or undercooked pork. In most cases, hepatitis E is a self-limiting disease and the virusis cleared spontaneously without the need of antiviral therapy. However, immunocompromised individuals candevelop chronic infection and liver fibrosis that can progress rapidly to cirrhosis and liver failure. For decades, thelack of efficient and relevant cell culture system and animal models has limited our understanding of the biologyof HEV and the development of effective drugs for chronic cases. In the present study, we developed a model ofpersistent HEV infection in human hepatocytes in which HEV replicates efficiently. This HEV cell culture systemis based on differentiated HepaRG cells infected with an isolate of HEV-3 derived from a patient suffering fromacute hepatitis E. Efficient replication was maintained for several weeks to several months as well as after sevensuccessive passages on HepaRG naïve cells. Moreover, after six passages onto HepaRG, the virus was still infectiousafter oral inoculation into pigs. We also showed that ribavirin inhibited HEV replication in HepaRG cells. Using wholegenome sequencing, 25 mutations including 8 non-synonymous mutations were detected in the genome of thevirus recovered after 6 passages into HepaRG. In conclusion, this system represents a relevant and efficient in vitromodel of HEV replication that could be useful to identify host–virus interactions and putative mutations withinthe viral genome than can occur in vitro in the context of prolonged hepatitis E infection and to test antiviral drugsagainst chronic HEV infection