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