@article {31229,
	title = {Pan-Genotype Hepatitis E Virus Replication in Stem Cell-Derived Hepatocellular Systems},
	journal = {Gastroenterology },
	volume = {154},
	year = {2018},
	pages = {663-674},
	abstract = {
Background \&amp; aims:\&nbsp;The 4 genotypes of hepatitis E virus (HEV) that infect humans (genotypes 1-4) vary in geographical distribution, transmission, and pathogenesis. Little is known about the properties of HEV or its hosts that contribute to these variations. Primary isolates grow poorly in cell culture; most studies have relied on variants adapted to cancer cell lines, which likely alter virus biology. We investigated the infection and replication of primary isolates of HEV in hepatocyte-like cells (HLCs) derived from human embryonic and induced pluripotent stem cells.
Methods:\&nbsp;Using a cell culture-adapted genotype 3 strain and primary isolates of genotypes 1 to 4, we compared viral replication kinetics, sensitivity to drugs, and ability of HEV to activate the innate immune response. We studied HLCs using quantitative reverse-transcriptase polymerase chain reaction and immunofluorescence assay and enzyme-linked immunosorbent assays. We used an embryonic stem cell line that can be induced to express the CRISPR-Cas9 machinery to disrupt the peptidylprolyl isomerase A gene, encoding cyclophilin A (CYPA), a protein reported to inhibit replication of cell culture-adapted HEV. We further modified this line to rescue expression of CYPA before terminal differentiation to HLCs and performed HEV infection studies.
Results:\&nbsp;HLCs were permissive for infection by nonadapted, primary isolates of HEV genotypes 1 to 4. HEV infection of HLCs induced a replication-dependent type III interferon response. Replication of primary HEV isolates, unlike the cell culture-adapted strain, was not affected by disruption of the peptidylprolyl isomerase A gene or exposure to the CYPA inhibitor cyclosporine A.
Conclusions:\&nbsp;Cell culture adaptations alter the replicative capacities of HEV. HLCs offer an improved, physiologically relevant, and genetically tractable system for studying the replication of primary HEV isolates. HLCs could provide a model to aid development of HEV drugs and a system to guide personalized regimens, especially for patients with chronic hepatitis E who have developed resistance to ribavirin.

Keywords:\&nbsp;Antiviral; HLCs; Personalized Medicine; Primary Isolates.},
	url = {https://pubmed.ncbi.nlm.nih.gov/29277559/},
	author = {Xianfang Wu and Viet Loan Dao Thi and Liu, Peng and Constantin N Takacs and Kuanhui Xiang and Linda Andrus and J{\'e}r{\^o}me Gouttenoire and Darius Moradpour and Charles M. Rice}
}
