{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,27]],"date-time":"2026-10-27T00:14:12Z","timestamp":1793060052926,"version":"4.5.0"},"reference-count":50,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,1,24]],"date-time":"2020-01-24T00:00:00Z","timestamp":1579824000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001677","name":"Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale","doi-asserted-by":"publisher","award":["Inserm UMR 1043"],"award-info":[{"award-number":["Inserm UMR 1043"]}],"id":[{"id":"10.13039\/501100001677","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Hepatitis E virus (HEV) is a major concern in public health worldwide. Infections with HEV genotypes 3, 4, or 7 can lead to chronic hepatitis while genotype 1 infections can trigger severe hepatitis in pregnant women. Infections with all genotypes can worsen chronic liver diseases. As virions are lipid-associated in blood and naked in feces, efficient methods of propagating HEV clinical strains in vitro and evaluating the infectivity of both HEV forms are needed. We evaluated the spread of clinical strains of HEV genotypes 1 (HEV1) and 3 (HEV3) by quantifying viral RNA in culture supernatants and cell lysates. Infectivity was determined by endpoint dilution and calculation of the tissue culture infectious dose 50 (TCID50). An enhanced HEV production could be obtained varying the composition of the medium, including fetal bovine serum (FBS) and dimethylsulfoxide (DMSO) content. This increased TCID50 from 10 to 100-fold and allowed us to quantify HEV1 infectivity. These optimized methods for propagating and measuring HEV infectivity could be applied to health safety processes and will be useful for testing new antiviral drugs.<\/jats:p>","DOI":"10.3390\/v12020139","type":"journal-article","created":{"date-parts":[[2020,1,24]],"date-time":"2020-01-24T11:01:00Z","timestamp":1579863660000},"page":"139","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Optimized Hepatitis E Virus (HEV) Culture and Its Application to Measurements of HEV Infectivity"],"prefix":"10.3390","volume":"12","author":[{"given":"Nicolas","family":"Capelli","sequence":"first","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martine","family":"Dubois","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u00e9lanie","family":"Pucelle","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isabelle","family":"Da Silva","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7908-1576","authenticated-orcid":false,"given":"S\u00e9bastien","family":"Lhomme","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florence","family":"Abravanel","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sabine","family":"Chapuy-Regaud","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8462-3234","authenticated-orcid":false,"given":"Jacques","family":"Izopet","sequence":"additional","affiliation":[{"name":"Department of Virology, National Reference Center for HEV, CHU Purpan, 31059 Toulouse, France"},{"name":"Centre de Physiopathologie de Toulouse Purpan (CPTP), Institut National de la Sant\u00e9 et de la Recherche M\u00e9dicale, Inserm UMR1043, Centre National de la Recherche Scientifique, CNRS UMR5282, Universit\u00e9 de Toulouse, 31024 Toulouse, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2645","DOI":"10.1099\/jgv.0.000940","article-title":"ICTV Virus Taxonomy Profile: Hepeviridae","volume":"98","author":"Purdy","year":"2017","journal-title":"J. Gen. Virol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Smith, D.B., and Simmonds, P. (2018). Classification and Genomic Diversity of Enterically Transmitted Hepatitis Viruses. Cold Spring Harb. Perspect. Med., 8.","DOI":"10.1101\/cshperspect.a031880"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"9860","DOI":"10.1073\/pnas.94.18.9860","article-title":"A novel virus in swine is closely related to the human hepatitis E virus","volume":"94","author":"Meng","year":"1997","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.virol.2004.10.006","article-title":"Complete or near-complete nucleotide sequences of hepatitis E virus genome recovered from a wild boar, a deer, and four patients who ate the deer","volume":"330","author":"Takahashi","year":"2004","journal-title":"Virology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1371","DOI":"10.1002\/jmv.21536","article-title":"A novel genotype of hepatitis E virus prevalent among farmed rabbits in China","volume":"81","author":"Zhao","year":"2009","journal-title":"J. Med. Virol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1274","DOI":"10.3201\/eid1808.120057","article-title":"Hepatitis E virus strains in rabbits and evidence of a closely related strain in humans, France","volume":"18","author":"Izopet","year":"2012","journal-title":"Emerg. Infect. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1053\/j.gastro.2015.10.048","article-title":"Chronic Infection with Camelid Hepatitis E Virus in a Liver Transplant Recipient Who Regularly Consumes Camel Meat and Milk","volume":"150","author":"Lee","year":"2016","journal-title":"Gastroenterology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1914","DOI":"10.3201\/eid2011.140516","article-title":"Hepatitis E virus infections in blood donors, France","volume":"20","author":"Gallian","year":"2014","journal-title":"Emerg. Infect. Dis."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Aggarwal, R., and Goel, A. (2018). Natural History, Clinical Manifestations, and Pathogenesis of Hepatitis E Virus Genotype 1 and 2 Infections. Cold Spring Harb. Perspect. Med., 9.","DOI":"10.1101\/cshperspect.a032136"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"17086","DOI":"10.1038\/nrdp.2017.86","article-title":"Hepatitis E virus infection","volume":"3","author":"Kamar","year":"2017","journal-title":"Nat. Rev. Dis. Primer"},{"key":"ref_11","first-page":"467","article-title":"Extrahepatic manifestations of hepatitis E virus","volume":"36","author":"Kamar","year":"2016","journal-title":"Liver Int. Off. J. Int. Assoc. Study Liver"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1111","DOI":"10.1056\/NEJMoa1215246","article-title":"Ribavirin for chronic hepatitis E virus infection in transplant recipients","volume":"370","author":"Kamar","year":"2014","journal-title":"N. Engl. J. Med."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"European Association for the Study of the Liver (2018). EASL Clinical Practice Guidelines on hepatitis E virus infection. J. Hepatol., 68, 1256\u20131271.","DOI":"10.1016\/j.jhep.2018.03.005"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Kenney, S.P., and Meng, X.-J. (2018). Hepatitis E Virus Genome Structure and Replication Strategy. Cold Spring Harb. Perspect. Med., 9.","DOI":"10.1101\/cshperspect.a031724"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2438","DOI":"10.1073\/pnas.1018878108","article-title":"Cross-species infections of cultured cells by hepatitis E virus and discovery of an infectious virus-host recombinant","volume":"108","author":"Shukla","year":"2011","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"12017","DOI":"10.1128\/JVI.01625-14","article-title":"Characterization of the polyproline region of the hepatitis E virus in immunocompromised patients","volume":"88","author":"Lhomme","year":"2014","journal-title":"J. Virol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4773","DOI":"10.1073\/pnas.1721345115","article-title":"Origin, antigenicity, and function of a secreted form of ORF2 in hepatitis E virus infection","volume":"115","author":"Yin","year":"2018","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1053\/j.gastro.2017.09.020","article-title":"Hepatitis E Virus Lifecycle and Identification of 3 Forms of the ORF2 Capsid Protein","volume":"154","author":"Montpellier","year":"2018","journal-title":"Gastroenterology"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6375","DOI":"10.1128\/JVI.02571-08","article-title":"The hepatitis E virus open reading frame 3 product interacts with microtubules and interferes with their dynamics","volume":"83","author":"Kannan","year":"2009","journal-title":"J. Virol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"9059","DOI":"10.1128\/JVI.00593-10","article-title":"Release of genotype 1 hepatitis E virus from cultured hepatoma and polarized intestinal cells depends on open reading frame 3 protein and requires an intact PXXP motif","volume":"84","author":"Emerson","year":"2010","journal-title":"J. Virol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1099\/vir.0.025791-0","article-title":"A PSAP motif in the ORF3 protein of hepatitis E virus is necessary for virion release from infected cells","volume":"92","author":"Nagashima","year":"2011","journal-title":"J. Gen. Virol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1073\/pnas.1614955114","article-title":"Hepatitis E virus ORF3 is a functional ion channel required for release of infectious particles","volume":"114","author":"Ding","year":"2017","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Gouttenoire, J., Poll\u00e1n, A., Abrami, L., Oechslin, N., Mauron, J., Matter, M., Oppliger, J., Szkolnicka, D., Dao Thi, V.L., and van der Goot, F.G. (2018). Palmitoylation mediates membrane association of hepatitis E virus ORF3 protein and is required for infectious particle secretion. PLoS Pathog., 14.","DOI":"10.1371\/journal.ppat.1007471"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1146\/annurev-virology-031413-085359","article-title":"Naked Viruses That Aren\u2019t Always Naked: Quasi-Enveloped Agents of Acute Hepatitis","volume":"1","author":"Feng","year":"2014","journal-title":"Annu. Rev. Virol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1112","DOI":"10.1128\/JCM.02002-09","article-title":"Hepatitis E Virus (HEV) strains in serum samples can replicate efficiently in cultured cells despite the coexistence of HEV antibodies: Characterization of HEV virions in blood circulation","volume":"48","author":"Takahashi","year":"2010","journal-title":"J. Clin. Microbiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.biochi.2017.05.003","article-title":"Characterization of the lipid envelope of exosome encapsulated HEV particles protected from the immune response","volume":"141","author":"Dubois","year":"2017","journal-title":"Biochimie"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Yin, X., Li, X., and Feng, Z. (2016). Role of Envelopment in the HEV Life Cycle. Viruses, 8.","DOI":"10.3390\/v8080229"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.antiviral.2019.01.007","article-title":"Cell culture systems for the study of hepatitis E virus","volume":"163","author":"Meister","year":"2019","journal-title":"Antiviral Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4232","DOI":"10.1128\/JVI.02804-15","article-title":"Distinct Entry Mechanisms for Nonenveloped and Quasi-Enveloped Hepatitis E Viruses","volume":"90","author":"Yin","year":"2016","journal-title":"J. Virol."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Capelli, N., Marion, O., Dubois, M., Allart, S., Bertrand-Michel, J., Lhomme, S., Abravanel, F., Izopet, J., and Chapuy-Regaud, S. (2019). Vectorial Release of Hepatitis E Virus in Polarized Human Hepatocytes. J. Virol., 93.","DOI":"10.1128\/JVI.01207-18"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Schemmerer, M., Johne, R., Erl, M., Jilg, W., and Wenzel, J.J. (2019). Isolation of Subtype 3c, 3e and 3f-Like Hepatitis E Virus Strains Stably Replicating to High Viral Loads in an Optimized Cell Culture System. Viruses, 11.","DOI":"10.3390\/v11060483"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Marion, O., Lhomme, S., Nayrac, M., Dubois, M., Pucelle, M., Requena, M., Migueres, M., Abravanel, F., Peron, J.M., and Carrere, N. (2019). Hepatitis E virus replication in human intestinal cells. Gut.","DOI":"10.1136\/gutjnl-2019-319004"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1128\/JCM.05942-11","article-title":"Genotype 3 diversity and quantification of hepatitis E virus RNA","volume":"50","author":"Abravanel","year":"2012","journal-title":"J. Clin. Microbiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.jcv.2018.06.013","article-title":"A fully automated system using transcription-mediated amplification for the molecular diagnosis of hepatitis E virus in human blood and faeces","volume":"105","author":"Abravanel","year":"2018","journal-title":"J. Clin. Virol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.jviromet.2005.07.004","article-title":"A broadly reactive one-step real-time RT-PCR assay for rapid and sensitive detection of hepatitis E virus","volume":"131","author":"Jothikumar","year":"2006","journal-title":"J. Virol. Methods"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.jcv.2019.05.006","article-title":"Development of a World Health Organization International Reference Panel for different genotypes of hepatitis E virus for nucleic acid amplification testing","volume":"119","author":"Baylis","year":"2019","journal-title":"J. Clin. Virol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1093\/oxfordjournals.aje.a118408","article-title":"A simple method of estimating fifty per cent endpoints","volume":"27","author":"Reed","year":"1938","journal-title":"Am. J. Epidemiol."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Halsey, L.G. (2019). The reign of the p-value is over: What alternative analyses could we employ to fill the power vacuum?. Biol. Lett., 15.","DOI":"10.1098\/rsbl.2019.0174"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Nikolaou, N., Green, C.J., Gunn, P.J., Hodson, L., and Tomlinson, J.W. (2016). Optimizing human hepatocyte models for metabolic phenotype and function: Effects of treatment with dimethyl sulfoxide (DMSO). Physiol. Rep., 4.","DOI":"10.14814\/phy2.12944"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.ymeth.2017.12.011","article-title":"Flow virometry as a tool to study viruses","volume":"134\u2013135","author":"Zamora","year":"2018","journal-title":"Methods San Diego Calif."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"26373","DOI":"10.3402\/jev.v4.26373","article-title":"Extracellular vesicle\u2013depleted fetal bovine and human sera have reduced capacity to support cell growth","volume":"4","author":"Eitan","year":"2015","journal-title":"J. Extracell. Vesicles"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2558","DOI":"10.1038\/s41598-017-02908-5","article-title":"Serum extracellular vesicle depletion processes affect release and infectivity of HIV-1 in culture","volume":"7","author":"Liao","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"15655","DOI":"10.1073\/pnas.232137699","article-title":"Infection of a human hepatoma cell line by hepatitis B virus","volume":"99","author":"Gripon","year":"2002","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"10253","DOI":"10.1128\/JVI.01059-06","article-title":"Production of Infectious Hepatitis C Virus by Well-Differentiated, Growth-Arrested Human Hepatoma-Derived Cells","volume":"80","author":"Sainz","year":"2006","journal-title":"J. Virol."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Belouzard, S., Danneels, A., F\u00e9n\u00e9ant, L., S\u00e9ron, K., Rouill\u00e9, Y., and Dubuisson, J. (2017). Entry and Release of Hepatitis C Virus in Polarized Human Hepatocytes. J. Virol., 91.","DOI":"10.1128\/JVI.00478-17"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1086\/432488","article-title":"Thermal stability of hepatitis E virus","volume":"192","author":"Emerson","year":"2005","journal-title":"J. Infect. Dis."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"15270","DOI":"10.1073\/pnas.251555098","article-title":"Recombinant hepatitis E virus genomes infectious for primates: Importance of capping and discovery of a cis-reactive element","volume":"98","author":"Emerson","year":"2001","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41467-018-07200-2","article-title":"Genotype specific pathogenicity of hepatitis E virus at the human maternal-fetal interface","volume":"9","author":"Gouilly","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1053\/j.gastro.2017.10.041","article-title":"Pan-Genotype Hepatitis E Virus Replication in Stem Cell\u2013Derived Hepatocellular Systems","volume":"154","author":"Wu","year":"2018","journal-title":"Gastroenterology"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1016\/j.jinf.2019.01.004","article-title":"Hepatitis E virus genotype 3 and capsid protein in the blood and urine of immunocompromised patients","volume":"78","author":"Marion","year":"2019","journal-title":"J. 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