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Orosz L, Sárvári KP, Dernovics Á, Rosztóczy A, Megyeri K. Pathogenesis and clinical features of severe hepatitis E virus infection. World J Virol 2024; 13:91580. [PMID: 38984076 PMCID: PMC11229844 DOI: 10.5501/wjv.v13.i2.91580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/08/2024] [Accepted: 04/15/2024] [Indexed: 06/24/2024] Open
Abstract
The hepatitis E virus (HEV), a member of the Hepeviridae family, is a small, non-enveloped icosahedral virus divided into eight distinct genotypes (HEV-1 to HEV-8). Only genotypes 1 to 4 are known to cause diseases in humans. Genotypes 1 and 2 commonly spread via fecal-oral transmission, often through the consumption of contaminated water. Genotypes 3 and 4 are known to infect pigs, deer, and wild boars, often transferring to humans through inadequately cooked meat. Acute hepatitis caused by HEV in healthy individuals is mostly asymptomatic or associated with minor symptoms, such as jaundice. However, in immunosuppressed individuals, the disease can progress to chronic hepatitis and even escalate to cirrhosis. For pregnant women, an HEV infection can cause fulminant liver failure, with a potential mortality rate of 25%. Mortality rates also rise amongst cirrhotic patients when they contract an acute HEV infection, which can even trigger acute-on-chronic liver failure if layered onto pre-existing chronic liver disease. As the prevalence of HEV infection continues to rise worldwide, highlighting the particular risks associated with severe HEV infection is of major medical interest. This text offers a brief summary of the characteristics of hepatitis developed by patient groups at an elevated risk of severe HEV infection.
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Affiliation(s)
- László Orosz
- Department of Medical Microbiology, University of Szeged, Szeged 6720, Csongrád-Csanád, Hungary
| | - Károly Péter Sárvári
- Department of Medical Microbiology, University of Szeged, Szeged 6720, Csongrád-Csanád, Hungary
| | - Áron Dernovics
- Department of Medical Microbiology, University of Szeged, Szeged 6720, Csongrád-Csanád, Hungary
| | - András Rosztóczy
- Department of Internal Medicine, Division of Gastroenterology, University of Szeged, Szeged 6725, Csongrád-Csanád, Hungary
| | - Klára Megyeri
- Department of Medical Microbiology, University of Szeged, Szeged 6720, Csongrád-Csanád, Hungary
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Shahini E, Argentiero A, Andriano A, Losito F, Maida M, Facciorusso A, Cozzolongo R, Villa E. Hepatitis E Virus: What More Do We Need to Know? MEDICINA (KAUNAS, LITHUANIA) 2024; 60:998. [PMID: 38929615 PMCID: PMC11205503 DOI: 10.3390/medicina60060998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/14/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024]
Abstract
Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.
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Affiliation(s)
- Endrit Shahini
- Gastroenterology Unit, National Institute of Gastroenterology-IRCCS “Saverio de Bellis”, Castellana Grotte, 70013 Bari, Italy; (F.L.); (R.C.)
| | | | - Alessandro Andriano
- Department of Precision and Regenerative Medicine and Ionian Area, University of Bari Aldo Moro Medical School, 70124 Bari, Italy;
| | - Francesco Losito
- Gastroenterology Unit, National Institute of Gastroenterology-IRCCS “Saverio de Bellis”, Castellana Grotte, 70013 Bari, Italy; (F.L.); (R.C.)
| | - Marcello Maida
- Gastroenterology and Endoscopy Unit, S. Elia-Raimondi Hospital, 93100 Caltanissetta, Italy;
| | - Antonio Facciorusso
- Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy;
| | - Raffaele Cozzolongo
- Gastroenterology Unit, National Institute of Gastroenterology-IRCCS “Saverio de Bellis”, Castellana Grotte, 70013 Bari, Italy; (F.L.); (R.C.)
| | - Erica Villa
- Gastroenterology Unit, CHIMOMO Department, University of Modena & Reggio Emilia, Via del Pozzo 71, 41121 Modena, Italy
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Klöhn M, Burkard T, Janzen J, Haase JA, Gömer A, Fu R, Ssebyatika G, Nocke MK, Brown RJP, Krey T, Dao Thi VL, Kinast V, Brüggemann Y, Todt D, Steinmann E. Targeting cellular cathepsins inhibits hepatitis E virus entry. Hepatology 2024:01515467-990000000-00876. [PMID: 38728662 DOI: 10.1097/hep.0000000000000912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 04/02/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND AND AIMS HEV is estimated to be responsible for 70,000 deaths annually, yet therapy options remain limited. In the pursuit of effective antiviral therapies, targeting viral entry holds promise and has proven effective for other viruses. However, the precise mechanisms and host factors required during HEV entry remain unclear. Cellular proteases have emerged as host factors required for viral surface protein activation and productive cell entry by many viruses. Hence, we investigated the functional requirement and therapeutic potential of cellular protease during HEV infection. APPROACH AND RESULTS Using our established HEV cell culture model and subgenomic HEV replicons, we found that blocking lysosomal cathepsins (CTS) with small molecule inhibitors impedes HEV infection without affecting replication. Most importantly, the pan-cathepsin inhibitor K11777 suppressed HEV infections with an EC 50 of ~0.02 nM. Inhibition by K11777, devoid of notable toxicity in hepatoma cells, was also observed in HepaRG and primary human hepatocytes. Furthermore, through time-of-addition and RNAscope experiments, we confirmed that HEV entry is blocked by inhibition of cathepsins. Cathepsin L (CTSL) knockout cells were less permissive to HEV, suggesting that CTSL is critical for HEV infection. Finally, we observed cleavage of the glycosylated ORF2 protein and virus particles by recombinant CTSL. CONCLUSIONS In summary, our study highlights the pivotal role of lysosomal cathepsins, especially CTSL, in the HEV entry process. The profound anti-HEV efficacy of the pan-cathepsin inhibitor K11777, especially with its notable safety profile in primary cells, further underscores its potential as a therapeutic candidate.
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Affiliation(s)
- Mara Klöhn
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Thomas Burkard
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Juliana Janzen
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Jil A Haase
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - André Gömer
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Rebecca Fu
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- Heidelberg Biosciences International Graduate School (HBIGS), Heidelberg, Germany
| | - George Ssebyatika
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Luebeck, Germany
| | - Maximilian K Nocke
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Richard J P Brown
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Thomas Krey
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Luebeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, Hannover, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Viet Loan Dao Thi
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Volker Kinast
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- Department of Medical Microbiology and Virology, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Yannick Brüggemann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Daniel Todt
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- European Virus Bioinformatics Center (EVBC), Jena, Germany
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- German Centre for Infection Research (DZIF), External Partner Site, Bochum, Germany
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4
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Das A, Rivera-Serrano EE, Yin X, Walker CM, Feng Z, Lemon SM. Cell entry and release of quasi-enveloped human hepatitis viruses. Nat Rev Microbiol 2023; 21:573-589. [PMID: 37185947 PMCID: PMC10127183 DOI: 10.1038/s41579-023-00889-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2023] [Indexed: 05/17/2023]
Abstract
Infectious hepatitis type A and type E are caused by phylogenetically distinct single-stranded, positive-sense RNA viruses that were once considered to be non-enveloped. However, studies show that both are released nonlytically from hepatocytes as 'quasi-enveloped' virions cloaked in host membranes. These virion types predominate in the blood of infected individuals and mediate virus spread within the liver. They lack virally encoded proteins on their surface and are resistant to neutralizing anti-capsid antibodies induced by infection, yet they efficiently enter cells and initiate new rounds of virus replication. In this Review, we discuss the mechanisms by which specific peptide sequences in the capsids of these quasi-enveloped virions mediate their endosomal sorting complexes required for transport (ESCRT)-dependent release from hepatocytes through multivesicular endosomes, what is known about how they enter cells, and the impact of capsid quasi-envelopment on host immunity and pathogenesis.
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Affiliation(s)
- Anshuman Das
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lentigen Technology, Inc., Gaithersburg, MD, USA
| | - Efraín E Rivera-Serrano
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biology, Elon University, Elon, NC, USA
| | - Xin Yin
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Christopher M Walker
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Department of Paediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Zongdi Feng
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.
- Department of Paediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
| | - Stanley M Lemon
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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5
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He Q, Zhang Y, Gong W, Zeng H, Wang L. Genetic Evolution of Hepatitis E Virus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1417:59-72. [PMID: 37223859 DOI: 10.1007/978-981-99-1304-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Comparative analysis of the genomic sequences of multiple hepatitis E virus (HEV) isolates has revealed extensive genomic diversity among them. Recently, a variety of genetically distinct HEV variants have also been isolated and identified from large numbers of animal species, including birds, rabbits, rats, ferrets, bats, cutthroat trout, and camels, among others. Furthermore, it has been reported that recombination in HEV genomes takes place in animals and in human patients. Also, chronic HEV infection in immunocompromised individuals has revealed the presence of viral strains carrying insertions from human genes. This paper reviews current knowledge on the genomic variability and evolution of HEV.
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Affiliation(s)
- Qiyu He
- Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yulin Zhang
- Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Wanyun Gong
- Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Hang Zeng
- Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Ling Wang
- Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.
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6
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Zhou Y, Zhao C, Tian Y, Xu N, Wang Y. Characteristics and Functions of HEV Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1417:15-32. [PMID: 37223856 DOI: 10.1007/978-981-99-1304-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Hepatitis E virus (HEV) is a non-enveloped virus containing a single-stranded, positive-sense RNA genome of 7.2 kb, which consists of a 5' non-coding region, three open reading frames (ORFs), and a 3' non-coding region. ORF1 is diverse between genotypes and encodes the nonstructural proteins, which include the enzymes needed for virus replication. In addition to its role in virus replication, the function of ORF1 is relevant to viral adaption in culture and may also relate to virus infection and HEV pathogenicity. ORF2 protein is the capsid protein, which is about 660 amino acids in length. It not only protects the integrity of the viral genome, but is also involved in many important physiological activities, such as virus assembly, infection, host interaction, and innate immune response. The main immune epitopes, especially neutralizing epitopes, are located on ORF2 protein, which is a candidate antigen for vaccine development. ORF3 protein is a phosphoprotein of 113 or 114 amino acids with a molecular weight of 13 kDa with multiple functions that can also induce strong immune reactivity. A novel ORF4 has been identified only in genotype 1 HEV and its translation promotes viral replication.
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Affiliation(s)
- Yan Zhou
- RegCMC, Great Regulatory Affairs, Sanofi (China) Investment Co., Ltd, Beijing, China
| | - Chenyan Zhao
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Yabin Tian
- Division II of In Vitro Diagnostics for Infectious Diseases, National Institutes for Food and Drug Control, Beijing, China
| | - Nan Xu
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Youchun Wang
- Institute of Medical Biology, Chinese Academy of Medical Science & Peking Union Medical College, Kunming, China.
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Gupta J, Kumar A, Surjit M. Production of a Hepatitis E Vaccine Candidate Using the Pichia pastoris Expression System. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2412:117-141. [PMID: 34918244 DOI: 10.1007/978-1-0716-1892-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hepatitis E virus (HEV) is associated with acute hepatitis disease, which may lead to chronic disease in immunocompromised individuals. The disease is particularly severe among pregnant women (20-30% mortality). No vaccine is available to combat the HEV except Hecolin, which is available only in China. Virus-like particle (VLP) generated from the capsid protein (ORF2) of HEV is known to be a potent vaccine antigen against HEV. Hecolin consists of 368-606 amino acid (aa) region of the capsid protein of HEV, which forms a VLP. It is expressed and purified from the inclusion bodies of E. coli. Here, we describe a method to express the 112-608aa region of the capsid protein (ORF2) of genotype-1 HEV in Pichia pastoris (P. pastoris) and purify VLPs from the culture medium. 112-608aa ORF2 VLPs are secreted into the culture medium in a methanol inducible manner. The purified VLPs are glycosylated and induce robust immune response in Balb/c mice. Further, 112-608aa ORF2 VLPs are bigger than the 368-606 VLP present in Hecolin, which may help them in inducing a superior immune response. P. pastoris offers a robust and economical heterologous expression system to produce large quantities of glycosylated 112-608aa ORF2 VLP, which appears to be a promising vaccine candidate against the HEV.
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Affiliation(s)
- Jyoti Gupta
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Amit Kumar
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Milan Surjit
- Virology Laboratory, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India.
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8
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Bentaleb C, Hervouet K, Montpellier C, Camuzet C, Ferrié M, Burlaud-Gaillard J, Bressanelli S, Metzger K, Werkmeister E, Ankavay M, Janampa NL, Marlet J, Roux J, Deffaud C, Goffard A, Rouillé Y, Dubuisson J, Roingeard P, Aliouat-Denis CM, Cocquerel L. The endocytic recycling compartment serves as a viral factory for hepatitis E virus. Cell Mol Life Sci 2022; 79:615. [PMID: 36460928 PMCID: PMC9718719 DOI: 10.1007/s00018-022-04646-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/04/2022] [Accepted: 11/23/2022] [Indexed: 12/04/2022]
Abstract
Although hepatitis E virus (HEV) is the major leading cause of enterically transmitted viral hepatitis worldwide, many gaps remain in the understanding of the HEV lifecycle. Notably, viral factories induced by HEV have not been documented yet, and it is currently unknown whether HEV infection leads to cellular membrane modeling as many positive-strand RNA viruses. HEV genome encodes the ORF1 replicase, the ORF2 capsid protein and the ORF3 protein involved in virion egress. Previously, we demonstrated that HEV produces different ORF2 isoforms including the virion-associated ORF2i form. Here, we generated monoclonal antibodies that specifically recognize the ORF2i form and antibodies that recognize the different ORF2 isoforms. One antibody, named P1H1 and targeting the ORF2i N-terminus, recognized delipidated HEV particles from cell culture and patient sera. Importantly, AlphaFold2 modeling demonstrated that the P1H1 epitope is exposed on HEV particles. Next, antibodies were used to probe viral factories in HEV-producing/infected cells. By confocal microscopy, we identified subcellular nugget-like structures enriched in ORF1, ORF2 and ORF3 proteins and viral RNA. Electron microscopy analyses revealed an unprecedented HEV-induced membrane network containing tubular and vesicular structures. We showed that these structures are dependent on ORF2i capsid protein assembly and ORF3 expression. An extensive colocalization study of viral proteins with subcellular markers, and silencing experiments demonstrated that these structures are derived from the endocytic recycling compartment (ERC) for which Rab11 is a central player. Hence, HEV hijacks the ERC and forms a membrane network of vesicular and tubular structures that might be the hallmark of HEV infection.
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Affiliation(s)
- Cyrine Bentaleb
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Kévin Hervouet
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Claire Montpellier
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Charline Camuzet
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Martin Ferrié
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Julien Burlaud-Gaillard
- grid.411167.40000 0004 1765 1600Inserm U1259, Morphogénèse et Antigénicité du VIH et des Virus des Hépatites (MAVIVH), Université de Tours and CHRU de Tours, 37032 Tours, France ,Université de Tours et CHRU de Tours, Plateforme IBiSA de Microscopie Electronique, Tours, France
| | - Stéphane Bressanelli
- grid.457334.20000 0001 0667 2738Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-Sur-Yvette, France
| | - Karoline Metzger
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Elisabeth Werkmeister
- grid.503422.20000 0001 2242 6780Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, UMR2014-US41-PLBS-Plateformes Lilloises de Biologie and Santé, Lille, France
| | - Maliki Ankavay
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France ,Present Address: Division of Gastroenterology and Hepatology, Institute of Microbiology, Lausanne, Switzerland
| | - Nancy Leon Janampa
- grid.411167.40000 0004 1765 1600Inserm U1259, Morphogénèse et Antigénicité du VIH et des Virus des Hépatites (MAVIVH), Université de Tours and CHRU de Tours, 37032 Tours, France
| | - Julien Marlet
- grid.411167.40000 0004 1765 1600Inserm U1259, Morphogénèse et Antigénicité du VIH et des Virus des Hépatites (MAVIVH), Université de Tours and CHRU de Tours, 37032 Tours, France
| | | | | | - Anne Goffard
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Yves Rouillé
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Jean Dubuisson
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Philippe Roingeard
- grid.411167.40000 0004 1765 1600Inserm U1259, Morphogénèse et Antigénicité du VIH et des Virus des Hépatites (MAVIVH), Université de Tours and CHRU de Tours, 37032 Tours, France ,Université de Tours et CHRU de Tours, Plateforme IBiSA de Microscopie Electronique, Tours, France
| | - Cécile-Marie Aliouat-Denis
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Laurence Cocquerel
- grid.503422.20000 0001 2242 6780University of Lille, CNRS, Inserm, CHU Lille, Pasteur Institute of Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
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9
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Zhou Z, Xie Y, Wu C, Nan Y. The Hepatitis E Virus Open Reading Frame 2 Protein: Beyond Viral Capsid. Front Microbiol 2021; 12:739124. [PMID: 34690982 PMCID: PMC8529240 DOI: 10.3389/fmicb.2021.739124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 09/20/2021] [Indexed: 12/20/2022] Open
Abstract
Hepatitis E virus (HEV) is a zoonotic pathogen causing hepatitis in both human and animal hosts, which is responsible for acute hepatitis E outbreaks worldwide. The 7.2 kb genome of the HEV encodes three well-defined open reading frames (ORFs), where the ORF2 translation product acts as the major virion component to form the viral capsid. In recent years, besides forming the capsid, more functions have been revealed for the HEV-ORF2 protein, and it appears that HEV-ORF2 plays multiple functions in both viral replication and pathogenesis. In this review, we systematically summarize the recent research advances regarding the function of the HEV-ORF2 protein such as application in the development of a vaccine, regulation of the innate immune response and cellular signaling, involvement in host tropism and participation in HEV pathogenesis as a novel secretory factor. Progress in understanding more of the function of HEV-ORF2 protein beyond the capsid protein would contribute to improved control and treatment of HEV infection.
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Affiliation(s)
- Zhaobin Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Yinqian Xie
- Shaanxi Animal Disease Prevention and Control Center, Xi’an, China
| | - Chunyan Wu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
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10
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Cellular Organelles Involved in Hepatitis E Virus Infection. Pathogens 2021; 10:pathogens10091206. [PMID: 34578238 PMCID: PMC8469867 DOI: 10.3390/pathogens10091206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 12/24/2022] Open
Abstract
Hepatitis E virus (HEV), a major cause of acute hepatitis worldwide, infects approximately 20 million individuals annually. HEV can infect a wide range of mammalian and avian species, and cause frequent zoonotic spillover, increasingly raising public health concerns. To establish a successful infection, HEV needs to usurp host machineries to accomplish its life cycle from initial attachment to egress. However, relatively little is known about the HEV life cycle, especially the functional role(s) of cellular organelles and their associated proteins at different stages of HEV infection. Here, we summarize current knowledge regarding the relation of HEV with the different cell organelles during HEV infection. Furthermore, we discuss the underlying mechanisms by which HEV infection is precisely regulated in infected cells and the modification of host cell organelles and their associated proteins upon HEV infection.
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11
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Xu M, Sun L, Wang Y, Gao S, Yang W, Li M. Different mutations at position 562 of the hepatitis E virus capsid proteins exhibit differential effects on viral neutralizing activity. Exp Ther Med 2020; 21:110. [PMID: 33335573 PMCID: PMC7739852 DOI: 10.3892/etm.2020.9542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 10/16/2020] [Indexed: 11/15/2022] Open
Abstract
The hepatitis E virus (HEV) capsid protein pORF2 comprises three potential N-linked glycosylation sites. One site, N562, is located at the cell attachment and neutralizing antigenic regions. The present study performed detailed analyses of the effects of specific amino acid substitutions at position 562 in the homodimerization, glycosylation, antigenicity, immunogenicity and neutralization activities of HEV pORF2. Recombinant HEV pORF2 glycoprotein E1 (amino acids 439-617) and three mutant variants (N562L, N562C and N562K) were expressed in Pichia pastoris (P. pastoris) and SDS-PAGE, Western blot analysis, tunicamycin assay, double-antibody sandwich ELISA and in vitro PCR-based neutralization assay were performed to characterize the different constructs. All proteins were indicated to be secreted by P. pastoris and formed homodimers. Tunicamycin assay revealed the glycosylated status of the wild-type protein, but the mutants were indicated to be non-glycosylated. All proteins were immunoreactive with a neutralizing monoclonal antibody but were not recognized by the antibody after denaturation into monomers. An in vitro PCR-based neutralization assay using mouse antibodies indicated efficient neutralization against N562L, whereas antibodies against N562C and N562K were revealed to be non-neutralizing. Collectively, the present study indicated that specific amino acid substitutions at position 562 serve crucial roles in the activity of the HEV neutralizing epitope.
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Affiliation(s)
- Mingjie Xu
- Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250013, P.R. China
| | - Lizhi Sun
- Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250013, P.R. China
| | - Yan Wang
- Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250013, P.R. China
| | - Shuchun Gao
- Department of Liver Disease, Jinan Infectious Disease Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China.,Department of Digestive Disease, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Weihua Yang
- Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250013, P.R. China
| | - Meng Li
- Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250013, P.R. China
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12
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Pallerla SR, Harms D, Johne R, Todt D, Steinmann E, Schemmerer M, Wenzel JJ, Hofmann J, Shih JWK, Wedemeyer H, Bock CT, Velavan TP. Hepatitis E Virus Infection: Circulation, Molecular Epidemiology, and Impact on Global Health. Pathogens 2020; 9:E856. [PMID: 33092306 PMCID: PMC7589794 DOI: 10.3390/pathogens9100856] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 12/11/2022] Open
Abstract
Infection with hepatitis E virus (HEV) represents the most common source of viral hepatitis globally. Although infecting over 20 million people annually in endemic regions, with major outbreaks described since the 1950s, hepatitis E remains an underestimated disease. This review gives a current view of the global circulation and epidemiology of this emerging virus. The history of HEV, from the first reported enteric non-A non-B hepatitis outbreaks, to the discovery of the viral agent and the molecular characterization of the different human pathogenic genotypes, is discussed. Furthermore, the current state of research regarding the virology of HEV is critically assessed, and the challenges towards prevention and diagnosis, as well as clinical risks of the disease described. Together, these points aim to underline the significant impact of hepatitis E on global health and the need for further in-depth research to better understand the pathophysiology and its role in the complex disease manifestations of HEV infection.
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Affiliation(s)
- Srinivas Reddy Pallerla
- Institute of Tropical Medicine, University of Tübingen, 72074 Tübingen, Germany; (S.R.P.); (T.P.V.)
- Vietnamese-German Center for Medical Research (VG-CARE), Hanoi 100000, Vietnam
| | - Dominik Harms
- Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Department of Infectious Diseases, Robert Koch Institute, 13353 Berlin, Germany;
| | - Reimar Johne
- Unit Viruses in Food, Department Biological Safety, German Federal Institute for Risk Assessment, 10589 Berlin, Germany;
| | - Daniel Todt
- Department of Molecular and Medical Virology, Ruhr University Bochum, 44801 Bochum, Germany; (D.T.); (E.S.)
- European Virus Bioinformatics Center (EVBC), 07743 Jena, Germany
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, 44801 Bochum, Germany; (D.T.); (E.S.)
| | - Mathias Schemmerer
- Institute of Clinical Microbiology and Hygiene, National Consultant Laboratory for HAV and HEV, University Medical Center Regensburg, 93053 Regensburg, Germany; (M.S.); (J.J.W.)
| | - Jürgen J. Wenzel
- Institute of Clinical Microbiology and Hygiene, National Consultant Laboratory for HAV and HEV, University Medical Center Regensburg, 93053 Regensburg, Germany; (M.S.); (J.J.W.)
| | - Jörg Hofmann
- Institute of Virology, Charité Universitätsmedizin Berlin, Labor Berlin-Charité-Vivantes GmbH, 13353 Berlin, Germany;
| | | | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, 30623 Hannover, Germany;
- German Center for Infection Research, Partner Hannover-Braunschweig, 38124 Braunschweig, Germany
| | - C.-Thomas Bock
- Institute of Tropical Medicine, University of Tübingen, 72074 Tübingen, Germany; (S.R.P.); (T.P.V.)
- Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Department of Infectious Diseases, Robert Koch Institute, 13353 Berlin, Germany;
| | - Thirumalaisamy P. Velavan
- Institute of Tropical Medicine, University of Tübingen, 72074 Tübingen, Germany; (S.R.P.); (T.P.V.)
- Vietnamese-German Center for Medical Research (VG-CARE), Hanoi 100000, Vietnam
- Faculty of Medicine, Duy Tan University, Da Nang 550000, Vietnam
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13
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Bai C, Cai J, Han P, Qi J, Yuen KY, Wang Q. The crystal structure of the emerging human-infecting hepatitis E virus E2s protein. Biochem Biophys Res Commun 2020; 532:25-31. [PMID: 32819713 DOI: 10.1016/j.bbrc.2020.07.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 07/16/2020] [Indexed: 01/13/2023]
Abstract
Hepatitis E virus (HEV) is a non-enveloped, globular particle that is responsible for acute hepatitis. HEV is classified into the Hepeviridae family and can be divided into four species (A-D). All HEV variants that infect humans are reported to belong to species A (HEV-A), except species C (HEV-C), which was reported to infect humans in December 2018. We determined the crystal structure of the HEV-C E2s domain at 1.8 Å resolution. It contains a classical 12-stranded β-sandwich motif and forms dimers by hydrogen bonding, though the amino acid residues that form hydrogen bonds are quite different from the residues of HEV-A. The HEV-C E2s domain shares the common groove region with other structurally related viruses, and some subtle differences in this region may be related to host adoption or antibody binding. Antibody binding experiments and structural analysis revealed that HEV-C E2s is able to bind to the previously reported broad-spectrum antibody 8G12 but not bind to the antibody 8C11. Meanwhile, the structure analysis shows that HEV-C E2s does not have the key sites for binding to host cells as displayed by HEV-A (Genotype 1) E2s. These structural and biological findings present important implications for understanding the molecular mechanisms of host recognition and entry of HEV-C, as well as provide clues to the development of therapeutic antibodies and vaccines against HEV-C infection.
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Affiliation(s)
- Chongzhi Bai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, 100101, China; Central Laboratory, Shanxi Province Hospital of Traditional Chinese Medicine, Taiyuan, 030012, China; Shanxi Academy of Advanced Research and Innovation, Taiyuan, 030032, China.
| | - Jianpiao Cai
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.
| | - Pengcheng Han
- Department of Biomedical Engineering, Emory University, Atlanta, GA, 10033, USA.
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, 100101, China.
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.
| | - Qihui Wang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, 100101, China.
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14
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On the Host Side of the Hepatitis E Virus Life Cycle. Cells 2020; 9:cells9051294. [PMID: 32456000 PMCID: PMC7291229 DOI: 10.3390/cells9051294] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis E virus (HEV) infection is one of the most common causes of acute hepatitis in the world. HEV is an enterically transmitted positive-strand RNA virus found as a non-enveloped particle in bile as well as stool and as a quasi-enveloped particle in blood. Current understanding of the molecular mechanisms and host factors involved in productive HEV infection is incomplete, but recently developed model systems have facilitated rapid progress in this area. Here, we provide an overview of the HEV life cycle with a focus on the host factors required for viral entry, RNA replication, assembly and release. Further developments of HEV model systems and novel technologies should yield a broader picture in the future.
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15
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Hingane S, Joshi N, Surjit M, Ranjith-Kumar CT. Hepatitis E Virus ORF2 Inhibits RIG-I Mediated Interferon Response. Front Microbiol 2020; 11:656. [PMID: 32351484 PMCID: PMC7174656 DOI: 10.3389/fmicb.2020.00656] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/23/2020] [Indexed: 01/18/2023] Open
Abstract
Understanding the dynamics of host innate immune responses against a pathogen marks the first step toward developing intervention strategies against the pathogen. The cytosolic pattern recognition receptor retinoic acid-inducible gene I (RIG-I) has been shown to be the major innate immune sensor for hepatitis E virus (HEV). Here, we show that HEV capsid protein (ORF2), a 660 amino acid long protein, interferes with the RIG-I signaling. Interestingly, only the full length ORF2 protein but not the 112-608 ORF2 protein inhibited RIG-I dependent interferon response. Both synthetic agonist and virus induced RIG-I activation was modulated by ORF2. Interference of interferon response was confirmed by reporter assays involving different interferon inducible promoters, qRT PCR, ELISA, and immunofluorescence microscopy. Neither glycosylation nor dimerization of the ORF2 protein had any effect on the observed inhibition. Further analyses revealed that the ORF2 protein antagonized Toll-like receptor (TLR) pathways as well. ORF2 inhibited signaling by RIG-I and TLR adapters, IPS-1, MyD88, and TRIF but was unable to inhibit activation by ectopically expressed IRF3 suggesting that it may be acting at a site upstream of IRF3 and downstream of adapter proteins. Our data uncover a new mechanism by which HEV may interfere with the host antiviral signaling.
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Affiliation(s)
- Smita Hingane
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Gurgaon, India
| | - Nishant Joshi
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Gurgaon, India
| | - Milan Surjit
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Gurgaon, India
| | - C T Ranjith-Kumar
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Gurgaon, India.,University School of Biotechnology, Guru Gobind Singh Indraprastha University, Dwarka, India
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16
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Gupta J, Kaul S, Srivastava A, Kaushik N, Ghosh S, Sharma C, Batra G, Banerjee M, Shalimar, Nayak B, Ranjith-Kumar CT, Surjit M. Expression, Purification and Characterization of the Hepatitis E Virus Like-Particles in the Pichia pastoris. Front Microbiol 2020; 11:141. [PMID: 32117160 PMCID: PMC7017414 DOI: 10.3389/fmicb.2020.00141] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/21/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis E virus (HEV) is associated with acute hepatitis disease, which may lead to chronic disease in immunocompromised individuals. The disease is particularly severe among pregnant women (20-30% mortality). The only licensed vaccine against HEV, which is available in China, is the Escherichia coli purified recombinant virus-like particles (VLPs) encompassing the 368-660 amino acids (aa) of the viral ORF2 protein. The viral capsid is formed by the ORF2 protein, which harbors three glycosylation sites. Baculo virus expression system has been employed to generate a glycosylated VLP, which encompasses 112-608aa of the ORF2 protein. Here, we sought to produce a recombinant VLP containing 112-608aa of the ORF2 protein in Pichia pastoris (P. pastoris) expression system. The cDNA sequence encoding 112-608aa of the ORF2 protein was fused with the α-mating factor secretion signal coding sequence (for release of the fusion protein to the culture medium) and cloned into the yeast vector pPICZα. Optimum expression of recombinant protein was obtained at 72 h induction in 1.5% methanol using inoculum density (A600) of 80 and at pH-3.0 of the culture medium. Identity of the purified protein was confirmed by mass spectrometry analysis. Further studies revealed the glycosylation pattern and VLP nature of the purified protein. Immunization of BALB/c mice with these VLPs induced potent immune response as evidenced by the high ORF2 specific IgG titer and augmented splenocyte proliferation in a dose dependent manner. 112-608aa ORF2 VLPs produced in P. pastoris appears to be a suitable candidate for development of diagnostic and prophylactic reagents against the hepatitis E.
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Affiliation(s)
- Jyoti Gupta
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Sheetal Kaul
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Akriti Srivastava
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Neha Kaushik
- Centre for Bio-Design and Diagnostics, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
- School of Life Sciences, Manipal University, Manipal, India
| | - Sukanya Ghosh
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Chandresh Sharma
- Centre for Bio-Design and Diagnostics, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Gaurav Batra
- Centre for Bio-Design and Diagnostics, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Manidipa Banerjee
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Shalimar
- Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India
| | - Baibaswata Nayak
- Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India
| | - C. T. Ranjith-Kumar
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Milan Surjit
- Virology Laboratory, Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
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17
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Bagchi P. Endoplasmic reticulum in viral infection. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 350:265-284. [PMID: 32138901 DOI: 10.1016/bs.ircmb.2019.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Virus exploits host cellular machinery to replicate and form new viral progeny and endoplasmic reticulum (ER) plays central role in the interplay between virus and host cell. Here I will discuss how cellular functions of ER being utilized by viruses from different families during different stages of pathogenesis. Flow of knowledge related to this area of research based on interdisciplinary approach, using biochemical and cell biological assays coupled with advanced microscopy strategies, is pushing our understanding of the virus-ER interaction during infection to the next level.
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Affiliation(s)
- Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, United States.
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18
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Hepatitis E virus infections in Europe. J Clin Virol 2019; 120:20-26. [DOI: 10.1016/j.jcv.2019.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/06/2019] [Indexed: 12/11/2022]
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19
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New insights into the ORF2 capsid protein, a key player of the hepatitis E virus lifecycle. Sci Rep 2019; 9:6243. [PMID: 31000788 PMCID: PMC6472401 DOI: 10.1038/s41598-019-42737-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/05/2019] [Indexed: 12/19/2022] Open
Abstract
Hepatitis E Virus (HEV) genome encodes three proteins including the ORF2 capsid protein. Recently, we demonstrated that HEV produces three different forms of ORF2: (i) the ORF2i form (infectious ORF2) which is the component of infectious particles, (ii) the secreted ORF2g (glycosylated ORF2) and ORF2c (cleaved ORF2) forms that are not associated with infectious particles, but are the major antigens in HEV-infected patient sera. The ORF2 protein sequence contains three highly conserved potential N-glycosylation sites (N1, N2 and N3). The status and biological relevance of ORF2 N-glycosylation in HEV lifecycle remain to be elucidated. Here, we generated and extensively characterized a series of ORF2 mutants in which the three N-glycosylation sites were mutated individually or in combination. We demonstrated that the ORF2g/c protein is N-glycosylated on N1 and N3 sites but not on the N2 site. We showed that N-glycosylation of ORF2 protein does not play any role in replication and assembly of infectious HEV particles. We found that glycosylated ORF2g/c forms are very stable proteins which are targeted by patient antibodies. We also demonstrated that the ORF2i protein is translocated into the nucleus of infected cells. Hence, our study led to new insights into the molecular mechanisms of ORF2 expression.
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20
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Dao Thi VL, Wu X, Rice CM. Stem Cell-Derived Culture Models of Hepatitis E Virus Infection. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a031799. [PMID: 29686039 DOI: 10.1101/cshperspect.a031799] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Similar to other hepatotropic viruses, hepatitis E virus (HEV) has been notoriously difficult to propagate in cell culture, limiting studies to unravel its biology. Recently, major advances have been made by passaging primary HEV isolates and selecting variants that replicate efficiently in carcinoma cells. These adaptations, however, can alter HEV biology. We have explored human embryonic or induced pluripotent stem cell (hESC/iPSC)-derived hepatocyte-like cells (HLCs) as an alternative to conventional hepatoma and hepatocyte cell culture systems for HEV studies. HLCs are permissive for nonadapted HEV isolate genotypes (gt)1-4 replication and can be readily genetically manipulated. HLCs, therefore, enable studies of pan-genotype HEV biology and will serve as a platform for testing anti-HEV treatments. Finally, we discuss how hepatocyte polarity is likely an important factor in the maturation and spread of infectious HEV particles.
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Affiliation(s)
- Viet Loan Dao Thi
- Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065
| | - Xianfang Wu
- Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065
| | - Charles M Rice
- Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065
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21
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Abstract
Hepatitis E virus (HEV) possesses many of the features of other positive-stranded RNA viruses but also adds HEV-specific nuances, making its virus-host interactions unique. Slow virus replication kinetics and fastidious growth conditions, coupled with the historical lack of an efficient cell culture system to propagate the virus, have left many gaps in our understanding of its structure and replication cycle. Recent advances in culturing selected strains of HEV and resolving the 3D structure of the viral capsid are filling in knowledge gaps, but HEV remains an extremely understudied pathogen. Many steps in the HEV life cycle and many aspects of HEV pathogenesis remain unknown, such as the host and viral factors that determine cross-species infection, the HEV-specific receptor(s) on host cells, what determines HEV chronicity and the ability to replicate in extrahepatic sites, and what regulates processing of the open reading frame 1 (ORF1) nonstructural polyprotein.
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Affiliation(s)
- Scott P Kenney
- Food Animal Health Research Program, The Ohio State University, Wooster, Ohio 44691
| | - Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
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22
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Phylogenetic analysis of two genotype 3 Hepatitis E viruses from wild boar, Italy. Virus Genes 2018; 54:812-817. [PMID: 30203361 DOI: 10.1007/s11262-018-1597-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/31/2018] [Indexed: 12/27/2022]
Abstract
The complete and near-complete genome sequences (7206 nt and 7229 nt) of two wild boar HEV strains detected in Southern Italy were obtained by the next generation sequencing. Phylogenetic analysis and p distance comparisons of one of the strains with HEV-3 reference subtype strains confirmed the detection of a subtype 3i (p distance = 0.110) strain in wild boar, never detected in Italy either in wild boar or pigs. The sequence of the second strain was not classifiable in any of the subtypes defined to date, showing a p distance > 0.138 and a low nucleotide identity with all HEV reference strains. The virus may represent a novel subtype, with a low relationship to other strains of genotype 3 detected in wild boar, pigs, or humans in Europe. This result suggests the circulation in Italy of an emerging or uncommon HEV strain. Sequencing followed by phylogenetic analyses of the complete HEV coding regions are important tools for understanding the evolutionary and epidemiological dynamics underlying the wide genetic diversity of HEV strains.
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23
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Conservation and variation of the hepatitis E virus ORF2 capsid protein. Gene 2018; 675:157-164. [PMID: 30180962 DOI: 10.1016/j.gene.2018.06.108] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/27/2018] [Accepted: 06/29/2018] [Indexed: 12/27/2022]
Abstract
Hepatitis E virus (HEV) is one of the major pathogens causing acute viral hepatitis. The infectious particle consists of an RNA genome and capsid proteins. The 7.2 kb genome encodes three open reading frames (ORF) and ORF2 is translated into the capsid protein. The knowledge of structure and function of the ORF2 protein is essential for understanding the evolution and life cycle of HEV. However, biophysical research in this respect remains limited due to technical challenges. We have carried out a series of computational analysis on HEV ORF2. We have identified 144 conserved sites among the 660 amino acid (AA) residues. 43 models based on the previously proposed reference sequences and a cell culture adapted infectious clone were successfully built by 3D protein structure prediction and refinement. Structure alignment of domains revealed structural conservation of the S and M domains, but to a lesser extent of the P domain. Moreover, molecular docking has predicted distinct binding affinities of a monoclonal antibody towards ORF2 across different genotypes. Thus, we have expanded the information on ORF2 at both sequence and structure levels. These findings may help to better understand the evolution and life cycle of HEV, but also facilitate the development of genetically engineered vaccines or antibodies.
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24
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Glingston RS, Deb R, Kumar S, Nagotu S. Organelle dynamics and viral infections: at cross roads. Microbes Infect 2018; 21:20-32. [PMID: 29953921 PMCID: PMC7110583 DOI: 10.1016/j.micinf.2018.06.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/14/2018] [Accepted: 06/15/2018] [Indexed: 01/12/2023]
Abstract
Viruses are obligate intracellular parasites of the host cells. A commonly accepted view is the requirement of internal membranous structures for various aspects of viral life cycle. Organelles enable favourable intracellular environment for several viruses. However, studies reporting organelle dynamics upon viral infections are scant. In this review, we aim to summarize and highlight modulations caused to various organelles upon viral infection or expression of its proteins.
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Affiliation(s)
- R Sahaya Glingston
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Rachayeeta Deb
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Sachin Kumar
- Viral Immunology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
| | - Shirisha Nagotu
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
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Hepatitis E in High-Income Countries: What Do We Know? And What Are the Knowledge Gaps? Viruses 2018; 10:v10060285. [PMID: 29799485 PMCID: PMC6024799 DOI: 10.3390/v10060285] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/16/2018] [Accepted: 05/23/2018] [Indexed: 12/11/2022] Open
Abstract
Hepatitis E virus (HEV) is a positive-strand RNA virus transmitted by the fecal–oral route. HEV genotypes 1 and 2 infect only humans and cause mainly waterborne outbreaks. HEV genotypes 3 and 4 are widely represented in the animal kingdom, and are mainly transmitted as a zoonosis. For the past 20 years, HEV infection has been considered an imported disease in developed countries, but now there is evidence that HEV is an underrecognized pathogen in high-income countries, and that the incidence of confirmed cases has been steadily increasing over the last decade. In this review, we describe current knowledge about the molecular biology of HEV, its clinical features, its main routes of transmission, and possible therapeutic strategies in developed countries.
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Origin, antigenicity, and function of a secreted form of ORF2 in hepatitis E virus infection. Proc Natl Acad Sci U S A 2018; 115:4773-4778. [PMID: 29669922 DOI: 10.1073/pnas.1721345115] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The enterically transmitted hepatitis E virus (HEV) adopts a unique strategy to exit cells by cloaking its capsid (encoded by the viral ORF2 gene) and circulating in the blood as "quasi-enveloped" particles. However, recent evidence suggests that the majority of the ORF2 protein present in the patient serum and supernatants of HEV-infected cell culture exists in a free form and is not associated with virus particles. The origin and biological functions of this secreted form of ORF2 (ORF2S) are unknown. Here we show that production of ORF2S results from translation initiated at the previously presumed AUG start codon for the capsid protein, whereas translation of the actual capsid protein (ORF2C) is initiated at a previously unrecognized internal AUG codon (15 codons downstream of the first AUG). The addition of 15 amino acids to the N terminus of the capsid protein creates a signal sequence that drives ORF2S secretion via the secretory pathway. Unlike ORF2C, ORF2S is glycosylated and exists as a dimer. Nonetheless, ORF2S exhibits substantial antigenic overlap with the capsid, but the epitopes predicted to bind the putative cell receptor are lost. Consistent with this, ORF2S does not block HEV cell entry but inhibits antibody-mediated neutralization. These results reveal a previously unrecognized aspect in HEV biology and shed new light on the immune evasion mechanisms and pathogenesis of this virus.
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Abstract
At least 20 million hepatitis E virus (HEV) infections occur annually, with >3 million symptomatic cases and ∼60,000 fatalities. Hepatitis E is generally self-limiting, with a case fatality rate of 0.5-3% in young adults. However, it can cause up to 30% mortality in pregnant women in the third trimester and can become chronic in immunocompromised individuals, such as those receiving organ transplants or chemotherapy and individuals with HIV infection. HEV is transmitted primarily via the faecal-oral route and was previously thought to be a public health concern only in developing countries. It is now also being frequently reported in industrialized countries, where it is transmitted zoonotically or through organ transplantation or blood transfusions. Although a vaccine for HEV has been developed, it is only licensed in China. Additionally, no effective, non-teratogenic and specific treatments against HEV infections are currently available. Although progress has been made in characterizing HEV biology, the scarcity of adequate experimental platforms has hampered further research. In this Review, we focus on providing an update on the HEV life cycle. We will further discuss existing cell culture and animal models and highlight platforms that have proven to be useful and/or are emerging for studying other hepatotropic (viral) pathogens.
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Affiliation(s)
- Ila Nimgaonkar
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544, USA
| | - Qiang Ding
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544, USA
| | - Robert E Schwartz
- Division of Gastroenterology and Hepatology, Department of Medicine, Weill Medical College of Cornell University, New York, New York 10021, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544, USA
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Montpellier C, Wychowski C, Sayed IM, Meunier JC, Saliou JM, Ankavay M, Bull A, Pillez A, Abravanel F, Helle F, Brochot E, Drobecq H, Farhat R, Aliouat-Denis CM, Haddad JG, Izopet J, Meuleman P, Goffard A, Dubuisson J, Cocquerel L. Hepatitis E Virus Lifecycle and Identification of 3 Forms of the ORF2 Capsid Protein. Gastroenterology 2018; 154:211-223.e8. [PMID: 28958858 DOI: 10.1053/j.gastro.2017.09.020] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 09/08/2017] [Accepted: 09/14/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Hepatitis E virus (HEV) infection is a major cause of acute hepatitis worldwide. Approximately 2 billion people live in areas endemic for HEV and are at risk of infection. The HEV genome encodes 3 proteins, including the ORF2 capsid protein. Detailed analyses of the HEV life cycle has been hampered by the lack of an efficient viral culture system. METHODS We performed studies with gt3 HEV cell culture-produced particles and patient blood and stool samples. Samples were fractionated on iodixanol gradients and cushions. Infectivity assays were performed in vitro and in human liver chimeric mice. Proteins were analyzed by biochemical and proteomic approaches. Infectious particles were analyzed by transmission electron microscopy. HEV antigen levels were measured with the Wantaï enzyme-linked immunosorbent assay. RESULTS We developed an efficient cell culture system and isolated HEV particles that were infectious in vitro and in vivo. Using transmission electron microscopy, we defined the ultrastructure of HEV cell culture-produced particles and particles from patient sera and stool samples. We also identified the precise sequence of the infectious particle-associated ORF2 capsid protein. In cultured cells and in samples from patients, HEV produced 3 forms of the ORF2 capsid protein: infectious/intracellular ORF2 (ORF2i), glycosylated ORF2 (ORF2g), and cleaved ORF2 (ORF2c). The ORF2i protein associated with infectious particles, whereas the ORF2g and ORF2c proteins were massively secreted glycoproteins not associated with infectious particles. ORF2g and ORF2c were the most abundant antigens detected in sera from patients. CONCLUSIONS We developed a cell culture system and characterized HEV particles; we identified 3 ORF2 capsid proteins (ORF2i, ORF2g, and ORFc). These findings will advance our understanding of the HEV life cycle and improve diagnosis.
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Affiliation(s)
- Claire Montpellier
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Czeslaw Wychowski
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France.
| | - Ibrahim M Sayed
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium; Microbiology and Immunology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | | | - Jean-Michel Saliou
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Maliki Ankavay
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Anne Bull
- Inserm-U966, University F. Rabelais, Tours, France
| | - André Pillez
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Florence Abravanel
- CHU Toulouse, Hôpital Purpan, Laboratoire de virologie, National Reference Center for Hepatitis E, Toulouse, France
| | - François Helle
- EA4294, Laboratoire de Virologie, Centre Universitaire de Recherche en Santé, Centre Hospitalier Universitaire et Université de Picardie Jules Verne, Amiens, France
| | - Etienne Brochot
- EA4294, Laboratoire de Virologie, Centre Universitaire de Recherche en Santé, Centre Hospitalier Universitaire et Université de Picardie Jules Verne, Amiens, France
| | - Hervé Drobecq
- University of Lille, CNRS, Institut Pasteur de Lille, UMR 8161-M3T-Mechanisms of Tumorigenesis and Target Therapies, Lille, France
| | - Rayan Farhat
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Cécile-Marie Aliouat-Denis
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Juliano G Haddad
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Jacques Izopet
- CHU Toulouse, Hôpital Purpan, Laboratoire de virologie, National Reference Center for Hepatitis E, Toulouse, France
| | - Philip Meuleman
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Anne Goffard
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Jean Dubuisson
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Laurence Cocquerel
- University of Lille, CNRS, INSERM, CHU Lille, Pasteur Institute of Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, Lille, France.
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Abstract
Hepatitis E virus (HEV) infection can lead to acute and chronic hepatitis as well as to extrahepatic manifestations such as neurological and renal disease; it is the most common cause of acute viral hepatitis worldwide. Four genotypes are responsible for most infection in humans, of which HEV genotypes 1 and 2 are obligate human pathogens and HEV genotypes 3 and 4 are mostly zoonotic. Until quite recently, HEV was considered to be mainly responsible for epidemics of acute hepatitis in developing regions owing to contamination of drinking water supplies with human faeces. However, HEV is increasingly being recognized as endemic in some developed regions. In this setting, infections occur through zoonotic transmission or contaminated blood products and can cause chronic hepatitis in immunocompromised individuals. HEV infections can be diagnosed by measuring anti-HEV antibodies, HEV RNA or viral capsid antigen in blood or stool. Although an effective HEV vaccine exists, it is only licensed for use in China. Acute hepatitis E is usually self-limiting and does not require specific treatment. Management of immunocompromised individuals involves lowering the dose of immunosuppressive drugs and/or treatment with the antiviral agent ribavirin.
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Paliwal D, Joshi P, Panda SK. Hepatitis E Virus (HEV) egress: Role of BST2 (Tetherin) and interferon induced long non- coding RNA (lncRNA) BISPR. PLoS One 2017; 12:e0187334. [PMID: 29091957 PMCID: PMC5665557 DOI: 10.1371/journal.pone.0187334] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 10/18/2017] [Indexed: 12/18/2022] Open
Abstract
Background The biology of Hepatitis E Virus (HEV), a common cause of epidemic and sporadic hepatitis, is still being explored. HEV exits liver through bile, a process which is essential for its natural transmission by feco-oral route. Though the process of this polarised HEV egress is not known in detail, HEV pORF3 and hepatocyte actin cytoskeleton have been shown to play a role. Methods Our transcriptome analysis in Hepatitis E virus (HEV) replicon transfected Huh7 cells at 24 and 72 hrs indicated that at 24hrs, both LncBISPR and BST2, expressed by a bidirectional promoter were highly upregulated whereas at 72 hrs, BST2 expression was comparatively reduced accompanied by normal levels of BISPR. These findings were confirmed by qPCR analysis. Co-localisation of BST2 and HEV pORF2 was confirmed in HEV transfected Huh7 by confocal microscopy. To investigate the role of BISPR/BST2 in HEV life cycle, particularly virus egress, we generated Huh7 cells with ~8kb deletion in BISPR gene using Crispr-Cas9 system. The deletion was confirmed by PCR screening, Sanger sequencing and Real time PCR. Virus egress in ΔBISPR Huh7 and Huh7 cells was compared by measuring HEV positive strand RNA copy numbers in cell lysates and culture supernatants at 24 and 72 hrs post HEV replicon transfection and further validated by western blot for HEV pORF2 capsid protein. Results ΔBISPR Huh7 cells showed ~8 fold increase in virus egress at 24 hrs compared to Huh7 cells. No significant difference in virus egress was observed at 72hrs. Immunohistochemistry in histologically normal liver and HEV associated acute liver failure revealed BST2 overexpression in HEV infected hepatocytes and a dominant canalicular BST2 distribution in normal liver in addition to the cytoplasmic localisation reported in literature. Conclusions These findings lead us to believe that BISPR and BST2 may regulate egress of HEV virions into bile in vivo. This system may also be used to scale up virus production in vitro.
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Affiliation(s)
- Daizy Paliwal
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Prashant Joshi
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Subrat Kumar Panda
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
- * E-mail:
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31
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Chapuy-Regaud S, Dubois M, Plisson-Chastang C, Bonnefois T, Lhomme S, Bertrand-Michel J, You B, Simoneau S, Gleizes PE, Flan B, Abravanel F, Izopet J. Characterization of the lipid envelope of exosome encapsulated HEV particles protected from the immune response. Biochimie 2017; 141:70-79. [PMID: 28483690 DOI: 10.1016/j.biochi.2017.05.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/03/2017] [Indexed: 02/08/2023]
Abstract
The hepatitis E virus (HEV) is the most common cause of acute hepatitis worldwide. Although HEV is a small, naked RNA virus, HEV particles become associated with lipids in the blood of infected patients and in the supernatant of culture systems. The egress of these particles from cells implies the exocytosis pathway but the question of the role of the resulting HEV RNA containing exosomes and the nature of the lipids they contain has not been fully addressed. We determined the lipid proportions of exosomes from uninfected and HEV-infected cells and their role in HEV spreading. We cultured a suitable HEV strain on HepG2/C3A cells and analyzed the population of exosomes containing HEV RNA using lipidomics methods and electron microscopy. We also quantified HEV infectivity using an infectivity endpoint method based on HEV RNA quantification to calculate the tissue culture infectious dose 50. Exosomes produced by HEV-infected HepG2/C3A cells contained encapsidated HEV RNA. These HEV RNA-containing exosomes were infectious but ten times less than stools. HEV from stools, but not exosome-associated HEV from culture supernatant, was neutralized by anti-HEV antibodies in a dose-dependent manner. HEV infection did not influence the morphology or lipid proportions of the bulk of exosomes. These exosomes contained significantly more cholesterol, phosphatidylserine, sphingomyelin and ceramides than the parent cells, but less phosphoinositides and polyunsaturated fatty acids. Exosomes play a major role in HEV egress but HEV infection does not modify the characteristics of the bulk of exosomes produced by infected cells. PS and cholesterol enriched in these vesicles could then be critical for HEV entry. HEV particles in exosomes are protected from the immune response which could lead to the wide circulation of HEV in its host.
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Affiliation(s)
- Sabine Chapuy-Regaud
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France; Toulouse University, Toulouse, France.
| | - Martine Dubois
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France
| | | | - Tiffany Bonnefois
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France
| | - Sébastien Lhomme
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France; Toulouse University, Toulouse, France
| | - Justine Bertrand-Michel
- Toulouse University, Toulouse, France; MetaToul-Lipidomic Core Facility, INSERM, UMR1048, Toulouse, France
| | - Bruno You
- LFB, Laboratoire Français du Fractionnement et des Biotechnologies, Courtaboeuf, France
| | - Steve Simoneau
- LFB, Laboratoire Français du Fractionnement et des Biotechnologies, Courtaboeuf, France
| | | | - Benoît Flan
- LFB, Laboratoire Français du Fractionnement et des Biotechnologies, Courtaboeuf, France
| | - Florence Abravanel
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France; Toulouse University, Toulouse, France
| | - Jacques Izopet
- INSERM, UMR1043, Toulouse, France; Department of Virology, CHU Purpan, Toulouse, France; Toulouse University, Toulouse, France
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Toward Mucosal DNA Delivery: Structural Modularity in Vaccine Platform Design. MICRO AND NANOTECHNOLOGY IN VACCINE DEVELOPMENT 2017. [PMCID: PMC7152392 DOI: 10.1016/b978-0-323-39981-4.00016-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hepatitis E virus is a small, nonenveloped RNA virus that is feco-orally transmitted and causes viral hepatitis in humans. A virus-like particle (VLP) expressed and purified from insect cells shares several properties with the virion but can be manipulated quite extensively through genetic engineering or chemical modification. This has exciting implications for exploiting the VLP as a nanocarrier for foreign epitopes or encapsulated deliverables. By exhaustively studying the structure of the virus, we have been successful in designing and synthesizing chimerized VLPs that either carry foreign epitopes, are capable of encapsulating foreign DNA, or both. Preliminary studies show that these particles provide specific and strong immune responses in mice when orally delivered. To appreciate the full potential of HEV VLPs, we have highlighted various properties of the virus with a strong focus on the VLP structure and the key features that make it suitable for oral delivery.
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Zhang L, Tian Y, Wen Z, Zhang F, Qi Y, Huang W, Zhang H, Wang Y. Asialoglycoprotein receptor facilitates infection of PLC/PRF/5 cells by HEV through interaction with ORF2. J Med Virol 2016; 88:2186-2195. [DOI: 10.1002/jmv.24570] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Li Zhang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
| | - Yabin Tian
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
| | - Zhiheng Wen
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
| | - Feng Zhang
- Division of Monoclonal Antibody Products; National Institutes for Food and Drug Control; Beijing China
| | - Ying Qi
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
| | - Weijin Huang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
| | - Heqiu Zhang
- Department of Bio-Diagnosis; Beijing Institute of Basic Medical Sciences; Beijing China
| | - Youchun Wang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines; National Institutes for Food and Drug Control; Beijing China
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Nan Y, Zhang YJ. Molecular Biology and Infection of Hepatitis E Virus. Front Microbiol 2016; 7:1419. [PMID: 27656178 PMCID: PMC5013053 DOI: 10.3389/fmicb.2016.01419] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/26/2016] [Indexed: 12/13/2022] Open
Abstract
Hepatitis E virus (HEV) is a viral pathogen transmitted primarily via fecal-oral route. In humans, HEV mainly causes acute hepatitis and is responsible for large outbreaks of hepatitis across the world. The case fatality rate of HEV-induced hepatitis ranges from 0.5 to 3% in young adults and up to 30% in infected pregnant women. HEV strains infecting humans are classified into four genotypes. HEV strains from genotypes 3 and 4 are zoonotic, whereas those from genotypes 1 and 2 have no known animal reservoirs. Recently, notable progress has been accomplished for better understanding of HEV biology and infection, such as chronic HEV infection, in vitro cell culture system, quasi-enveloped HEV virions, functions of the HEV proteins, mechanism of HEV antagonizing host innate immunity, HEV pathogenesis and vaccine development. However, further investigation on the cross-species HEV infection, host tropism, vaccine efficacy, and HEV-specific antiviral strategy is still needed. This review mainly focuses on molecular biology and infection of HEV and offers perspective new insight of this enigmatic virus.
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Affiliation(s)
- Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F UniversityYangling, China; Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, College ParkMD, USA
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, College Park MD, USA
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Update on hepatitis E virology: Implications for clinical practice. J Hepatol 2016; 65:200-212. [PMID: 26966047 DOI: 10.1016/j.jhep.2016.02.045] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/15/2016] [Accepted: 02/21/2016] [Indexed: 12/18/2022]
Abstract
Hepatitis E virus (HEV) is a positive-strand RNA virus transmitted by the fecal-oral route. The 7.2kb genome encodes three open reading frames (ORF) which are translated into (i) the ORF1 polyprotein, representing the viral replicase, (ii) the ORF2 protein, corresponding to the viral capsid, and (iii) the ORF3 protein, a small protein involved in particle secretion. Although HEV is a non-enveloped virus in bile and feces, it circulates in the bloodstream wrapped in cellular membranes. HEV genotypes 1 and 2 infect only humans and cause mainly waterborne outbreaks. HEV genotypes 3 and 4 are widely represented in the animal kingdom and are transmitted as a zoonosis mainly via contaminated meat. HEV infection is usually self-limited but may persist and cause chronic hepatitis in immunocompromised patients. Reduction of immunosuppressive treatment or antiviral therapy with ribavirin have proven effective in most patients with chronic hepatitis E but therapy failures have been reported. Alternative treatment options are needed, therefore. Infection with HEV may also cause a number of extrahepatic manifestations, especially neurologic complications. Progress in the understanding of the biology of HEV should contribute to improved control and treatment of HEV infection.
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Ravindran MS, Bagchi P, Cunningham CN, Tsai B. Opportunistic intruders: how viruses orchestrate ER functions to infect cells. Nat Rev Microbiol 2016; 14:407-420. [PMID: 27265768 PMCID: PMC5272919 DOI: 10.1038/nrmicro.2016.60] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Viruses exploit the functions of the endoplasmic reticulum (ER) to promote both early and later stages of their life cycle, including entry, translation, replication, assembly, morphogenesis and egress. This observation reveals a shared principle that underlies virus–host cell relationships. Viral entry often requires disassembly of the incoming virus particle. This is best exemplified in the case of polyomavirus entry, in which ER-associated machineries are hijacked to disassemble the virus and promote entry to the cytosol en route to the nucleus. Many enveloped viruses, such as HIV and influenza virus, co-opt the ER-associated protein biosynthetic machinery to translate their genome and produce structural proteins that are necessary for the formation of virus particles and non-structural proteins that are essential during genome replication. Replication of the viral genome, particularly for positive-sense RNA ((+)RNA) viruses including hepatitis C virus (HCV), dengue virus (DENV) and West Nile virus (WNV), occurs in virus-induced membranous structures that are most often derived from the ER. The formation of these structures requires morphological changes to the ER membrane, involving membrane rearrangements that are induced by viral non-structural proteins that are targeted to the ER. As virus assembly is often coupled to genome replication, the assembly process frequently relies on the ER membrane. This strategy is seen for both RNA and DNA viruses. Morphogenesis of assembled virus particles can also take advantage of the ER. This is best observed in the non-enveloped rotavirus, for which a transient enveloped intermediate is converted to the mature and infectious particle in the lumen of the ER. After maturation in the ER, progeny virus particles egress the host through the ER-dependent secretory pathway, which provides a physical conduit to the extracellular environment. The overall observations that the ER actively promotes all steps of viral infection have therapeutic implications. The development of chemical inhibitors of selective ER-associated components is emerging as a potential avenue of antiviral therapy, provided that these inhibitors have minimal toxicity to the host cell.
Many host structures are vital for viral infection and the endoplasmic reticulum (ER), in particular, is essential. In this Review, Tsai and colleagues highlight examples of subversion of the ER by diverse viruses to promote all stages of their life cycle, from entry to egress. Viruses subvert the functions of their host cells to replicate and form new viral progeny. The endoplasmic reticulum (ER) has been identified as a central organelle that governs the intracellular interplay between viruses and hosts. In this Review, we analyse how viruses from vastly different families converge on this unique intracellular organelle during infection, co-opting some of the endogenous functions of the ER to promote distinct steps of the viral life cycle from entry and replication to assembly and egress. The ER can act as the common denominator during infection for diverse virus families, thereby providing a shared principle that underlies the apparent complexity of relationships between viruses and host cells. As a plethora of information illuminating the molecular and cellular basis of virus–ER interactions has become available, these insights may lead to the development of crucial therapeutic agents.
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Affiliation(s)
- Madhu Sudhan Ravindran
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Parikshit Bagchi
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Corey Nathaniel Cunningham
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, Michigan 48109, USA
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Identification of critical residues in Hepatitis E virus macro domain involved in its interaction with viral methyltransferase and ORF3 proteins. Sci Rep 2016; 6:25133. [PMID: 27113483 PMCID: PMC4844956 DOI: 10.1038/srep25133] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/12/2016] [Indexed: 01/16/2023] Open
Abstract
Hepatitis E virus (HEV) is a major cause of hepatitis in normal and organ transplant individuals. HEV open reading frame-1 encodes a polypeptide comprising of the viral nonstructural proteins as well as domains of unknown function such as the macro domain (X-domain), V, DUF3729 and Y. The macro domain proteins are ubiquitously present from prokaryotes to human and in many positive-strand RNA viruses, playing important roles in multiple cellular processes. Towards understanding the function of the HEV macro domain, we characterized its interaction partners among other HEV encoded proteins. Here, we report that the HEV X-domain directly interacts with the viral methyltransferase and the ORF3 proteins. ORF3 association with the X-domain was mediated through two independent motifs, located within its N-terminal 35aa (amino acids) and C-terminal 63-123aa. Methyltransferase interaction domain was mapped to N-terminal 30-90aa. The X-domain interacted with both ORF3 and methyltransferase through its C-terminal region, involving 66th,67th isoleucine and 101st,102nd leucine, conserved across HEV genotypes. Furthermore, ORF3 and methyltransferase competed with each other for associating with the X-domain. These findings provide molecular understanding of the interaction between the HEV macro domain, methyltransferase and ORF3, suggesting an important role of the macro domain in the life cycle of HEV.
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Kobayashi T, Takahashi M, Jirintai S, Nagashima S, Nishizawa T, Okamoto H. Characterization and epitope mapping of monoclonal antibodies raised against rat hepatitis E virus capsid protein: An evaluation of their neutralizing activity in a cell culture system. J Virol Methods 2016; 233:78-88. [PMID: 26992654 DOI: 10.1016/j.jviromet.2016.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 03/10/2016] [Accepted: 03/12/2016] [Indexed: 01/23/2023]
Abstract
Hepatitis E virus (HEV) is the causative agent of acute hepatitis. Rat HEV is a recently discovered virus related to, but distinct from, human HEV. Since laboratory rats can be reproducibly infected with rat HEV and a cell culture system has been established for rat HEV, this virus may be used as a surrogate virus for human HEV, enabling studies on virus replication and mechanism of infection. However, monoclonal antibodies (MAbs) against rat HEV capsid (ORF2) protein are not available. In this study, 12 murine MAbs were generated against a recombinant ORF2 protein of rat HEV (rRatHEV-ORF2: amino acids 101-644) and were classified into at least six distinct groups by epitope mapping and a cross-reactivity analysis with human HEV ORF2 proteins. Two non-cross-reactive MAbs recognizing the protruding (P) domain detected both non-denatured and denatured rRatHEV-ORF2 protein and efficiently captured cell culture-produced rat HEV particles that had been treated with deoxycholate and trypsin, but not those without prior treatment. In addition, these two MAbs were able to efficiently neutralize replication of cell culture-generated rat HEV particles without lipid membranes (but not those with lipid membranes) in a cell culture system, similar to human HEV.
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Affiliation(s)
- Tominari Kobayashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan
| | - Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan
| | - Suljid Jirintai
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-Shi, Tochigi 329-0498, Japan.
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Full coding hepatitis E virus genotype 3 genome amplification method. J Virol Methods 2016; 230:18-23. [PMID: 26784284 PMCID: PMC7172825 DOI: 10.1016/j.jviromet.2016.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 02/07/2023]
Abstract
A new amplification method for the complete HEV coding genome was described. HEV genome organization and function were reviewed. Polymorphic amino acids of each HEV genome region were analyzed in reference sequences. Complete coding HEV sequence of an immunocompromised patient with acute infection was analyzed.
Hepatitis E virus (HEV) genotype 3 produces zoonotic infection associated with the consumption of infected animals. HEV infections can become chronic in immunocompromised (IC) patients. The viral genome has three well defined open reading frames (ORF1, ORF2 and ORF3) within which various domains and functions have been described. This paper (i) describes a new method of complete sequencing of the HEV coding region through overlapping PCR systems, (ii) establishes a consensus sequence and polymorphic positions (PP) for each domain, and (iii) analyzes the complete coding sequence of an IC patient. With regard to the consensus, a high percentage of PP was observed in protease (PP = 19%) and the X domain (PP = 22%) within ORF1, the N-terminal region of the S domain (PP = 22%) in ORF2, and the P1 (PP = 35%) and P2 (PP = 25%) domains in ORF3. In contrast, the ORF1 Y, ORF2 S, ORF2 M and ORF3 D1 domains were conserved in the reference sequences (0.40, 1, 0.70 and 0% of PP, respectively). The sequence from the IC patient had more mutations in the RpRp (D1235G, Q1242R, S1454T, V1480I, I1502 V, K1511R, G1373 V, E1442D, V1693 M), the terminal ORF2 S- domain (F10L, S26T, G36S, S70P, A105 V, I113 V), the X domain (T938 M, T856 V, S898A) and the helicase (S1014N, S975T, Q1133 K).
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Zhou Y, Zhao C, Tian Y, Xu N, Wang Y. Characteristics and Functions of HEV Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 948:17-38. [PMID: 27738977 DOI: 10.1007/978-94-024-0942-0_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hepatitis E virus (HEV) is a non-enveloped virus containing a single-stranded, positive-sense RNA genome of 7.2 kb, which consists of a 5' noncoding region, three open reading frames (ORFs), and a 3' noncoding region. ORF1 is diverse between genotypes and encodes the nonstructural proteins, which include the enzymes needed for virus replication. In addition to its role in virus replication, the function of ORF1 is relevant to viral adaption in cultured cells and may also relate to virus infection and HEV pathogenicity. ORF2 protein is the capsid protein, which is about 660 amino acids in length. It not only protects the integrity of the viral genome but is also involved in many important physiological activities, such as virus assembly, infection, and host interaction. The main immune epitopes, especially neutralizing epitopes, are located on ORF2 protein, which is a candidate antigen for vaccine development. ORF3 protein is a phosphoprotein of 113 or 114 amino acids with a molecular weight of 13 kDa with multiple functions that can also induce strong immune reactivity.
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Affiliation(s)
- Yan Zhou
- Division of Drug and Cosmetics Inspection, Center for Food and Drug Inspection, China Food and Drug Administration, No.11 Fa Hua Nan Li, Dongcheng District, Beijing, 100061, China
| | - Chenyan Zhao
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Yabin Tian
- Division of Diagnosis, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Nan Xu
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China
| | - Youchun Wang
- Division of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, No. 2 Tiantanxili, Dongcheng District, Beijing, 100050, China.
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Holla P, Ahmad I, Ahmed Z, Jameel S. Hepatitis E virus enters liver cells through a dynamin-2, clathrin and membrane cholesterol-dependent pathway. Traffic 2015; 16:398-416. [PMID: 25615268 DOI: 10.1111/tra.12260] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 01/08/2015] [Accepted: 01/08/2015] [Indexed: 12/22/2022]
Abstract
The hepatitis E virus (HEV) causes large outbreaks and sporadic cases of acute viral hepatitis in developing countries. In the developed world, HEV occurrence has increased as a result of zoonotic transmission from swine. The cellular aspects of HEV infection, especially the determinants of entry, are poorly understood. In the absence of a robust in vitro culture system for HEV, it is not possible to produce high titre infectious virus that can be labeled for tracking its internalization. We have therefore used an Escherichia coli expressed HEV-like particle (HEV-LP) to study HEV entry. Following internalization, the HEV-LP initially trafficks to Rab5-positive compartments en route to acidic lysosomal compartments where it is degraded. Using pharmacological inhibitors, dominant negative and constitutively active mutants, and siRNA-mediated perturbations, we show that HEV entry requires dynamin-2, clathrin, membrane cholesterol and actin, but is independent of factors associated with macropinocytosis. The HEV-LP results were further validated through infection of liver cells with virus from the stool of an infected patient. The comparative analysis also showed involvement of the phosphatidylinositol-3-kinase/Akt pathway in an early post-entry step of viral replication. This report provides a detailed description of endocytic processes associated with HEV infection.
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Affiliation(s)
- Prasida Holla
- Virology Group, International Centre for Genetic Engineering Biotechnology, New Delhi, India
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Qi Y, Zhang F, Zhang L, Harrison TJ, Huang W, Zhao C, Kong W, Jiang C, Wang Y. Hepatitis E Virus Produced from Cell Culture Has a Lipid Envelope. PLoS One 2015; 10:e0132503. [PMID: 26161670 PMCID: PMC4498737 DOI: 10.1371/journal.pone.0132503] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/15/2015] [Indexed: 01/10/2023] Open
Abstract
The absence of a productive cell culture system hampered detailed analysis of the structure and protein composition of the hepatitis E virion. In this study, hepatitis E virus from a robust HEV cell culture system and from the feces of infected monkeys at the peak of virus excretion was purified by ultra-centrifugation. The common feature of the two samples after ultracentrifugation was that the ORF2 protein mainly remained in the top fractions. The ORF2 protein from cell culture system was glycosylated, with an apparent molecular weight of 88 kDa, and was not infectious in PLC/PRF/5 cells. The ORF2 protein in this fraction can bind to and protect HEV RNA from digestion by RNase A. The RNA-ORF2 product has a similar sedimentation coefficient to the virus from feces. The viral RNA in the cell culture supernatant was mainly in the fraction of 1.15 g/cm3 but that from the feces was mainly in the fraction of 1.21 g/cm3. Both were infectious in PLC/PRF/5 cells. And the fraction in the middle of the gradient (1.06 g/cm3) from the cell culture supernatant,but not that from the feces, also has ORF2 protein and HEV RNA but was not infectious in PLC/PRF/5.The infectious RNA-rich fraction from the cell culture contained ORF3 protein and lipid but the corresponding fraction from feces had no lipid and little ORF3 protein. The lipid on the surface of the virus has no effect on its binding to cells but the ORF3 protein interferes with binding. The result suggests that most of the secreted ORF2 protein is not associated with HEV RNA and that hepatitis E virus produced in cell culture differs in structure from the virus found in feces in that it has a lipid envelope.
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Affiliation(s)
- Ying Qi
- National Engineering Laboratory for AIDS Vaccine, Jilin University, Changchun, 130012, China
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Feng Zhang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Li Zhang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Tim J. Harrison
- Division of Medicine, University College London Medical School, London, WC1E 6BT, United Kingdom
| | - Weijin Huang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Chenyan Zhao
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Wei Kong
- National Engineering Laboratory for AIDS Vaccine, Jilin University, Changchun, 130012, China
| | - Chunlai Jiang
- National Engineering Laboratory for AIDS Vaccine, Jilin University, Changchun, 130012, China
| | - Youchun Wang
- Division of HIV/AIDS and Sexually-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, 100050, China
- * E-mail:
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Novel molecular alterations in the ORF 2 capsid gene of hepatitis E virus in patients with acute liver failure in North India. Arch Virol 2014; 159:3391-4. [DOI: 10.1007/s00705-014-2198-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/29/2014] [Indexed: 10/24/2022]
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Feng Z, Hirai-Yuki A, McKnight KL, Lemon SM. Naked Viruses That Aren't Always Naked: Quasi-Enveloped Agents of Acute Hepatitis. Annu Rev Virol 2014; 1:539-60. [PMID: 26958733 DOI: 10.1146/annurev-virology-031413-085359] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Historically, viruses were considered to be either enveloped or nonenveloped. However, recent work on hepatitis A virus and hepatitis E virus challenges this long-held tenet. Whereas these human pathogens are shed in feces as naked nonenveloped virions, recent studies indicate that both circulate in the blood completely masked in membranes during acute infection. These membrane-wrapped virions are as infectious as their naked counterparts, although they do not express a virally encoded protein on their surface, thus distinguishing them from conventional enveloped viruses. The absence of a viral fusion protein implies that these quasi-enveloped virions have unique mechanisms for entry into cells. Like true enveloped viruses, however, these phylogenetically distinct viruses usurp components of the host ESCRT system to hijack host cell membranes and noncytolytically exit infected cells. The membrane protects these viruses from neutralizing antibodies, facilitating dissemination within the host, whereas nonenveloped virions shed in feces are stable in the environment, allowing for epidemic transmission.
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Affiliation(s)
- Zongdi Feng
- Lineberger Comprehensive Cancer Center, Inflammatory Diseases Institute, and Departments of Medicine and Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7292;
| | - Asuka Hirai-Yuki
- Lineberger Comprehensive Cancer Center, Inflammatory Diseases Institute, and Departments of Medicine and Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7292;
| | - Kevin L McKnight
- Lineberger Comprehensive Cancer Center, Inflammatory Diseases Institute, and Departments of Medicine and Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7292;
| | - Stanley M Lemon
- Lineberger Comprehensive Cancer Center, Inflammatory Diseases Institute, and Departments of Medicine and Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7292;
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Paliwal D, Panda SK, Kapur N, Varma SPK, Durgapal H. Hepatitis E virus (HEV) protease: a chymotrypsin-like enzyme that processes both non-structural (pORF1) and capsid (pORF2) protein. J Gen Virol 2014; 95:1689-1700. [PMID: 24795447 DOI: 10.1099/vir.0.066142-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis E virus (HEV), a major cause of acute viral hepatitis across the world, is a non-enveloped, plus-strand RNA virus. Its genome codes three proteins, pORF1 (multifunctional polyprotein), pORF2 (capsid protein) and pORF3 (multi-regulatory protein). pORF1 encodes methyltransferase, putative papain-like cysteine protease, helicase and replicase enzymes. Of these, the protease domain has not been characterized. On the basis of sequence analysis, we cloned and expressed a protein covering aa 440-610 of pORF1, expression of which led to cell death in Escherichia coli BL-21 and Huh7 hepatoma cells. Finally, we expressed and purified this protein from E. coli C43 cells (resistant to toxic proteins). The refolded form of this protein showed protease activity in gelatin zymography. Digestion assays showed cleavage of both pORF1 and pORF2 as observed previously. MS revealed digestion of capsid protein at both the N and C termini. N-terminal sequencing of the ~35 kDa methyltransferase, ~35 kDa replicase and ~56 kDa pORF2 proteins released by protease digestion revealed that the cleavage sites were alanine15/isoleucine16, alanine1364/valine1365 in pORF1 and leucine197/valine198 in pORF2. Specificity of these cleavage sites was validated by site-directed mutagenesis. Further characterization of the HEV protease, carried out using twelve inhibitors, showed chymostatin and PMSF to be the most efficient inhibitors, indicating this protein as a chymotrypsin-like protease. The specificity was further confirmed by cleavage of the chymotrypsin-specific fluorogenic peptide N-succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin. Mutational analysis of the conserved serine/cysteine/histidine residues suggested that H443 and C472/C481/C483 are possibly the active site residues. To our knowledge, this is the first direct demonstration of HEV protease and its function.
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Affiliation(s)
- Daizy Paliwal
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Subrat Kumar Panda
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Neeraj Kapur
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Satya Pavan Kumar Varma
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Hemlata Durgapal
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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Abstract
A novel virus was detected in a sample collected from a Swedish moose (Alces alces). The virus was suggested as a member of the Hepeviridae family, although it was found to be highly divergent from the known four genotypes (gt1–4) of hepatitis E virus (HEV). Moose are regularly hunted for consumption in the whole of Scandinavia. Thus, the finding of this virus may be important from several aspects: (a) as a new diverged HEV in a new animal species, and (b) potential unexplored HEV transmission pathways for human infections. Considering these aspects, we have started the molecular characterization of this virus. A 5.1 kb amplicon was sequenced, and corresponded to the partial ORF1, followed by complete ORF2, ORF3 and poly(A) sequence. In comparison with existing HEVs, the moose HEV genome showed a general nucleotide sequence similarity of 37–63 % and an extensively divergent putative ORF3 sequence. The junction region between the ORFs was also highly divergent; however, two putative secondary stem–loop structures were retained when compared to gt1–4, but with altered structural appearance. In the phylogenetic analysis, the moose HEV deviated and formed its own branch between the gt1–4 and other divergent animal HEVs. The characterization of this highly divergent genome provides important information regarding the diversity of HEV infecting various mammalian species. However, further studies are needed to investigate its prevalence in the moose populations and possibly in other host species, including the risk for human infection.
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Affiliation(s)
- Jay Lin
- Department of Virology, Immunobiology and Parasitology (VIP), National Veterinary Institute (SVA), Uppsala, Sweden
| | - Heléne Norder
- Department of Infectious Diseases/Section of Clinical Virology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Henrik Uhlhorn
- Department of Pathology and Wildlife Diseases, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Sándor Belák
- Department of Virology, Immunobiology and Parasitology (VIP), National Veterinary Institute (SVA), Uppsala, Sweden
| | - Frederik Widén
- Department of Virology, Immunobiology and Parasitology (VIP), National Veterinary Institute (SVA), Uppsala, Sweden
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Feng Z, Lemon SM. Peek-a-boo: membrane hijacking and the pathogenesis of viral hepatitis. Trends Microbiol 2013; 22:59-64. [PMID: 24268716 DOI: 10.1016/j.tim.2013.10.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 10/14/2013] [Accepted: 10/17/2013] [Indexed: 12/11/2022]
Abstract
Historically, animal viruses have been classified on the basis of the presence or absence of an envelope - an external lipid bilayer membrane typically carrying one or more viral glycoproteins. However, growing evidence indicates that some 'non-enveloped' viruses circulate in the blood of infected individuals enveloped in host-derived membranes that provide protection from neutralizing antibodies. In this opinion article, we discuss this novel strategy for virus survival and consider how it contributes to the pathogenesis of acute viral hepatitis. The acquisition of an envelope by non-enveloped viruses profoundly influences their interaction with the host at both the cellular and system level and challenges how we think about vaccine protection against these infections.
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Affiliation(s)
- Zongdi Feng
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7292, USA
| | - Stanley M Lemon
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7292, USA; Division of Infectious Diseases, Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7292, USA; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7292, USA.
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Osterman A, Vizoso-Pinto MG, Jung J, Jaeger G, Eberle J, Nitschko H, Baiker A. A novel indirect immunofluorescence test for the detection of IgG and IgA antibodies for diagnosis of Hepatitis E Virus infections. J Virol Methods 2013; 191:48-54. [PMID: 23557668 DOI: 10.1016/j.jviromet.2013.03.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/07/2013] [Accepted: 03/14/2013] [Indexed: 12/27/2022]
Abstract
Hepatitis E Virus (HEV) causes epidemic infections in regions of poor hygiene in the developing world. Over the last years, however, increasing numbers of autochthonous infections in industrialized countries have been described, leading to new interest in this pathogen. Currently available serological test formats to detect IgG and IgM antibodies are mainly based on bacterially expressed ORF2 and ORF3 antigens and often give ambiguous results. The objective of this study was the development of a different assay format for HEV diagnosis--a HEV immunofluorescence test (HEV-IFT) based on mammalian cells transiently expressing recombinant HEV ORF2 protein with a simple production and staining protocol and the investigation of its performance and methodical feasibility under diagnostic laboratory conditions. 31 sera of patients at different phases of HEV infection and 40 control sera from a non-endemic region were analyzed for anti-HEV IgG, IgM, and IgA antibodies. The HEV-IFT detected successfully anti-HEV IgG and IgA, but not anti-HEV IgM antibodies. In the study group the HEV-IFT was able to confirm HEV infections and to support diagnosis when ambiguous results were obtained by commercial assays. Signal localization and staining patterns helped to gather additional information about reactive antibodies present in patient sera. In conclusion the developed IFT for the detection of anti-HEV IgG and IgA antibodies can be used for diagnosis and for the serological confirmation of HEV infections.
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Affiliation(s)
- Andreas Osterman
- Max von Pettenkofer-Institute, Virology, Ludwig-Maximilians-University of Munich, Pettenkoferstrasse 9a, D-80336 Munich, Germany.
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Deshmukh TM, Shah RR, Gurav YK, Arankalle VA. Serum immunoglobulin G subclass responses in different phases of hepatitis E virus infection. J Med Virol 2013; 85:828-32. [DOI: 10.1002/jmv.23537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2013] [Indexed: 12/17/2022]
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