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Hu X, Wang J, Wang Y, Liu L, Miao J, Ren H, Wang J, Xu X. Uncovering the Prevalence and Genetic Characterization of Rabbit-Derived Paslahepevirus Balayani (Hepatitis E Virus) in Hebei Province, China. FOOD AND ENVIRONMENTAL VIROLOGY 2025; 17:20. [PMID: 40032702 DOI: 10.1007/s12560-025-09636-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2025] [Accepted: 02/19/2025] [Indexed: 03/05/2025]
Abstract
Paslahepevirus balayani (hepatitis E virus) is a zoonotic pathogen, with rabbit Paslahepevirus balayani (HEV-3ra) being widely distributed among global rabbit populations. Notably, in China, rabbits constitute a significant HEV host, second only to swine. Emerging evidence suggests that HEV-3ra possesses the capability to cross species barriers and infect humans. Against this backdrop, our investigation aimed to delineate the HEV infection status and epidemiological patterns in the commercial rabbits of Hebei Province, China. We collected 386 liver and 100 fecal samples across four regions in Hebei Province. Detection of HEV RNA in these specimens was achieved by employing reverse transcription quantitative polymerase chain reaction (RT-qPCR) and reverse transcription nested PCR (RT-Nested PCR), focusing on the amplification of a segment of the open reading frame 2 (ORF2) and the complete genome. Among the 486 samples, 73 were tested positive for HEV RNA, resulting in an overall positive rate of 15.0%. The positive rates for liver and fecal samples were 11.7% (45/386) and 28.0% (28/100), respectively. The study successfully obtained 38 partial ORF2 sequences and 5 complete genome sequences. Sequence analysis revealed that the complete genome sequences shared 86.0-94.5% nucleotide identity with HEV-3ra sequences in GenBank. Phylogenetic analysis confirmed that all strains belonged to HEV-3ra and were closely related to previously reported sequences from China. This study provides the first comprehensive genomic overview of circulating HEV-3ra strains in Hebei, offering valuable insights into the infection dynamics and prevalence of HEV-3ra among commercial rabbits, which can inform public health strategies.
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Affiliation(s)
- Xinyue Hu
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang, China, 050051
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017
| | - Jinfeng Wang
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang, China, 050051
| | - Yinuo Wang
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang, China, 050051
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017
| | - Libing Liu
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang, China, 050051
| | - Junjie Miao
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017
| | - Huan Ren
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017
| | - Jianchang Wang
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017.
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang, China, 050051.
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017.
| | - Xiangdong Xu
- School of Public Health, Hebei Medical University, Shijiazhuang, China, 050017.
- Hebei Key Laboratory of Environment and Human Health, Shijiazhuang, China, 050017.
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Brüggemann Y, Klöhn M, Wedemeyer H, Steinmann E. Hepatitis E virus: from innate sensing to adaptive immune responses. Nat Rev Gastroenterol Hepatol 2024; 21:710-725. [PMID: 39039260 DOI: 10.1038/s41575-024-00950-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/24/2024]
Abstract
Hepatitis E virus (HEV) infections are a major cause of acute viral hepatitis in humans worldwide. In immunocompetent individuals, the majority of HEV infections remain asymptomatic and lead to spontaneous clearance of the virus, and only a minority of individuals with infection (5-16%) experience symptoms of acute viral hepatitis. However, HEV infections can cause up to 30% mortality in pregnant women, become chronic in immunocompromised patients and cause extrahepatic manifestations. A growing body of evidence suggests that the host immune response to infection with different HEV genotypes is a critical determinant of distinct HEV infection outcomes. In this Review, we summarize key components of the innate and adaptive immune responses to HEV, including the underlying immunological mechanisms of HEV associated with acute and chronic liver failure and interactions between T cell and B cell responses. In addition, we discuss the current status of vaccines against HEV and raise outstanding questions regarding the immune responses induced by HEV and treatment of the disease, highlighting areas for future investigation.
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Affiliation(s)
- Yannick Brüggemann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Mara Klöhn
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Partner Sites Hannover-Braunschweig, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany.
- German Center for Infection Research (DZIF), External Partner Site, Bochum, Germany.
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Kanda T, Li TC, Takahashi M, Nagashima S, Primadharsini PP, Kunita S, Sasaki-Tanaka R, Inoue J, Tsuchiya A, Nakamoto S, Abe R, Fujiwara K, Yokosuka O, Suzuki R, Ishii K, Yotsuyanagi H, Okamoto H. Recent advances in hepatitis E virus research and the Japanese clinical practice guidelines for hepatitis E virus infection. Hepatol Res 2024; 54:1-30. [PMID: 38874115 DOI: 10.1111/hepr.14062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/22/2024] [Accepted: 05/09/2024] [Indexed: 06/15/2024]
Abstract
Acute hepatitis E was considered rare until reports emerged affirming the existence of hepatitis E virus (HEV) genotypes 3 and 4 infections in Japan in the early 2000s. Extensive studies by Japanese researchers have highlighted the pivotal role of pigs and wild animals, such as wild boars and deer, as reservoirs for HEV, linking them to zoonotic infections in Japan. Currently, when hepatitis occurs subsequent to the consumption of undercooked or grilled pork, wild boar meat, or offal (including pig liver and intestines), HEV infection should be considered. Following the approval of anti-HEV immunoglobulin A antibody as a diagnostic tool for hepatitis E by Japan's Health Insurance System in 2011, the annual number of diagnosed cases of HEV infection has surged. Notably, the occurrence of post-transfusion hepatitis E promoted nationwide screening of blood products for HEV using nucleic acid amplification tests since 2020. Furthermore, chronic hepatitis E has been observed in immunosuppressed individuals. Considering the significance of hepatitis E, heightened preventive measures are essential. The Japan Agency for Medical Research and Development Hepatitis A and E viruses (HAV and HEV) Study Group, which includes special virologists and hepatologists, held a virtual meeting on February 17, 2024. Discussions encompassed pathogenesis, transmission routes, diagnosis, complications, severity factors, and ongoing and prospective vaccination or treatments for hepatitis E. Rigorous assessment of referenced studies culminated in the formulation of recommendations, which are detailed within this review. This comprehensive review presents recent advancements in HEV research and Japanese clinical practice guidelines for HEV infection.
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Affiliation(s)
- Tatsuo Kanda
- Division of Gastroenterology and Hepatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
- Division of Gastroenterology and Hepatology, Uonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital, Minamiuonuma, Japan
- Division of Gastroenterology and Hepatology, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Tian-Cheng Li
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Masaharu Takahashi
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | - Shigeo Nagashima
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | - Putu Prathiwi Primadharsini
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | - Satoshi Kunita
- Center for Experimental Medicine, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | - Reina Sasaki-Tanaka
- Division of Gastroenterology and Hepatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
- Division of Gastroenterology and Hepatology, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Jun Inoue
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Atsunori Tsuchiya
- Division of Gastroenterology and Hepatology, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Shingo Nakamoto
- Department of Gastroenterology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba, Japan
| | - Ryuzo Abe
- Department of Emergency Medicine, Oita University, Oita, Japan
| | - Keiichi Fujiwara
- Department of Gastroenterology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba, Japan
| | - Osamu Yokosuka
- Department of Gastroenterology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba, Japan
| | - Ryosuke Suzuki
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Koji Ishii
- Department of Quality Assurance and Radiological Protection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hiroshi Yotsuyanagi
- Division of Infectious Diseases, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Infectious Diseases and Applied Immunology, Hospital of the Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
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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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Meyer L, Duquénois I, Gellenoncourt S, Pellerin M, Marcadet-Hauss A, Pavio N, Doceul V. Identification of interferon-stimulated genes with modulated expression during hepatitis E virus infection in pig liver tissues and human HepaRG cells. Front Immunol 2023; 14:1291186. [PMID: 38058490 PMCID: PMC10696647 DOI: 10.3389/fimmu.2023.1291186] [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: 09/08/2023] [Accepted: 10/31/2023] [Indexed: 12/08/2023] Open
Abstract
Introduction Hepatitis E virus (HEV) is a common cause of enterically transmitted acute hepatitis worldwide. The virus is transmitted by the fecal-oral route via the consumption of contaminated water supplies and is also a zoonotic foodborne pathogen. Swine are the main reservoir of zoonotic HEV. In humans, HEV infection is usually asymptomatic or causes acute hepatitis that is self-limited. However, fulminant hepatic failure and chronic cases of HEV infection can occur in some patients. In contrast, HEV infection in pigs remains asymptomatic, although the virus replicates efficiently, suggesting that swine are able to control the virus pathogenesis. Upon viral infection, IFN is secreted and activates cellular pathways leading to the expression of many IFN-stimulated genes (ISGs). ISGs can restrict the replication of specific viruses and establish an antiviral state within infected and neighboring cells. Methods In this study, we used PCR arrays to determine the expression level of up to 168 ISGs and other IFN-related genes in the liver tissues of pigs infected with zoonotic HEV-3c and HEV-3f and in human bipotent liver HepaRG cells persistently infected with HEV-3f. Results and discussion The expression of 12 and 25 ISGs was found to be up-regulated in infected swine livers and HepaRG cells, respectively. The expression of CXCL10, IFIT2, MX2, OASL and OAS2 was up-regulated in both species. Increased expression of IFI16 mRNA was also found in swine liver tissues. This study contributes to the identification of potential ISGs that could play a role in the control or persistence of HEV infection.
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Affiliation(s)
| | | | | | | | | | | | - Virginie Doceul
- Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), École Nationale Vétérinaire d'Alfort (ENVA), UMR Virology, Maisons-Alfort, France
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Pierce DM, Buchanan FJT, Macrae FL, Mills JT, Cox A, Abualsaoud KM, Ward JC, Ariëns RAS, Harris M, Stonehouse NJ, Herod MR. Thrombin cleavage of the hepatitis E virus polyprotein at multiple conserved locations is required for genome replication. PLoS Pathog 2023; 19:e1011529. [PMID: 37478143 PMCID: PMC10395923 DOI: 10.1371/journal.ppat.1011529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 07/03/2023] [Indexed: 07/23/2023] Open
Abstract
The genomes of positive-sense RNA viruses encode polyproteins that are essential for mediating viral replication. These viral polyproteins must undergo proteolysis (also termed polyprotein processing) to generate functional protein units. This proteolysis can be performed by virally-encoded proteases as well as host cellular proteases, and is generally believed to be a key step in regulating viral replication. Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis. The positive-sense RNA genome is translated to generate a polyprotein, termed pORF1, which is necessary and sufficient for viral genome replication. However, the mechanism of polyprotein processing in HEV remains to be determined. In this study, we aimed to understand processing of this polyprotein and its role in viral replication using a combination of in vitro translation experiments and HEV sub-genomic replicons. Our data suggest no evidence for a virally-encoded protease or auto-proteolytic activity, as in vitro translation predominantly generates unprocessed viral polyprotein precursors. However, seven cleavage sites within the polyprotein (suggested by bioinformatic analysis) are susceptible to the host cellular protease, thrombin. Using two sub-genomic replicon systems, we demonstrate that mutagenesis of these sites prevents replication, as does pharmacological inhibition of serine proteases including thrombin. Overall, our data supports a model where HEV uses host proteases to support replication and could have evolved to be independent of a virally-encoded protease for polyprotein processing.
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Affiliation(s)
- Danielle M Pierce
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Frazer J T Buchanan
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Fraser L Macrae
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Jake T Mills
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Abigail Cox
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Khadijah M Abualsaoud
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
- Department of Laboratory and Blood Bank, Al Mikhwah General Hospital, Al Mikhwah, Saudi Arabia
| | - Joseph C Ward
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Robert A S Ariëns
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Nicola J Stonehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Morgan R Herod
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
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Zhou YH, Zhao H. Immunobiology and Host Response to HEV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1417:93-118. [PMID: 37223861 DOI: 10.1007/978-981-99-1304-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Hepatitis E virus (HEV) usually causes acute self-limiting hepatitis but sometimes leads to chronic infection in immunocompromised persons. HEV is not directly cytopathic. Immunologically mediated events after HEV infection are believed to play important roles in the pathogenesis and clearance of infection. The anti-HEV antibody responses have been largely clarified since the determination of major antigenic determinant of HEV, which is located in the C-terminal portion of ORF2. This major antigenic determinant also forms the conformational neutralization epitopes. Robust anti-HEV immunoglobulin M (IgM) and IgG responses usually develop 3-4 weeks after infection in experimentally infected nonhuman primates. In humans, potent specific IgM and IgG responses occur in the very early phase of the disease and are critical in eliminating the virus, in concert with the innate and adaptive T-cell immune responses. Testing anti-HEV IgM is valuable in the diagnosis of acute hepatitis E. The long-term persistence and protection of anti-HEV IgG provide the basis for estimating the prevalence of HEV infection and for the development of a hepatitis E vaccine. Although human HEV has four genotypes, all the viral strains are considered to belong to a single serotype. It is becoming increasingly clear that the innate and adaptive T-cell immune responses play critical roles in the clearance of the virus. Potent and multispecific CD4+ and CD8+ T cell responses to the ORF2 protein occur in patients with acute hepatitis E, and weaker HEV-specific CD4+ and CD8+ T cell responses appear to be associated with chronic hepatitis E in immunocompromised individuals.
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Affiliation(s)
- Yi-Hua Zhou
- Departments of Experimental Medicine and Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Hong Zhao
- Department of Infectious Diseases, Second Hospital of Nanjing, Southeast University School of Medicine, Nanjing, China
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Cancela F, Noceti O, Arbiza J, Mirazo S. Structural aspects of hepatitis E virus. Arch Virol 2022; 167:2457-2481. [PMID: 36098802 PMCID: PMC9469829 DOI: 10.1007/s00705-022-05575-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/04/2022] [Indexed: 12/14/2022]
Abstract
Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. Hepatitis E is an enterically transmitted zoonotic disease that causes large waterborne epidemic outbreaks in developing countries and has become an increasing public-health concern in industrialized countries. In this setting, the infection is usually acute and self-limiting in immunocompetent individuals, although chronic cases in immunocompromised patients have been reported, frequently associated with several extrahepatic manifestations. Moreover, extrahepatic manifestations have also been reported in immunocompetent individuals with acute HEV infection. HEV belongs to the alphavirus-like supergroup III of single-stranded positive-sense RNA viruses, and its genome contains three partially overlapping open reading frames (ORFs). ORF1 encodes a nonstructural protein with eight domains, most of which have not been extensively characterized: methyltransferase, Y domain, papain-like cysteine protease, hypervariable region, proline-rich region, X domain, Hel domain, and RNA-dependent RNA polymerase. ORF2 and ORF3 encode the capsid protein and a multifunctional protein believed to be involved in virion release, respectively. The novel ORF4 is only expressed in HEV genotype 1 under endoplasmic reticulum stress conditions, and its exact function has not yet been elucidated. Despite important advances in recent years, the biological and molecular processes underlying HEV replication remain poorly understood, primarily due to a lack of detailed information about the functions of the viral proteins and the mechanisms involved in host-pathogen interactions. This review summarizes the current knowledge concerning HEV proteins and their biological properties, providing updated detailed data describing their function and focusing in detail on their structural characteristics. Furthermore, we review some unclear aspects of the four proteins encoded by the ORFs, highlighting the current key information gaps and discussing potential novel experimental strategies for shedding light on those issues.
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Affiliation(s)
- Florencia Cancela
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ofelia Noceti
- grid.414402.70000 0004 0469 0889Programa Nacional de Trasplante Hepático y Unidad Docente Asistencial Centro Nacional de Tratamiento Hepatobiliopancreatico. Hospital Central de las Fuerzas Armadas, Montevideo, Uruguay
| | - Juan Arbiza
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Santiago Mirazo
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay ,grid.11630.350000000121657640Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay ,Av. Alfredo Navarro 3051, PC 11600 Montevideo, Uruguay
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9
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Yadav KK, Kenney SP. Hepatitis E Virus Immunopathogenesis. Pathogens 2021; 10:pathogens10091180. [PMID: 34578211 PMCID: PMC8465319 DOI: 10.3390/pathogens10091180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/05/2021] [Accepted: 09/06/2021] [Indexed: 12/22/2022] Open
Abstract
Hepatitis E virus is an important emerging pathogen producing a lethal impact on the pregnant population and immunocompromised patients. Starting in 1983, it has been described as the cause for acute hepatitis transmitted via the fecal–oral route. However, zoonotic and blood transfusion transmission of HEV have been reported in the past few decades, leading to the detailed research of HEV pathogenesis. The reason behind HEV being highly virulent to the pregnant population particularly during the third trimester, leading to maternal and fetal death, remains unknown. Various host factors (immunological, nutritional, hormonal) and viral factors have been studied to define the key determinants assisting HEV to be virulent in pregnant and immunocompromised patients. Similarly, chronic hepatitis is seen particularly in solid organ transplant patients, resulting in fatal conditions. This review describes recent advances in the immunopathophysiology of HEV infections in general, pregnant, and immunocompromised populations, and further elucidates the in vitro and in vivo models utilized to understand HEV pathogenesis.
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Interplay between Hepatitis E Virus and Host Cell Pattern Recognition Receptors. Int J Mol Sci 2021; 22:ijms22179259. [PMID: 34502167 PMCID: PMC8431321 DOI: 10.3390/ijms22179259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 11/23/2022] Open
Abstract
Hepatitis E virus (HEV) usually causes self-limiting acute hepatitis, but the disease can become chronic in immunocompromised individuals. HEV infection in pregnant women is reported to cause up to 30% mortality, especially in the third trimester. Additionally, extrahepatic manifestations like neuronal and renal diseases and pancreatitis are also reported during the course of HEV infection. The mechanism of HEV pathogenesis remains poorly understood. Innate immunity is the first line of defense triggered within minutes to hours after the first pathogenic insult. Growing evidence based on reverse genetics systems, in vitro cell culture models, and representative studies in animal models including non-human primates, has implicated the role of the host’s innate immune response during HEV infection. HEV persists in presence of interferons (IFNs) plausibly by evading cellular antiviral defense. This review summarizes our current understanding of recognizing HEV-associated molecular patterns by host cell Pattern Recognition Receptors (PRRs) in eliciting innate immune response during HEV infection as well as mechanisms of virus-mediated immune evasion.
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11
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Identification of the interferon-inducible GTPase GBP1 as major restriction factor for the Hepatitis E virus. J Virol 2021; 95:JVI.01564-20. [PMID: 33472929 PMCID: PMC8092694 DOI: 10.1128/jvi.01564-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This study aims to gain deeper insight into HEV-induced innate immunity by characterizing the crosstalk between the virus and the host factor guanylate-binding protein 1 (GBP1). We observe that the amount of GBP1 is elevated upon infection, although number of transcripts is decreased, which is explained by a prolonged protein half-life. Modulation of GBP1 levels via overexpression significantly inhibits the viral life cycle. Use of various GBP-1 mutants revealed that the antiviral effect of GBP-1 on HEV is independent from the GTPase-activity, but depends on the capacity of GBP-1 to form GBP1 homodimers. This connects GBP-1 to the autophagosomal pathway. Indeed, dimerization competent GBP1 targets the viral capsid protein to the lysosomal compartment leading to inactivation of the viral particle. Most importantly, silencing of GBP1 abolishes the antiviral effect of IFNγ on HEV. In IFNγ treated cells the virus is targeted to lysosomal structures and destroyed therein. This process depends in part on GBP1. These observations about the relevance of GBP1 for type II interferon-mediated innate immunity against HEV could be a base for tailoring novel antivirals and improvement of disease management.IMPORTANCE Although HEV represents a worldwide public health problem with 20 million infections and 44.000 death cases per year, there are still no specific antivirals available and many aspects of the viral life cycle are not well understood. Here we identify the guanylate binding protein 1 (GBP1) as a restriction factor affecting life cycle of HEV. Surprisingly, the antiviral effect of GBP1 does not depend on its GTPase function, but on its capacity to homodimerize. We revealed that GBP1 exerts its antiviral activity by targeting HEV to the lysosomal compartment where the virus is inactivated. Most importantly, we observed that the antiviral effect of interferon-γ on HEV strongly depends on GBP1. Our observation that GBP1 impairs HEV and is crucial for the antiviral effect of interferons on HEV extends understanding of host defense-mechanisms. As the interferon-system represents a universal defense-mechanism, our study could help to design novel antivirals targeting.
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Pellerin M, Hirchaud E, Blanchard Y, Pavio N, Doceul V. Characterization of a Cell Culture System of Persistent Hepatitis E Virus Infection in the Human HepaRG Hepatic Cell Line. Viruses 2021; 13:406. [PMID: 33806591 PMCID: PMC8001476 DOI: 10.3390/v13030406] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/19/2021] [Accepted: 02/26/2021] [Indexed: 12/12/2022] Open
Abstract
Hepatitis E virus (HEV) is considered as an emerging global health problem. In most cases, hepatitis E is a self-limiting disease and the virus is cleared spontaneously without the need of antiviral therapy. However, immunocompromised individuals can develop chronic infection and liver fibrosis that can progress rapidly to cirrhosis and liver failure. The lack of efficient and relevant cell culture system and animal models has limited our understanding of the biology of HEV and the development of effective drugs for chronic cases. In the present study, we developed a model of persistent HEV infection in human hepatocytes in which HEV replicates efficiently. This HEV cell culture system is based on differentiated HepaRG cells infected with an isolate of HEV-3 derived from a patient suffering from acute hepatitis E. Efficient replication was maintained for several weeks to several months as well as after seven successive passages on HepaRG naïve cells. Moreover, after six passages onto HepaRG, we found that the virus was still infectious after oral inoculation into pigs. We also showed that ribavirin had an inhibitory effect on HEV replication in HepaRG. In conclusion, this system represents a relevant and efficient in vitro model of HEV replication that could be useful to study HEV biology and identify effective antiviral drugs against chronic HEV infection.
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Affiliation(s)
- Marie Pellerin
- UMR 1161 Virologie, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94700 Maisons-Alfort, France; (M.P.); (N.P.)
| | - Edouard Hirchaud
- Agence Nationale de Sécurité Sanitaire, De L’environnement et du Travail (ANSES), Laboratory of Ploufragan-Plouzané-Niort, Viral Genetic and Biosafety (GVB) Unit, 22440 Ploufragan, France; (E.H.); (Y.B.)
| | - Yannick Blanchard
- Agence Nationale de Sécurité Sanitaire, De L’environnement et du Travail (ANSES), Laboratory of Ploufragan-Plouzané-Niort, Viral Genetic and Biosafety (GVB) Unit, 22440 Ploufragan, France; (E.H.); (Y.B.)
| | - Nicole Pavio
- UMR 1161 Virologie, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94700 Maisons-Alfort, France; (M.P.); (N.P.)
| | - Virginie Doceul
- UMR 1161 Virologie, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94700 Maisons-Alfort, France; (M.P.); (N.P.)
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Lhomme S, Migueres M, Abravanel F, Marion O, Kamar N, Izopet J. Hepatitis E Virus: How It Escapes Host Innate Immunity. Vaccines (Basel) 2020; 8:E422. [PMID: 32731452 PMCID: PMC7564545 DOI: 10.3390/vaccines8030422] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis E virus (HEV) is a leading cause of viral hepatitis in the world. It is usually responsible for acute hepatitis, but can lead to a chronic infection in immunocompromised patients. The host's innate immune response is the first line of defense against a virus infection; there is growing evidence that HEV RNA is recognized by toll-like receptors (TLRs) and retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), leading to interferon (IFN) production. The IFNs activate interferon-stimulated genes (ISGs) to limit HEV replication and spread. HEV has developed strategies to counteract this antiviral response, by limiting IFN induction and signaling. This review summarizes the advances in our knowledge of intracellular pathogen recognition, interferon and inflammatory response, and the role of virus protein in immune evasion.
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Affiliation(s)
- Sébastien Lhomme
- National Reference Center for Hepatitis E Virus, Toulouse Purpan University Hospital, 31300 Toulouse, France; (M.M.); (F.A.); (J.I.)
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
| | - Marion Migueres
- National Reference Center for Hepatitis E Virus, Toulouse Purpan University Hospital, 31300 Toulouse, France; (M.M.); (F.A.); (J.I.)
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
| | - Florence Abravanel
- National Reference Center for Hepatitis E Virus, Toulouse Purpan University Hospital, 31300 Toulouse, France; (M.M.); (F.A.); (J.I.)
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
| | - Olivier Marion
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
- Department of Nephrology and Organs Transplantation, Toulouse Rangueil University Hospital, 31400 Toulouse, France
| | - Nassim Kamar
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
- Department of Nephrology and Organs Transplantation, Toulouse Rangueil University Hospital, 31400 Toulouse, France
| | - Jacques Izopet
- National Reference Center for Hepatitis E Virus, Toulouse Purpan University Hospital, 31300 Toulouse, France; (M.M.); (F.A.); (J.I.)
- INSERM UMR1043, CNRS UMR5282, Center for Pathophysiology of Toulouse Purpan, 31300 Toulouse, France; (O.M.); (N.K.)
- Université Toulouse III Paul Sabatier, 31330 Toulouse, France
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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: 20] [Impact Index Per Article: 4.0] [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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Hepatitis E Virus Shows More Genomic Alterations in Cell Culture than In Vivo. Pathogens 2019; 8:pathogens8040255. [PMID: 31766624 PMCID: PMC6963849 DOI: 10.3390/pathogens8040255] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/12/2019] [Accepted: 11/18/2019] [Indexed: 12/16/2022] Open
Abstract
Hepatitis E Virus (HEV) mutations following ribavirin treatment have been associated with treatment non-response and viral persistence, but spontaneous occurring genomic variations have been less well characterized. We here set out to study the HEV genome composition in 2 patient sample types and 2 infection models. Near full HEV genome Sanger sequences of serum- and feces-derived HEV from two chronic HEV genotype 3 (gt3) patients were obtained. In addition, viruses were sequenced after in vitro or in vivo expansion on A549 cells or a humanized mouse model, respectively. We show that HEV acquired 19 nucleotide mutations, of which 7 nonsynonymous amino acids changes located in Open Reading Frame 1 (ORF1), ORF2, and ORF3 coding regions, after prolonged in vitro culture. In vivo passage resulted in selection of 8 nucleotide mutations with 2 altered amino acids in the X domain and Poly-proline region of ORF1. Intra-patient comparison of feces- and serum-derived HEV gt3 of two patients showed 7 and 2 nucleotide mutations with 2 and 0 amino acid changes, respectively. Overall, the number of genomic alterations was up to 1.25× per 1000 nucleotides or amino acids in in vivo samples, and up to 2.84× after in vitro expansion of the same clinical HEV strain. In vitro replication of a clinical HEV strain is therefore associated with more mutations, compared to the minor HEV genomic alterations seen after passage of the same strain in an immune deficient humanized mouse; as well as in feces and blood of 2 immunosuppressed chronically infected HEV patients. These data suggest that HEV infected humanized mice more closely reflect the HEV biology seen in solid organ transplant recipients.
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The Interplay between Host Innate Immunity and Hepatitis E Virus. Viruses 2019; 11:v11060541. [PMID: 31212582 PMCID: PMC6630959 DOI: 10.3390/v11060541] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/24/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022] Open
Abstract
Hepatitis E virus (HEV) infection represents an emerging global health issue, whereas the clinical outcomes vary dramatically among different populations. The host innate immune system provides a first-line defense against the infection, but dysregulation may partially contribute to severe pathogenesis. A growing body of evidence has indicated the active response of the host innate immunity to HEV infection both in experimental models and in patients. In turn, HEV has developed sophisticated strategies to counteract the host immune system. In this review, we aim to comprehensively decipher the processes of pathogen recognition, interferon, and inflammatory responses, and the involvement of innate immune cells in HEV infection. We further discuss their implications in understanding the pathogenic mechanisms and developing antiviral therapies.
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