1
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Liu T, Liu A, Liu Y, Cen S, Zhang Q. In vitro investigation of HBV clinical isolates from Chinese patients reveals that genotype C isolates possess higher infectivity than genotype B isolates. Virol Sin 2022; 37:398-407. [PMID: 35314401 PMCID: PMC9243618 DOI: 10.1016/j.virs.2022.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/15/2022] [Indexed: 10/26/2022] Open
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2
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Shen S, Wang Y. Expression and Prognostic Role of E2F2 in Hepatocellular Carcinoma. Int J Gen Med 2021; 14:8463-8472. [PMID: 34824545 PMCID: PMC8609201 DOI: 10.2147/ijgm.s334033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/03/2021] [Indexed: 12/11/2022] Open
Abstract
Introduction Hepatocellular carcinoma (HCC) is a common clinical malignancy. Recent studies reported that E2F transcription factor 2 (E2F2) plays a significant role in tumor progression. However, its expression and biological function in HCC are still unclear. Therefore, we explored the relationship between E2F2 expression and tumor progression in HCC. Methods In this study, we utilized some online tools to explore the E2F2 expression in pan-carcinoma and HCC. The association of E2F2 expression with the clinical characteristics and prognosis of HCC was further studied. In addition, we explored the co-expressed genes of E2F2 and mined the positively/negatively corrected significant genes and excavated the possible functions. Meanwhile, the hub gene set was constructed based on protein-protein interaction (PPI) network, and the relationship between E2F2 and immunity was discovered. Results We observed that the expression level of E2F2 was generally upregulated in HCC. However, E2F2 expression was not significantly different between HCC and normal tissues in regard to the disease stage 4. Furthermore, we also observed the poor prognosis in patients with high E2F2 expression. The co-expressed genes of E2F2 were identified and further detected. Thereafter, we identified the positively/negatively corrected significant genes and constructed the hub gene network of E2F2 based on PPI network. We also found that E2F2 expression was positively correlated with the infiltration levels of CD4+ T, CD8+ T cells, macrophages, neutrophils, and dendritic cells. Conclusion Our findings suggested that E2F2 could be a potential prognostic factor for HCC, which could provide a therapeutic target for the molecular treatment of HCC.
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Affiliation(s)
- Shen Shen
- Gene Hospital of Henan Province, Precision Medicine Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China.,Department of Infectious Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, People's Republic of China
| | - Yanfang Wang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
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3
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Seitz S, Habjanič J, Schütz AK, Bartenschlager R. The Hepatitis B Virus Envelope Proteins: Molecular Gymnastics Throughout the Viral Life Cycle. Annu Rev Virol 2020; 7:263-288. [PMID: 32600157 DOI: 10.1146/annurev-virology-092818-015508] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
New hepatitis B virions released from infected hepatocytes are the result of an intricate maturation process that starts with the formation of the nucleocapsid providing a confined space where the viral DNA genome is synthesized via reverse transcription. Virion assembly is finalized by the enclosure of the icosahedral nucleocapsid within a heterogeneous envelope. The latter contains integral membrane proteins of three sizes, collectively known as hepatitis B surface antigen, and adopts multiple conformations in the course of the viral life cycle. The nucleocapsid conformation depends on the reverse transcription status of the genome, which in turn controls nucleocapsid interaction with the envelope proteins for virus exit. In addition, after secretion the virions undergo a distinct maturation step during which a topological switch of the large envelope protein confers infectivity. Here we review molecular determinants for envelopment and models that postulate molecular signals encoded in the capsid scaffold conducive or adverse to the recruitment of envelope proteins.
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Affiliation(s)
- Stefan Seitz
- Department of Infectious Diseases, University of Heidelberg, 69120 Heidelberg, Germany;
| | - Jelena Habjanič
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Anne K Schütz
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, University of Heidelberg, 69120 Heidelberg, Germany; .,Division of Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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4
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Pastor F, Herrscher C, Patient R, Eymieux S, Moreau A, Burlaud-Gaillard J, Seigneuret F, de Rocquigny H, Roingeard P, Hourioux C. Direct interaction between the hepatitis B virus core and envelope proteins analyzed in a cellular context. Sci Rep 2019; 9:16178. [PMID: 31700077 PMCID: PMC6838148 DOI: 10.1038/s41598-019-52824-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/23/2019] [Indexed: 01/01/2023] Open
Abstract
Hepatitis B virus (HBV) production requires intricate interactions between the envelope and core proteins. Analyses of mutants of these proteins have made it possible to map regions involved in the formation and secretion of virions. Tests of binding between core and envelope peptides have also been performed in cell-free conditions, to study the interactions potentially underlying these mechanisms. We investigated the residues essential for core-envelope interaction in a cellular context in more detail, by transiently producing mutant or wild-type L, S, or core proteins separately or in combination, in Huh7 cells. The colocalization and interaction of these proteins were studied by confocal microscopy and co-immunoprecipitation, respectively. The L protein was shown to constitute a molecular platform for the recruitment of S and core proteins in a perinuclear environment. Several core amino acids were found to be essential for direct interaction with L, including residue Y132, known to be crucial for capsid formation, and residues L60, L95, K96 and I126. Our results confirm the key role of L in the tripartite core-S-L interaction and identify the residues involved in direct core-L interaction. This model may be valuable for studies of the potential of drugs to inhibit HBV core-envelope interaction.
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Affiliation(s)
- Florentin Pastor
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | - Charline Herrscher
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | - Romuald Patient
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | - Sebastien Eymieux
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | - Alain Moreau
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | - Julien Burlaud-Gaillard
- Plate-Forme IBiSA des Microscopies, PPF ASB - University of Tours and CHRU of Tours, Tours, France
| | - Florian Seigneuret
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France
| | | | - Philippe Roingeard
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France. .,Plate-Forme IBiSA des Microscopies, PPF ASB - University of Tours and CHRU of Tours, Tours, France.
| | - Christophe Hourioux
- INSERM U1259 MAVIVH - University of Tours and CHRU of Tours, Tours, France. .,Plate-Forme IBiSA des Microscopies, PPF ASB - University of Tours and CHRU of Tours, Tours, France.
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5
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Structure-Guided Approach to Identify Potential Inhibitors of Large Envelope Protein to Prevent Hepatitis B Virus Infection. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1297484. [PMID: 31772697 PMCID: PMC6854180 DOI: 10.1155/2019/1297484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/10/2019] [Accepted: 07/02/2019] [Indexed: 01/05/2023]
Abstract
Hepatitis B virus (HBV) infection is one of the major causes of liver diseases, which can lead to hepatocellular carcinoma. The role of HBV envelope proteins is crucial in viral morphogenesis, infection, and propagation. Thus, blocking the pleiotropic functions of these proteins especially the PreS1 and PreS2 domains of the large surface protein (LHBs) is a promising strategy for designing efficient antivirals against HBV infection. Unfortunately, the structure of the LHBs protein has not been elucidated yet, and it seems that any structure-based drug discovery is critically dependent on this. To find effective inhibitors of LHBs, we have modeled and validated its three-dimensional structure and subsequently performed a virtual high-throughput screening against the ZINC database using RASPD and ParDOCK tools. We have identified four compounds, ZINC11882026, ZINC19741044, ZINC00653293, and ZINC15000762, showing appreciable binding affinity with the LHBs protein. The drug likeness was further validated using ADME screening and toxicity analysis. Interestingly, three of the four compounds showed the formation of hydrogen bonds with amino acid residues lying in the capsid binding region of the PreS1 domain of LHBs, suggesting the possibility of inhibiting the viral assembly and maturation process. The identification of potential lead molecules will help to discover more potent inhibitors with significant antiviral activities.
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6
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Chen L, Zhang Y, Zhang S, Chen Y, Shu X, Lai J, Cao H, Lian Y, Stamataki Z, Huang Y. A novel T-cell epitope in the transmembrane region of the hepatitis B virus envelope protein responds upon dendritic cell expansion. Arch Virol 2018; 164:483-495. [PMID: 30415392 PMCID: PMC6373280 DOI: 10.1007/s00705-018-4095-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/21/2018] [Indexed: 12/17/2022]
Abstract
Restoring antiviral immunity is a promising immunotherapeutic approach to the treatment of chronic hepatitis B virus (HBV) infection. Dendritic cells play a crucial role in triggering antiviral immunity. In this study, we identified immunodominant epitopes prevalent in CD8+ T cell responses. We characterized the hierarchy of HBV epitopes targeted by CD8+ T cells following autologous monocyte-derived dendritic cell (moDC) expansion in HBV-infected subjects with distinct disease stages: treatment-naïve (TN group, n = 168), treatment with complete virological response (TR group, n = 72), and resolved HBV infection (RS group, n = 28). T cell responses against 32 HBV epitopes were measured upon moDC expansion. Several subdominant epitopes that triggered HBV-specific CD8+ T cell responses were identified. These epitopes’ responses varied in individuals with different disease stages. Moreover, the most immunodominant and immunoprevalent epitope included the envelope residues 256-270 (Env256-270), corresponding to amino acid residues 93-107 in the small HBV surface protein (SHBs) across three patient groups. The frequency of Env256-270-specific interferon-γ-producing T cells was the highest in the RS group and the lowest in the TN group. In addition, individuals with HLA-A*02:03/02:06/02:07 were capable of responding to Env256-270. Env256-270-specific CD8+ T cells tolerated amino acid variations within the epitope detected in HBV genotypes B and C. This suggests that Env256-270 in SHBs is crucial in HBV-specific T cell immunity following autologous moDC expansion. It might be a potential target epitope for dendritic-cell-based immunotherapy for CHB patients with complete viral suppression by long-term NAs treatment.
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Affiliation(s)
- Lubiao Chen
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Ying Zhang
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Shaoquan Zhang
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Youming Chen
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Xin Shu
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Jing Lai
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Hong Cao
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China
| | - Yifan Lian
- Guangdong Provincial Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zania Stamataki
- National Institute for Health Research Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Yuehua Huang
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China.
- Guangdong Provincial Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
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7
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Virus entry and its inhibition to prevent and treat hepatitis B and hepatitis D virus infections. Curr Opin Virol 2018; 30:68-79. [DOI: 10.1016/j.coviro.2018.04.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 12/13/2022]
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8
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Sobhy H. A Review of Functional Motifs Utilized by Viruses. Proteomes 2016; 4:proteomes4010003. [PMID: 28248213 PMCID: PMC5217368 DOI: 10.3390/proteomes4010003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/07/2016] [Accepted: 01/13/2016] [Indexed: 01/05/2023] Open
Abstract
Short linear motifs (SLiM) are short peptides that facilitate protein function and protein-protein interactions. Viruses utilize these motifs to enter into the host, interact with cellular proteins, or egress from host cells. Studying functional motifs may help to predict protein characteristics, interactions, or the putative cellular role of a protein. In virology, it may reveal aspects of the virus tropism and help find antiviral therapeutics. This review highlights the recent understanding of functional motifs utilized by viruses. Special attention was paid to the function of proteins harboring these motifs, and viruses encoding these proteins. The review highlights motifs involved in (i) immune response and post-translational modifications (e.g., ubiquitylation, SUMOylation or ISGylation); (ii) virus-host cell interactions, including virus attachment, entry, fusion, egress and nuclear trafficking; (iii) virulence and antiviral activities; (iv) virion structure; and (v) low-complexity regions (LCRs) or motifs enriched with residues (Xaa-rich motifs).
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Affiliation(s)
- Haitham Sobhy
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.
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9
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Selzer L, Zlotnick A. Assembly and Release of Hepatitis B Virus. Cold Spring Harb Perspect Med 2015; 5:cshperspect.a021394. [PMID: 26552701 DOI: 10.1101/cshperspect.a021394] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The hepatitis B virus (HBV) core protein is a dynamic and versatile protein that directs many viral processes. During capsid assembly, core protein allosteric changes ensure efficient formation of a stable capsid that assembles while packaging viral RNA-polymerase complex. Reverse transcription of the RNA genome as well as transport of the capsid to multiple cellular compartments are directed by dynamic phosphorylation and structural changes of core protein. Subsequently, interactions of the capsid with the surface proteins and/or host proteins trigger envelopment and release of the viral capsids or the transport to the nucleus. Held together by many weak protein-protein interactions, the viral capsid is an extraordinary metastable machine that is stable enough to persist in the cellular and extracellular environment but dissociates to allow release of the viral genome at the right time during infection.
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Affiliation(s)
- Lisa Selzer
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Adam Zlotnick
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
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10
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Zeisel MB, Lucifora J, Mason WS, Sureau C, Beck J, Levrero M, Kann M, Knolle PA, Benkirane M, Durantel D, Michel ML, Autran B, Cosset FL, Strick-Marchand H, Trépo C, Kao JH, Carrat F, Lacombe K, Schinazi RF, Barré-Sinoussi F, Delfraissy JF, Zoulim F. Towards an HBV cure: state-of-the-art and unresolved questions--report of the ANRS workshop on HBV cure. Gut 2015; 64:1314-26. [PMID: 25670809 DOI: 10.1136/gutjnl-2014-308943] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/10/2015] [Indexed: 12/11/2022]
Abstract
HBV infection is a major cause of liver cirrhosis and hepatocellular carcinoma. Although HBV infection can be efficiently prevented by vaccination, and treatments are available, to date there is no reliable cure for the >240 million individuals that are chronically infected worldwide. Current treatments can only achieve viral suppression, and lifelong therapy is needed in the majority of infected persons. In the framework of the French National Agency for Research on AIDS and Viral Hepatitis 'HBV Cure' programme, a scientific workshop was held in Paris in June 2014 to define the state-of-the-art and unanswered questions regarding HBV pathobiology, and to develop a concerted strategy towards an HBV cure. This review summarises our current understanding of HBV host-interactions leading to viral persistence, as well as the roadblocks to be overcome to ultimately address unmet medical needs in the treatment of chronic HBV infection.
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Affiliation(s)
- Mirjam B Zeisel
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France Université de Strasbourg, Strasbourg, France
| | - Julie Lucifora
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France
| | | | - Camille Sureau
- INTS, Laboratoire de Virologie Moléculaire, Paris, France
| | - Jürgen Beck
- Department of Internal Medicine 2/Molecular Biology, University Hospital Freiburg, Freiburg, Germany
| | - Massimo Levrero
- Center for Life Nanosciences (CNLS)-IIT/Sapienza, Rome, Italy Laboratory of Gene Expression, Department of Internal Medicine (DMISM), Sapienza University of Rome, Italy
| | - Michael Kann
- Université de Bordeaux, Microbiologie fondamentale et Pathogénicité, UMR 5234, Bordeaux, France CNRS, Microbiologie fondamentale et Pathogénicité, UMR 5234, Bordeaux, France CHU de Bordeaux, Bordeaux, France
| | - Percy A Knolle
- Technische Universität München, Institut für Molekulare Immunologie, München, Germany
| | - Monsef Benkirane
- Institut de Génétique Humaine, Laboratoire de Virologie Moléculaire, CNRS UPR1142, Montpellier, France
| | - David Durantel
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France
| | - Marie-Louise Michel
- Laboratoire de Pathogenèse des Virus de l'Hépatite B, Département de Virologie, Institut Pasteur, Paris, France
| | - Brigitte Autran
- Laboratory of Immunity and Infection, Inserm U945, Paris, France Laboratory of Immunity and Infection, UPMC University Paris 06, Unité mixte de recherche-S945, Paris, France Inserm, IFR 113, Immunité-Cancer-Infection, Paris, France
| | - François-Loïc Cosset
- CIRI-International Center for Infectiology Research, Team EVIR, Université de Lyon, Lyon, France. Inserm, U1111, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France. CNRS, UMR5308, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | | | - Christian Trépo
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France Department of Hepatology, Croix-Rousse Hospital, Hospices Civils de Lyon, Lyon, France
| | - Jia-Horng Kao
- Department of Internal Medicine, Department of Medical Research, Graduate Institute of Clinical Medicine, and Hepatitis Research Center, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Fabrice Carrat
- Inserm, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France Sorbonne Universités, UPMC Univ Paris 06, Paris, France Assistance Publique Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
| | - Karine Lacombe
- Inserm, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France Sorbonne Universités, UPMC Univ Paris 06, Paris, France Assistance Publique Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
| | - Raymond F Schinazi
- Center for AIDS Research, Emory University School of Medicine and Veterans Affairs Medical Center, Atlanta, Georgia, USA
| | - Françoise Barré-Sinoussi
- Inserm and Unit of Regulation of Retroviral Infections, Department of Virology, Institut Pasteur, Paris, France
| | | | - Fabien Zoulim
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France Department of Hepatology, Croix-Rousse Hospital, Hospices Civils de Lyon, Lyon, France
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Bouezzedine F, Fardel O, Gripon P. Interleukin 6 inhibits HBV entry through NTCP down regulation. Virology 2015; 481:34-42. [PMID: 25765005 DOI: 10.1016/j.virol.2015.02.026] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 12/22/2014] [Accepted: 02/15/2015] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) infection is a major public health problem. Recently, the human liver bile acid transporter Na(+)/taurocholate cotransporting polypeptide (NTCP) has been identified as an HBV specific receptor. NTCP expression is known to be strongly regulated by IL-6. This study was aimed at characterizing the effect of IL-6 on HBV entry. HBV entry was inhibited by up to 90% when cells were pretreated with IL-6 as shown by a strong inhibition of long term HBsAg secretion. This effect was confirmed by showing a severe reduction of intracellular HBV cccDNA. In parallel, we observed a 98% decrease in NTCP mRNA steady state level and an 80% reduction in NTCP-mediated taurocholate uptake. IL-6-mediated inhibition of NTCP-mediated taurocholate uptake and viral entry exhibited similar dose-dependence and kinetics while restoration of NTCP expression suppressed the inhibitory effect of IL-6. NTCP-mediated HBV entry is therefore markedly inhibited by IL-6.
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Affiliation(s)
- Fidaa Bouezzedine
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1085, Institut de Recherche Santé Environnement et Travail (IRSET), Rennes, France; Université de Rennes 1, F-35043 Rennes, France; Fédération de Recherche BioSit de Rennes UMS 3480, F-35043 Rennes, France
| | - Olivier Fardel
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1085, Institut de Recherche Santé Environnement et Travail (IRSET), Rennes, France; Université de Rennes 1, F-35043 Rennes, France; Fédération de Recherche BioSit de Rennes UMS 3480, F-35043 Rennes, France
| | - Philippe Gripon
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1085, Institut de Recherche Santé Environnement et Travail (IRSET), Rennes, France; Université de Rennes 1, F-35043 Rennes, France; Fédération de Recherche BioSit de Rennes UMS 3480, F-35043 Rennes, France.
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12
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Chang KC, Chang Y, Wang LHC, Tsai HW, Huang W, Su IJ. Pathogenesis of virus-associated human cancers: Epstein–Barr virus and hepatitis B virus as two examples. J Formos Med Assoc 2014; 113:581-90. [DOI: 10.1016/j.jfma.2013.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 08/02/2013] [Accepted: 09/02/2013] [Indexed: 12/12/2022] Open
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13
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Urban S, Bartenschlager R, Kubitz R, Zoulim F. Strategies to inhibit entry of HBV and HDV into hepatocytes. Gastroenterology 2014; 147:48-64. [PMID: 24768844 DOI: 10.1053/j.gastro.2014.04.030] [Citation(s) in RCA: 235] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 03/11/2014] [Accepted: 04/21/2014] [Indexed: 02/07/2023]
Abstract
Although there has been much research into the pathogenesis and treatment of hepatitis B virus (HBV) and hepatitis D virus (HDV) infections, we still do not completely understand how these pathogens enter hepatocytes. This is because in vitro infection studies have only been performed in primary human hepatocytes. Development of a polarizable, HBV-susceptible human hepatoma cell line and studies of primary hepatocytes from Tupaia belangeri have provided important insights into the viral and cellular factors involved in virus binding and infection. The large envelope (L) protein on the surface of HBV and HDV particles has many different functions and is required for virus entry. The L protein mediates attachment of virions to heparan sulfate proteoglycans on the surface of hepatocytes. The myristoylated N-terminal preS1 domain of the L protein subsequently binds to the sodium taurocholate cotransporting polypeptide (NTCP, encoded by SLC10A1), the recently identified bona fide receptor for HBV and HDV. The receptor functions of NTCP and virus entry are blocked, in vitro and in vivo, by Myrcludex B, a synthetic N-acylated preS1 lipopeptide. Currently, the only agents available to treat chronic HBV infection target the viral polymerase, and no selective therapies are available for HDV infection. It is therefore important to study the therapeutic potential of virus entry inhibitors, especially when combined with strategies to induce immune-mediated killing of infected hepatocytes.
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Affiliation(s)
- Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Infection Research, Heidelberg University, Heidelberg, Germany.
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Infection Research, Heidelberg University, Heidelberg, Germany
| | - Ralf Kubitz
- Department of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Fabien Zoulim
- INSERM Unité 1052, Cancer Research Center of Lyon, Lyon University, Lyon, France
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14
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Marimani M, Hean J, Bloom K, Ely A, Arbuthnot P. Recent advances in developing nucleic acid-based HBV therapy. Future Microbiol 2014; 8:1489-504. [PMID: 24199806 DOI: 10.2217/fmb.13.87] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Chronic HBV infection remains an important public health problem and currently licensed therapies rarely prevent complications of viral persistence. Silencing HBV gene expression using gene therapy, particularly with exogenous activators of RNAi, holds promise for developing an HBV gene therapy. However, immune stimulation, off-targeting effects and inefficient delivery of RNAi activators remain problematic. Several new approaches have recently been employed to address these issues. Chemical modifications to anti-HBV synthetic siRNAs have been investigated and a variety of vectors are being developed for delivery of RNAi effectors. In this article, we review the potential utility of gene therapy for treating HBV infection.
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Affiliation(s)
- Musa Marimani
- Antiviral Gene Therapy Research Unit, School of Pathology, Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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15
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Tan YLJ, Chen WN. MicroRNAs as therapeutic strategy for hepatitis B virus-associated hepatocellular carcinoma: Current status and future prospects. World J Gastroenterol 2014; 20:5973-5986. [PMID: 24876720 PMCID: PMC4033437 DOI: 10.3748/wjg.v20.i20.5973] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/13/2014] [Accepted: 04/09/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) remains to be one of the top causing cancer-related deaths today. The majority of HCC cases are reported to be the result of chronic hepatitis B virus (HBV) infection. Current treatments for HBV-related HCC revolve around the use of drugs to inhibit viral replication, as a high level of viral load and antigen in circulation often presents a poor patient prognosis. However, existing therapies are inefficient in the complete eradication of HBV, often resulting in tumour recurrence. The involvement of microRNAs (miRNAs) in important processes in HBV-related HCC makes it an important player in the progression of HCC in chronic hepatitis B infected patients. In this review, we discuss the key aspects of HBV infection and the important viral products that may regulate cancer-related processes via their interaction with miRNAs or their closely related protein machinery. Conversely, we also look at how miRNAs may go about regulating the virus, especially in vital processes like viral replication. Apart from miRNAs acting as either oncogenes or tumour-suppressors, we also look at how miRNAs may function as biomarkers that may possibly serve as better candidates than those currently employed in the diagnosis of HBV infection or HBV-related HCC. A summary of the roles of miRNAs in HBV-related HCC will hopefully lead to a gain in understanding of the pathogenesis process and pave the way for new insights in medical therapy.
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Coexistence of hepatitis B virus quasispecies enhances viral replication and the ability to induce host antibody and cellular immune responses. J Virol 2014; 88:8656-66. [PMID: 24850745 DOI: 10.1128/jvi.01123-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Hepatitis B virus (HBV) quasispecies contain a large number of variants that serve as a reservoir for viral selection under antiviral treatment and the immune response, leading to the acute exacerbation and subsequent development of liver failure. However, there is no clear experimental evidence for a significant role of HBV quasispecies in viral pathogenesis. In the present study, HBV sequences were amplified from a patient with severe liver disease and used for construction of HBV replication-competent plasmids. Western blotting, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence staining were performed to analyze the expression, secretion, and subcellular localization of viral proteins in vitro. Viral replication intermediates were detected by Southern blotting. HBV gene expression and replication and the induction of specific immune responses in an HBV hydrodynamic injection (HI) mouse model were investigated. The results demonstrated that two naturally occurring HBV variants, SH and SH-DPS, were identified. The variant SH-DPS expressed only a nonexportable hepatitis B virus surface antigen (HBsAg) with abnormal intracellular accumulation. The coexistence of the HBV variants at a ratio of 1 to 4 (SH to SH-DPS) increased HBV replication. Significantly stronger intrahepatic cytotoxic T lymphocyte (CTL) responses and antibody responses specific to HBsAg were induced in mice by the HBV variants when coapplied by HI. These findings uncovered an unexpected aspect of HBV quasispecies: the coexistence of different variants can significantly modulate specific host immune responses, representing a novel mechanism for the immunopathogenesis of HBV infection. IMPORTANCE Hepatitis B virus (HBV) is an important human pathogen. HBV quasispecies with genetically heterogenous variants are thought to play a role in the progression of HBV-associated liver diseases. So far, direct evidence is available in only a few cases to confirm the proposed role of HBV variants in the pathogenesis. We report here that the coexistence of two naturally occurring HBV variants at a ratio of 1 to 4 increased HBV replication and induced significantly stronger intrahepatic cytotoxic T lymphocyte responses and antibody responses specific to HBV surface antigen (HBsAg) in mice. Our discovery uncovered an unexpected aspect of HBV quasispecies: the coexistence of different variants can significantly modulate specific host immune responses and may enhance immune-mediated liver damage under some circumstances, representing a novel mechanism for the immunopathogenesis of HBV infection.
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Nkongolo S, Ni Y, Lempp FA, Kaufman C, Lindner T, Esser-Nobis K, Lohmann V, Mier W, Mehrle S, Urban S. Cyclosporin A inhibits hepatitis B and hepatitis D virus entry by cyclophilin-independent interference with the NTCP receptor. J Hepatol 2014; 60:723-31. [PMID: 24295872 DOI: 10.1016/j.jhep.2013.11.022] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/20/2013] [Accepted: 11/22/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Chronic hepatitis B and hepatitis D are global health problems caused by the human hepatitis B and hepatitis D virus. The myristoylated preS1 domain of the large envelope protein mediates specific binding to hepatocytes by sodium taurocholate co-transporting polypeptide (NTCP). NTCP is a bile salt transporter known to be inhibited by cyclosporin A. This study aimed to characterize the effect of cyclosporin A on HBV/HDV infection. METHODS HepaRG cells, primary human hepatocytes, and susceptible NTCP-expressing hepatoma cell lines were applied for infection experiments. The mode of action of cyclosporin A was studied by comparing the effect of different inhibitors, cyclophilin A/B/C-silenced cell lines as well as NTCP variants and mutants. Bile salt transporter and HBV receptor functions were investigated by taurocholate uptake and quantification of HBVpreS binding. RESULTS Cyclosporin A inhibited hepatitis B and D virus infections during and--less pronounced--prior to virus inoculation. Binding of HBVpreS to NTCP was blocked by cyclosporin A concentrations at 8 μM. An NTCP variant deficient in HBVpreS binding but competent for bile salt transport showed resistance to cyclosporin A. Silencing of cyclophilins A/B/C did not abrogate transporter and receptor inhibition. In contrast, tacrolimus, a cyclophilin-independent calcineurin inhibitor, was inactive. CONCLUSIONS HBV and HDV entry via sodium taurocholate co-transporting polypeptide is inhibited by cyclosporin A. The interaction between the drug and the viral receptor is direct and overlaps with a functional binding site of the preS1 domain, which mediates viral entry.
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Affiliation(s)
- Shirin Nkongolo
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Christina Kaufman
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany; Department of Nuclear Medicine, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Thomas Lindner
- Department of Nuclear Medicine, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Katharina Esser-Nobis
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Volker Lohmann
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Stefan Mehrle
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, D 69120 Heidelberg, Germany.
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18
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Baumert TF, Meredith L, Ni Y, Felmlee DJ, McKeating JA, Urban S. Entry of hepatitis B and C viruses - recent progress and future impact. Curr Opin Virol 2014; 4:58-65. [PMID: 24418809 DOI: 10.1016/j.coviro.2013.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/28/2013] [Accepted: 12/02/2013] [Indexed: 02/07/2023]
Abstract
Chronic hepatitis B and C virus infections are major causes of liver disease and hepatocellular carcinoma worldwide. Although both viruses infect hepatocytes, the molecular virology and cellular biology of their respective replication cycles differ. Viral entry is the first step of the life cycle and recent developments in functional genomic and proteomic methodologies have increased our understanding of the entry pathways for these two important human pathogens. In this review we provide a comparative analysis of the internalization routes for these viruses and highlight differences and how they impact the viral life cycle, immune responses and development of antivirals.
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Affiliation(s)
- Thomas F Baumert
- Inserm U1110, University of Strasbourg and Center for Liver and Digestive Diseases, Strasbourg University Hospitals, 3 Rue Koeberlé, F-67000 Strasbourg, France
| | - Luke Meredith
- Centre for Human Virology, NIHR Centre for Liver Disease, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, ImNeuenheimer Feld 345, D-69120 Heidelberg, Germany
| | - Daniel J Felmlee
- Inserm U1110, University of Strasbourg and Center for Liver and Digestive Diseases, Strasbourg University Hospitals, 3 Rue Koeberlé, F-67000 Strasbourg, France
| | - Jane A McKeating
- Centre for Human Virology, NIHR Centre for Liver Disease, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, ImNeuenheimer Feld 345, D-69120 Heidelberg, Germany.
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Borin BN, Tang W, Nice TJ, McCune BT, Virgin HW, Krezel AM. Murine norovirus protein NS1/2 aspartate to glutamate mutation, sufficient for persistence, reorients side chain of surface exposed tryptophan within a novel structured domain. Proteins 2013; 82:1200-9. [PMID: 24273131 DOI: 10.1002/prot.24484] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 11/12/2013] [Accepted: 11/20/2013] [Indexed: 11/06/2022]
Abstract
Compact viral genomes such as those found in noroviruses, which cause significant enteric disease in humans, often encode only a few proteins, but affect a wide range of processes in their hosts and ensure efficient propagation of the virus. Both human and mouse noroviruses (MNVs) persistently replicate and are shed in stool, a highly effective strategy for spreading between hosts. For MNV, the presence of a glutamate rather than an aspartate at position 94 of the NS1/2 protein was previously shown to be essential for persistent replication and shedding. Here, we analyze these critical sequences of NS1/2 at the structural level. Using solution nuclear magnetic resonance methods, we determined folded NS1/2 domain structures from a nonpersistent murine norovirus strain CW3, a persistent strain CR6, and a persistent mutant strain CW3(D94E). We found an unstructured PEST-like domain followed by a novel folded domain in the N-terminus of NS1/2. All three forms of the domain are stable and monomeric in solution. Residue 94, critical for determining persistence, is located in a reverse turn following an α-helix in the folded domain. The longer side chain of glutamate, but not aspartate, allows interaction with the indole group of the nearby tryptophan, reshaping the surface of the domain. The discrimination between glutamyl and aspartyl residue is imposed by the stable tertiary conformation. These structural requirements correlate with the in vivo function of NS1/2 in persistence, a key element of norovirus biology and infection.
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20
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Immunoprevalence and immunodominance of HLA-Cw*0801-restricted T cell response targeting the hepatitis B virus envelope transmembrane region. J Virol 2013; 88:1332-41. [PMID: 24227846 DOI: 10.1128/jvi.02600-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
HLA-C-restricted T cells have been shown to play an important role in HIV control, but their impact on protection or pathogenesis in other viral infections remains elusive. Here, we characterized the hierarchy of HLA class I-restricted hepatitis B virus (HBV) epitopes targeted by CD8 T cells in HBV-infected subjects. The frequency of CD8 T cells specific for a panel of 18 HBV epitopes (restricted by HLA-A∗0201/03/07 [hereinafter HLA-A0201/03/07], -A1101, -A2402/07, -B5801, -B4001, -B1301, and -Cw0801) was quantified in a total of 59 subjects who resolved HBV infection. We found that the HLA-Cw0801-restricted epitope comprised of Env residues 171 to 180 (Env171-180) is immunoprevalent in the Southeast Asian subjects (10/17 HLA-Cw0801-positive subjects) and immunodominant in the majority of HLA-Cw0801-positive subjects able to control HBV infection. HLA-Cw0801-restricted Env171-180-specific CD8 T cells recognized endogenously produced HBV surface antigen (HBsAg) and tolerated amino acid variations within the epitope detected in HBV genotypes B and C. In conclusion, we demonstrate that the HLA-Cw0801-restricted Env171-180 T cell response is an important component of the HBV-specific adaptive T cell immunity in Asians infected with HBV. Thus, HLA-C restricted T cells might play an important role in various viral infections.
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Dupinay T, Gheit T, Roques P, Cova L, Chevallier-Queyron P, Tasahsu SI, Le Grand R, Simon F, Cordier G, Wakrim L, Benjelloun S, Trépo C, Chemin I. Discovery of naturally occurring transmissible chronic hepatitis B virus infection among Macaca fascicularis from Mauritius Island. Hepatology 2013; 58:1610-20. [PMID: 23536484 DOI: 10.1002/hep.26428] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/25/2013] [Indexed: 01/05/2023]
Abstract
UNLABELLED Despite a high prevalence of hepatitis B virus (HBV) infection in endangered apes, no HBV infection has been reported in small, old-world monkeys. In search for a small, nonhuman primate model, we investigated the prevalence of HBV infection in 260 macaque (Cercopithecidae) sera of various geographical origins (i.e., Morocco, Mauritius Island, and Asia). HBV-positive markers were detected in cynomolgus macaques (Macaca fascicularis) from Mauritius Island only, and, remarkably, HBV DNA was positive in 25.8% (31 of 120) and 42% (21 of 50) of serum and liver samples, respectively. Strong liver expression of hepatitis B surface antigen and hepatitis B core antigen was detected in approximately 20%-30% of hepatocytes. Furthermore, chronic infection with persisting HBV DNA was documented in all 6 infected macaques during an 8-month follow-up period. Whole HBV genome-sequencing data revealed that it was genotype D subtype ayw3 carrying substitution in position 67 of preS1. To confirm infectivity of this isolate, 3 Macaca sylvanus were inoculated with a pool of M. fascicularis serum and developed an acute HBV infection with 100% sequence homology, compared with HBV inoculum. We demonstrated the presence of a chronic HBV infection in M. fascicularis from Mauritius Island. This closely human-related HBV might have been transmitted from humans, because the initial breeding colony originated from very few ancestors 300 years ago when it was implemented by Portuguese who imported a handful of macaques from Java to Mauritius Island. CONCLUSION This report on natural, persisting HBV infection among cynomolgus macaques provides the first evidence for the existence of a novel, small simian model of chronic HBV infection, immunologically close to humans, that should be most valuable for the study of immunotherapeutic approaches against chronic hepatitis B.
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Affiliation(s)
- Tatiana Dupinay
- Université de Lyon, Lyon, France; INSERM U1052, Centre de Recherche en Cancérologie de Lyon, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Lyon, France; Ecole pratique des hautes études, Paris, France
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Mutations of two transmembrane cysteines of hemagglutinin (HA) from influenza A H3N2 virus affect HA thermal stability and fusion activity. Virus Genes 2013; 47:20-6. [PMID: 23749101 DOI: 10.1007/s11262-013-0924-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
Abstract
Influenza A H3N2 virus caused 1968 Hong Kong influenza pandemic, and has since been one of the most prevalent seasonal influenza viruses in global populations, representing a credible pandemic candidate in future. Previous studies have established that the hemagglutinin (HA) protein is the predominant antigen and executes receptor binding and membrane fusion. Homologous sequence analysis of all HA subtypes of influenza viruses revealed that two cysteine residues (540 and 544) are uniquely present in the transmembrane domain (TM) of HA proteins from all influenza A H3N2 viruses. However, the functions of these two cysteines have not been fully studied. Here, we generated three mutants (C540S, C544L, and 2C/SL) to investigate the effects of the two TM cysteines on the biological functions of H3 HA. We herein presented evidences that the mutations of one or two of the cysteines did not affect the proper expressions of HA proteins in cells, and more importantly all mutant H3 HAs showed decreased thermal stability but increased fusion activity in comparison with wildtype HA. Our results taken together demonstrated that the two TM cysteines are important for the biological functions of H3 HA proteins.
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Role of transmembrane domains of hepatitis B virus small surface proteins in subviral-particle biogenesis. J Virol 2012; 87:1491-6. [PMID: 23152523 DOI: 10.1128/jvi.02500-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The hepatitis B virus (HBV) surface proteins not only are incorporated into the virion envelope but in addition form subviral particles (SVP) consisting solely of surface proteins and lipids. Heterologous expression of the small HBV envelope protein S produces secreted spherical SVP 20 nm in diameter, with approximately 100 S molecules per particle. The pathway leading from the initial S translation product as a multispanning transmembrane protein to the final SVP is largely unknown. To investigate the role of the four transmembrane domains (TM) of S in this process, we introduced mutations in these regions and characterized their effects on SVP formation in transfected Huh7 cells. We found that the insertion of one amino acid in the center of the α-helix of TM1 or the exchange of TM1 with a heterologous TM blocked SVP release and SVP formation by coexpressed wild-type S chains in a transdominant negative fashion. Surprisingly, this effect was partially neutralized when the mutations were expressed in the background of the HBV surface protein M, suggesting that mutations in TM1 could partially be complemented by the pre-S2 domain. The exchange of TM2 with heterologous TMs that form α-helices of the same lengths was also incompatible with SVP formation. However, these mutants no longer blocked SVP formation by coexpressed wild-type S. We conclude that TM2 is essential for the stable assembly of S chains by establishing intramembrane interactions.
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Prange R. Host factors involved in hepatitis B virus maturation, assembly, and egress. Med Microbiol Immunol 2012; 201:449-61. [PMID: 22965171 DOI: 10.1007/s00430-012-0267-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 08/24/2012] [Indexed: 01/12/2023]
Abstract
Hepatitis B virus (HBV) is a major cause of liver disease. Due to the tiny size of its genome, HBV depends on the critical interplay between viral and host factors for the generation of new viral particles from infected cells. Recent work has illuminated a multiplicity of spatially and temporally coordinated virus-host interactions that accompany HBV particle genesis. These interactions include the requirement of cellular chaperones for the maturation of the three viral envelope proteins, the cellular factors involved in dynamic modification, maturation, and intracellular trafficking of the nucleocapsids, and the host components of the multivesicular body (MVB) pathway enabling virion budding at intracellular compartments. Beside infectious virions, HBV produces at least two other types of particles, subviral empty envelope particles and subviral naked capsid particles, likely as a result of the engagement of different host factors by the viral structural proteins. Accordingly, HBV exploits distinct cellular pathways to release its particle types. Here, I review recent progress in these areas of the cell biology of HBV genesis.
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Affiliation(s)
- Reinhild Prange
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg University Mainz, Augustusplatz, 55131 Mainz, Germany.
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25
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Ge G, Wang S, Han Y, Zhang C, Lu S, Huang Z. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine. PLoS One 2012; 7:e41573. [PMID: 22844502 PMCID: PMC3402421 DOI: 10.1371/journal.pone.0041573] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/24/2012] [Indexed: 12/19/2022] Open
Abstract
Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L), expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T), which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T) DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens.
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Affiliation(s)
- Guohong Ge
- Department of Infectious Diseases, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shixia Wang
- China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Yaping Han
- Department of Infectious Diseases, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Chunhua Zhang
- Department of Infectious Diseases, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shan Lu
- Department of Infectious Diseases, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
| | - Zuhu Huang
- Department of Infectious Diseases, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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Chakravarty R. Role of molecular diagnostics in the management of viral hepatitis B. ACTA ACUST UNITED AC 2012; 6:395-406. [PMID: 23480805 DOI: 10.1517/17530059.2012.690391] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Despite the availability of a safe and effective vaccine, chronic hepatitis B virus (HBV) infection continues to be a global health concern with an estimated 350 - 400 million people infected worldwide. Globally, HBV is the leading cause of chronic liver disease that may progress to cirrhosis and hepatocellular carcinoma. Therefore, accurate diagnosis and classification of the disease are important to determine whether therapy is needed. AREAS COVERED The review contains an overview of recent data on the existing and emerging developments in the molecular diagnostic and monitoring tools for chronic liver disease. EXPERT OPINION Monitoring of HBV viral load is the most widely used method in assessing liver disease severity, predicting development of cirrhosis and hepatocellular carcinoma, deciding initiation of antiviral therapy, assessing treatment response as well as early detection of emergence of drug resistance. Some recent studies have downplayed the importance of viral load in HBV management. Phenotyping/genotyping methods can establish emergent resistance to antivirals. Increasing number of reports suggest that clinical outcome and efficacy of antiviral treatment might vary with HBV genotype and precore/core promoter mutants. The importance of covalently closed circular DNA is also becoming apparent in this regard. Further studies on the development of newer molecular methods for a better management of chronic hepatitis B (CHB) will minimize morbidity in CHB.
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Affiliation(s)
- Runu Chakravarty
- ICMR Virus Unit , GB 4, 1st Floor, ID & BG Hospital Campus, 57, Dr. Suresh Chandra Banerjee Road, Kolkata 700010 , India +91 33 2353 7425 ; +91 33 2353 7424 ;
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Liu WH, Yeh SH, Chen PJ. Role of microRNAs in hepatitis B virus replication and pathogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:678-85. [DOI: 10.1016/j.bbagrm.2011.04.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 04/24/2011] [Accepted: 04/25/2011] [Indexed: 02/08/2023]
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Hepatitis B virus surface antigen assembly function persists when entire transmembrane domains 1 and 3 are replaced by a heterologous transmembrane sequence. J Virol 2010; 85:2439-48. [PMID: 21177825 DOI: 10.1128/jvi.02061-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Native hepatitis B surface antigen (HBsAg) spontaneously assembles into 22-nm subviral particles. The particles are lipoprotein micelles, in which HBsAg is believed to span the lipid layer four times. The first two transmembrane domains, TM1 and TM2, are required for particle assembly. We have probed the requirements for particle assembly by replacing the entire first or third TM domain of HBsAg with the transmembrane domain of HIV gp41. We found that either TM domain of HBsAg could be replaced, resulting in HBsAg-gp41 chimeras that formed particles efficiently. HBsAg formed particles even when both TM1 and TM3 were replaced with the gp41 domain. The results indicate remarkable flexibility in HBsAg particle formation and provide a novel way to express heterologous membrane proteins that are anchored to a lipid surface by their own membrane-spanning domain. The membrane-proximal exposed region (MPER) of gp41 is an important target of broadly reactive neutralizing antibodies against HIV-1, and HBsAg-MPER particles may provide a good platform for future vaccine development.
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Wei Y, Neuveut C, Tiollais P, Buendia MA. Molecular biology of the hepatitis B virus and role of the X gene. ACTA ACUST UNITED AC 2010; 58:267-72. [PMID: 20483545 DOI: 10.1016/j.patbio.2010.03.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 03/05/2010] [Indexed: 12/16/2022]
Abstract
The hepatitis B virus (HBV) is a widespread human pathogen and a major health problem in many countries. Molecular cloning and sequencing of the viral DNA genome has demonstrated a small and compact structure organized into four overlapping reading frames that encode the viral proteins. Besides structural proteins of the core and the envelope, HBV encodes a DNA polymerase with reverse transcriptase activity, a secreted antigen of unknown function, and a transcriptional activator that is essential for viral replication. Major steps of the viral life cycle have been unraveled, including transcription of all viral RNAs from nuclear covalently closed circular DNA (cccDNA), followed by encapsidation of pregenomic RNA, a more-than-genome length transcript, and reverse transcription of pregenomic RNA leading to asymmetric synthesis of the DNA strands. Although HBV has been recognized as a human tumor virus, no direct transforming activity could be evidenced in different cellular and animal models. However, the transcriptional regulatory protein HBx encoded by the X gene is endowed with weak oncogenic activity. HBx harbors pleiotropic activities and plays a major role in HBV pathogenesis and in liver carcinogenesis.
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Affiliation(s)
- Y Wei
- Unité oncogenèse et virologie moléculaire, département de virologie, Institut Pasteur, 28, rue du Dr-Roux, 75724 Paris cedex 15, France
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