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Ganeva V, Kranz A. Selective extraction of recombinant membrane proteins from Hansenula polymorpha by pulsed electric field and lytic enzyme pretreatment. Microb Cell Fact 2023; 22:251. [PMID: 38066481 PMCID: PMC10704748 DOI: 10.1186/s12934-023-02259-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND In yeast, recombinant membrane proteins including viral scaffold proteins used for the formation of enveloped Virus-like particles (eVLPs) typically accumulate intracellularly. Their recovery is carried out by mechanical disruption of the cells, often in combination with detergent treatment. Cell permeabilization is an attractive alternative to mechanical lysis because it allows for milder and more selective recovery of different intracellular products. RESULTS Here, we present a novel approach for extraction of integral membrane proteins from yeast based on cell envelope permeabilization through a combination of pulsed electric field and lytic enzyme pretreatment of the cells. Our primary experiments focused on Hansenula polymorpha strain #25-5 co-expressing the integral membrane small surface protein (dS) of the duck hepatitis B virus and a fusion protein of dS with a trimer of a Human papillomavirus (HPV) L2-peptide (3xL2-dS). Irreversible plasma membrane permeabilization was induced by treating the cell suspension with monopolar rectangular pulses using a continuous flow system. The permeabilized cells were incubated with lyticase and dithiothreitol. This treatment increased the cell wall permeability, resulting in the release of over 50% of the soluble host proteins without causing significant cell lysis. The subsequent incubation with Triton X-100 resulted in the solubilization and release of a significant portion of 3xL2-dS and dS from the cells. By applying two steps: (i) brief heating of the cells before detergent treatment, and (ii) incubation of the extracts with KSCN, an 80% purity on the protein level has been achieved. Experiments performed with H. polymorpha strain T#3-3, co-expressing dS and the fusion protein EDIIIWNV-dS consisting of dS and the antigen from the West Nile virus (WSV), confirmed the applicability of this approach for recovering dS. The treatment, optimal for solubilization of 3xL2-dS and a significant part of dS, was not effective in isolating the fused protein EDIIIWNV-dS from the membranes, resulting in its retention within the cells. CONCLUSIONS This study presents an alternative approach for the recovery and partial purification of viral membrane proteins expressed in H. polymorpha. The factors influencing the effectiveness of this procedure and its potential use for the recovery of other integral membrane proteins are discussed.
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Affiliation(s)
- Valentina Ganeva
- Biological Faculty, Department of Biophysics & Radiobiology, Sofia University, 8 Dragan Tzankov blvd, Sofia, 1164, Bulgaria.
| | - Andreas Kranz
- ARTES Biotechnology GmbH, Elizabeth Selbert str. 9, 40764, Langenfeld, Germany
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Wetzel D, Barbian A, Jenzelewski V, Schembecker G, Merz J, Piontek M. Bioprocess optimization for purification of chimeric VLP displaying BVDV E2 antigens produced in yeast Hansenula polymorpha. J Biotechnol 2019; 306:203-212. [PMID: 31634510 DOI: 10.1016/j.jbiotec.2019.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/15/2022]
Abstract
Chimeric virus-like particles (VLP) are known as promising tools in the development of safe and effective subunit vaccines. Recently, a technology platform to produce VLP based on the small surface protein (dS) of the duck hepatitis B virus was established. In this study, chimeric VLP were investigated displaying the 195 N-terminal amino acids derived from the glycoprotein E2 of the bovine viral diarrhea virus (BVDV) on their surface. Isolation of the VLP from methylotrophic yeast Hansenula polymorpha was allowed upon co-expression of wild-type dS and a fusion protein composed of the BVDV-derived antigen N-terminally fused to the dS. It was shown the VLP could be purified by a process adapted from the production of a recombinant hepatitis B VLP vaccine. However, the process essentially depended on costly ultracentrifugation which is critical for low cost production. In novel process variants, this step was avoided after modification of the initial batch capture step, the introduction of a precipitation step and adjusting the ion exchange chromatography. The product yield could be improved by almost factor 8 to 93 ± 12 mg VLP protein per 100 g dry cell weight while keeping similar product purity and antigenicity. This allows scalable and cost efficient VLP production.
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Affiliation(s)
- David Wetzel
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Strasse 9, 40764 Langenfeld, Germany; Technical University of Dortmund, Laboratory of Plant and Process Design, Emil-Figge-Strasse 70, 44227 Dortmund, Germany.
| | - Andreas Barbian
- Duesseldorf University Hospital, Institute for anatomy I, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Volker Jenzelewski
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Strasse 9, 40764 Langenfeld, Germany
| | - Gerhard Schembecker
- Technical University of Dortmund, Laboratory of Plant and Process Design, Emil-Figge-Strasse 70, 44227 Dortmund, Germany
| | - Juliane Merz
- Evonik Technology & Infrastructure GmbH, Rodenbacher Chaussee 4, 63457 Hanau, Germany
| | - Michael Piontek
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Strasse 9, 40764 Langenfeld, Germany
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Wetzel D, Chan JA, Suckow M, Barbian A, Weniger M, Jenzelewski V, Reiling L, Richards JS, Anderson DA, Kouskousis B, Palmer C, Hanssen E, Schembecker G, Merz J, Beeson JG, Piontek M. Display of malaria transmission-blocking antigens on chimeric duck hepatitis B virus-derived virus-like particles produced in Hansenula polymorpha. PLoS One 2019; 14:e0221394. [PMID: 31483818 PMCID: PMC6726142 DOI: 10.1371/journal.pone.0221394] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/07/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Malaria caused by Plasmodium falciparum is one of the major threats to human health globally. Despite huge efforts in malaria control and eradication, highly effective vaccines are urgently needed, including vaccines that can block malaria transmission. Chimeric virus-like particles (VLP) have emerged as a promising strategy to develop new malaria vaccine candidates. METHODS We developed yeast cell lines and processes for the expression of malaria transmission-blocking vaccine candidates Pfs25 and Pfs230 as VLP and VLP were analyzed for purity, size, protein incorporation rate and expression of malaria antigens. RESULTS In this study, a novel platform for the display of Plasmodium falciparum antigens on chimeric VLP is presented. Leading transmission-blocking vaccine candidates Pfs25 and Pfs230 were genetically fused to the small surface protein (dS) of the duck hepatitis B virus (DHBV). The resulting fusion proteins were co-expressed in recombinant Hansenula polymorpha (syn. Pichia angusta, Ogataea polymorpha) strains along with the wild-type dS as the VLP scaffold protein. Through this strategy, chimeric VLP containing Pfs25 or the Pfs230-derived fragments Pfs230c or Pfs230D1M were purified. Up to 100 mg chimeric VLP were isolated from 100 g dry cell weight with a maximum protein purity of 90% on the protein level. Expression of the Pfs230D1M construct was more efficient than Pfs230c and enabled VLP with higher purity. VLP showed reactivity with transmission-blocking antibodies and supported the surface display of the malaria antigens on the native VLP. CONCLUSION The incorporation of leading Plasmodium falciparum transmission-blocking antigens into the dS-based VLP scaffold is a promising novel strategy for their display on nano-scaled particles. Competitive processes for efficient production and purification were established in this study.
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Affiliation(s)
- David Wetzel
- ARTES Biotechnology GmbH, Langenfeld, Germany
- Laboratory of Plant and Process Design, Technical University of Dortmund, Dortmund, Germany
| | - Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | | | - Andreas Barbian
- Düsseldorf University Hospital, Institute for Anatomy I, Düsseldorf, Germany
| | | | | | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Jack S. Richards
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - David A. Anderson
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Betty Kouskousis
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Catherine Palmer
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Eric Hanssen
- The Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Gerhard Schembecker
- Laboratory of Plant and Process Design, Technical University of Dortmund, Dortmund, Germany
| | - Juliane Merz
- Evonik Technology & Infrastructure GmbH, Hanau, Germany
| | - James G. Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
- Central Clinical School and Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
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Quinet J, Jamard C, Burtin M, Lemasson M, Guerret S, Sureau C, Vaillant A, Cova L. Nucleic acid polymer REP 2139 and nucleos(T)ide analogues act synergistically against chronic hepadnaviral infection in vivo in Pekin ducks. Hepatology 2018; 67:2127-2140. [PMID: 29251788 PMCID: PMC6001552 DOI: 10.1002/hep.29737] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/24/2017] [Accepted: 12/12/2017] [Indexed: 12/18/2022]
Abstract
Nucleic acid polymer (NAP) REP 2139 treatment was shown to block the release of viral surface antigen in duck HBV (DHBV)-infected ducks and in patients with chronic HBV or HBV/hepatitis D virus infection. In this preclinical study, a combination therapy consisting of REP 2139 with tenofovir disoproxil fumarate (TDF) and entecavir (ETV) was evaluated in vivo in the chronic DHBV infection model. DHBV-infected duck groups were treated as follows: normal saline (control); REP 2139 TDF; REP 2139 + TDF; and REP 2139 + TDF + ETV. After 4 weeks of treatment, all animals were followed for 8 weeks. Serum DHBsAg and anti-DHBsAg antibodies were monitored by enzyme-linked immunosorbent assay and viremia by qPCR. Total viral DNA and covalently closed circular DNA (cccDNA) were quantified in autopsy liver samples by qPCR. Intrahepatic DHBsAg was assessed at the end of follow-up by immunohistochemistry. On-treatment reduction of serum DHBsAg and viremia was more rapid when REP 2139 was combined with TDF or TDF and ETV, and, in contrast to TDF monotherapy, no viral rebound was observed after treatment cessation. Importantly, combination therapy resulted in a significant decrease in intrahepatic viral DNA (>3 log) and cccDNA (>2 log), which were tightly correlated with the clearance of DHBsAg in the liver. CONCLUSION Synergistic antiviral effects were observed when REP 2139 was combined with TDF or TDF + ETV leading to control of infection in blood and liver, associated with intrahepatic viral surface antigen elimination that persisted after treatment withdrawal. Our findings suggest the potential of developing such combination therapy for treatment of chronically infected patients in the absence of pegylated interferon. (Hepatology 2018;67:2127-2140).
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Affiliation(s)
- Jonathan Quinet
- Institut National de Santé et Recherche Médicale (INSERM) U1052LyonFrance
| | - Catherine Jamard
- Institut National de Santé et Recherche Médicale (INSERM) U1052LyonFrance
| | - Madeleine Burtin
- Institut National de Santé et Recherche Médicale (INSERM) U1052LyonFrance
| | | | | | - Camille Sureau
- Institut National de la Transfusion Sanguine (INTS)ParisFrance
| | | | - Lucyna Cova
- Institut National de Santé et Recherche Médicale (INSERM) U1052LyonFrance
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David G, Fogeron ML, Schledorn M, Montserret R, Haselmann U, Penzel S, Badillo A, Lecoq L, André P, Nassal M, Bartenschlager R, Meier BH, Böckmann A. Structural Studies of Self-Assembled Subviral Particles: Combining Cell-Free Expression with 110 kHz MAS NMR Spectroscopy. Angew Chem Int Ed Engl 2018; 57:4787-4791. [PMID: 29457857 DOI: 10.1002/anie.201712091] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/25/2018] [Indexed: 01/08/2023]
Abstract
Viral membrane proteins are prime targets in combatting infection. Still, the determination of their structure remains a challenge, both with respect to sample preparation and the need for structural methods allowing for analysis in a native-like lipid environment. Cell-free protein synthesis and solid-state NMR spectroscopy are promising approaches in this context, the former with respect to its great potential in the native expression of complex proteins, and the latter for the analysis of membrane proteins in lipids. Herein, we show that milligram amounts of the small envelope protein of the duck hepatitis B virus (DHBV) can be produced by cell-free expression, and that the protein self-assembles into subviral particles. Proton-detected 2D NMR spectra recorded at a magic-angle-spinning frequency of 110 kHz on <500 μg protein show a number of isolated peaks with line widths comparable to those of model membrane proteins, paving the way for structural studies of this protein that is homologous to a potential drug target in HBV infection.
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Affiliation(s)
- Guillaume David
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France
| | - Marie-Laure Fogeron
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France
| | | | - Roland Montserret
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France
| | - Uta Haselmann
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120, Heidelberg, Germany.,Division of Virus-Associated Carcinogenesis Germany, Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany
| | - Susanne Penzel
- Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland
| | - Aurélie Badillo
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France.,RD-Biotech, Recombinant Protein Unit, 3 rue Henri Baigue, 25000, Besançon, France
| | - Lauriane Lecoq
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France
| | - Patrice André
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale Unité 1111, Centre National de la Recherche Scientifique Unités Mixte de Recherche, 5308, Lyon, France.,Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France.,Université de Lyon, Laboratoire de Virologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, France
| | - Michael Nassal
- University Hospital Freiburg, Internal Medicine II/Molecular Biology, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120, Heidelberg, Germany.,Division of Virus-Associated Carcinogenesis Germany, Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland
| | - Anja Böckmann
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, 7 passage du Vercors, 69367, Lyon, France
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6
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David G, Fogeron M, Schledorn M, Montserret R, Haselmann U, Penzel S, Badillo A, Lecoq L, André P, Nassal M, Bartenschlager R, Meier BH, Böckmann A. Strukturelle Untersuchung subviraler Partikel durch die Kombination von zellfreier Proteinherstellung mit 110 kHz MAS‐NMR‐Spektroskopie. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Guillaume David
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
| | - Marie‐Laure Fogeron
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
| | | | - Roland Montserret
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
| | - Uta Haselmann
- Department für Infektiologie Molekulare Virologie Universitätsklinikum Heidelberg Im Neuenheimer Feld 345 69120 Heidelberg Deutschland
- Abteilung Virus-assoziierte Karzinogenese Deutsches Krebsforschungszentrum (DKFZ) Im Neuenheimer Feld 242 69120 Heidelberg Deutschland
| | - Susanne Penzel
- Lab. für Physikalische Chemie ETH Zürich 8093 Zürich Schweiz
| | - Aurélie Badillo
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
- RD-Biotech Recombinant Protein Unit 3 rue Henri Baigue 25000 Besançon Frankreich
| | - Lauriane Lecoq
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
| | - Patrice André
- Centre International de Recherche en Infectiologie Institut National de la Santé et de la Recherche Médicale Unité 1111 Centre National de la Recherche Scientifique Unités Mixte de Recherche 5308 Lyon Frankreich
- Ecole Normale Supérieure de Lyon, Lyon, France Université Claude Bernard Lyon 1 Villeurbanne Frankreich
- Université de Lyon, Lyon, France Laboratoire de Virologie Hôpital de la Croix-Rousse Hospices Civils de Lyon Lyon Frankreich
| | - Michael Nassal
- Universitätsklinikum Freiburg Klinik für Innere Medizin II/ Molekulare Biologie Hugstetter Straße 55 79106 Freiburg Deutschland
| | - Ralf Bartenschlager
- Department für Infektiologie Molekulare Virologie Universitätsklinikum Heidelberg Im Neuenheimer Feld 345 69120 Heidelberg Deutschland
- Abteilung Virus-assoziierte Karzinogenese Deutsches Krebsforschungszentrum (DKFZ) Im Neuenheimer Feld 242 69120 Heidelberg Deutschland
| | - Beat H. Meier
- Lab. für Physikalische Chemie ETH Zürich 8093 Zürich Schweiz
| | - Anja Böckmann
- Institut de Biologie et Chimie des Protéines, MMSB, Labex Ecofect, UMR 5086 CNRS Université de Lyon 7 passage du Vercors 69367 Lyon Frankreich
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Wetzel D, Rolf T, Suckow M, Kranz A, Barbian A, Chan JA, Leitsch J, Weniger M, Jenzelewski V, Kouskousis B, Palmer C, Beeson JG, Schembecker G, Merz J, Piontek M. Establishment of a yeast-based VLP platform for antigen presentation. Microb Cell Fact 2018; 17:17. [PMID: 29402276 PMCID: PMC5798182 DOI: 10.1186/s12934-018-0868-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 01/27/2018] [Indexed: 12/26/2022] Open
Abstract
Background Chimeric virus-like particles (VLP) allow the display of foreign antigens on their surface and have proved valuable in the development of safe subunit vaccines or drug delivery. However, finding an inexpensive production system and a VLP scaffold that allows stable incorporation of diverse, large foreign antigens are major challenges in this field. Results In this study, a versatile and cost-effective platform for chimeric VLP development was established. The membrane integral small surface protein (dS) of the duck hepatitis B virus was chosen as VLP scaffold and the industrially applied and safe yeast Hansenula polymorpha (syn. Pichia angusta, Ogataea polymorpha) as the heterologous expression host. Eight different, large molecular weight antigens of up to 412 amino acids derived from four animal-infecting viruses were genetically fused to the dS and recombinant production strains were isolated. In all cases, the fusion protein was well expressed and upon co-production with dS, chimeric VLP containing both proteins could be generated. Purification was accomplished by a downstream process adapted from the production of a recombinant hepatitis B VLP vaccine. Chimeric VLP were up to 95% pure on protein level and contained up to 33% fusion protein. Immunological data supported surface exposure of the foreign antigens on the native VLP. Approximately 40 mg of chimeric VLP per 100 g dry cell weight could be isolated. This is highly comparable to values reported for the optimized production of human hepatitis B VLP. Purified chimeric VLP were shown to be essentially stable for 6 months at 4 °C. Conclusions The dS-based VLP scaffold tolerates the incorporation of a variety of large molecular weight foreign protein sequences. It is applicable for the display of highly immunogenic antigens originating from a variety of pathogens. The yeast-based production system allows cost-effective production that is not limited to small-scale fundamental research. Thus, the dS-based VLP platform is highly efficient for antigen presentation and should be considered in the development of future vaccines.
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Affiliation(s)
- David Wetzel
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany. .,Laboratory of Plant and Process Design, Technical University of Dortmund, Emil-Figge-Straße 70, 44227, Dortmund, Germany.
| | - Theresa Rolf
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Manfred Suckow
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Andreas Kranz
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Andreas Barbian
- Institute for Anatomy I, Düsseldorf University Hospital, Moorenstraße 5, 40225, Düsseldorf, Germany
| | - Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Joachim Leitsch
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Michael Weniger
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Volker Jenzelewski
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
| | - Betty Kouskousis
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Catherine Palmer
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Gerhard Schembecker
- Laboratory of Plant and Process Design, Technical University of Dortmund, Emil-Figge-Straße 70, 44227, Dortmund, Germany
| | - Juliane Merz
- Laboratory of Plant and Process Design, Technical University of Dortmund, Emil-Figge-Straße 70, 44227, Dortmund, Germany
| | - Michael Piontek
- ARTES Biotechnology GmbH, Elisabeth-Selbert-Straße 9, 40764, Langenfeld, Germany
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Roehl I, Seiffert S, Brikh C, Quinet J, Jamard C, Dorfler N, Lockridge JA, Cova L, Vaillant A. Nucleic Acid Polymers with Accelerated Plasma and Tissue Clearance for Chronic Hepatitis B Therapy. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 8:1-12. [PMID: 28918011 PMCID: PMC5466589 DOI: 10.1016/j.omtn.2017.04.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 12/18/2022]
Abstract
REP 2139 is a nucleic acid polymer (NAP) currently under clinical development for chronic hepatitis B (HBV) therapy. This preclinical study investigated different REP 2139 analogs that would display reduced accumulation in the serum and tissues, while retaining an antiviral effect against HBV infection. REP 2139 analogs were evaluated in human plasma, CD-1 mice, cynomolgus monkeys, and Pekin ducks. Discrete ribose transformation to 2'OH in selected riboadenosines resulted in a slow degradation in acidified human plasma that plateaued after 48 hr. REP 2165, a REP 2139 analog containing three unmodified riboadenosines equally spaced throughout the polymer, showed similar plasma clearance and tissue distribution as REP 2139 in mice and cynomolgus monkeys after a single dose. Interestingly, after repeated administration, accumulation of REP 2165 in plasma and organs was reduced, indicating a dramatically faster rate of clearance from organs after therapy was ended in both species. Both REP 2139 and REP 2165 were well tolerated at clinically relevant doses, with no alterations in liver, kidney, or hematological function. In chronic duck HBV (DHBV) infection, REP 2165 displayed significantly reduced liver accumulation after repeated dosing but retained antiviral activity similar to REP 2139. These results indicate the therapeutic potential of REP 2165 against chronic HBV infection in patients is similar to REP 2139, but with significantly reduced drug accumulation and improved tissue clearance.
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9
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Yan L, Qu S, Liu G, Liu L, Yu Y, Ding G, Zhao Y, Li Y, Xie Y, Zhang J, Qu D. Comparative Transcriptomic Analysis of Primary Duck Hepatocytes Provides Insight into Differential Susceptibility to DHBV Infection. PLoS One 2016; 11:e0149702. [PMID: 26900848 PMCID: PMC4763071 DOI: 10.1371/journal.pone.0149702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/02/2016] [Indexed: 02/06/2023] Open
Abstract
Primary duck hepatocytes (PDH) displays differential susceptibility to duck hepatitis B virus when maintained in the media supplemented with fetal bovine serum or dimethyl sulfoxide (DMSO) which has been widely used for the maintenance of hepatocytes, and prolonging susceptibility to hepadnavirus. However the mechanism underlying maintenance of susceptibility to hepadnavirus by DMSO treatment remains unclear. In this study, a global transcriptome analysis of PDHs under different culture conditions was conducted for investigating the effects of DMSO on maintenance of susceptibility of PDH to DHBV in vitro. The 384 differential expressed genes (DEGs) were identified by comparisons between each library pair (PDHs cultured with or without DMSO or fresh isolated PDH). We analyzed canonical pathways in which the DEGs were enriched in Hepatic Fibrosis / Hepatic Stellate Cell Activation, Bile Acid Biosynthesis and Tight Junction signaling. After re-annotation against human genome data, the 384 DEGs were pooled together with proteins belonging to hepatitis B pathway to construct a protein-protein interaction network. The combination of decreased expression of liver-specific genes (CYP3A4, CYP1E1, CFI, RELN and GSTA1 et al) with increased expression of hepatocyte-dedifferentiation-associated genes (PLA2G4A and PLCG1) suggested that in vitro culture conditions results in the fading of hepatocyte phenotype in PDHs. The expression of seven DEGs associated with tight junction formation (JAM3, PPP2R2B, PRKAR1B, PPP2R2C, MAGI2, ACTA2 and ACTG2) was up-regulated after short-term culture in vitro, which was attenuated in the presence of DMSO. Those results could shed light on DHBV infection associated molecular events affected by DMSO.
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Affiliation(s)
- Liang Yan
- Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Su Qu
- Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Gang Liu
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lei Liu
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yao Yu
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Guohui Ding
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yanfeng Zhao
- Department of Laboratory Medicine, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yixue Li
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Youhua Xie
- Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
- * E-mail: (DQ); (JZ); (YX)
| | - Junqi Zhang
- Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
- * E-mail: (DQ); (JZ); (YX)
| | - Di Qu
- Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
- * E-mail: (DQ); (JZ); (YX)
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10
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Zhang YY. Duck Hepatitis B Virus cccDNA Amplification Efficiency in Natural Infection Is Regulated by Virus Secretion Efficiency. PLoS One 2015; 10:e0145465. [PMID: 26713436 PMCID: PMC4694612 DOI: 10.1371/journal.pone.0145465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 12/03/2015] [Indexed: 01/01/2023] Open
Abstract
Previous mutation based studies showed that ablating synthesis of viral envelope proteins led to elevated hepadnaviral covalently closed circular DNA (cccDNA) amplification, but it remains unknown how cccDNA amplification is regulated in natural hepadnaviral infection because of a lack of research system. In this study we report a simple procedure to prepare two identical duck hepatitis B virus inocula, but they possess 10-100-fold difference in cccDNA amplification in infected cell culture. We demonstrate that the infected cells with higher cccDNA amplification significantly reduce the virus secretion efficiency that results in higher accumulation of relaxed circular DNA (rcDNA) and DHBsAg in the cells. The infected cells with lower cccDNA amplification significantly increase the virus secretion efficiency that leads to lower intracellular rcDNA and DHBsAg accumulation. In contrast with the findings generated in the mutation based experimental system, the regulation of cccDNA amplification in natural hepadnaviral infection bypasses direct regulation of the cellular envelope proteins concentration, instead it modulates virus secretion efficiency that ultimately impacts the intracellular rcDNA concentration, an important factor determining the destination of the synthesized rcDNA in infected cells.
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Affiliation(s)
- Yong-Yuan Zhang
- HBVtech, Germantown, Maryland, United States of America
- * E-mail:
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11
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Noordeen F, Scougall CA, Grosse A, Qiao Q, Ajilian BB, Reaiche-Miller G, Finnie J, Werner M, Broering R, Schlaak JF, Vaillant A, Jilbert AR. Therapeutic Antiviral Effect of the Nucleic Acid Polymer REP 2055 against Persistent Duck Hepatitis B Virus Infection. PLoS One 2015; 10:e0140909. [PMID: 26560490 PMCID: PMC4641618 DOI: 10.1371/journal.pone.0140909] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/01/2015] [Indexed: 12/18/2022] Open
Abstract
Previous studies have demonstrated that nucleic acid polymers (NAPs) have both entry and post-entry inhibitory activity against duck hepatitis B virus (DHBV) infection. The inhibitory activity exhibited by NAPs prevented DHBV infection of primary duck hepatocytes in vitro and protected ducks from DHBV infection in vivo and did not result from direct activation of the immune response. In the current study treatment of primary human hepatocytes with NAP REP 2055 did not induce expression of the TNF, IL6, IL10, IFNA4 or IFNB1 genes, confirming the lack of direct immunostimulation by REP 2055. Ducks with persistent DHBV infection were treated with NAP 2055 to determine if the post-entry inhibitory activity exhibited by NAPs could provide a therapeutic effect against established DHBV infection in vivo. In all REP 2055-treated ducks, 28 days of treatment lead to initial rapid reductions in serum DHBsAg and DHBV DNA and increases in anti-DHBs antibodies. After treatment, 6/11 ducks experienced a sustained virologic response: DHBsAg and DHBV DNA remained at low or undetectable levels in the serum and no DHBsAg or DHBV core antigen positive hepatocytes and only trace amounts of DHBV total and covalently closed circular DNA (cccDNA) were detected in the liver at 9 or 16 weeks of follow-up. In the remaining 5/11 REP 2055-treated ducks, all markers of DHBV infection rapidly rebounded after treatment withdrawal: At 9 and 16 weeks of follow-up, levels of DHBsAg and DHBcAg and DHBV total and cccDNA in the liver had rebounded and matched levels observed in the control ducks treated with normal saline which remained persistently infected with DHBV. These data demonstrate that treatment with the NAP REP 2055 can lead to sustained control of persistent DHBV infection. These effects may be related to the unique ability of REP 2055 to block release of DHBsAg from infected hepatocytes.
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Affiliation(s)
- Faseeha Noordeen
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Microbiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Catherine A. Scougall
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Arend Grosse
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Qiao Qiao
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Behzad B. Ajilian
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Georget Reaiche-Miller
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - John Finnie
- SA Pathology, Hanson Institute, Centre For Neurological Diseases, Adelaide, SA, Australia
| | - Melanie Werner
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Ruth Broering
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Joerg F. Schlaak
- Department of Gastroenterology and Hepatology, University Hospital, University of Duisburg-Essen, Essen, Germany
| | | | - Allison R. Jilbert
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- * E-mail: (AJ); (AV)
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12
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Biđin M, Tišljar M, Biđin Z, Lojkić I, Majnarić D. Genetic characterization of hepadnaviruses associated with histopathological changes in the liver of duck and goose embryos. Vet Microbiol 2014; 174:302-308. [PMID: 25457362 DOI: 10.1016/j.vetmic.2014.09.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 09/20/2014] [Accepted: 09/26/2014] [Indexed: 11/25/2022]
Abstract
Avian hepadnaviruses are etiological agents of hepatitis B, that has been identified primarily in ducks, and more recently in various avian species. In this paper, 16 hepadnaviruses were detected by polymerase chain reaction (PCR) in the field samples from dead embryos of commercially reared domestic duck and goose. Based on the molecular analysis of the S-protein gene sequences and phylogenetic Neighbor-joining tree, identified viruses were clustered in the same genetic group, indicating no host-related diversity. Both duck and goose-origin hepadnaviruses were grouped within the cluster consisting of "Western-country" and "Chinese" duck hepatitis B (DHBV) isolates, showing more evolutionary distances with other known avian hepadnaviruses. Histopathologically, the lesions observed in the liver tissue from hepadnavirus positive duck and goose embryos varied from low to mild degree of perivascular mononuclear cells and mixed cell infiltrations, followed by mild vacuolar changes. Small focal necrotic changes in the liver parenchyma, and bile ductular proliferation were also found in examined liver samples. Generally, the microscopic findings resemble those described in experimentally infected ducks, while this was the first description of hepadnavirus associated lesions in domestic goose. Although hepadnaviruses are considered to have a very narrow host range, this study showed that domestic ducks and geese are susceptible to infection with genetically almost identical hepadnaviruses, that were likely to produce similar microscopic changes in the liver of both duck and goose embryos. The impact of naturally occurred hepadnavirus infection and possible synergistic interactions with other infectious or non-infectious agents on embryo viability needs further investigation.
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Affiliation(s)
- Marina Biđin
- Department of Poultry Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia.
| | - Marina Tišljar
- Poultry Centre, Croatian Veterinary Institute, Heinzelova 55, 10000 Zagreb, Croatia
| | - Zdenko Biđin
- Department of Poultry Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia
| | - Ivana Lojkić
- Department of Virology, Croatian Veterinary Institute, Savska cesta 143, 10000 Zagreb, Croatia
| | - Darko Majnarić
- Veterinary Department Križevci, Croatian Veterinary Institute, Dijankovečka 10, 48260 Križevci, Croatia
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13
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Reaiche-Miller GY, Thorpe M, Low HC, Qiao Q, Scougall CA, Mason WS, Litwin S, Jilbert AR. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver. Virology 2013; 446:357-64. [PMID: 24074600 DOI: 10.1016/j.virol.2013.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/24/2013] [Accepted: 08/14/2013] [Indexed: 01/05/2023]
Abstract
Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10(5)-fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis.
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Affiliation(s)
- Georget Y Reaiche-Miller
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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14
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Nucleic acid polymers prevent the establishment of duck hepatitis B virus infection in vivo. Antimicrob Agents Chemother 2013; 57:5299-306. [PMID: 23939904 DOI: 10.1128/aac.01005-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nucleic acid polymers (NAPs) are novel, broad-spectrum antiviral compounds that use the sequence-independent properties of phosphorothioate oligonucleotides (PS-ONs) as amphipathic polymers to block amphipathic interactions involved in viral entry. Using the duck hepatitis B virus (DHBV) model of human hepatitis B virus infection, NAPs have been shown to have both entry and postentry antiviral activity against DHBV infection in vitro in primary duck hepatocytes (PDH). In the current study, various NAPs were assessed for their prophylactic activity in vivo against DHBV infection in ducks. The degenerate NAP REP 2006 prevented the development of widespread and persistent DHBV infection in 14-day-old ducks, while the acidic-pH-sensitive NAP REP 2031 had little or no prophylactic effect. REP 2006 displayed significant toxicity in ducks, which was attributed to CpG-mediated proinflammation, while REP 2031 (which has no CpG motifs) displayed no toxicity. A third NAP, REP 2055, which was designed to retain amphipathic activity at acidic pH and contained no CpG motifs, was well tolerated and displayed prophylactic activity against DHBV infection at doses as low as 1 mg/kg of body weight/day. These studies suggest that NAPs can be easily and predictably tailored to retain anti-DHBV activity and to have minimal toxic effects in vivo. Future studies are planned to establish the therapeutic efficacy of NAPs against persistent DHBV infection.
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15
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Nucleic acid polymers inhibit duck hepatitis B virus infection in vitro. Antimicrob Agents Chemother 2013; 57:5291-8. [PMID: 23939902 DOI: 10.1128/aac.01003-13] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nucleic acid polymers (NAPs) utilize the sequence-independent properties of phosphorothioate oligonucleotides (PS-ONs) to target protein interactions involved in viral replication. NAPs are broadly active against a diverse range of enveloped viruses that use type I entry mechanisms. The antiviral activity of NAPs against hepatitis B virus (HBV) infection was assessed in vitro in duck hepatitis B virus (DHBV)-infected primary duck hepatocytes (PDH). NAPs efficiently entered PDH in the absence of any transfection agent and displayed antiviral activity at concentrations of 0.01 to 10 μM, measured by their ability to prevent the intracellular accumulation of DHBV surface antigen, which was independent of their nucleotide sequence and was specifically dependent on phosphorothioation. Higher levels of antiviral activity were observed with NAPs 40 nucleotides in length or longer. The fully degenerate NAP (REP 2006) was active during DHBV infection or when added 12 h after infection. In contrast, an acidic-pH-sensitive NAP (REP 2031) that was broadly active against other viruses displayed antiviral activity when present during DHBV infection but no activity when added 12 h after infection, suggesting that NAPs exert their postentry effect in an acidic environment unique to DHBV infection. Both REP 2006 and REP 2031 displayed negligible cytotoxicity in PDH at concentrations of up to 10 μM, as assessed using an XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] cytotoxicity assay. The antiviral activity of NAPs against DHBV in vitro was strictly dependent on their amphipathic character, suggesting that NAPs interact with amphipathic target(s) that are important for DHBV entry and postentry mechanisms required for infection.
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16
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Seeger C, Mason WS. Sodium-dependent taurocholic cotransporting polypeptide: a candidate receptor for human hepatitis B virus. Gut 2013; 62:1093-5. [PMID: 23542357 DOI: 10.1136/gutjnl-2013-304594] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Christoph Seeger
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
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17
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Feng F, Teoh CQ, Qiao Q, Boyle D, Jilbert AR. The development of persistent duck hepatitis B virus infection can be prevented using antiviral therapy combined with DNA or recombinant fowlpoxvirus vaccines. Vaccine 2010; 28:7436-43. [PMID: 20833122 DOI: 10.1016/j.vaccine.2010.08.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 08/12/2010] [Accepted: 08/24/2010] [Indexed: 10/19/2022]
Abstract
We recently reported the development of a successful post-exposure combination antiviral and "prime-boost" vaccination strategy using the duck hepatitis B virus (DHBV) model of human hepatitis B virus infection. The current study aimed to simplify the vaccination strategy and to test the post-exposure efficacy of combination therapy with the Bristol-Myers Squibb antiviral drug, entecavir (ETV) and either a single dose of DHBV DNA vaccines on day 0 post-infection (p.i.) or a single dose of recombinant fowlpoxvirus (rFPV-DHBV) vaccines on day 7 p.i. Whilst untreated control ducks infected with an equal dose of DHBV all developed persistent and wide spread DHBV infection of the liver, ducks treated with ETV combined with either the DHBV DNA vaccines on day 0 p.i. or the rFPV-DHBV vaccines on day 7 p.i. had no detectable DHBV-infected hepatocytes by day 14 p.i. and were protected from the development of persistent DHBV infection.
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Affiliation(s)
- Feng Feng
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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18
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The persistence in the liver of residual duck hepatitis B virus covalently closed circular DNA is not dependent upon new viral DNA synthesis. Virology 2010; 406:286-92. [PMID: 20705309 DOI: 10.1016/j.virol.2010.07.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 05/26/2010] [Accepted: 07/11/2010] [Indexed: 11/22/2022]
Abstract
Residual hepatitis B virus (HBV) DNA can be detected following the resolution of acute HBV infection. Our previous work using duck hepatitis B virus (DHBV) infected ducks, indicated that ~80% of residual DHBV DNA in the liver is in the covalently closed circular DNA (cccDNA) form, suggesting that viral DNA synthesis is suppressed. The current study asked more directly if maintenance of residual DHBV cccDNA is dependent upon ongoing viral DNA synthesis. Ducks that recovered from acute DHBV infection were divided into 2 groups and treated with the antiviral drug, Entecavir (ETV), or placebo. No major differences in the stability of cccDNA or levels of residual cccDNA were observed in liver biopsy tissues taken 95 days apart from ETV treated and placebo control ducks. The data suggest that residual DHBV cccDNA is highly stable and present in a cell population with a rate of turnover similar to normal, uninfected hepatocytes.
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19
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Tohidi-Esfahani R, Vickery K, Cossart Y. The early host innate immune response to duck hepatitis B virus infection. J Gen Virol 2009; 91:509-20. [PMID: 19846670 DOI: 10.1099/vir.0.015529-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The early phase after hepatitis B virus infection could play a crucial role in clearance and/or persistence of the virus, particularly in neonates. This work compared the early phase of duck hepatitis B virus infection in 1-day-old (D1) and 28-day-old (D28) ducks to determine whether differences in viral or host innate immune response can be related to the difference in outcome. In the first phase, almost immediately after inoculation, virus was taken up by components of the reticulo-endothelial systems, particularly liver-specific macrophages, Kupffer cells. Very early after infection, the induction of alpha interferon by infected hepatocytes occurred and was rapidly reinforced by recruitment of effector lymphocytes, which directly or indirectly caused apoptosis, eliminating infected hepatocytes, as was seen in mature birds. In addition, a lack of lymphocytic infiltration of the liver was found in D1 ducks, which supports the suggestion that the innate immune network is less effective in D1 ducks. Taken together, these results suggest that failure of the co-ordinated innate immune response rather than a defect in induced antiviral cell-mediated immunity may be the key factor which makes baby ducks vulnerable to persistence of hepadnavirus infection.
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Affiliation(s)
- Rahma Tohidi-Esfahani
- Department of Infectious Diseases and Immunology, University of Sydney, Camperdown, NSW 2006, Australia
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20
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Miller DS, Boyle D, Feng F, Reaiche GY, Kotlarski I, Colonno R, Jilbert AR. Antiviral therapy with entecavir combined with post-exposure "prime-boost" vaccination eliminates duck hepatitis B virus-infected hepatocytes and prevents the development of persistent infection. Virology 2008; 373:329-41. [PMID: 18206204 DOI: 10.1016/j.virol.2007.11.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Revised: 10/26/2007] [Accepted: 11/27/2007] [Indexed: 12/21/2022]
Abstract
Short-term antiviral therapy with the nucleoside analogue entecavir (ETV), given at an early stage of duck hepatitis B virus (DHBV) infection, restricts virus spread and leads to clearance of DHBV-infected hepatocytes in approximately 50% of ETV-treated ducks, whereas widespread and persistent DHBV infection develops in 100% of untreated ducks. To increase the treatment response rate, ETV treatment was combined in the current study with a post-exposure "prime-boost" vaccination protocol. Four groups of 14-day-old ducks were inoculated intravenously with a dose of DHBV previously shown to induce persistent DHBV infection. One hour post-infection (p.i.), ducks were primed with DNA vaccines that expressed DHBV core (DHBc) and surface (pre-S/S and S) antigens (Groups A, B) or the DNA vector alone (Groups C, D). ETV (Groups A, C) or water (Groups B, D) was simultaneously administered by gavage and continued for 14 days. Ducks were boosted 7 days p.i. with recombinant fowlpoxvirus (rFPV) strains also expressing DHBc and pre-S/S antigens (Groups A, B) or the FPV-M3 vector (Groups C, D). DHBV-infected hepatocytes were observed in the liver of all ducks at day 4 p.i. with reduced numbers in the ETV-treated ducks. Ducks treated with ETV plus the control vectors showed restricted spread of DHBV infection during ETV treatment, but in 60% of cases, infection became widespread after ETV was stopped. In contrast, at 14 and 67 days p.i., 100% of ducks treated with ETV and "prime-boost" vaccination had no detectable DHBV-infected hepatocytes and had cleared the DHBV infection. These findings suggest that ETV treatment combined with post-exposure "prime-boost" vaccination induced immune responses that eliminated DHBV-infected hepatocytes and prevented the development of persistent DHBV infection.
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Affiliation(s)
- D S Miller
- School of Molecular and Biomedical Science, University of Adelaide, SA 5005, Australia
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21
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Mhamdi M, Funk A, Hohenberg H, Will H, Sirma H. Assembly and budding of a hepatitis B virus is mediated by a novel type of intracellular vesicles. Hepatology 2007; 46:95-106. [PMID: 17567837 DOI: 10.1002/hep.21666] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
UNLABELLED Formation of enveloped viruses involves assembly and budding at cellular membranes. In this study, we elucidated the morphogenesis of hepadnaviruses on the ultrastructural and biochemical level using duck hepatitis B virus (DHBV) as a model system. Formation of virus progeny initiates at the endoplasmic reticulum (ER) and is conserved both in vitro and in vivo. The morphogenesis proceeds via membrane-surrounded vesicles containing both virions and subviral particles, indicating a common morphogenetic pathway. The virus particle-containing vesicles (VCVs) are generated and maintained by reorganization of endomembranes accompanied by a striking disorganization of the rough ER (rER). VCVs are novel organelles with unique identity and properties of ER, intermediate compartment, endosomes, and multivesicular bodies. VCVs are dynamic structures whose size and shape are regulated by both membrane fusion and fission. CONCLUSION Our data indicate a strong reorganization of endomembranes during DHBV infection, resulting in the biogenesis of novel organelles serving as multifunctional platforms for assembly and budding of virus progeny.
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Affiliation(s)
- Mouna Mhamdi
- Heinrich-Pette-Institut für experimentelle Virologie und Immunologie an der Universität Hamburg, Hamburg, Germany
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22
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Bhat P, Anderson DA. Hepatitis B virus translocates across a trophoblastic barrier. J Virol 2007; 81:7200-7. [PMID: 17442714 PMCID: PMC1933314 DOI: 10.1128/jvi.02371-06] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 04/08/2007] [Indexed: 12/20/2022] Open
Abstract
Mother-infant transmission of hepatitis B virus (HBV) accounts for up to 30% of worldwide chronic infections. The mechanism and high-risk period of HBV transmission from mother to infant are unknown. Although largely prevented by neonatal vaccination, significant transmission continues to occur in high-risk populations. It is unclear whether HBV can traverse an intact epithelial barrier to infect a new host. Transplacental transmission of a number of viruses relies on transcytotic pathways across placental cells. We wished to determine whether infectious HBV can traverse a polarized trophoblast monolayer. We used a human placenta-derived cell line, BeWo, cultured on membranes as polarized monolayers, to model the maternal-fetal barrier. We assessed the effects of placental maturity and maternal immunoglobulin on viral transport. Intracellular viral trafficking pathways were investigated by confocal microscopy. Free HBV (and infectious duck hepatitis B virus) transcytosed across trophoblastic cells at a rate of 5% in 30 min. Viral transport occurred in microtubule-dependent endosomal vesicles. Additionally, confocal microscopy showed that the internalized virus traverses a monensin-sensitive endosomal compartment. Differentiation of the cytotrophoblasts to syncytiotrophoblasts resulted in a 25% reduction in viral transcytosis, suggesting that placental maturity may protect the fetus. Virus translocation was also reduced in the presence of HBV immunoglobulin. We show for the first time that transcytosis of infectious hepadnavirus can occur across a trophoblastic barrier early in gestation, with the risk of transmission being reduced by placental maturity and specific maternal antibody. This study suggests a mechanism by which mother-infant transmission may occur.
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Affiliation(s)
- Purnima Bhat
- School of Biomedical Sciences, The University of Queensland, St. Lucia 4072, Australia.
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23
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Funk A, Mhamdi M, Will H, Sirma H. Avian hepatitis B viruses: Molecular and cellular biology, phylogenesis, and host tropism. World J Gastroenterol 2007; 13:91-103. [PMID: 17206758 PMCID: PMC4065881 DOI: 10.3748/wjg.v13.i1.91] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The human hepatitis B virus (HBV) and the duck hepatitis B virus (DHBV) share several fundamental features. Both viruses have a partially double-stranded DNA genome that is replicated via a RNA intermediate and the coding open reading frames (ORFs) overlap extensively. In addition, the genomic and structural organization, as well as replication and biological characteristics, are very similar in both viruses. Most of the key features of hepadnaviral infection were first discovered in the DHBV model system and subsequently confirmed for HBV. There are, however, several differences between human HBV and DHBV. This review will focus on the molecular and cellular biology, evolution, and host adaptation of the avian hepatitis B viruses with particular emphasis on DHBV as a model system.
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Affiliation(s)
- Anneke Funk
- Department of General Virology, Heinrich-Pette-Institut fur experimentelle Virologie und Immunologie an der Universitat Hamburg, PO Box 201652, Hamburg 20206, Germany
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24
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Abstract
Hepadnaviridae is a family of hepatotropic DNA viruses that is divided into the genera orthohepadnavirus of mammals and avihepadnavirus of birds. All members of this family can cause acute and chronic hepatic infection, which in the case of human hepatitis B virus (HBV) constitutes a major global health problem. Although our knowledge about the molecular biology of these highly liver-specific viruses has profoundly increased in the last two decades, the mechanisms of attachment and productive entrance into the differentiated host hepatocytes are still enigmatic. The difficulties in studying hepadnaviral entry were primarily caused by the lack of easily accessible in vitro infection systems. Thus, for more than twenty years, differentiated primary hepatocytes from the respective species were the only in vitro models for both orthohepadnaviruses (e.g. HBV) and avihepadnaviruses (e.g. duck hepatitis B virus [DHBV]). Two important discoveries have been made recently regarding HBV: (1) primary hepatocytes from tree-shrews; i.e., Tupaia belangeri, can be substituted for primary human hepatocytes, and (2) a human hepatoma cell line (HepaRG) was established that gains susceptibility for HBV infection upon induction of differentiation in vitro. A number of potential HBV receptor candidates have been described in the past, but none of them have been confirmed to function as a receptor. For DHBV and probably all other avian hepadnaviruses, carboxypeptidase D (CPD) has been shown to be indispensable for infection, although the exact role of this molecule is still under debate. While still restricted to the use of primary duck hepatocytes (PDH), investigations performed with DHBV provided important general concepts on the first steps of hepadnaviral infection. However, with emerging data obtained from the new HBV infection systems, the hope that DHBV utilizes the same mechanism as HBV only partially held true. Nevertheless, both HBV and DHBV in vitro infection systems will help to: (1) functionally dissect the hepadnaviral entry pathways, (2) perform reverse genetics (e.g. test the fitness of escape mutants), (3) titrate and map neutralizing antibodies, (4) improve current vaccines to combat acute and chronic infections of hepatitis B, and (5) develop entry inhibitors for future clinical applications.
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Affiliation(s)
- Dieter Glebe
- Institute of Medical Virology, Justus-Liebig University of Giessen, Frankfurter Strasse 107, D-35392 Giessen, Germany.
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25
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Franke C, Matschl U, Bruns M. Enzymatic treatment of duck hepatitis B virus: topology of the surface proteins for virions and noninfectious subviral particles. Virology 2006; 359:126-36. [PMID: 17045625 DOI: 10.1016/j.virol.2006.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 08/14/2006] [Accepted: 09/02/2006] [Indexed: 12/29/2022]
Abstract
The large surface antigen L of duck hepatitis B virus exhibits a mixed topology with the preS domains of the protein alternatively exposed to the particles' interior or exterior. After separating virions from subviral particles (SVPs), we compared their L topologies and showed that both particle types exhibit the same amount of L with the following differences: 1--preS of intact virions was enzymatically digested with chymotrypsin, whereas in SVPs only half of preS was accessible, 2--phosphorylation of L at S118 was completely removed by phosphatase treatment only in virions, 3--iodine-125 labeling disclosed a higher ratio of exposed preS to S domains in virions compared to SVPs. These data point towards different surface architectures of virions and SVPs. Because the preS domain acts in binding to a cellular receptor of hepatocytes, our findings implicate the exclusion of SVPs as competitors for the receptor binding and entry of virions.
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Affiliation(s)
- Claudia Franke
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistrasse 52, D-20251 Hamburg, Germany
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26
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Miller DS, Kotlarski I, Jilbert AR. DNA vaccines expressing the duck hepatitis B virus surface proteins lead to reduced numbers of infected hepatocytes and protect ducks against the development of chronic infection in a virus dose-dependent manner. Virology 2006; 351:159-69. [PMID: 16624364 DOI: 10.1016/j.virol.2006.02.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2006] [Revised: 02/21/2006] [Accepted: 02/27/2006] [Indexed: 12/01/2022]
Abstract
We tested the efficacy of DNA vaccines expressing the duck hepatitis B virus (DHBV) pre-surface (pre-S/S) and surface (S) proteins in modifying the outcome of infection in 14-day-old ducks. In two experiments, Pekin Aylesbury ducks were vaccinated on days 4 and 14 of age with plasmid DNA vaccines expressing either the DHBV pre-S/S or S proteins, or the control plasmid vector, pcDNA1.1Amp. All ducks were then challenged intravenously on day 14 of age with 5 x 10(7) or 5 x 10(8) DHBV genomes. Levels of initial DHBV infection were assessed using liver biopsy tissue collected at day 4 post-challenge (p.c.) followed and immunostained for DHBV surface antigen to determine the percentage of infected hepatocytes. All vector vaccinated ducks challenged with 5 x 10(7) and 5 x 10(8) DHBV genomes had an average of 3.21% and 20.1% of DHBV-positive hepatocytes respectively at day 4 p.c. and 16 out of 16 ducks developed chronic DHBV infection. In contrast, pre-S/S and S vaccinated ducks challenged with 5 x 10(7) DHBV genomes had reduced levels of initial infection with an average of 1.38% and 1.93% of DHBV-positive hepatocytes at day 4 p.c. respectively and 10 of 18 ducks were protected against chronic infection. The pre-S/S and the S DNA vaccinated ducks challenged with 5 x 10(8) DHBV genomes had an average of 31.5% and 9.2% of DHBV-positive hepatocytes on day 4 p.c. respectively and only 4 of the 18 vaccinated ducks were protected against chronic infection. There was no statistically significant difference in the efficacy of the DHBV pre-S/S or S DNA vaccines. In conclusion, vaccination of young ducks with DNA vaccines expressing the DHBV pre-S/S and S proteins induced rapid immune responses that reduced the extent of initial DHBV infection in the liver and prevented the development of chronic infection in a virus dose-dependent manner.
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MESH Headings
- Animals
- Antibodies, Viral/immunology
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Disease Models, Animal
- Ducks/immunology
- Ducks/virology
- Hepatitis B Vaccines/administration & dosage
- Hepatitis B Vaccines/genetics
- Hepatitis B Vaccines/immunology
- Hepatitis B Virus, Duck/genetics
- Hepatitis B Virus, Duck/immunology
- Hepatitis B, Chronic/prevention & control
- Hepatocytes/virology
- Humans
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- Darren S Miller
- Hepatitis Virus Research Laboratory, School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
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27
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Miller DS, Halpern M, Kotlarski I, Jilbert AR. Vaccination of ducks with a whole-cell vaccine expressing duck hepatitis B virus core antigen elicits antiviral immune responses that enable rapid resolution of de novo infection. Virology 2006; 348:297-308. [PMID: 16469347 DOI: 10.1016/j.virol.2005.12.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 10/12/2005] [Accepted: 12/22/2005] [Indexed: 01/12/2023]
Abstract
As a first step in developing immuno-therapeutic vaccines for patients with chronic hepatitis B virus infection, we examined the ability of a whole-cell vaccine, expressing the duck hepatitis B virus (DHBV) core antigen (DHBcAg), to target infected cells leading to the resolution of de novo DHBV infections. Three separate experiments were performed. In each experiment, ducks were vaccinated at 7 and 14 days of age with primary duck embryonic fibroblasts (PDEF) that had been transfected 48 h earlier with plasmid DNA expressing DHBcAg with and without the addition of anti-DHBcAg (anti-DHBc) antibodies. Control ducks were injected with either 0.7% NaCl or non-transfected PDEF. The ducks were then challenged at 18 days of age by intravenous inoculation with DHBV (5 x 10(8) viral genome equivalents). Liver biopsies obtained on day 4 post-challenge demonstrated that vaccination did not prevent infection of the liver as similar numbers of infected hepatocytes were detected in all vaccinated and control ducks. However, analysis of liver tissue obtained 9 or more days post-challenge revealed that 9 out of 11 of the PDEF-DHBcAg vaccinated ducks and 8 out of 11 ducks vaccinated with PDEF-DHBcAg plus anti-DHBc antibodies had rapidly resolved the DHBV infection with clearance of infected cells. In contrast, 10 out of 11 of the control unvaccinated ducks developed chronic DHBV infection. In conclusion, vaccination of ducks with a whole-cell PDEF vaccine expressing DHBcAg elicited immune responses that induced a rapid resolution of DHBV infection. The results establish that chronic infection can be prevented via the vaccine-mediated induction of a core-antigen-specific immune response.
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MESH Headings
- Animals
- Antibodies, Viral/biosynthesis
- Antigens, Viral/genetics
- Base Sequence
- DNA, Viral/genetics
- DNA, Viral/isolation & purification
- Ducks/immunology
- Ducks/virology
- Fibroblasts/immunology
- Fibroblasts/virology
- Hepadnaviridae Infections/immunology
- Hepadnaviridae Infections/prevention & control
- Hepadnaviridae Infections/veterinary
- Hepadnaviridae Infections/virology
- Hepatitis B Virus, Duck/genetics
- Hepatitis B Virus, Duck/immunology
- Hepatitis, Viral, Animal/immunology
- Hepatitis, Viral, Animal/prevention & control
- Hepatitis, Viral, Animal/virology
- Humans
- Plasmids/genetics
- Poultry Diseases/immunology
- Poultry Diseases/prevention & control
- Poultry Diseases/virology
- Transfection
- Viral Core Proteins/genetics
- Viral Core Proteins/immunology
- Viral Hepatitis Vaccines/genetics
- Viral Hepatitis Vaccines/immunology
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Affiliation(s)
- Darren S Miller
- School of Molecular and Biomedical Science, The University of Adelaide, Australia.
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28
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Chojnacki J, Anderson DA, Grgacic EVL. A hydrophobic domain in the large envelope protein is essential for fusion of duck hepatitis B virus at the late endosome. J Virol 2006; 79:14945-55. [PMID: 16282493 PMCID: PMC1287569 DOI: 10.1128/jvi.79.23.14945-14955.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The duck hepatitis B virus (DHBV) envelope is comprised of two transmembrane (TM) proteins, the large (L) and the small (S), that assemble into virions and subviral particles. Secondary-structure predictions indicate that L and S have three alpha-helical, membrane-spanning domains, with TM1 predicted to act as the fusion peptide following endocytosis of DHBV into the hepatocyte. We used bafilomycin A1 during infection of primary duck hepatocytes to show that DHBV must be trafficked from the early to the late endosome for fusion to occur. Alanine substitution mutations in TM1 of L and S, which lowered TM1 hydrophobicity, were used to examine the role of TM1 in infectivity. The high hydrophobicity of the TM1 domain of L, but not of S, was shown to be essential for virus infection at a step downstream of receptor binding and virus internalization. Using wild-type and mutant synthetic peptides, we demonstrate that the hydrophobicity of this domain is required for the aggregation and the lipid mixing of phospholipid vesicles, supporting the role of TM1 as the fusion peptide. While lipid mixing occurred at pH 7, the kinetics of insertion of the fusion peptide was increased at pH 5, consistent with the location of DHBV in the late-endosome compartment and previous studies of the nonessential role of low pH for infectivity. Exchange of the TM1 of DHBV with that of hepatitis B virus yielded functional, infectious DHBV particles, suggesting that TM1 of all of the hepadnaviruses act similarly in the fusion mechanism.
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Affiliation(s)
- J Chojnacki
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia
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29
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Counihan NA, Daniel LM, Chojnacki J, Anderson DA. Infrared fluorescent immunofocus assay (IR-FIFA) for the quantitation of non-cytopathic and minimally cytopathic viruses. J Virol Methods 2005; 133:62-9. [PMID: 16300833 DOI: 10.1016/j.jviromet.2005.10.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 10/17/2005] [Accepted: 10/18/2005] [Indexed: 11/16/2022]
Abstract
A novel method was developed for the precise quantitation of viruses using infrared fluorescent detection of foci of infection in conventional cell culture plates. In this assay, termed the infrared fluorescent immunofocus assay (IR-FIFA), appropriate cell cultures were infected with serial dilutions of hepatitis A virus (HAV) or measles virus (MV) and maintained with a semi-solid overlay for 1-5 days. Cell monolayers were fixed with formaldehyde, and then stained in succession with a primary monoclonal antibody and an Alexa Fluor 680 conjugate. Foci of infection (analogous to plaques) were detected by scanning culture plates using the Odyssey infrared imaging system and counted to determine the virus titre, expressed as focus forming units (FFU) per mL, as is done for conventional plaque assays. HAV and MV were used as models of minimally cytopathic viruses, and showed a linear dose-response between focus formation and virus dilution. Viral titres calculated using this method were comparable to conventionally used methods. The IR-FIFA was also successfully adapted to quantify duck hepatitis B virus (DHBV) as a model for a non-cytopathic virus. This simple and sensitive assay will have wide use for the quantitation of non-cytopathic and minimally cytopathic viruses.
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Affiliation(s)
- Natalie A Counihan
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Vic. 3004, Australia
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30
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Le Mire MF, Miller DS, Foster WK, Burrell CJ, Jilbert AR. Covalently closed circular DNA is the predominant form of duck hepatitis B virus DNA that persists following transient infection. J Virol 2005; 79:12242-52. [PMID: 16160150 PMCID: PMC1211519 DOI: 10.1128/jvi.79.19.12242-12252.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Residual hepatitis B virus (HBV) DNA can be detected in serum and liver after apparent recovery from transient infection. However, it is not known if this residual HBV DNA represents ongoing viral replication and antigen expression. In the current study, ducks inoculated with duck hepatitis B virus (DHBV) were monitored for residual DHBV DNA following recovery from transient infection until 9 months postinoculation (p.i.). Resolution of DHBV infection occurred in 13 out of 15 ducks by 1-month p.i., defined as clearance of DHBV surface antigen-positive hepatocytes from the liver and development of anti-DHBV surface antibodies. At 9 months p.i., residual DHBV DNA was detected using nested PCR in 10/11 liver, 7/11 spleen, 2/11 kidney, 1/11 heart, and 1/11 adrenal samples. Residual DHBV DNA was not detected in serum or peripheral blood mononuclear cells. Within the liver, levels of residual DHBV DNA were 0.0024 to 0.016 copies per cell, 40 to 80% of which were identified as covalently closed circular viral DNA by quantitative PCR assay. This result, which was confirmed by Southern blot hybridization, is consistent with suppressed viral replication or inactive infection. Samples of liver and spleen cells from recovered animals did not transmit DHBV infection when inoculated into 1- to 2-day-old ducklings, and immunosuppressive treatment of ducks with cyclosporine and dexamethasone for 4 weeks did not alter levels of residual DHBV DNA in the liver. These findings further characterize a second form of hepadnavirus persistence in a suppressed or inactive state, quite distinct from the classical chronic carrier state.
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MESH Headings
- Adrenal Glands/virology
- Animals
- DNA, Circular/analysis
- DNA, Circular/isolation & purification
- DNA, Viral/analysis
- DNA, Viral/isolation & purification
- Ducks
- Genome, Viral
- Heart/virology
- Hepadnaviridae Infections/virology
- Hepatitis B Virus, Duck/genetics
- Hepatitis B Virus, Duck/physiology
- Hepatitis, Viral, Animal/virology
- Kidney/virology
- Leukocytes, Mononuclear/virology
- Liver/virology
- Polymerase Chain Reaction
- Spleen/virology
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Affiliation(s)
- Marc F Le Mire
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide, South Australia 5000, Australia
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31
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Wagner SJ, Skripchenko A, Cincotta L, Thompson-Montgomery D, Awatefe H. Use of a flexible thiopyrylium photosensitizer and competitive inhibitor for pathogen reduction of viruses and bacteria with retention of red cell storage properties. Transfusion 2005; 45:752-60. [PMID: 15847665 DOI: 10.1111/j.1537-2995.2005.04188.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Progress in developing photochemical methods for pathogen reduction of red blood cells (RBCs) has been hampered by hemolysis. A flexible, nucleic acid-intercalating thiopyrylium (TP) dye that is only photochemically active in the bound state and a competitive inhibitor of RBC membrane binding, dipyridamole (DP), was used to reduce photoinduced hemolysis stemming from free- and membrane-bound dye. STUDY DESIGN AND METHODS Oxygenated leukodepleted 20% hct RBC suspensions were deliberately inoculated with virus or bacteria, incubated with 200 micromol per L DP and less than or equal to 100 micromol per L TP, illuminated with 1.1 J/cm(2) of red light, and titered. RBC suspensions containing 200 micromol per L DP and 160 micromol per L TP were identically phototreated, concentrated to 45% hct, and assayed for RBC storage properties. RESULTS In RBC suspensions containing DP, TP photoinactivated vesicular stomatitis virus, pseudorabies virus, duck hepatitis B virus, bovine virus diarrhea virus, extracellular human immunodeficiency virus (HIV) to the limit of detection and 6.2 log intracellular HIV. More than 5 log inactivation of 6 bacterial species was demonstrated. DP prevented approximately 30% of TP binding to RBCs. Phototreated RBCs that were subsequently stored for 42 days exhibited acceptable levels of hemolysis, morphology scores, extracellular pH, ATP, glucose utilization rates, and lactate production. Treated samples exhibited substantially increased potassium efflux compared to controls. CONCLUSION Use of TP photosensitizer and DP enables significant levels of pathogen reduction while retaining most, but not all RBC properties during 42 day storage.
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Affiliation(s)
- Stephen J Wagner
- American Red Cross Biomedical Services, Holland Laboratory, Blood and Cell Therapy Development, Rockville, Maryland, USA.
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32
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Grgacic EVL, Anderson DA. St, a truncated envelope protein derived from the S protein of duck hepatitis B virus, acts as a chaperone for the folding of the large envelope protein. J Virol 2005; 79:5346-52. [PMID: 15827149 PMCID: PMC1082741 DOI: 10.1128/jvi.79.9.5346-5352.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 12/14/2004] [Indexed: 02/06/2023] Open
Abstract
Envelope proteins of hepadnaviruses undergo a unique folding mechanism which results in the posttranslational translocation of 50% of the large envelope protein (L) chains across the endoplasmic reticulum. This mechanism is essential for the eventual positioning of the receptor-binding domain on the surface of the virus particle and in duck hepatitis B virus (DHBV) is dependent on the small (S) envelope protein as part of the assembly process. In this study, we report the identification of a third envelope protein, St, derived from the S protein and carrying functions previously attributed to S. Antibody mapping and mutagenesis studies indicated St to be C terminally truncated, spanning the N-terminal transmembrane domain (TM1) plus the adjacent cysteine loop. We have previously shown that the mutation of two conserved polar residues in TM1 of S (SAA) eliminates L translocation and assembly. A plasmid expressing a functional equivalent of St was able to rescue assembly, demonstrating that this assembly defect is due to mutations of the corresponding residues in St and not in S per se. Immunofluorescence analysis showed that St directly affects L protein cellular localization. These results indicate that St acts as a viral chaperone for L folding, remaining associated with the DHBV envelope upon secretion. The presence of St at a molar ratio of half that of L suggests that it is St which regulates L translocation to 50%.
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Affiliation(s)
- Elizabeth V L Grgacic
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne 3004, Australia.
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33
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Schultz U, Grgacic E, Nassal M. Duck hepatitis B virus: an invaluable model system for HBV infection. Adv Virus Res 2005; 63:1-70. [PMID: 15530560 DOI: 10.1016/s0065-3527(04)63001-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ursula Schultz
- Department of Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106 Freiburg, Germany
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34
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Yeh CT, Lai HY, Chu SP, Tseng IC. Anti-sense expression of a metallopeptidase gene enhances nuclear entry of HBV-DNA. Biochem Biophys Res Commun 2004; 323:32-7. [PMID: 15351696 DOI: 10.1016/j.bbrc.2004.08.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Indexed: 01/14/2023]
Abstract
Although several putative hepatitis B virus (HBV) receptors have been identified, none of them is capable of initiating HBV replication in a non-permissive human cell line. Using an Epstein-Barr virus-based extrachromosomal replication system, we have screened through a human liver cDNA library and successfully identified a clone capable of facilitating nuclear transport of HBV-DNA during the early phase of HBV infection. This clone contained a cDNA encoding a metallopeptidase-like protein in anti-sense orientation. Pretreatment of naïve HepG2 cells with 1,10-phenanthroline, an inhibitor for liver metallopeptidases, led to nuclear entry of HBV-DNA after HBV infection. However, cccDNA was still undetectable in the nuclei, indicating other cellular factors required to complete the replication cycle were still missing. Our present data suggest that in the initial stage of HBV infection, liver metallopeptidase constitutes a barrier for effective nuclear entry of HBV genomic DNA. Attenuation of metallopeptidase activity may facilitate HBV infection.
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Affiliation(s)
- Chau-Ting Yeh
- Liver Research Unit, Chang Gung Memorial Hospital and Chang Gung University, College of Medicine, Taipei, Taiwan, ROC.
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35
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Funk A, Mhamdi M, Lin L, Will H, Sirma H. Itinerary of hepatitis B viruses: delineation of restriction points critical for infectious entry. J Virol 2004; 78:8289-300. [PMID: 15254201 PMCID: PMC446123 DOI: 10.1128/jvi.78.15.8289-8300.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Little is known about cellular determinants essential for human hepatitis B virus infection. Using the duck hepatitis B virus as a model, we first established a sensitive binding assay for both virions and subviral particles and subsequently elucidated the characteristics of the early viral entry steps. The infection itinerary was found to initiate with the attachment of viral particles to a low number of binding sites on hepatocytes (about 10(4) per cell). Virus internalization was fully accomplished in less than 3 h but was then followed by a period of unprecedented length, about 14 h, until completion of nuclear import of the viral genome. Steps subsequent to virus entry depended on both intact microtubules and their dynamic turnover but not on actin cytoskeleton. Notably, cytoplasmic trafficking of viral particles and emergence of nuclear covalently closed circular DNA requires microtubules during entry only at and for specific time periods. Taken together, these data disclose for the first time a series of steps and their kinetics that are essential for the entry of hepatitis B viruses into hepatocytes and are different from those of any other virus reported so far.
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Affiliation(s)
- Anneke Funk
- Department of General Virology, Heinrich-Pette-Institut, Hamburg, Germany
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36
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Meier P, Scougall CA, Will H, Burrell CJ, Jilbert AR. A duck hepatitis B virus strain with a knockout mutation in the putative X ORF shows similar infectivity and in vivo growth characteristics to wild-type virus. Virology 2004; 317:291-8. [PMID: 14698667 DOI: 10.1016/j.virol.2003.08.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hepadnaviruses including human hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) express X proteins, HBx and DHBx, respectively. Both HBx and DHBx are transcriptional activators and modulate cellular signaling in in vitro assays. To test whether the DHBx protein plays a role in virus infection, we compared the in vivo infectivity and growth characteristics of a DHBV3 strain with a stop codon in the X-like ORF (DHBV3-X-K.O.) to those of the wild-type DHBV3 strain. Here we report that the two strains showed no significant difference in (i). their ability to induce infection that resulted in stable viraemia measured by serum surface antigen (DHBsAg) and DHBV DNA, and detection of viral proteins and replicative DNA intermediates in the liver; (ii). the rate of spread of infection in liver and extrahepatic sites after low-dose virus inoculation; and (iii). the ability to produce transient or persistent infection under balanced age/dose conditions designed to detect small differences between the strains. Thus, none of the infection parameters assayed were detectably affected by the X-ORF knockout mutation, raising the question whether DHBx expression plays a physiological role during in vivo infection with wild-type DHBV.
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Affiliation(s)
- P Meier
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia.
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37
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Foster WK, Miller DS, Marion PL, Colonno RJ, Kotlarski I, Jilbert AR. Entecavir therapy combined with DNA vaccination for persistent duck hepatitis B virus infection. Antimicrob Agents Chemother 2003; 47:2624-35. [PMID: 12878529 PMCID: PMC166090 DOI: 10.1128/aac.47.8.2624-2635.2003] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2002] [Revised: 12/20/2002] [Accepted: 05/23/2003] [Indexed: 01/14/2023] Open
Abstract
This study was designed to test the efficacy of antiviral treatment with entecavir (ETV) in combination with DNA vaccines expressing duck hepatitis B virus (DHBV) antigens as a therapy for persistent DHBV infection in ducks. Ducks were inoculated with 10(9) DHBV genomes at 7 days of age, leading to widespread infection of the liver and viremia within 7 days, and were then treated orally with either ETV (0.1 mg/kg of body weight/day) or distilled water from 21 days posthatch for 244 days. Treatment with ETV caused a 4-log drop in serum DHBV DNA levels within 80 days and a slower 2- to 3-log drop in serum DHBV surface antigen (DHBsAg) levels within 120 days. Following withdrawal of ETV, levels of serum DHBV DNA and DHBsAg rebounded to match those in the water-treated animals within 40 days. Sequential liver biopsy samples collected throughout the study showed that ETV treatment reduced DHBV DNA replicative intermediates 70-fold in the liver, while the level of the stable, template form, covalently closed circular DNA decreased only 4-fold. ETV treatment reduced both the intensity of antigen staining and the percentage of antigen-positive hepatocytes in the liver, but the intensity of antigen staining in bile duct cells appeared not to be effected. Intramuscular administration of five doses of a DNA vaccine expressing the DHBV presurface, surface, precore, and core antigens, both alone and concurrently with ETV treatment, on days 50, 64, 78, 127, and 141 did not result in any significant effect on viral markers.
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MESH Headings
- Animals
- Antiviral Agents/therapeutic use
- Combined Modality Therapy
- DNA, Viral/blood
- DNA, Viral/metabolism
- Ducks/virology
- Guanine/analogs & derivatives
- Guanine/therapeutic use
- Hepatitis B Surface Antigens/blood
- Hepatitis B Virus, Duck/immunology
- Hepatitis, Viral, Animal/drug therapy
- Hepatitis, Viral, Animal/immunology
- Hepatitis, Viral, Animal/therapy
- Hepatocytes/metabolism
- Hepatocytes/virology
- Liver/metabolism
- Liver/pathology
- Liver/virology
- Liver Function Tests
- Vaccination
- Vaccines, DNA/therapeutic use
- Viral Hepatitis Vaccines/therapeutic use
- Virus Replication/drug effects
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Affiliation(s)
- Wendy K Foster
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia
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38
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Cooper A, Paran N, Shaul Y. The earliest steps in hepatitis B virus infection. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1614:89-96. [PMID: 12873769 DOI: 10.1016/s0005-2736(03)00166-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The early steps in hepatitis B virus (HBV) infection, a human hepadnavirus, initiates from cell attachment followed by entry and delivery of the genetic information to the nucleus. Despite the fact that these steps determine the virus-related pathogenesis, their molecular basis is poorly understood. Cumulative data suggest that this process can be divided to cell attachment, endocytosis, membrane fusion and post-fusion consecutive steps. These steps are likely to be regulated by the viral envelope proteins and by the cellular membrane, receptors and extracellular matrix. In the absence of animal model for HBV, the duck hepadnavirus DHBV turned out to be a fruitful animal model. Therefore data concerning the early, post-attachment steps in hepadnaviral entry are largely based on studies performed with DHBV in primary duck liver hepatocytes. These studies are now starting to illuminate the mechanisms of hepadnavirus route of cell entry and to provide some new insights on the molecular basis of the strict species specificity of hepadnavirus infection.
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Affiliation(s)
- Arik Cooper
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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39
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Abstract
Virus infection is initiated by recognition and attachment of the virus to the cell surface. Despite the fact that this interaction determines the virus-related pathogenesis, its molecular basis remained obscure for HBV. This process is mediated primarily by the viral envelope and the cellular receptors. HBV infection is not exceptional in this regard but its putative receptors have not been identified yet. The recent development of protocols to establish HBV susceptible cell lines and unique tools to measure HBV-cell attachment at a single cell resolution set the stage for the study of HBV-host cell interaction. These studies revealed that the QLDPAF epitope of the HBV surface antigen large protein (LHBsAg) plays a major role in this process. Quantitative measurements suggested the presence of a second player in this process and both act synergistically to improve cell attachment. As the step of virus-cell attachment is potentially susceptible to specific inhibitors, understanding the molecular basis of virus-cell attachment can be expected to have therapeutic impacts.
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Affiliation(s)
- Nir Paran
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Grgacic EVL. Identification of structural determinants of the first transmembrane domain of the small envelope protein of duck hepatitis B virus essential for particle morphogenesis. J Gen Virol 2002; 83:1635-1644. [PMID: 12075081 DOI: 10.1099/0022-1317-83-7-1635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The envelope of duck hepatitis B virus (DHBV) consists of the small (S) and large (L) envelope proteins, which share a common C-terminal multispanning transmembrane region but differ by the long N-terminal pre-S domain of L, which is essential for interactions with both the receptor and nucleocapsid. To achieve these dual functions, L acquires mixed topologies through S-dependent post-translational translocation of its pre-S domain. This study has examined the role of S in this unusual mechanism of translocation by analysis of the alpha-helical transmembrane domains and their potential to engage in lateral interactions for envelope assembly. Through mutagenesis in constructs expressing the S and L envelope proteins independently, transmembrane domain 1 was identified as an essential structural determinant in S. Two polar residues in this helix were identified as contributing to L protein translocation through the assembly of S into particles, implying that the topological switch of L is part of the assembly and maturation process. The same domain in L was shown to be dispensable for L translocation and assembly, suggesting that transmembrane domain 1 of L and S have different functional roles and structural arrangements on the assembled particle. The conservation in all hepadnavirus envelope proteins of two polar residues at positions 24 and 27 of transmembrane domain 1, the former positively charged, points to this being a common determinant in particle morphogenesis for all hepadnaviruses.
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Affiliation(s)
- Elizabeth V L Grgacic
- Australian Centre for Hepatitis Virology, Macfarlane Burnet Institute for Medical Research and Public Health, Yarra Bend Road, Fairfield 3078, Victoria, Australia1
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Wagner SJ, Skripchenko A, Pugh JC, Suchmann DB, Ijaz MK. Duck hepatitis B photoinactivation bydimethylmethylene blue in RBC suspensions. Transfusion 2001; 41:1154-8. [PMID: 11552074 DOI: 10.1046/j.1537-2995.2001.41091154.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Dimethylmethylene blue (DMMB) has been used to photoinactivate a number of model viruses, including VSV, in RBC suspensions under conditions that preserve in vitro RBC properties during storage. The relative sensitivity of duck HBV (DHBV) and VSV to photoinactivation by DMMB was investigated by performing an indirect immunofluorescence assay (IFA) using primary duck hepatocyte (PDH) cultures or a standard plaque assay for the respective viruses. STUDY DESIGN AND METHODS DMMB was added to 45-percent Hct, WBC-reduced, oxygenated AS-3 RBCs at 10-, 1-, and 0.1-microM concentrations. Samples (1-mm thick) were illuminated with 5.4-mW per cm(2) of red light for 2 or 9 seconds. Unilluminated samples without DMMB or with 10 microM DMMB served as control. RESULTS DHBV and VSV were rapidly photoinactivated by DMMB in a concentration and light-dose-dependent fashion. Neither virus was substantially inactivated by incubation with DMMB in the dark. For a given light exposure, DHBV required a concentration of DMMB one-one hundredth that of VSV to achieve approximately the same level of inactivation. CONCLUSION DHBV appears to be considerably more sensitive than VSV to DMMB photoinactivation. Photoinactivation in 45-percent Hct RBCs can be achieved in seconds by using micromolar quantities of dye.
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Affiliation(s)
- S J Wagner
- American Red Cross Holland Laboratory for the Biomedical Sciences, Rockville, Maryland, USA.
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42
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Paran N, Geiger B, Shaul Y. HBV infection of cell culture: evidence for multivalent and cooperative attachment. EMBO J 2001; 20:4443-53. [PMID: 11500372 PMCID: PMC125578 DOI: 10.1093/emboj/20.16.4443] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepadnaviruses do not infect cultured cells, therefore our knowledge of the mechanism of the early stages of virus-cell interaction is rather poor. In this study, we show that dimethylsulfoxide (DMSO)-treated HepG2 hepatoblastoma cells are infected efficiently by serum-derived hepatitis B virus (HBV) as monitored by viral gene expression and replication markers. To measure virus attachment, a variety of HBV surface proteins (HBsAgs) were conjugated to polystyrene beads and their capacity to attach cells was visualized and quantified by light microscopy at a single-cell resolution. Remarkably, DMSO increases the attachment efficiency by >200-fold. We further identify the QLDPAF sequence within preS1 as the receptor-binding viral domain epitope. Interestingly, a similar sequence is shared by several cellular, bacterial and viral proteins involved in cell adhesion, attachment and fusion. We also found that the small HBsAg contains a secondary attachment site that recognizes a distinct receptor on the cell membrane. Furthermore, we provide evidence in support of multivalent HBV attachment with synergistic interplay. Our data depict a mechanistic view of virus attachment and ingestion.
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Affiliation(s)
- Nir Paran
- Departments of
Molecular Genetics and Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel Corresponding author e-mail:
| | - Benjamin Geiger
- Departments of
Molecular Genetics and Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel Corresponding author e-mail:
| | - Yosef Shaul
- Departments of
Molecular Genetics and Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel Corresponding author e-mail:
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43
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Riddell MA, Li F, Anderson DA. Identification of immunodominant and conformational epitopes in the capsid protein of hepatitis E virus by using monoclonal antibodies. J Virol 2000; 74:8011-7. [PMID: 10933710 PMCID: PMC112333 DOI: 10.1128/jvi.74.17.8011-8017.2000] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antibody to the capsid (PORF2) protein of hepatitis E virus (HEV) is sufficient to confer immunity, but knowledge of B-cell epitopes in the intact capsid is limited. A panel of murine monoclonal antibodies (MAbs) was generated following immunization with recombinant ORF2.1 protein, representing the C-terminal 267 amino acids (aa) of the 660-aa capsid protein. Two MAbs reacted exclusively with the conformational ORF2.1 epitope (F. Li, J. Torresi, S. A. Locarnini, H. Zhuang, W. Zhu, X. Guo, and D. A. Anderson, J. Med. Virol. 52:289-300, 1997), while the remaining five demonstrated reactivity with epitopes in the regions aa 394 to 414, 414 to 434, and 434 to 457. The antigenic structures of both the ORF2.1 protein expressed in Escherichia coli and the virus-like particles (VLPs) expressed using the baculovirus system were examined by competitive enzyme-linked immunosorbent assays (ELISAs) using five of these MAbs and HEV patient sera. Despite the wide separation of epitopes within the primary sequence, all the MAbs demonstrated some degree of cross-inhibition with each other in ORF2. 1 and/or VLP ELISAs, suggesting a complex antigenic structure. MAbs specific for the conformational ORF2.1 epitope and a linear epitope within aa 434 to 457 blocked convalescent patient antibody reactivity against VLPs by approximately 60 and 35%, respectively, while MAbs against epitopes within aa 394 to 414 and 414 to 434 were unable to block patient serum reactivity. These results suggest that sequences spanning aa 394 to 457 of the capsid protein participate in the formation of strongly immunodominant epitopes on the surface of HEV particles which may be important in immunity to HEV infection.
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Affiliation(s)
- M A Riddell
- Hepatitis Research Unit and Australian Centre for Hepatitis Virology, Macfarlane Burnet Centre for Medical Research, Fairfield 3078, Victoria, Australia
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44
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Guo JT, Zhou H, Liu C, Aldrich C, Saputelli J, Whitaker T, Barrasa MI, Mason WS, Seeger C. Apoptosis and regeneration of hepatocytes during recovery from transient hepadnavirus infections. J Virol 2000; 74:1495-505. [PMID: 10627561 PMCID: PMC111485 DOI: 10.1128/jvi.74.3.1495-1505.2000] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
It is well known that hepatitis B virus infections can be transient or chronic, but the basis for this dichotomy is not known. To gain insight into the mechanism responsible for the clearance of hepadnavirus infections, we have performed a molecular and histologic analysis of liver tissues obtained from transiently infected woodchucks during the critical phase of the recovery period. We found as expected that clearance from transient infections occurred subsequent to the appearance of CD4(+) and CD8(+) T cells and the production of interferon gamma and tumor necrosis factor alpha in the infected liver. These events were accompanied by a significant increase in apoptosis and regeneration of hepatocytes. Surprisingly, however, accumulation of virus-free hepatocytes was delayed for several weeks following this initial influx of lymphocytes. In addition, we observed that chronically infected animals can exhibit levels of T-cell accumulation, cytokine expression, and apoptosis that are comparable with those observed during the initial phase of transient infections. Our results are most consistent with a model for recovery predicting replacement of infected hepatocytes with regenerated cells, which by unknown mechanisms remain protected from reinfection in animals that can be cured.
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Affiliation(s)
- J T Guo
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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45
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Chang SF, Netter HJ, Bruns M, Schneider R, Frölich K, Will H. A new avian hepadnavirus infecting snow geese (Anser caerulescens) produces a significant fraction of virions containing single-stranded DNA. Virology 1999; 262:39-54. [PMID: 10489339 DOI: 10.1006/viro.1999.9844] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We describe the identification and functional analysis of an evolutionary distinct new avian hepadnavirus. Infection of snow geese (Anser caerulescens) with a duck hepatitis B virus (DHBV)-related virus, designated SGHBV, was demonstrated by detection of envelope proteins in sera with anti-DHBV preS and S antibodies. Comparative sequence analysis of the PCR-amplified SGHBV genomes revealed unique SGHBV sequence features compared with other avian hepadnaviruses. Unlike DHBV, SGHBV shows an open reading frame in an analogous position to orthohepadnavirus X genes. Four of five cloned genomes were competent in replication, gene expression, and virus particle secretion in chicken hepatoma cells. Primary duck hepatocytes were permissive for infection with SGHBV, suggesting a similar or identical host range. SGHBV was found to secrete a significant fraction of virion-like particles containing single-stranded viral DNA. This was observed both in cell culture medium of SGHBV DNA-transfected LMH cells and in viremic sera of several birds, suggesting that it is a stable trait of SGHBV. Taken together, SGHBV has several unique features that expand the knowledge of the functional and evolutionary diversity of hepadnaviruses and offers new experimental opportunities for studies on the life cycle of hepadnaviruses.
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Affiliation(s)
- S F Chang
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistrabetae 52, Hamburg, 20251, Germany
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46
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Protzer U, Nassal M, Chiang PW, Kirschfink M, Schaller H. Interferon gene transfer by a hepatitis B virus vector efficiently suppresses wild-type virus infection. Proc Natl Acad Sci U S A 1999; 96:10818-23. [PMID: 10485909 PMCID: PMC17966 DOI: 10.1073/pnas.96.19.10818] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B viruses specifically target the liver, where they efficiently infect quiescent hepatocytes. Here we show that human and avian hepatitis B viruses can be converted into vectors for liver-directed gene transfer. These vectors allow hepatocyte-specific expression of a green fluorescent protein in vitro and in vivo. Moreover, when used to transduce a type I interferon gene, expression of interferon efficiently suppresses wild-type virus replication in the duck model of hepatitis B virus infection. These data suggest local cytokine production after hepatitis-B-virus-mediated gene transfer as a promising concept for the treatment of acquired liver diseases, including chronic hepatitis B.
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Affiliation(s)
- U Protzer
- Zentrum für Molekulare Biologie Heidelberg, University of Heidelberg, Im Neuenheimer Feld, D-69120 Heidelberg, Germany
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47
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Sunyach C, Rollier C, Robaczewska M, Borel C, Barraud L, Kay A, Trépo C, Will H, Cova L. Residues critical for duck hepatitis B virus neutralization are involved in host cell interaction. J Virol 1999; 73:2569-75. [PMID: 10074101 PMCID: PMC104011 DOI: 10.1128/jvi.73.4.2569-2575.1999] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To date, no detailed analysis of the neutralization properties of duck hepatitis B virus (DHBV) has been reported, and it is not clear whether any of the known neutralization epitopes correspond to the viral receptor binding site or to sequences involved in the cell entry pathway. We demonstrate here that antibodies directed against two overlapping peptides (amino acids 83 to 97 and 93 to 107), covering the sequences of most DHBV pre-S neutralizing epitopes, both inhibit virus binding to primary duck hepatocytes and neutralize virus infectivity. An extensive mutagenesis of the motif 88WTP90, which is the shortest sequence of the epitope recognized by the virus-neutralizing monoclonal antibody (MAb) 900 was performed in order to define the amino acids involved in these interactions. Single point mutations within this epitope affected neither virus replication nor infectivity but abolished virus neutralization by MAb 900 completely. Interestingly, mutants with two and three consecutive residue replacements (SIP and SIH) within this epitope retained replication competence but were no longer infectious. The loss of infectivity of SIH and SIP mutant particles was associated with significantly reduced binding to primary duck hepatocytes and could be rescued by trans complementation with wild-type pre-S protein. Taken together, these results indicate that each amino acid of the DHBV pre-S sequence 88WTP90 is critical for recognition by the neutralizing MAb 900 and that replacement of the first two or all three residues strongly reduces virus interaction with hepatocytes and abrogates infectivity. These data imply that the motif 88WTP90 contains key residues which are critical for interaction with both the neutralizing MAb and the host cell.
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Affiliation(s)
- C Sunyach
- Unité de Recherche sur les Virus des Hépatites, les Rétrovirus Humains, et les Pathologies Associées, Institut National de la Santé et de la Recherche Médicale 271, 69424 Lyon Cedex 03, France
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48
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Soni PN, Brown D, Saffie R, Savage K, Moore D, Gregoriadis G, Dusheiko GM. Biodistribution, stability, and antiviral efficacy of liposome-entrapped phosphorothioate antisense oligodeoxynucleotides in ducks for the treatment of chronic duck hepatitis B virus infection. Hepatology 1998; 28:1402-10. [PMID: 9794928 DOI: 10.1002/hep.510280532] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study investigated the feasibility of using liposomes to increase the hepatic delivery and antiviral efficacy of phosphorothioate antisense oligodeoxynucleotides (PS-ODN) for the in vivo treatment of hepatitis B virus (HBV) infection. Ducks infected with duck hepatitis B virus (DHBV) were used as the model. We studied the stability of an antisense PS-ODN in duck plasma, its integrity during the process of liposome entrapment, its in vivo biodistribution, plasma clearance, and excretion. In addition, the intrahepatic distribution of a labeled free and liposome-entrapped ODN was also investigated. The results of our studies show that: 1) phosphorothioate ODN remain stable during the process of liposome entrapment; 2) are stable in duck plasma for many hours; 3) are rapidly cleared from the plasma when injected intravenously; 4) intravenous injection of antisense ODNs entrapped within liposomes enhances delivery of the ODN to the liver; and 5) inhibit DHBV replication. Serum DHBV DNA levels fell rapidly, with a corresponding decrease in intrahepatic viral replicative intermediates at the end of the 5-day study period. Although inhibition of viral replication and a fall in the target protein was observed, a marked inhibition of viral replication was also observed with high doses of a random-sequence ODN. Thus, it is not certain that inhibition of viral replication was entirely through an antisense mechanism. Therefore, liposomes may be effective vehicles to improve the delivery of antisense oligonucleotides to the liver for the therapy of hepatotropic viruses.
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Affiliation(s)
- P N Soni
- Department of Medicine, University of Natal, Durban, South Africa
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Urban S, Breiner KM, Fehler F, Klingmüller U, Schaller H. Avian hepatitis B virus infection is initiated by the interaction of a distinct pre-S subdomain with the cellular receptor gp180. J Virol 1998; 72:8089-97. [PMID: 9733849 PMCID: PMC110146 DOI: 10.1128/jvi.72.10.8089-8097.1998] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Functionally relevant hepadnavirus-cell surface interactions were investigated with the duck hepatitis B virus (DHBV) animal model by using an in vitro infection competition assay. Recombinant DHBV pre-S polypeptides, produced in Escherichia coli, were shown to inhibit DHBV infection in a dose-dependent manner, indicating that monomeric pre-S chains were capable of interfering with virus-receptor interaction. Particle-associated pre-S was, however, 30-fold more active, suggesting that cooperative interactions enhance particle binding. An 85-amino-acid pre-S sequence, spanning about half of the DHBV pre-S chain, was characterized by deletion analysis as essential for maximal inhibition. Pre-S polypeptides from heron hepatitis B virus (HHBV) competed DHBV infection equally well despite a 50% difference in amino acid sequence and a much-reduced infectivity of HHBV for duck hepatocytes. These observations are taken to indicate (i) that the functionality of the DHBV pre-S subdomain, which interacts with the cellular receptor, is determined predominantly by a defined three-dimensional structure rather than by primary sequence elements; (ii) that cellular uptake of hepadnaviruses is a multistep process involving more than a single cellular receptor component; and (iii) that gp180, a cellular receptor candidate unable to discriminate between DHBV and HHBV, is a common component of the cellular receptor complex for avian hepadnaviruses.
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Affiliation(s)
- S Urban
- Zentrum für Molekulare Biologie, Universität Heidelberg, 69120 Heidelberg, Germany
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50
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Jilbert AR, Botten JA, Miller DS, Bertram EM, Hall PM, Kotlarski J, Burrell CJ. Characterization of age- and dose-related outcomes of duck hepatitis B virus infection. Virology 1998; 244:273-82. [PMID: 9601498 DOI: 10.1006/viro.1998.9095] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Experimental inoculation of naive ducks with duck hepatitis B virus (DHBV) can lead to one of three outcomes, namely, persistent viremia, transient infection with or without viremia, or no evidence of infection. The ability of individual ducks to resolve DHBV infection was found to be linked to the age of the duck at the time of inoculation and the dose of inoculated virus. (1) In recently hatched ducks inoculated intravenously (i.v.) with 4 x 10(4) DHBV DNA genomes, a switch from persistent viremia to transient antibody appearance was seen at an age of inoculation between 7 and 14 days. A 25-fold increase in the dose of virus (1 x 10(6) DHBV genomes) delayed this switch by 7 days. (2) When 4-month-old ducks were inoculated i.v. with different doses of virus, only those receiving the highest dose (2 x 10(11) DHBV genomes) showed viremia and extensive viral replication and histological changes in the liver; 2/3 ducks in this group had a transient infection, while the third duck had viral replication and histological changes in the liver that were still present at day 120 postinoculation (p.i.). In all ducks receiving lower doses (1 x 10(3), 1 x 10(6), 1 x 10(9) DHBV genomes) antibodies to viral surface and core antigens developed without detectable viral replication in the liver on days 6, 9, or 12 p.i. (3) When 10- to 16-month-old ducks were inoculated i.v. with 2 x 10(11) DHBV genomes, all showed extensive viral replication in hepatocytes and mild to moderate histological changes in the liver on days 4 or 6 p.i. In 4/5 ducks viremia was not detected, anti-surface antibodies were first detected on day 8 p.i., and viral DNA and antigen were cleared from the liver by days 35-47 p.i. The remaining duck became viremic with persistence of virus in the liver until at least day 46 p.i. The findings of the study are consistent with a model for noncytopathic viruses (R. M. Zinkernagel (1996) Science 271, 173-178).
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Affiliation(s)
- A R Jilbert
- Infectious Diseases Laboratories, Institute of Medical and Veterinary Science, Adelaide, Australia.
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