1
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Tu T, Zehnder B, Qu B, Ni Y, Main N, Allweiss L, Dandri M, Shackel N, George J, Urban S. A novel method to precisely quantify hepatitis B virus covalently closed circular (ccc)DNA formation and maintenance. Antiviral Res 2020; 181:104865. [PMID: 32726641 DOI: 10.1016/j.antiviral.2020.104865] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 01/05/2023]
Abstract
Hepatitis B virus (HBV) is the major cause of virus-associated liver disease. Persistent HBV infection is maintained by its episomal genome (covalently closed circular DNA, cccDNA), which acts as a template for viral transcripts. The formation of cccDNA is poorly characterised due to limited ability to quantify it accurately in the presence of replicative intermediates. Here, we describe a novel cccDNA quantification assay (cccDNA inversion quantitative PCR, cinqPCR), which uses restriction enzymes to invert a DNA sequence close to the gap region of Genotype D HBV strains, including the isolate widely used in experimental studies. Importantly, cinqPCR allows simultaneous normalisation to cellular DNA in a single reaction, provides absolute copy numbers without requiring a standard curve, and has high precision, sensitivity, and specificity for cccDNA compared to previous assays. We first established that cinqPCR gives values consistent with classical approaches in both in vitro and in vivo (humanised mice) HBV infections. We then used cinqPCR to find that cccDNA is formed within 12 h post-inoculation (hpi). cccDNA formation slowed by 28 hpi despite de novo synthesis of HBV DNA, indicating inefficient conversion of new viral genomes to cccDNA within infected cells. Finally, we show that cinqPCR can be used as a 96-well screening assay. Thus, we have developed an ideal method for testing current and future anti-cccDNA therapeutics with high precision and sensitivity.
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Affiliation(s)
- Thomas Tu
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Infection Research (DZIF), Heidelberg Partner Site, Heidelberg, Germany; Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, NSW, Australia.
| | - Benno Zehnder
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Bingqian Qu
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Nathan Main
- Gastroenterology and Liver Laboratory, Ingham Institute for Applied Medical Research, Sydney, Australia; Department of Gastroenterology and Hepatology, Liverpool Hospital, Sydney, New South Wales, Australia
| | - Lena Allweiss
- Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maura Dandri
- Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZIF, Hamburg-Lübeck-Borstel Partner Site, Germany
| | - Nicholas Shackel
- Gastroenterology and Liver Laboratory, Ingham Institute for Applied Medical Research, Sydney, Australia; Department of Gastroenterology and Hepatology, Liverpool Hospital, Sydney, New South Wales, Australia; South Western Sydney Clinical School, University of New South Wales, Australia
| | - Jacob George
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, NSW, Australia
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Infection Research (DZIF), Heidelberg Partner Site, Heidelberg, Germany
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2
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Li M, Zu J. The review of differential equation models of HBV infection dynamics. J Virol Methods 2019; 266:103-113. [PMID: 30716348 DOI: 10.1016/j.jviromet.2019.01.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/30/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022]
Abstract
Understanding the infection and pathogenesis mechanism of hepatitis B virus (HBV) is very important for the prevention and treatment of hepatitis B. Mathematical models contribute to illuminate the dynamic process of HBV replication in vivo. Therefore, in this paper we review the viral dynamics in HBV infection, which may help us further understand the dynamic mechanism of HBV infection and efficacy of antiviral treatment. Firstly, we introduce a family of deterministic models by considering different biological mechanisms, such as, antiviral therapy, CTL immune response, multi-types of infected hepatocytes, time delay and spatial diffusion. Particularly, we briefly describe the stochastic models of HBV infection. Secondly, we introduce the commonly used parameter estimation methods for HBV viral dynamic models and briefly discuss how to use these methods to estimate unknown parameters (such as drug efficacy) through two specific examples. We also discuss the idea and method of model identification and use a specific example to illustrate its application. Finally, we propose three new research programs, namely, considering HBV drug-resistant strain, coupling within-host and between-host dynamics in HBV infection and linking population dynamics with evolutionary dynamics of HBV diversity.
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Affiliation(s)
- Miaolei Li
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, PR China
| | - Jian Zu
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, PR China.
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3
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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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4
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Schöneweis K, Motter N, Roppert PL, Lu M, Wang B, Roehl I, Glebe D, Yang D, Morrey JD, Roggendorf M, Vaillant A. Activity of nucleic acid polymers in rodent models of HBV infection. Antiviral Res 2017; 149:26-33. [PMID: 29126900 DOI: 10.1016/j.antiviral.2017.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/19/2017] [Accepted: 10/27/2017] [Indexed: 12/18/2022]
Abstract
Nucleic acid polymers (NAPs) block the release of HBsAg from infected hepatocytes. These compounds have been previously shown to have the unique ability to eliminate serum surface antigen in DHBV-infected Pekin ducks and achieve multilog reduction of HBsAg or HBsAg loss in patients with chronic HBV infection and HBV/HDV coinfection. In ducks and humans, the blockage of HBsAg release by NAPs occurs by the selective targeting of the assembly and/or secretion of subviral particles (SVPs). The clinically active NAP species REP 2055 and REP 2139 were investigated in other relevant animal models of HBV infection including woodchucks chronically infected with WHV, HBV transgenic mice and HBV infected SCID-Hu mice. The liver accumulation of REP 2139 in woodchucks following subcutaneous administration was examined and was found to be similar to that observed in mice and ducks. However, in woodchucks, NAP treatment was associated with only mild (36-79% relative to baseline) reductions in WHsAg (4/10 animals) after 3-5 weeks of treatment without changes in serum WHV DNA. In HBV infected SCID-Hu mice, REP 2055 treatment was not associated with any reduction of HBsAg, HBeAg or HBV DNA in the serum after 28 days of treatment. In HBV transgenic mice, no reductions in serum HBsAg were observed with REP 2139 with up to 12 weeks of treatment. In conclusion, the antiviral effects of NAPs in DHBV infected ducks and patients with chronic HBV infection were weak or absent in woodchuck and mouse models despite similar liver accumulation of NAPs in all these species, suggesting that the mechanisms of SVP assembly and or secretion present in rodent models differs from that in DHBV and chronic HBV infections.
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Affiliation(s)
- Katrin Schöneweis
- Department of Virology, University of Duisburg-Essen, Essen, Germany
| | - Neil Motter
- Institute for Antiviral Research, Utah State University, Logan, UT, USA
| | - Pia L Roppert
- Institute of Medical Virology, National Reference Centre for Hepatitis B and D Viruses, German Centre for Infection Research (DZIF), Justus Liebig University of Giessen, Giessen, Germany
| | - Mengji Lu
- Department of Virology, University of Duisburg-Essen, Essen, Germany
| | - Baoju Wang
- Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Dieter Glebe
- Institute of Medical Virology, National Reference Centre for Hepatitis B and D Viruses, German Centre for Infection Research (DZIF), Justus Liebig University of Giessen, Giessen, Germany
| | - Dongliang Yang
- Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - John D Morrey
- Institute for Antiviral Research, Utah State University, Logan, UT, USA
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5
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Kennedy PTF, Litwin S, Dolman GE, Bertoletti A, Mason WS. Immune Tolerant Chronic Hepatitis B: The Unrecognized Risks. Viruses 2017; 9:v9050096. [PMID: 28468285 PMCID: PMC5454409 DOI: 10.3390/v9050096] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/14/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022] Open
Abstract
Chronic infection with hepatitis B virus (HBV) progresses through multiple phases, including immune tolerant, immune active, immune control, and, in a subset of patients who achieve immune control, reactivation. The first, the immune tolerant phase, is considered to be prolonged in duration but essentially benign in nature, lacking long-term consequences, and thus not recommended for antiviral therapy. This review challenges the notion that the immune tolerant phase is truly benign and considers the possibility that events during this phase may contribute significantly to cirrhosis, hepatocellular carcinoma (HCC), and the premature death of 25% of HBV carriers worldwide. Thus, earlier treatment than recommended by current guidelines should be considered. Low therapeutic coverage exacerbated by restrictive treatment guidelines may facilitate disease progression in many patients but also increase the risk of neonatal and horizontal transmission from untreated mothers to their children. While a prophylactic vaccine exists, there are many areas worldwide where the treatment of adults and the delivery of an effective vaccination course to newborns present difficult challenges.
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Affiliation(s)
- Patrick T F Kennedy
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine & Dentistry, QMUL, London E1 2AT, UK.
| | - Samuel Litwin
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
| | - Grace E Dolman
- Centre for Immunobiology, Blizard Institute, Barts and the London School of Medicine & Dentistry, QMUL, London E1 2AT, UK.
| | - Antonio Bertoletti
- Emerging Infectious Diseases Program, Duke-NUS Graduate Medical School, Singapore.
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6
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Das S, Sarker S, Ghorashi SA, Forwood JK, Raidal SR. A comparison of PCR assays for beak and feather disease virus and high resolution melt (HRM) curve analysis of replicase associated protein and capsid genes. J Virol Methods 2016; 237:47-57. [PMID: 27565820 DOI: 10.1016/j.jviromet.2016.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/20/2016] [Accepted: 08/22/2016] [Indexed: 12/22/2022]
Abstract
Beak and feather disease virus (BFDV) threatens a wide range of endangered psittacine birds worldwide. In this study, we assessed a novel PCR assay and genetic screening method using high-resolution melt (HRM) curve analysis for BFDV targeting the capsid (Cap) gene (HRM-Cap) alongside conventional PCR detection as well as a PCR method that targets a much smaller fragment of the virus genome in the replicase initiator protein (Rep) gene (HRM-Rep). Limits of detection, sensitivity, specificity and discriminatory power for differentiating BFDV sequences were compared. HRM-Cap had a high positive predictive value and could readily differentiate between a reference genotype and 17 other diverse BFDV genomes with more discriminatory power (genotype confidence percentage) than HRM-Rep. Melt curve profiles generated by HRM-Cap correlated with unique DNA sequence profiles for each individual test genome. The limit of detection of HRM-Cap was lower (2×10-5ng/reaction or 48 viral copies) than that for both HRM-Rep and conventional BFDV PCR which had similar sensitivity (2×10-6ng or 13 viral copies/reaction). However, when used in a diagnostic setting with 348 clinical samples there was strong agreement between HRM-Cap and conventional PCR (kappa=0.87, P<0.01, 98% specificity) and HRM-Cap demonstrated higher specificity (99.9%) than HRM-Rep (80.3%).
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Affiliation(s)
- Shubhagata Das
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, NSW 2678, Australia.
| | - Subir Sarker
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, NSW 2678, Australia.
| | - Seyed Ali Ghorashi
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, NSW 2678, Australia.
| | - Jade K Forwood
- School of Biomedical Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Shane R Raidal
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, NSW 2678, Australia.
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7
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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: 63] [Impact Index Per Article: 7.0] [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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8
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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: 30] [Impact Index Per Article: 2.7] [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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9
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Kitamura K, Wang Z, Chowdhury S, Simadu M, Koura M, Muramatsu M. Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA. PLoS Pathog 2013; 9:e1003361. [PMID: 23696735 PMCID: PMC3656096 DOI: 10.1371/journal.ppat.1003361] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 03/31/2013] [Indexed: 12/17/2022] Open
Abstract
The covalently closed circular DNA (cccDNA) of the hepatitis B virus (HBV) plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC) DNA (partially double-stranded DNA) into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U) hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG), a host factor for base excision repair (BER). When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI), hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV) replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.
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Affiliation(s)
- Kouichi Kitamura
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Zhe Wang
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Sajeda Chowdhury
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Miyuki Simadu
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Miki Koura
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Masamichi Muramatsu
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
- * E-mail:
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10
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Saade F, Buronfosse T, Guerret S, Pradat P, Chevallier M, Zoulim F, Jamard C, Cova L. In vivo infectivity of liver extracts after resolution of hepadnaviral infection following therapy associating DNA vaccine and cytokine genes. J Viral Hepat 2013; 20:e56-65. [PMID: 23490390 DOI: 10.1111/jvh.12023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 08/24/2012] [Indexed: 12/19/2022]
Abstract
DNA-based vaccination appears of promise for chronic hepatitis B immunotherapy, although there is an urgent need to increase its efficacy. In this preclinical study, we evaluated the therapeutic benefit of cytokine (IL-2, IFN-γ) genes co-delivery with DNA vaccine targeting hepadnaviral proteins in the chronic duck hepatitis B virus (DHBV) infection model. Then, we investigated the persistence of replication-competent virus in the livers of apparently resolved animals. DHBV carriers received four injections of plasmids encoding DHBV envelope and core alone or co-delivered with duck IL-2 (DuIL-2) or duck IFN-γ (DuIFN-γ) plasmids. After long-term (8 months) follow-up, viral covalently closed circular (ccc) DNA was analysed in duck necropsy liver samples. Liver homogenates were also tested for in vivo infectivity in neonatal ducklings. Co-delivery of DuIFN-γ resulted in significantly lower mean viremia starting from week 21. Viral cccDNA was undetectable by conventional methods in the livers of 25% and 57% of animals co-immunized with DuIL-2 and DuIFN-γ, respectively. Interestingly, inoculation of liver homogenates from 7 such apparently resolved animals, exhibiting cccDNA undetectable in Southern blotting and DHBV expression undetectable or restricted to few hepatocytes, revealed that three liver homogenates transmitted high-titre viremia (3-5×10(10) vge/mL) to naïve animals. In conclusion, our results indicate that IFN-γ gene co-delivery considerably enhances immunotherapeutic efficacy of DNA vaccine targeting hepadnaviral proteins. Importantly, we also showed that livers exhibiting only minute amounts of hepadnaviral cccDNA could induce extremely high-titre infection, highlighting the caution that should be taken in occult hepatitis B patients to prevent HBV transmission in liver transplantation context.
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Affiliation(s)
- F Saade
- Université de Lyon, Lyon, Lyon, France
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11
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Khawaja G, Buronfosse T, Jamard C, Abdul F, Guerret S, Zoulim F, Luxembourg A, Hannaman D, Evans CF, Hartmann D, Cova L. In vivo electroporation improves therapeutic potency of a DNA vaccine targeting hepadnaviral proteins. Virology 2012; 433:192-202. [PMID: 22921316 DOI: 10.1016/j.virol.2012.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/01/2012] [Accepted: 07/16/2012] [Indexed: 12/15/2022]
Abstract
This preclinical study investigated the therapeutic efficacy of electroporation (EP)-based delivery of plasmid DNA (pDNA) encoding viral proteins (envelope, core) and IFN-γ in the duck model of chronic hepatitis B virus (DHBV) infection. Importantly, only DNA EP-therapy resulted in a significant decrease in mean viremia titers and in intrahepatic covalently closed circular DNA (cccDNA) levels in chronic DHBV-carrier animals, compared with standard needle pDNA injection (SI). In addition, DNA EP-therapy stimulated in all virus-carriers a humoral response to DHBV preS protein, recognizing a broader range of major antigenic regions, including neutralizing epitopes, compared with SI. DNA EP-therapy led also to significant higher intrahepatic IFN-γ RNA levels in DHBV-carriers compared to other groups, in the absence of adverse effects. We provide the first evidence on DNA EP-therapy benefit in terms of hepadnaviral infection clearance and break of immune tolerance in virus-carriers, supporting its clinical application for chronic hepatitis B.
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MESH Headings
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/immunology
- Chronic Disease
- DNA, Circular/genetics
- DNA, Circular/immunology
- Disease Models, Animal
- Ducks
- Electroporation
- Epitopes
- Hepadnaviridae Infections/immunology
- Hepadnaviridae Infections/prevention & control
- Hepadnaviridae Infections/veterinary
- Hepadnaviridae Infections/virology
- Hepatitis B Vaccines/administration & dosage
- Hepatitis B Vaccines/immunology
- Hepatitis B Virus, Duck/immunology
- Hepatitis, Viral, Animal/immunology
- Hepatitis, Viral, Animal/prevention & control
- Hepatitis, Viral, Animal/virology
- Immune Tolerance
- Immunity, Humoral
- Interferon-gamma/biosynthesis
- Interferon-gamma/immunology
- Plasmids
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
- Viral Core Proteins/genetics
- Viral Core Proteins/immunology
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
- Viremia/immunology
- Viremia/prevention & control
- Viremia/veterinary
- Viremia/virology
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12
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Abstract
Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.
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13
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Abstract
Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.
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14
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Moses SE, Lim Z, Zuckerman MA. Hepatitis B virus infection: pathogenesis, reactivation and management in hematopoietic stem cell transplant recipients. Expert Rev Anti Infect Ther 2012; 9:891-9. [PMID: 21973301 DOI: 10.1586/eri.11.105] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hepatitis B virus (HBV) is a partially double stranded DNA virus that can integrate into host cell chromosomes as covalently closed circular DNA forms. HBV reactivation following hematopoietic stem cell transplantation in recipients with evidence of past HBV exposure, as well as exacerbation of a current HBV infection in HBV carrier recipients, secondary to chemotherapy and post-transplant immunosuppression that affect both humoral and cell-mediated control of HBV infection, are well documented in the literature. Management options include HBV-DNA screening and antiviral prophylaxis. Nucleos(t)ide analogues have been used at the start of chemotherapy and pretransplantation, with the course continuing for 6 months. However, depending on the serum HBV-DNA level, the antiviral agent might be given until a therapeutic end point is reached.
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Affiliation(s)
- Samuel E Moses
- Health Protection Agency Microbiology Services-Newcastle Laboratory, Specialist Virology Centre, Newcastle, UK.
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15
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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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16
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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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17
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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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18
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19
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Thermet A, Buronfosse T, Werle-Lapostolle B, Chevallier M, Pradat P, Trepo C, Zoulim F, Cova L. DNA vaccination in combination or not with lamivudine treatment breaks humoral immune tolerance and enhances cccDNA clearance in the duck model of chronic hepatitis B virus infection. J Gen Virol 2008; 89:1192-1201. [PMID: 18420797 DOI: 10.1099/vir.0.83583-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This study used a duck hepatitis B virus (DHBV) model to evaluate whether a novel DNA vaccination protocol alone or associated with antiviral (lamivudine) treatment was able to clear the intrahepatic covalently closed, circular viral DNA (cccDNA) pool responsible for persistence of infection. DHBV carriers received DNA vaccine (on weeks 6, 10, 13, 14, 28 and 35) targeting the large envelope and/or core proteins alone or combined with lamivudine treatment (on weeks 1-8) or lamivudine monotherapy. After 10 months of follow-up, a dramatic decrease in viraemia and liver DHBV cccDNA (below 0.08 cccDNA copies per cell) was observed in 9/30 ducks (30 %) receiving DNA mono- or combination therapy, compared with 0/12 (0 %) from lamivudine monotherapy or the control groups, suggesting a significant antiviral effect of DNA immunization. However, association with the drug did not significantly improve DHBV DNA vaccine efficacy (33 % cccDNA clearance for the combination vs 27 % for DNA monotherapy), probably due to the low antiviral potency of lamivudine in the duck model. Seroconversion to anti-preS was observed in 6/9 (67 %) ducks showing cccDNA clearance, compared with 1/28 (3.6 %) without clearance, suggesting a significant correlation (P<0.001) between humoral response restoration and cccDNA elimination. Importantly, an early (weeks 10-12) drop in viraemia was observed in seroconverted animals, and virus replication did not rebound following the cessation of immunotherapy, indicating a sustained effect. This study provides the first evidence that therapeutic DNA vaccination is able to enhance hepadnaviral cccDNA clearance, which is tightly associated with a break in humoral immune tolerance. These results also highlight the importance of antiviral drug potency and an effective DNA immunization protocol for the design of therapeutic vaccines against chronic hepatitis B.
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Affiliation(s)
- Alexandre Thermet
- Université Lyon 1, IFR62, F-69008 Lyon, France.,INSERM, Unit 871, F-69424 Lyon, France
| | - Thierry Buronfosse
- Ecole Nationale Vétérinaire de Lyon, F-69280 Marcy l'Etoile, France.,Université Lyon 1, IFR62, F-69008 Lyon, France.,INSERM, Unit 871, F-69424 Lyon, France
| | | | | | - Pierre Pradat
- Hospices Civiles de Lyon, Department of Hepatology, Hotel-Dieu, F-69002 Lyon, France
| | - Christian Trepo
- Hospices Civiles de Lyon, Department of Hepatology, Hotel-Dieu, F-69002 Lyon, France.,Université Lyon 1, IFR62, F-69008 Lyon, France.,INSERM, Unit 871, F-69424 Lyon, France
| | - Fabien Zoulim
- Hospices Civiles de Lyon, Department of Hepatology, Hotel-Dieu, F-69002 Lyon, France.,Université Lyon 1, IFR62, F-69008 Lyon, France.,INSERM, Unit 871, F-69424 Lyon, France
| | - Lucyna Cova
- Université Lyon 1, IFR62, F-69008 Lyon, France.,INSERM, Unit 871, F-69424 Lyon, France
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20
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Nassal M. Hepatitis B viruses: reverse transcription a different way. Virus Res 2008; 134:235-49. [PMID: 18339439 DOI: 10.1016/j.virusres.2007.12.024] [Citation(s) in RCA: 282] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 11/28/2007] [Accepted: 12/05/2007] [Indexed: 02/07/2023]
Abstract
Hepatitis B virus (HBV), the causative agent of B-type hepatitis in humans, is the type member of the Hepadnaviridae, hepatotropic DNA viruses that replicate via reverse transcription. Beyond long-established differences to retroviruses in gene expression and overall replication strategy newer work has uncovered additional distinctions in the mechanism of reverse transcription per se. These include protein-priming by the unique extra terminal protein domain of the reverse transcriptase (RT) utilizing an RNA hairpin for de novo initiation of first strand DNA synthesis, and the strict dependence of this process on cellular chaperones. Recent in vitro reconstitution systems enabled first biochemical insights into this multifactorial reaction, complemented by high resolution structural information on the RNA, though not yet the protein, level. Genetic approaches have revealed long-distance interactions in the nucleic acid templates as an important factor enabling the puzzling template switches required to produce the relaxed circular (RC) DNA found in infectious virions. Finally, the failure of even potent HBV RT inhibitors to eliminate nuclear covalently closed circular (ccc) DNA, the functional equivalent of integrated proviral DNA, has spurred a renewed interest in the mechanism of cccDNA generation. These new developments are in the focus of this review.
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Affiliation(s)
- Michael Nassal
- University Hospital Freiburg, Internal Medicine 2/Molecular Biology, Hugstetter Str. 55, D-79106 Freiburg, Germany.
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21
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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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22
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Kulkarni K, Jacobson IM, Tennant BC. The role of the woodchuck model in the treatment of hepatitis B virus infection. Clin Liver Dis 2007; 11:707-25, vii. [PMID: 17981226 DOI: 10.1016/j.cld.2007.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Experimental studies of animals with chronic hepadnavirus infection could provide valuable insight into optimal therapeutic strategies for individuals with chronic HBV infection. In this review, we focus on the contributions of the woodchuck model to our understanding of HBV biology and on its role in the development of antiviral drug. Furthermore, we consider the implications of studies focusing on the natural history of WHV infection for the management of HBV and the capacity of treatment to prevent complications of chronic hepatitis B infection.
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Affiliation(s)
- Ketan Kulkarni
- Division of Gastroenterology and Hepatology, Department of Medicine, Weill Medical College of Cornell University, 1305 York Avenue, 4th floor, New York, NY 10021, USA
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23
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Hoofnagle JH, Doo E, Liang TJ, Fleischer R, Lok ASF. Management of hepatitis B: summary of a clinical research workshop. Hepatology 2007; 45:1056-75. [PMID: 17393513 DOI: 10.1002/hep.21627] [Citation(s) in RCA: 420] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chronic hepatitis B is caused by persistent infection with the hepatitis B virus (HBV), a unique DNA virus that replicates through an RNA intermediate produced from a stable covalently closed circular DNA molecule. Viral persistence appears to be due to inadequate innate and adaptive immune responses. Chronic infection has a variable course after several decades resulting in cirrhosis in up to one-third of patients and liver cancer in a proportion of those with cirrhosis. Sensitive assays for HBV DNA levels in serum have been developed that provide important insights into pathogenesis and natural history. Therapy of hepatitis B is evolving. Peginterferon induces long-term remissions in disease in one-third of patients with typical hepatitis B e antigen (HBeAg) positive chronic hepatitis B, but a lesser proportion of those without HBeAg. Several oral nucleoside analogues with activity against HBV have been shown to be effective in suppressing viral levels and improving biochemical and histological features of disease in a high proportion of patients with and without HBeAg, at least in the short term. What is uncertain is which agent or combination of agents is most effective, how long therapy should last, and which criteria should be used to start, continue, switch or stop therapy. Long-term therapy with nucleoside analogues may be the most appropriate approach to treatment, but the expense and lack of data on long-term safety and efficacy make recommendations difficult. Clearly, many basic and clinical research challenges remain in defining optimal means of management of chronic hepatitis B.
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Affiliation(s)
- Jay H Hoofnagle
- Liver Disease Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
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24
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Abstract
Hepadnaviruses, including human hepatitis B virus (HBV), replicate through reverse transcription of an RNA intermediate, the pregenomic RNA (pgRNA). Despite this kinship to retroviruses, there are fundamental differences beyond the fact that hepadnavirions contain DNA instead of RNA. Most peculiar is the initiation of reverse transcription: it occurs by protein-priming, is strictly committed to using an RNA hairpin on the pgRNA, ε, as template, and depends on cellular chaperones; moreover, proper replication can apparently occur only in the specialized environment of intact nucleocapsids. This complexity has hampered an in-depth mechanistic understanding. The recent successful reconstitution in the test tube of active replication initiation complexes from purified components, for duck HBV (DHBV), now allows for the analysis of the biochemistry of hepadnaviral replication at the molecular level. Here we review the current state of knowledge at all steps of the hepadnaviral genome replication cycle, with emphasis on new insights that turned up by the use of such cell-free systems. At this time, they can, unfortunately, not be complemented by three-dimensional structural information on the involved components. However, at least for the ε RNA element such information is emerging, raising expectations that combining biophysics with biochemistry and genetics will soon provide a powerful integrated approach for solving the many outstanding questions. The ultimate, though most challenging goal, will be to visualize the hepadnaviral reverse transcriptase in the act of synthesizing DNA, which will also have strong implications for drug development.
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MESH Headings
- Animals
- Base Sequence
- Capsid/physiology
- DNA, Circular/genetics
- DNA, Circular/physiology
- DNA, Viral/genetics
- DNA, Viral/physiology
- Disease Models, Animal
- Ducks
- Hepatitis B Virus, Duck/genetics
- Hepatitis B Virus, Duck/physiology
- Hepatitis B virus/genetics
- Hepatitis B virus/physiology
- Humans
- Molecular Sequence Data
- RNA/genetics
- RNA/physiology
- RNA, Circular
- RNA, Viral/genetics
- RNA, Viral/physiology
- RNA-Directed DNA Polymerase/physiology
- Virus Replication/genetics
- Virus Replication/physiology
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Affiliation(s)
- Juergen Beck
- Department of Internal Medicine II/Molecular Biology, University Hospital Freiburg, Hugstetter Street 55, D-79106 Freiburg, Germany
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25
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Narayan R, Buronfosse T, Schultz U, Chevallier-Gueyron P, Guerret S, Chevallier M, Saade F, Ndeboko B, Trepo C, Zoulim F, Cova L. Rise in gamma interferon expression during resolution of duck hepatitis B virus infection. J Gen Virol 2006; 87:3225-3232. [PMID: 17030856 DOI: 10.1099/vir.0.82170-0] [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] [Indexed: 12/11/2022] Open
Abstract
Gamma interferon (IFN-γ) expression plays a crucial role in the control of mammalian hepatitis B virus (HBV) infection. However, the role of duck INF-γ (DuIFN-γ) in the outcome of duck HBV (DHBV) infection, a reference model for hepadnavirus replication studies, has not yet been investigated. This work explored the dynamics of DuIFN-γ expression in liver and peripheral blood mononuclear cells (PBMCs) during resolution of DHBV infection in adolescent ducks in relation to serum and liver markers of virus replication, histological changes and humoral response induction. DHBV infection of 3-week-old ducks resulted in transient expression of intrahepatic preS protein (days 3–14) and mild histological changes. Low-level viraemia was detected only during the first 10 days of infection and was accompanied by early anti-preS antibody response induction. Importantly, a strong increase in intrahepatic DuIFN-γ RNA was detected by real-time RT-PCR at days 6–14, which coincided with a sharp decrease in both viral DNA and preS protein in the liver. Interestingly, liver DuIFN-γ expression remained augmented to the end of the follow-up period (day 66) and correlated with portal lymphocyte infiltration and persistence of trace quantities of intrahepatic DHBV DNA in animals that had apparently completely resolved the infection. Moreover, in infected ducks, a moderate increase was detected in the levels of DuIFN-γ in PBMCs (days 12–14), which coincided with the peak in liver DuIFN-γ RNA levels. These data reveal that increased DuIFN-γ expression in liver and PBMCs is concomitant with viral clearance, characterizing the resolution of infection, and provide new insights into the host–virus interactions that control DHBV infection.
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MESH Headings
- Animals
- DNA, Viral/analysis
- DNA, Viral/genetics
- Ducks
- Hepadnaviridae Infections/blood
- Hepadnaviridae Infections/metabolism
- Hepadnaviridae Infections/veterinary
- Hepadnaviridae Infections/virology
- Hepatitis B Antibodies/blood
- Hepatitis B Surface Antigens/immunology
- Hepatitis B Surface Antigens/metabolism
- Hepatitis B Virus, Duck/isolation & purification
- Hepatitis, Viral, Animal/blood
- Hepatitis, Viral, Animal/metabolism
- Hepatitis, Viral, Animal/virology
- Interferon-gamma/genetics
- Interferon-gamma/metabolism
- Leukocytes, Mononuclear/metabolism
- Liver/metabolism
- Liver/virology
- Polymerase Chain Reaction
- RNA, Viral/analysis
- RNA, Viral/genetics
- Time Factors
- Viremia
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Affiliation(s)
| | - Thierry Buronfosse
- Ecole Nationale Vétérinaire, Marcy l'Etoile, France
- INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France
| | - Ursula Schultz
- Department of Internal Medicine II/Molecular Biology, University Hospital, Freiburg, Germany
| | | | | | | | - Fadi Saade
- INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France
| | | | - Christian Trepo
- INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France
| | - Fabien Zoulim
- INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France
| | - Lucyna Cova
- INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France
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26
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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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