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Li J, Li J, Chen S, Xu W, Zhang J, Tong S. Clinical isolates of hepatitis B virus genotype C have higher in vitro transmission efficiency than genotype B isolates. J Med Virol 2023; 95:e28879. [PMID: 37314050 PMCID: PMC10404337 DOI: 10.1002/jmv.28879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/18/2023] [Accepted: 06/02/2023] [Indexed: 06/15/2023]
Abstract
Serum samples were collected from 54 hepatitis B e antigen (HBeAg)-positive Chinese patients infected with hepatitis B virus (HBV) subgenotype B2 or C2. They were compared for transmission efficiency using same volume of samples or infectivity using same genome copy number. Adding polyethylene glycol (PEG) during inoculation did not increase infectivity of fresh samples but markedly increased infectivity following prolonged sample storage. Differentiated HepaRG cells infected without PEG produced more hepatitis B surface antigen (HBsAg) and higher HBsAg/HBeAg ratio than sodium taurocholate cotransporting polypeptide (NTCP)-reconstituted HepG2 cells infected with PEG. They better supported replication of core promoter mutant in contrast to wild-type (WT) virus by HepG2/NTCP cells. Overall, subgenotype C2 samples had higher viral load than B2 samples, and in general produced more HBeAg, HBsAg, and replicative DNA following same-volume inoculation. Precore mutant was more prevalent in subgenotype B2 and had reduced transmission efficiency. When same genome copy number of viral particles was inoculated, viral signals were not necessarily higher for three WT C2 isolates than four WT B2 isolates. Using viral particles generated from cloned HBV genome, three WT C2 isolates showed slightly reduced infectivity than three B2 isolates. In conclusion, subgenotype C2 serum samples had higher transmission efficiency than B2 isolates in association with higher viral load and lower prevalence of precore mutant, but not necessarily higher infectivity. PEG-independent infection by HBV viremic serum samples is probably attributed to a labile host factor.
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Affiliation(s)
- Jing Li
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
- Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA
- Department of Infectious Diseases, First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi’an, Shaanxi Province 710061, China
| | - Jisu Li
- Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA
| | - Shiqi Chen
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Weicheng Xu
- Department of Infectious Diseases, First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi’an, Shaanxi Province 710061, China
| | - Jiming Zhang
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Shuping Tong
- Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA
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Lee DH, Chung SW, Lee JH, Kim HY, Chung GE, Kim MS, Yang BR, Nam JY, Lee YB, Kim YJ, Yoon JH. Association of Chronic Hepatitis B Infection and Antiviral Treatment With the Development of the Extrahepatic Malignancies: A Nationwide Cohort Study. J Clin Oncol 2022; 40:3394-3405. [PMID: 35561284 DOI: 10.1200/jco.21.01285] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Epidemiologic studies suggest that chronic hepatitis B (CHB) is a risk factor for various primary extrahepatic malignancies. Our aim was to evaluate the associations of CHB and nucleos(t)ide analog (NA) treatment with the risk of the development of extrahepatic malignancies. PATIENTS AND METHODS We conducted an 18-month landmark analysis using nationwide claims data from the National Health Insurance Service of South Korea. Patients newly diagnosed with CHB in 2012-2014 (n = 90,944) and matched-controls (n = 685,436) were included. Patients with CHB were further classified as the NA-treated (CHB+/NA+, n = 6,539) or the NA-untreated (CHB+/NA-, n = 84,405) group. Inverse probability of treatment weighting analysis was applied to balance the treatment groups. Time-varying Cox analysis was performed to evaluate time-varying effect of NA treatment. The primary outcome was the development of any primary extrahepatic malignancy. Development of intrahepatic malignancy and death were considered as competing events. RESULTS During the study period (median = 47.4 months), 30,413 patients (3.9%) developed any extrahepatic malignancy. The CHB+/NA- group had a higher overall risk of extrahepatic malignancy than the CHB+/NA+ group (adjusted subdistribution hazard ratio [aSHR] = 1.28; 95% CI, 1.12 to 1.45; P < .001) or controls (aSHR = 1.22; 95% CI, 1.18 to 1.26; P < .001). There was no difference in the risk of extrahepatic malignancy between the CHB+/NA+ group and the controls (CHB+/NA+ v control: aSHR = 0.96; 95% CI, 0.84 to 1.08; P = .48). In time-varying Cox analysis, the CHB+/NA- patients were associated with a higher risk of extrahepatic malignancy than the CHB+/NA+ patients (aSHR = 1.37; 95% CI, 1.23 to 1.52; P < .001). CONCLUSION Patients with CHB have an elevated risk of developing primary extrahepatic malignancy. Long-term NA treatment was associated with a lower risk of extrahepatic malignancy development among patients with CHB.
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Affiliation(s)
- Dong Hyeon Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea
| | - Sung Won Chung
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Jeong-Hoon Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Hwi Young Kim
- Department of Internal Medicine, Ewha Womans University Medical Center, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Goh Eun Chung
- Department of Internal Medicine, Healthcare System Gangnam Center Seoul National University Hospital, Seoul, South Korea
| | - Mi-Sook Kim
- Medical Research Collaborating Center, Seoul National University Hospital, Seoul, South Korea
| | - Bo Ram Yang
- Medical Research Collaborating Center, Seoul National University Hospital, Seoul, South Korea.,College of Pharmacy, Chungnam National University, Daejeon, South Korea
| | - Joon Yeul Nam
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Yun Bin Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Yoon Jun Kim
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Jung-Hwan Yoon
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea
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3
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Nosaka T, Naito T, Matsuda H, Ohtani M, Hiramatsu K, Nemoto T, Nishizawa T, Okamoto H, Nakamoto Y. Molecular signature of hepatitis B virus regulation by interferon-γ in primary human hepatocytes. Hepatol Res 2020; 50:292-302. [PMID: 31733138 DOI: 10.1111/hepr.13450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/08/2019] [Accepted: 10/22/2019] [Indexed: 12/24/2022]
Abstract
AIM A complete cure for chronic hepatitis B virus (HBV) infection requires elimination of covalently closed circular DNA; however, this remains to be clinically achieved. Interferon (IFN)-γ, a type II IFN, is produced by intrahepatic cytotoxic T lymphocytes and has non-cytolytic antiviral potential. However, the mechanism by which IFN-γ regulates HBV infection has not been fully elucidated. Thus, we developed an in vitro HBV infection assay system and analyzed the molecular signature of HBV regulation by IFN-γ. METHODS The in vitro HBV infection assay system was established in primary human hepatocytes infected with HBV derived from the plasmid containing 1.3-mer HBV genome, and treated with IFN-γ. The antiviral effects and signaling pathways of IFN-γ were examined using microarray, and assessed by siRNA knockdown experiments of the related genes. RESULTS IFN-γ treatment suppressed both HBV propagation and transcription as efficiently as IFN-α. Microarray analysis showed that IFN-γ stimulation induced the activation of both IFN-γ and IFN-α signaling, regulating HBV covalently closed circular DNA. HBV production was decreased by IFN-γ through Janus kinase/signal transducer and activator of transcription signaling and interferon-stimulated genes, such as 2'-5'-oligoadenylate synthase 2 and apolipoprotein B mRNA editing enzyme catalytic subunit 3G. CONCLUSIONS IFN-γ can suppress HBV propagation and transcription in hepatocytes by activating specific intracellular signaling pathways in hepatocytes, and suggests the future application of these particular signaling pathways or genes for the complete elimination of HBV.
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Affiliation(s)
- Takuto Nosaka
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Tatsushi Naito
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Hidetaka Matsuda
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Masahiro Ohtani
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Katsushi Hiramatsu
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Tomoyuki Nemoto
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Japan
| | - Hiroaki Okamoto
- Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Japan
| | - Yasunari Nakamoto
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Japan
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Wang Q, Qin Y, Zhang J, Jia L, Fu S, Wang Y, Li J, Tong S. Tracing the evolutionary history of hepadnaviruses in terms of e antigen and middle envelope protein expression or processing. Virus Res 2019; 276:197825. [PMID: 31785305 DOI: 10.1016/j.virusres.2019.197825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/11/2022]
Abstract
Hepatitis B virus (HBV) is the prototype of hepadnaviruses, which can be subgrouped into orthohepadnaviruses infecting mammals, avihehepadnaviruses of birds, metahepadnaviruses of fish, and herpetohepadnaviruses of amphibians and reptiles. The middle (M) envelope protein and e antigen are new additions in the evolution of hepadnaviruses. They are alternative translation products of the transcripts for small (S) envelope and core proteins, respectively. For HBV, e antigen is converted from precore/core protein by removal of N-terminal signal peptide followed by furin-mediated cleavage of the basic C-terminus. This study compared old and newly discovered hepadnaviruses for their envelope protein and e antigen expression or processing. The S protein of bat hepatitis B virus (BHBV) and two metahepadnaviruses is probably myristoylated, in addition to two avihepadnaviruses. While most orthohepadnaviruses express a functional M protein with N-linked glycosylation near the amino-terminus, most metahepadnaviruses and herpetohepadnaviruses probably do not. These viruses and one orthohepadnavirus, the shrew hepatitis B virus, lack an open precore region required for e antigen expression. Potential furin cleavage sites (RXXR sequence) can be found in e antigen precursors of orthohepadnaviruses and avihepadnaviruses. Despite much larger precore/core proteins of avihepadnaviruses and their limited sequence homology with those of orthohepadnaviruses, their proximal RXXR motif can be aligned with a distal RXXR motif for orthohepadnaviruses. Thus, furin or another basic endopeptidase is probably the shared enzyme for hepadnaviral e antigen maturation. A precore-derived cysteine residue is involved in forming intramolecular disulfide bond of HBV e antigen to prevent particle formation, and such a cysteine residue is conserved for both orthohepadnaviruses and avihepadnaviruses. All orthohepadnaviruses have an X gene, while all avihepadnaviruses can express the e antigen. M protein expression appears to be the most recent event in the evolution of hepadnaviruses.
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Affiliation(s)
- Qianru Wang
- Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yanli Qin
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Zhang
- Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lucy Jia
- Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Shuwen Fu
- Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yongxiang Wang
- Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jisu Li
- Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Shuping Tong
- Department of Pathobiology, Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Liver Research Center, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, RI, USA.
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5
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Al-Sadeq DW, Taleb SA, Zaied RE, Fahad SM, Smatti MK, Rizeq BR, Al Thani AA, Yassine HM, Nasrallah GK. Hepatitis B Virus Molecular Epidemiology, Host-Virus Interaction, Coinfection, and Laboratory Diagnosis in the MENA Region: An Update. Pathogens 2019; 8:pathogens8020063. [PMID: 31083509 PMCID: PMC6630671 DOI: 10.3390/pathogens8020063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/18/2019] [Accepted: 05/08/2019] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B virus (HBV) is an enveloped partial double-stranded DNA virus that can cause acute and chronic hepatitis. According to the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), 257 million people are living with HBV. Moreover, 20,900 acute hepatitis B cases were reported in 2016. Hepatitis B is highly prevalent in the African, Western Pacific, Eastern Mediterranean, South-East Asia, and European regions, respectively. Due to the high mutational rate of HBV and lack of reverse transcriptase proofreading activity, ten different genotypes with different geographical distributions have been identified. HBV pathogenesis and severity of infection depend on several host and viral factors, particularly, the genetic variability of both the host and virus. Although HBV infection is a global health concern, there is a lack of adequate studies and reports in the Middle East and North Africa (MENA) region. Here, we provide a review on HBV epidemiology, pathogenesis, host-pathogen interactions, coinfection with selected viruses, and laboratory diagnosis, focusing on studies conducted in the MENA region to determine the current situation of the HBV infection and outline the future study areas.
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Affiliation(s)
- Duaa W Al-Sadeq
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
- Biomedical Science Department, College of Health Sciences, Qatar University, Doha 2713, Qatar.
| | - Sara A Taleb
- Biomedical Science Department, College of Health Sciences, Qatar University, Doha 2713, Qatar.
| | - Roan E Zaied
- Biomedical Science Department, College of Health Sciences, Qatar University, Doha 2713, Qatar.
| | - Sara M Fahad
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
| | - Maria K Smatti
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
| | - Balsam R Rizeq
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
- Department of Biological and Environmental Sciences, College of Arts & Sciences, Qatar University, Doha 2713, Qatar.
| | - Asmaa A Al Thani
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
- Biomedical Science Department, College of Health Sciences, Qatar University, Doha 2713, Qatar.
| | - Hadi M Yassine
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
| | - Gheyath K Nasrallah
- Biomedical Research Center, Qatar University, Doha 2713, Qatar.
- Biomedical Science Department, College of Health Sciences, Qatar University, Doha 2713, Qatar.
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6
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Successful Treatment of a South African Pediatric Case of Acute Liver Failure Caused by Perinatal Transmission of Hepatitis B. Pediatr Infect Dis J 2019; 38:e51-e53. [PMID: 29601455 DOI: 10.1097/inf.0000000000002054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We report on the successful treatment of a South African infant with hepatitis B virus (HBV)-induced acute liver failure using lamivudine with no evidence of clinical resistance. Perinatal HBV transmission occurred despite timely HBV vaccination at 6, 10 and 14 weeks, as per South African vaccination schedule, highlighting the need to introduce the birth-dose HBV vaccine in South Africa.
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7
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Norder H, Twagirumugabe T, Said J, Tian Y, Tang KW, Lindh M. High Frequency of Either Altered Pre-Core StartCodon or Weakened Kozak Sequence in the CorePromoter Region in Hepatitis B Virus A1 Strainsfrom Rwanda. Genes (Basel) 2019; 10:genes10030182. [PMID: 30813638 PMCID: PMC6471190 DOI: 10.3390/genes10030182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) is endemic in Rwanda and is a major etiologic agent for chronic liver disease in the country. In a previous analysis of HBV strains from Rwanda, the S genes of most strains segregated into one single clade of subgenotype, A1. More than half (55%) of the anti-HBe positive individuals were viremic. In this study, 23 complete HBV genomes and the core promoter region (CP) from 18 additional strains were sequenced. Phylogenetic analysis of complete genomes confirmed that most Rwandan strain formed a single unique clade, within subgenotype A1. Strains from 17 of 22 (77%) anti-HBe positive HBV carriers had either mutated the precore start codon (9 strains with either CUG, ACG, UUG, or AAG) or mutations in the Kozak sequence preceding the pre-core start codon (8 strains). These mutually exclusive mutations were also identified in subgenotypes A1 (70/266; 26%), A2 (12/255; 5%), and A3 (26/49; 53%) sequences from the GenBank. The results showed that previous, rarely described HBV variants, expressing little or no HBeAg, are selected in anti-HBe positive subgenotype Al carriers from Rwanda and that mutations reducing HBeAg synthesis might be unique for a particular HBV clade, not just for a specific genotype or subgenotype.
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Affiliation(s)
- Heléne Norder
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Theogene Twagirumugabe
- School of Medicine and Pharmacy, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda.
| | - Joanna Said
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Yarong Tian
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Ka-Wei Tang
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Magnus Lindh
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
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8
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Core gene insertion in hepatitis B virus genotype G functions at both the encoded amino acid sequence and RNA structure levels to stimulate core protein expression. Virology 2018; 526:203-213. [PMID: 30415131 DOI: 10.1016/j.virol.2018.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 02/08/2023]
Abstract
Hepatitis B virus genotype G possesses a 36-nucleotide (nt) insertion at the 5' end of core gene, adding 12 residues to core protein. The insertion markedly increased core protein level irrespective of viral genotype, with the effect reproducible using CMV-core gene construct. Here we used such expression constructs and transient transfection experiments in Huh7 cells to identify the structural bases. The insertion is predicted to create a stem-loop structure 14nt downstream of core gene AUG. A + 1 or + 2 frameshift into the 36nt mitigated enhancement of core protein level. Point mutations to disrupt or restore the stem-loop had opposite effects on core protein expression. Shifting the translation initiation site downstream or further upstream of the stem-loop rendered it inhibitory or no longer stimulatory of core protein expression. Therefore, both the reading frame and a properly positioned stem-loop structure contribute to marked increase in core protein expression by the 36-nt insertion.
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9
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Zong L, Qin Y, Jia H, Ye L, Wang Y, Zhang J, Wands JR, Tong S, Li J. Differential regulation of hepatitis B virus core protein expression and genome replication by a small upstream open reading frame and naturally occurring mutations in the precore region. Virology 2017; 505:155-161. [PMID: 28260621 DOI: 10.1016/j.virol.2017.02.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/21/2017] [Accepted: 02/23/2017] [Indexed: 01/12/2023]
Abstract
Hepatitis B virus (HBV) transcribes two subsets of 3.5-kb RNAs: precore RNA for hepatitis B e antigen (HBeAg) expression, and pregenomic RNA for core and P protein translation as well as genome replication. HBeAg expression could be prevented by mutations in the precore region, while an upstream open reading frame (uORF) has been proposed as a negative regulator of core protein translation. We employed replication competent HBV DNA constructs and transient transfection experiments in Huh7 cells to verify the uORF effect and to explore the alternative function of precore RNA. Optimized Kozak sequence for the uORF or extra ATG codons as present in some HBV genotypes reduced core protein expression. G1896A nonsense mutation promoted more efficient core protein expression than mutated precore ATG, while a +1 frameshift mutation was ineffective. In conclusion, various HBeAg-negative precore mutations and mutations affecting uORF differentially regulate core protein expression and genome replication.
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Affiliation(s)
- Li Zong
- Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, RI, USA; Key Lab of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yanli Qin
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Haodi Jia
- Key Lab of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lei Ye
- Key Lab of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yongxiang Wang
- Key Lab of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jiming Zhang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Jack R Wands
- Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, RI, USA
| | - Shuping Tong
- Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, RI, USA; Key Lab of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jisu Li
- Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, RI, USA.
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10
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Tong S, Revill P. Overview of hepatitis B viral replication and genetic variability. J Hepatol 2016; 64:S4-S16. [PMID: 27084035 PMCID: PMC4834849 DOI: 10.1016/j.jhep.2016.01.027] [Citation(s) in RCA: 276] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/18/2016] [Accepted: 01/25/2016] [Indexed: 02/06/2023]
Abstract
Chronic infection with hepatitis B virus (HBV) greatly increases the risk for liver cirrhosis and hepatocellular carcinoma (HCC). HBV isolates worldwide can be divided into ten genotypes. Moreover, the immune clearance phase selects for mutations in different parts of the viral genome. The outcome of HBV infection is shaped by the complex interplay of the mode of transmission, host genetic factors, viral genotype and adaptive mutations, as well as environmental factors. Core promoter mutations and mutations abolishing hepatitis B e antigen (HBeAg) expression have been implicated in acute liver failure, while genotypes B, C, subgenotype A1, core promoter mutations, preS deletions, C-terminal truncation of envelope proteins, and spliced pregenomic RNA are associated with HCC development. Our efforts to treat and prevent HBV infection are hampered by the emergence of drug resistant mutants and vaccine escape mutants. This paper provides an overview of the HBV life cycle, followed by review of HBV genotypes and mutants in terms of their biological properties and clinical significance.
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Affiliation(s)
- Shuping Tong
- Liver Research Center, Rhode Island Hospital, The Alpert Warren School of Medicine, Brown University, Providence, RI, USA; Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China.
| | - Peter Revill
- Research and Molecular Development, Victorian Infectious Diseases Reference Laboratory, Doherty Institute, Melbourne, VIC, Australia ()
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11
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New perspective on the natural course of chronic HBV infection. Front Med 2014; 8:129-34. [PMID: 24871442 DOI: 10.1007/s11684-014-0339-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/27/2014] [Indexed: 12/17/2022]
Abstract
Chronic hepatitis B virus (HBV) infection is a significant threat to public health and an enormous burden on society. Mechanisms responsible for chronic HBV infection remain poorly understood. A better understanding of the natural course of chronic HBV infection may shed new light on the mechanisms underlying this disease and help in designing new antiviral strategies. Natural course of chronic HBV infection is conventionally viewed as an uninterrupted process that is usually marked by HBV e antigen (HBeAg) seroconversion or characterized by different phases associated with assumed host responses to HBV infection. However, none of these descriptions captures or highlights the core events that determine the natural course of chronic HBV infection. In this review, we briefly present the current knowledge on this subject and explain the significance and implication of events that occur during infection. A pre-core mutant becomes predominant in the viral population following elimination of the wild-type virus in duck hepatitis B virus-chronically infected animals. The coupled events in which first there is viral clearance that clears wild-type virus and then there is the reinfection of wild-type virus cleared livers with mutant virus are highly relevant to understanding of the natural course of chronic HBV infection under both treated and untreated conditions. In our new perspective, a general natural course of chronic HBV infection comprises cycles of viral clearance and reinfection, and such cycles prolong the chronic HBV infection course. Reviewing published data on the natural course of chronic HBV infection can reduce the possibility of missing important points in the initial data interpretation.
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12
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Tong S, Li J, Wands JR, Wen YM. Hepatitis B virus genetic variants: biological properties and clinical implications. Emerg Microbes Infect 2013; 2:e10. [PMID: 26038454 PMCID: PMC3636426 DOI: 10.1038/emi.2013.10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/30/2013] [Accepted: 02/04/2013] [Indexed: 12/15/2022]
Abstract
Hepatitis B virus (HBV) causes a chronic infection in 350 million people worldwide and greatly increases the risk of liver cirrhosis and hepatocellular carcinoma. The majority of chronic HBV carriers live in Asia. HBV can be divided into eight genotypes with unique geographic distributions. Mutations accumulate during chronic infection or in response to external pressure. Because HBV is an RNA-DNA virus the emergence of drug resistance and vaccine escape mutants has become an important clinical and public health concern. Here, we provide an overview of the molecular biology of the HBV life cycle and an evaluation of the changing role of hepatitis B e antigen (HBeAg) at different stages of infection. The impact of viral genotypes and mutations/deletions in the precore, core promoter, preS, and S gene on the establishment of chronic infection, development of fulminant hepatitis and liver cancer is discussed. Because HBV is prone to mutations, the biological properties of drug-resistant and vaccine escape mutants are also explored.
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Affiliation(s)
- Shuping Tong
- Liver Research Center, Rhode Island Hospital, The Alpert Warren School of Medicine, Brown University , Providence, RI 02906, USA ; Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University , Shanghai 200032, China
| | - Jisu Li
- Liver Research Center, Rhode Island Hospital, The Alpert Warren School of Medicine, Brown University , Providence, RI 02906, USA
| | - Jack R Wands
- Liver Research Center, Rhode Island Hospital, The Alpert Warren School of Medicine, Brown University , Providence, RI 02906, USA
| | - Yu-Mei Wen
- Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University , Shanghai 200032, China
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13
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Tedder RS, Rodger AJ, Fries L, Ijaz S, Thursz M, Rosenberg W, Naoumov N, Banatvala J, Williams R, Dusheiko G, Chokshi S, Wong T, Rosenberg G, Moreea S, Bassendine M, Jacobs M, Mills PR, Mutimer D, Ryder SD, Bathgate A, Hussaini H, Dillon JF, Wright M, Bird G, Collier J, Anderson M, Johnson AM. The diversity and management of chronic hepatitis B virus infections in the United Kingdom: a wake-up call. Clin Infect Dis 2012; 56:951-60. [PMID: 23223601 DOI: 10.1093/cid/cis1013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Through migration, diversity of chronic hepatitis B virus (HBV) infection has changed, affecting disease burden and control. We describe clinical and viral characteristics of chronic HBV in the United Kingdom. METHODS A total of 698 individuals with chronic HBV infection were recruited from referral liver centers. Demographic, clinical, and laboratory data were collected. RESULTS Sixty-one percent of patients were male, 80% were not born in the United Kingdom, and the largest ethnicity was East/Southeast Asian (36%). Twenty-two percent were hepatitis B e antigen (HBeAg) seropositive; 20.4% (59/289) had cirrhosis and 10 (1.7%) had hepatocellular carcinoma. Genotype D was most common (31%) followed by A, C, B, and E (20%, 20%, 19%, and 9%, respectively). Genotype was significantly associated with country of birth, length of time in the United Kingdom, HBeAg status, and precore and basal core promoter mutations. One-third were on treatment, with men independently more likely to be treated. Only 18% of those on treatment were on recommended first-line therapies, and 30% were on lamivudine monotherapy. Among treated individuals, 27% had antiviral drug resistance. Testing rates for human immunodeficiency virus, hepatitis C virus, and delta coinfections were low. CONCLUSIONS We demonstrated diversity of chronic HBV infections in UK patients, suggesting that optimal management requires awareness of the variable patterns of chronic HBV in countries of origin. We also found less-than-optimal clinical management practices, possible gender-based treatment bias, and the need to improve testing for coinfections.
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Affiliation(s)
- Richard S Tedder
- Microbiology Services-Colindale, Health Protection Agency, London, UK
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14
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Yang HI, Hung HL, Lee MH, Liu J, Jen CL, Su J, Wang LY, Lu SN, You SL, Iloeje UH, Chen CJ. Incidence and determinants of spontaneous seroclearance of hepatitis B e antigen and DNA in patients with chronic hepatitis B. Clin Gastroenterol Hepatol 2012; 10:527-34.e1-2. [PMID: 22178461 DOI: 10.1016/j.cgh.2011.12.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/05/2011] [Accepted: 12/01/2011] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The spontaneous seroclearance of hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA are important markers of progression of chronic HBV infection. We performed a long-term cohort study to elucidate the incidence and determinants of HBeAg and HBV DNA seroclearance in patients with chronic hepatitis B. METHODS A total of 1289 participants with a serum HBV DNA level of 10,000 copies/mL or more and without cirrhosis when the study began (1991-1992) were followed up until June 2004. A subset of patients that tested positive for HBeAg at baseline (n = 439) was included in the analysis of HBeAg seroclearance. Cox proportional hazards models were used to estimate seroclearance rate ratios for various determinants associated with the outcomes. RESULTS After 3161.2 person-years of follow-up evaluation, HBeAg seroclearance occurred in 187 participants (incidence rate, 5.9 per 100 person-years). The cumulative lifetime incidence of HBeAg seroclearance among patients who were 30 to 40, or 50, 60, 70, or 74 years old was 38.8%, 69.4%, 81.9%, 89.1%, and 95.5%, respectively. Major predictors of HBeAg seroclearance included female sex, genotype B, the precore 1896 mutant, increased serum levels of alanine aminotransferase, and low baseline serum levels of HBV DNA. The median (interquartile range) serum level of HBV DNA at the time of HBeAg seroclearance was 177,801 copies/mL (4941-3,247,560 copies/mL). HBV DNA seroclearance occurred in 199 participants (15.4%) during the mean follow-up period of 7.8 years (incidence rate, 1.97 per 100 person-years). The cumulative lifetime incidence of HBV DNA seroclearance at 40, 50, 60, 70, and 77 years old was 10.0%, 25.0%, 38.8%, 54.2%, and 82.8%, respectively. Lower levels of HBV DNA at study entry and among those with the precore 1896 wild-type variant were associated with an increased rate of HBV DNA seroclearance. Among individuals who were HBeAg-seropositive at study entry and cleared serum HBV DNA during the follow-up period, 89% had cleared HBeAg by the time they had an undetectable serum level of HBV DNA. CONCLUSIONS Serum level of HBV DNA is the most important predictor of seroclearance of HBeAg and HBV DNA. This finding supports current clinical guidelines for antiviral treatments of chronic hepatitis B.
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Affiliation(s)
- Hwai-I Yang
- Molecular and Genomic Epidemiology Center, China Medical University Hospital, Taichung, Taiwan.
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15
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Characterization of the pleiotropic effects of the genotype G-specific 36-nucleotide insertion in the context of other hepatitis B virus genotypes. J Virol 2011; 85:13278-89. [PMID: 21994450 DOI: 10.1128/jvi.05583-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The pregenomic RNA (pgRNA) of hepatitis B virus (HBV) serves as the messenger for both core and P proteins, with the downstream P gene translated by ribosomal leaky scanning. HBV replication begins with packaging of the pgRNA and P protein into core protein particles, followed by conversion of RNA into DNA. Genotype G has a low replication capacity due to a low pgRNA level. It has a 36-nucleotide (nt) insertion in the 5' end of the core gene, adding 12 residues to the core protein. The insertion is needed to maintain efficient core protein expression and genome replication but causes inefficient virion secretion yet high maturity of virion DNA. In the present study, we confirmed that the 36-nt insertion had similar effects on core protein expression and virion secretion when it was introduced into genotype A and D clones but no impact on virion genome maturity. Surprisingly, the insertion impaired genome replication in both genotypes. Transcomplementation assays suggest that increased efficiency of core protein translation diminishes ribosomal scanning toward the downstream P gene. Indeed, mutating the core gene Kozak sequence restored core protein to lower levels but increased replication of the insertion mutant. Similar mutations impaired replication in genotype G. On the other hand, replacement of the core promoter sequence of genotype G with genotype A sequence increased pgRNA transcription and genome replication, implicating this region in the low replication capacity of genotype G. Why the 36-nt insertion is present in genotype G but absent in other genotypes is discussed.
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16
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Hepatitis B virus genotype C isolates with wild-type core promoter sequence replicate less efficiently than genotype B isolates but possess higher virion secretion capacity. J Virol 2011; 85:10167-77. [PMID: 21775451 DOI: 10.1128/jvi.00819-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Infection by hepatitis B virus (HBV) genotype C is associated with a prolonged viremic phase, delayed hepatitis B e antigen (HBeAg) seroconversion, and an increased incidence of liver cirrhosis and hepatocellular carcinoma compared with genotype B infection. Genotype C is also associated with the more frequent emergence of core promoter mutations, which increase genome replication and are independently associated with poor clinical outcomes. We amplified full-length HBV genomes from serum samples from Chinese and U. S. patients with chronic HBV infection and transfected circularized genome pools or dimeric constructs of individual clones into Huh7 cells. The two genotypes could be differentiated by Western blot analysis due to the reactivities of M and L proteins toward a monoclonal pre-S2 antibody and slightly different S-protein mobilities. Great variability in replication capacity was observed for both genotypes. The A1762T/G1764A core promoter mutations were prevalent in genotype C isolates and correlated with increased replication capacity, while the A1752G/T mutation frequently found in genotype B isolates correlated with a low replication capacity. Importantly, most genotype C isolates with wild-type core promoter sequence replicated less efficiently than the corresponding genotype B isolates due to less efficient transcription of the 3.5-kb RNA. However, genotype C isolates often displayed more efficient virion secretion. We propose that the low intracellular levels of viral DNA and core protein of wild-type genotype C delay immune clearance and trigger the subsequent emergence of A1762T/G1764A core promoter mutations to upregulate replication; efficient virion secretion compensates for the low replication capacity to ensure the establishment of persistent infection by genotype C.
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17
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Araujo NM, Waizbort R, Kay A. Hepatitis B virus infection from an evolutionary point of view: how viral, host, and environmental factors shape genotypes and subgenotypes. INFECTION GENETICS AND EVOLUTION 2011; 11:1199-207. [PMID: 21539937 DOI: 10.1016/j.meegid.2011.04.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 03/22/2011] [Accepted: 04/14/2011] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) has an overwhelming distribution in the world and causes important human health problems. It has infected one-third of the global population and more than 350 million people are chronic carriers. Several aspects of HBV infection confer adaptive advantages that lead to a highly efficient dissemination of the virus through different routes of transmission. HBV genotypes and subgenotypes have been associated with differences in clinical and virological characteristics, indicating that they may play a role in the virus-host relationship. In particular, a clear association between genotype A and chronic outcomes in both children and adults depending on the subgenotype involved, and between genotype C and a higher risk of complications from HBV infection, has been demonstrated. Interestingly, subgenotype A2 and genotype C are respectively likely to predominate in high-risk groups for sexual transmission and in areas where perinatal transmission is the major mode of HBV dissemination. An evolutionary approach to HBV infection, based on the principles of natural selection, may offer explanations for how modes of transmission may favor some genotypes and subgenotypes over others and, ultimately, influence HBV virulence.
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Affiliation(s)
- Natalia M Araujo
- Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Av. Brasil, 4365, CEP 21040-360, Rio de Janeiro, RJ, Brazil.
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18
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Qin Y, Zhang J, Mao R, Guo H, Yin Y, Wu X, Weng X, Wands J, Tong S. Prevalence of basal core promoter and precore mutations in Chinese chronic hepatitis B patients and correlation with serum HBeAG titers. J Med Virol 2009; 81:807-14. [PMID: 19319958 PMCID: PMC6329877 DOI: 10.1002/jmv.21439] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The A1762T and G1764A mutations in the basal core promoter (BCP) region and the G1896A mutation in the precore (PC) region of hepatitis B virus (HBV) genome are found commonly in HBeAg-negative patients. Experiments in vitro suggest that BCP and PC mutation reduce and abolish HBeAg expression, respectively. In the present study, the prevalence of the BCP and PC mutations were determined in 207 patients with HBeAg positive chronic hepatitis B from China and correlated with the titers of serum HBeAg. None of the patients received antiviral therapy. The HBV genotype was determined by direct sequencing of the HBsAg gene. The BCP and PC mutations were detected by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and confirmed by DNA sequencing. The HBeAg titer was measured by the microparticle enzyme immunoassay. Fifty-one of the 207 patients (24.6%) were infected with genotype B and the remainder with genotype C. The BCP mutations were detected in 103 patients (50%) while the PC mutation was present in 43 (20.8%). Thirteen patients (6.3%) harbored both BCP and PC mutations. No significant difference in the titers of HBeAg was found between patients infected with the two HBV genotypes, but the presence of either the BCP or PC mutation was associated with reduced HBeAg titer (P < 0.05). The presence of both the BCP and PC mutations was accompanied by even lower HBeAg titer (P < 0.05). These findings confirm that in patients with HBeAg, the BCP and PC mutations reduced the expression of HBeAg.
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Affiliation(s)
- Yanli Qin
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiming Zhang
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Richeng Mao
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hongying Guo
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Youkuan Yin
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xianghui Wu
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xinhua Weng
- Department of Infectious Diseases, Huashan Hospital, and Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jack Wands
- The Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, Rhode Island
| | - Shuping Tong
- The Liver Research Center, Rhode Island Hospital, Warren Alpert School of Medicine, Brown University, Providence, Rhode Island
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19
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Yim HJ. [Hepatitis B virus genetic diversity and mutant]. THE KOREAN JOURNAL OF HEPATOLOGY 2009; 14:446-64. [PMID: 19119240 DOI: 10.3350/kjhep.2008.14.4.446] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatitis B virus (HBV) is a partially double stranded DNA virus with genetic diversity represented by eight genotypes (A to H). Natural course and response to treatment could be affected by HBV genotypes. HBV shows high rates of turn over in the absence of proof-reading ability. As a result, large amounts of quasispecies are produced naturally or antiviral-associated. HBV consists of four open reading frames, namely preS/S gene, precore/core gene, polymerase gene, and X gene. Mutations on preS gene can result in undetectable HBsAg even in case that HBV is replicating. Surface gene mutation leads to decreased binding affinity to anti-HBs, which is associated with a vaccine escape mutant. Precore mutation abolishes HBeAg whereas mutations on basal core promoter gene down-regulate the HBeAg production. Mutations on basal core promoter are associated with increased HBV replication and high incidence of progressive liver diseases such as liver cirrhosis and hepatocellular carcinoma. Mutations on polymerase genes are often induced by antiviral therapy. Emergence of antiviral-resistant mutation is the major cause of treatment failure. Furthermore, existence of prior antiviral-resistant mutations limits the options of subsequent antiviral agents. Therefore, judicious use of antivirals and selection of the most potent drug with the lowest resistance rate are of the utmost importance for the prevention of antiviral-associated mutants. Detailed knowledge and understanding of HBV genetic diversity and mutant would be critical to establish strategies for the diagnosis and management of HBV infection.
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Affiliation(s)
- Hyung Joon Yim
- Department of Internal Medicine, Korea University College of Medicine, Ansan, Korea.
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20
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Cheng H, Su H, Wang S, Shao Z, Men K, Li M, Li S, Zhang J, Xu J, Zhang H, Yan Y, Xu D. Association between genomic heterogeneity of hepatitis B virus and intrauterine infection. Virology 2009; 387:168-75. [PMID: 19272629 DOI: 10.1016/j.virol.2009.02.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 12/03/2008] [Accepted: 02/03/2009] [Indexed: 12/18/2022]
Abstract
Hepatitis B virus (HBV) intrauterine infection remains to be an important cause for a large number of persistent hepatitis B surface antigen (HBsAg) positive carriers in areas with a high HBV prevalence, particularly in China and Southeast Asia. In this study, the possible association between the HBV genomic heterogeneity and intrauterine infection was investigated by comparing the quasi species isolated from eight pairs of HBsAg-positive mothers and their neonates, who were infected intrauterinely with HBV, with clones from eight HBsAg-positive mothers whose neonates were not infected with HBV. The proportion of clones with specific mutations was compared among different subject groups, and phylogenetic analysis was performed to evaluate the significance of specific mutations. It was observed that the core promoter with conserved major functional regions and conserved hepatitis B e antigen (HBeAg) might be beneficial to HBV maternal-fetal transmission. Particularly, A1762T/G1764A mutations seemed to be disadvantageous for fetal infection. It was also shown that amino acid substitutions located in the immune epitopes of HBsAg were strongly associated with intrauterine HBV transmission. The clones with mutations such as amino acid P110S in preS1 region, P36L in preS2 region and C107R in S region might infect fetuses more readily. In addition, positively selected site analysis confirmed the above results.
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Affiliation(s)
- Hai Cheng
- Department of Epidemiology, Faculty of Preventive Medicine, Fourth Military Medical University, No. 17, Changle West Road, Xi'an 710032, China
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21
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Characterization of genotype-specific carboxyl-terminal cleavage sites of hepatitis B virus e antigen precursor and identification of furin as the candidate enzyme. J Virol 2009; 83:3507-17. [PMID: 19193799 DOI: 10.1128/jvi.02348-08] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Hepatitis B e antigen (HBeAg) is a secreted version of hepatitis B virus (HBV) core protein that promotes immune tolerance and persistent infection. It is derived from a translation product of the precore/core gene by two proteolytic cleavage events: removal of the amino-terminal signal peptide and removal of the carboxyl-terminal arginine-rich sequence. Four RXXR motifs are present at the carboxyl terminus of the HBeAg precursor, with the first two fused as (151)RRGRSPR(157). Genotype A possesses two extra amino acids at the first motif ((151)RRDRGRSPR(159)), which weakens the first motif and separates it from the second one. Western blot analysis of patient sera revealed a single HBeAg form for genotypes B to D but two additional forms of larger sizes for genotype A. Site-directed mutagenesis and transfection experiments with human hepatoma cell lines indicated that HBeAg of genotype B is derived from cleavage at the first ((151)RRGR(154)) motif. The major HBeAg form of genotype A corresponds to cleavage at the second ((156)RSPR(159)) motif, and the other two forms are cleavage products of the first ((151)RRDR(154)) and third ((166)RRRR(169)) motifs, respectively. Only the cleavage product of the third motif of genotype A was observed in furin-deficient LoVo cells, and an inhibitor of furin-like proprotein convertases blocked cleavage of the first and second motifs in human hepatoma cells. In conclusion, our study reveals genotypic differences in HBeAg processing and implicates furin as the major enzyme involved in the cleavage of the first and second RXXR motifs.
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22
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Shen T, Yan XM, Zou YL, Gao JM, Dong H. Virologic characteristics of hepatitis B virus in patients infected via maternal-fetal transmission. World J Gastroenterol 2008; 14:5674-5682. [PMID: 18837083 PMCID: PMC2748201 DOI: 10.3748/wjg.14.5674] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 08/22/2008] [Accepted: 08/29/2008] [Indexed: 02/06/2023] Open
Abstract
AIM To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts. METHODS Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected by double-restriction endonuclease digestion (EcoRI and HindIII) and PCR. Twenty seven clones were randomly selected from an asymptomatic mother [at two time points: 602 (1 d) and 6022 (6 mo)] and her son [602 (S)], and the phylogenetic and mutational analysis was performed using BioEditor, Clustal X and MEGA software. Potential immune epitopes were determined by the Stabilized Matrix Method (SMM), SMM-Align Method and Emini Surface Accessibility Prediction. RESULTS All of the 27 sequences were genotype C, the divergence between the mother and son was 0%-0.8%. Compared with another 50 complete sequences of genotype C, the mother and her son each had 13 specific nucleotides that differed from the other genotype C isolates. AA 1-11 deletion in preS1 was the dominant mutation in the mother (14/18). The 1762T/1764A double mutation existed in all clones of the mother, 3 of them were also coupled with G1896A mutation, but none were found in the son. 17 bp deletion starting at nucleotide 2330 was the major mutation (5/9) in the son, which caused seven potential HLA class I epitopes and one B cell epitope deletion, and produced a presumptive new start codon, downstream from the original one of the P gene. CONCLUSION The HBV strain in the son came from his mother, and discrepant mutation occurred in the mother and her son during infection.
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Poustchi H, Mohamadkhani A, Bowden S, Montazeri G, Ayres A, Revill P, Farrell GC, Locarnini S, George J, Malekzadeh R. Clinical significance of precore and core promoter mutations in genotype D hepatitis B-related chronic liver disease. J Viral Hepat 2008; 15:753-60. [PMID: 18507754 DOI: 10.1111/j.1365-2893.2008.00998.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The impact of mutations in the precore and basal core promoter (BCP) regions of the hepatitis B virus on the course of chronic liver disease is not well established. We sought to examine the relationship of these characteristics to the clinical expression of liver disease in patients infected with genotype D chronic hepatitis B (CHB). BCP and precore mutations in 110 patients with genotype D1 CHB were determined and correlated with clinical phenotype. Of 110 patients, 95 (86.5%) were HBeAg-negative. Compared with HBeAg-positive subjects, HBeAg-negative patients were over a decade older and had lower viral loads (3.70 +/- 0.98 vs 5.77 +/- 0.69 log copies/ml, P < 0.001). The double mutation A1762T-G1764A was more prevalent in patients with advanced liver disease (AdLD) and was associated with higher alanine aminotransferase and viral load. After adjusting for age, there was a more than fourfold increase in the risk of AdLD with this mutation (OR = 4.4; 95% CI: 1.13-16.92, P < 0.03). Conversely, the G1757A substitution was associated with protection, being 90% less frequent among patients with AdLD (P = 0.001). The results indicate that in genotype D CHB, the presence of the A1762T-G1764A mutation was associated with more aggressive liver disease while the G1757A substitution was associated with protection from advanced disease.
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Affiliation(s)
- H Poustchi
- Medical Science , University Tehran, Iran
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24
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Abbas N, Ahmad A, Shakoori AR. Overexpression and purification of PreS region of hepatitis B virus antigenic surface protein adr subtype in Escherichia coli. BMB Rep 2008; 40:1002-8. [PMID: 18047797 DOI: 10.5483/bmbrep.2007.40.6.1002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli DH5alpha cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-41 degrees C) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at 37 degrees C for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at -80 degrees.
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Affiliation(s)
- Naaz Abbas
- School of Biological Sciences, University of the Punjab, New Campus, Lahore 54590, Pakistan
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25
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Abstract
This article reviews the molecular biology of the hepatitis B virus in an effort to explain its natural history from a molecular perspective. The life cycle of the virus, with special attention to virus replication, polypeptide production, and morphogenesis, is described. The way in which these steps may influence the natural history of viral pathogenesis, as well as the effectiveness of interventions, receives special consideration.
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Li K, Zoulim F, Pichoud C, Kwei K, Villet S, Wands J, Li J, Tong S. Critical role of the 36-nucleotide insertion in hepatitis B virus genotype G in core protein expression, genome replication, and virion secretion. J Virol 2007; 81:9202-15. [PMID: 17567705 PMCID: PMC1951435 DOI: 10.1128/jvi.00390-07] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 05/31/2007] [Indexed: 12/21/2022] Open
Abstract
Frequent coinfection of hepatitis B virus genotype G with genotype A suggests that genotype G may require genotype A for replication or transmission. In this regard, genotype G is unique in having a 12-amino-acid extension in the core protein due to a 36-nucleotide insertion near the core gene translation initiation codon. The insertion alters base pairing in the lower stem of the pregenome encapsidation signal, which harbors the core gene initiator, and thus has the potential to affect both core protein translation and pregenomic RNA encapsidation. Genotype G is also unusual for possessing two nonsense mutations in the precore region, which together with the core gene encode a secreted nonstructural protein called hepatitis B e antigen (HBeAg). We found that genotype G clones were indeed incapable of HBeAg expression but were competent in RNA transcription, genome replication, and virion secretion. Interestingly, the 36-nucleotide insertion markedly increased the level of core protein, which was achieved at the level of protein translation but did not involve alteration in the mRNA level. Consequently, the variant core protein was readily detectable in patient blood. The 12-amino-acid insertion also enhanced the genome maturity of secreted virus particles, possibly through less efficient envelopment of core particles. Cotransfection of genotypes G and A did not lead to mutual interference of genome replication or virion secretion. Considering that HBeAg is an immunotolerogen required for the establishment of persistent infection, its lack of expression rather than a replication defect could be the primary determinant for the rare occurrence of genotype G monoinfection.
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Affiliation(s)
- Ke Li
- Liver Research Center, Rhode Island Hospital, Brown University, Providence, Rhode Island 02903, USA
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27
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Peng JL, Zhao YG, Mai JH, Pang WK, Guo W, Chen GM, Mo GY, Rao GR, Xu YH. Non-cytolytic antigen clearance in DNA-vaccinated mice with electroporation. Acta Pharmacol Sin 2007; 28:1024-30. [PMID: 17588339 DOI: 10.1111/j.1745-7254.2007.00591.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
AIM To explore the potential of electroporation (EP)-mediated hepatitis B virus (HBV) DNA vaccination for the treatment of chronic HBV infection. METHODS BALB/c mice were vaccinated with HBV DNA vaccine encoding for the HBV preS(2)-S antigen, combined with or without EP. HBV surface antigen expression plasmid was administered into mice liver via a hydrodynamic injection to mimic HBV infection. The clearance of antigen in the serum and liver was detected by ELISA assay and immunohistochemical staining. The histopathology of the liver tissues was examined by HE staining and serum alanine aminotransferase assay. RESULTS The immunogenicity of HBV DNA vaccine encoding for the HBV preS(2)- S antigen can be improved by EP-mediated vaccine delivery. The elicited immune responses can indeed reduce the expression of HBV surface antigen (HBsAg) in hepatocytes of the mouse model that was transfected to express HBsAg using the hydrodynamic injection method. The antigen clearance process did not cause significant toxicity to liver tissue, suggesting a non-cytolytic mechanism. CONCLUSION The EP-aided DNA vaccination may have potential in mediating viral clearance in chronic hepatitis B patients.
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Affiliation(s)
- Jin-liang Peng
- Schools of Life Sciences and Technology, Shanghai Jiao Tong University, Shanghai 200240, China
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Tong S. Impact of viral genotypes and naturally occurring mutations on biological properties of hepatitis B virus. Hepatol Res 2007; 37:S3-8. [PMID: 17627632 DOI: 10.1111/j.1872-034x.2007.00097.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hepatitis B patients worldwide are infected with different viral genotypes. Within the same individual the dominant viral species evolves over the course of chronic infection to generate viral variants or mutants. The mutations, often selected by the host immune response or antiviral therapy, are sometimes restricted by viral genotypes. We are interested in characterizing mutations that affect the expression of hepatitis B e-antigen (HBeAg), a protein with a large effect on duration of infection and severity of liver diseases. HBeAg is encoded by the precore region in addition to the core gene. Core promoter mutations reduce HBeAg expression at the transcriptional level. We found that the hot spot mutations (A1762T/G1764A) only mildly reduced HBeAg expression and enhanced genome replication, while incorporation of additional core promoter mutations intensified both phenotypes. At the step of translation, a G1896A nonsense mutation in the precore region abolishes HBeAg expression. We first reportedthat the G1896A mutation rarely occurred in genotype A. Subsequent studies by others established the role of polymorphism at nucleotide 1858, rather than genotype, as the determinant for the G1896A mutation. Conversion of the precore/core protein to HBeAg requires proteolytic removal of both the amino and carboxy termini, and a (151)RRGR(154) motif has been implicated as the carboxy terminal cleavage site. In this regard, genotype A is unique in possessing a dipeptide insertion that expands the motif into (151)RRDRGR(156). We found that genotype A is cleaved primarily at R156, generating a mature HBeAg that is two amino acids longer than HBeAg from other genotypes. There are different avenues whereby HBeAg expression or its antigenicity can be modulated by viral genotype and naturally occurring mutations.
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Affiliation(s)
- Shuping Tong
- Liver Research Center, Rhode Island Hospital, Brown University, Providence, Rhode Island, USA
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29
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De Maddalena C, Giambelli C, Tanzi E, Colzani D, Schiavini M, Milazzo L, Bernini F, Ebranati E, Cargnel A, Bruno R, Galli M, Zehender G. High level of genetic heterogeneity in S and P genes of genotype D hepatitis B virus. Virology 2007; 365:113-24. [PMID: 17451771 DOI: 10.1016/j.virol.2007.03.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 01/30/2007] [Accepted: 03/09/2007] [Indexed: 12/17/2022]
Abstract
The genetic heterogeneity of hepatitis B virus (HBV) genotypes and subgenotypes was investigated by directly sequencing amplified PreS, S and P genes of HBV isolates obtained from the plasma of 99 subjects with chronic HBV infection. Genotype D showed the greatest intragenotypic and intrasubgenotypic divergence: in particular, the a determinant was mutated in 58.2% of the genotype D patients, two of whom showed prototypic vaccine-induced escape mutants at codon 145. Moreover, five sites under significant positive selection were found in the S protein of the D isolates: one in the a determinant and four in the highly hydrophobic C terminal. Our results suggest that careful surveillance of vaccine-induced escape mutants should be considered in populations with highly frequent genotype D infections, and raise questions concerning the possible relationship between the genetic heterogeneity, host immunity and pathogenicity of this HBV genotype.
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Affiliation(s)
- Chiara De Maddalena
- Department of Clinical Sciences Luigi Sacco, Section of Infectious Diseases, University of Milan, Milan, Italy
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30
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Kay A, Zoulim F. Hepatitis B virus genetic variability and evolution. Virus Res 2007; 127:164-76. [PMID: 17383765 DOI: 10.1016/j.virusres.2007.02.021] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Revised: 01/12/2007] [Accepted: 02/22/2007] [Indexed: 02/07/2023]
Abstract
Hepatitis B virus has been evolving gradually over a long period of time, resulting in a large amount of genetic diversity, despite the constraints imposed by the complex genetic organization of the viral genome. This diversity is partly due to virus/host interactions and partly due to parallel evolution in geographically distinct areas. Recombination also appears to be an important element in HBV evolution. Also, human intervention in the form of mass vaccination and antiviral treatment will reduce the burden of HBV-related liver disease but may also be accelerating evolution of the virus.
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Affiliation(s)
- Alan Kay
- INSERM, U871, Physiopathologie moléculaire et nouveaux traitements des hépatites virales, 151 cours A. Thomas, Lyon F-69424, France.
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31
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Zhao YG, Peng B, Deng H, Chen G, Yang F, Shao M, Lu H, Li Y, Peng J, Xu L, Xu Y. Anti-HBV immune responses in rhesus macaques elicited by electroporation mediated DNA vaccination. Vaccine 2006; 24:897-903. [PMID: 16253404 DOI: 10.1016/j.vaccine.2005.08.093] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 05/25/2005] [Accepted: 08/25/2005] [Indexed: 11/27/2022]
Abstract
Electroporation has been shown to be an effective method to improve the efficiency of gene expression and the immunogenicity of DNA vaccines. In order to optimize the procedure and test for its efficacy in more clinically relevant large animal models, we examined the detailed immune responses in rhesus macaques after vaccination intramuscularly with electroporation using the plasmid encoding for HBV preS(2)-S antigen and an adjuvant plasmid encoding for hIL-2 and hIFN-gamma. Several important factors were examined, including the dose response relationships, the effect of various prime and boost regimens, and different combinations of electro-pulse parameters. The immune responses were closely followed for more than a year. The results showed that in rhesus macaques, electroporation can significantly enhance the immunogenicity of the DNA vaccines, resulting in greatly improved antibody responses as well as peptide-stimulated IFN-gamma producing T cell responses. In addition, we also reported the different antibody response behaviors resulted from different electro-pulse parameters. The detailed data would be useful to suggest possible optimization strategies for better DNA vaccine efficacy.
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Affiliation(s)
- Yong-Gang Zhao
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China
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32
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Faure E. Alternative peptide-fusion proteins generated by out-of-frame mutations, just upstream ORFs or elongations in mutants of human hepatitis B viruses. Virus Res 2005; 117:185-201. [PMID: 16364485 DOI: 10.1016/j.virusres.2005.10.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 10/28/2005] [Accepted: 10/28/2005] [Indexed: 12/18/2022]
Abstract
By various means including out-of-frame mutations, just upstream ORFs and elongations, additional peptide fusions could be generated by mutants of Human Hepatitis B Virus (HBV). Numerous frameshift mutations inducing long alternative open reading frames have been evidenced in all HBV genes. Interestingly, these mutants are frequently detected in severe liver diseases, but seldom in asymptomatic carriers. The high level of conservation of some of these sequences in spite of the fact that they could be generated by different types of mutations, as their presence in mutants found on various continents, suggest that these mutations could play a role. These mutants could combine two advantages, that related to the loss of a part of a wild-type protein and that related to the putative advantage conferred by the additional sequences. In addition, in numerous Asian genomes (more than 300 to date) pre-X or pre-pre-S regions were found just upstream to, respectively, the X and the pre-S1 genes. These two regions are translated with their respective genes in frame and recent studies have evidenced the transactivating role of the corresponding proteins. With some exceptions, these regions are genotype- and serotype-specific (C/adr). In addition, these mutants have been found principally in patients with severe hepatitis diseases, for example, hepatocarcinoma in more than one third of the cases. As additional sequences generated by HBV variants may be relevant for viral life cycle, persistence and pathogenesis, further investigations are necessary to give a clearer picture of the subject.
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Affiliation(s)
- E Faure
- E.R. Biodiversity and environment, case 5, University of Provence, Place Victor Hugo, 13331 Marseilles cedex 3, France.
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33
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Bozdayi G, Türkyilmaz AR, Idilman R, Karatayli E, Rota S, Yurdaydin C, Bozdayi AM. Complete genome sequence and phylogenetic analysis of hepatitis B virus isolated from Turkish patients with chronic HBV infection. J Med Virol 2005; 76:476-81. [PMID: 15977237 DOI: 10.1002/jmv.20386] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hepatitis viruses are the leading causes of chronic liver disease resulting in chronic hepatitis, cirrhosis, and hepatocellular carcinoma in the world and also in Turkey. Although Turkey has an intermediate rate of hepatitis B virus (HBV) infection with a prevalence reported as 5%, a complete HBV genome sequence has not been published. In this study, the molecular characterization and phylogenetic analysis are described of 11 complete HBV genomes isolated from 11 naïve patients (5 male, 6 female; ages: 18--54 years old, median 35 years old) with chronic HBV infection. Of 11 patients, 7 and 4 were HBeAg positive/anti-HBe negative and HBeAg negative/anti-HBe positive, respectively. All patients had no co-infection with HCV, HDV, or HIV. HBV DNA was extracted from the sera of the patients. The complete genome was amplified by PCR and cloned into a TA vector. The PCR products were sequenced directly and the complete HBV genome sequences were determined. Ten HBV genomes were 3182 base pairs in length. There was a 183 bp deletion (between nucleotides 2987--3169) in pre-S region in one HBeAg positive patient. There were two pre-core stop codons (G1896A) in two HBeAg negative and three core promoter dual mutations (T1762/A1764) in one HBeAg positive and two HBeAg negative patients' HBV genomes. Phylogenetic analysis of all complete genomes yielded that all Turkish sequences were clustered in genotype D branch (ten in subgenotype D1 and one in subgenotype D2). The analysis of S gene amino acid sequences revealed that surface gene subtypes of one and ten HBV strains were subtype ayw3 and ayw2, respectively. This study indicates that Turkish patients with chronic hepatitis B infection show very little genotypic heterogeneity. Genotype D of HBV DNA and subtype ayw2 of surface gene represent almost the whole Turkish patient population infected with HBV.
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Affiliation(s)
- Gülendam Bozdayi
- Department of Microbiology, School of Medicine, Gazi University, Ankara, Turkey.
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34
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Peng XM, Huang GM, Li JG, Huang YS, Mei YY, Gao ZL. High level of hepatitis B virus DNA after HBeAg-to-anti-HBe seroconversion is related to coexistence of mutations in its precore and basal core promoter. World J Gastroenterol 2005; 11:3131-4. [PMID: 15918203 PMCID: PMC4305853 DOI: 10.3748/wjg.v11.i20.3131] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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
AIM: G1896A mutation in precore or A1762T/G1764A mutations in basal core promoter are suspected to be responsible for patients with detectable level of HBV DNA in serum after seroconversion from HBeAg to anti-HBe. However, G1896A variant has impaired, while A1762T/G1764A variant may have intact replication ability. They themselves or their coexistence status may play different roles in such meaningless seroconversion. For these reasons, the significances of these two types of mutations were comparatively investigated in this study.
METHODS: One hundred and sixty-five sera with positive anti-HBe and HBV DNA were collected from different patients. Mutations of G1896A and A1762T/G1764A among these serum samples were detected using competitively differentiated PCR. HBV DNA was demonstrated using real-time quantitative PCR.
RESULTS: G1896A and/or A1762T/G1764A mutations were detected in 89.1% (147/165) out of patients with detectable HBV DNA in serum after HBeAg-to-anti-HBe seroconversion. The positive rate of G1896A variants was significantly higher than that of A1762T/G1764A mutations (77.6% vs 50.3%, χ2 = 26.61, P<0.01). The coexistence positive rate of these two types of mutations was 38.8% (64/165). Coexistence mutations were found in 77.1% (64/83) out of sera with A1762T/G1764A mutations, and in 50.0% (64/128) out of sera with G1896A mutation. Compared with variants with G1896A mutation only, the coexistence mutations were predominant in patients with high level of serum HBV DNA, and related to higher total bilirubin, lower serum albumin and progressive liver diseases.
CONCLUSION: The coexistence of G1896A mutation and A1762T/G1764A mutations is very common, and responsible for the major cases with high level of HBV DNA in serum and progressive liver diseases after HBeAg-to-anti-HBe seroconversion. This coexistence mutation variant may have higher pathogenicity and replication ability.
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Affiliation(s)
- Xiao-Mou Peng
- Department of Infectious Diseases, Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, Guangdong Province, China.
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35
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Michitaka K, Horiike N, Chen Y, Duong TN, Matsuura K, Tokumoto Y, Hiasa Y, Akbar FSM, Onji M. Co-Infection with Hepatitis B Virus Genotype D and Other Genotypes in Western Japan. Intervirology 2005; 48:262-7. [PMID: 15920351 DOI: 10.1159/000084604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Accepted: 10/29/2004] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE Genotypes B and C are the prevalent hepatitis B virus (HBV) genotypes in eastern Asia. Although very rare in this region of the world, genotype D was found to be prevalent in a small area of western Japan. In this study, we confirm the frequency and clinical significance of co-infection with different genotypes among patients from that area infected with genotype D. METHODS Twenty-three patients from the same area of western Japan infected with HBV genotype D, determined using a genotyping enzyme immunoassay, were studied. Cloning was done using DNA extracted from serum samples, and polymerase chain reaction assays with the restriction fragment length polymorphism for HBV genotyping were performed with 10 clones from each patient. RESULTS Four (17.4%) of the 23 patients were found to be co-infected with HBV genotype C, and the HB surface antigen subtype was ayw in both mono- and co-infected patients. No clinical differences were found between mono-infected and co-infected patients carrying genotype D. CONCLUSION A significant number of patients from the study area found to be infected with HBV genotype D were co-infected with genotype C. Additional study with a larger number of patients is needed to elucidate the possible clinical significance.
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Affiliation(s)
- Kojiro Michitaka
- Third Department of Internal Medicine, Ehime University School of Medicine, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan
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36
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Amini-Bavil-Olyaee S, Sarrami-Forooshani R, Adeli A, Mahboudi F, Sabahi F, Nafisi H, Zali MR, Azizi M. A novel accurate amplification created restriction site method for determination of the wild type and the precore mutant hepatitis B virus variants. J Virol Methods 2005; 127:19-23. [PMID: 15893561 DOI: 10.1016/j.jviromet.2005.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 02/15/2005] [Accepted: 02/16/2005] [Indexed: 01/05/2023]
Abstract
The most commonly occurring hepatitis B virus (HBV) mutation is the G to A mutation at nucleotide 1896 in the precore region. The aim of this study was to develop a novel accurate amplification created restriction site (ACRS) method for determination of the TGG wild type and the TAG precore mutant HBV variants. Two conserved and consensus specific and diagnostic primers introducing BstXI and XagI cleavage sites were designed in order to determine the G1896 wild type and the A1896 precore mutant HBV variants in all HBV genotypes. The results of the ACRS method were compared with sequencing data. With the ACRS method, three different patterns could be distinguished for the wild type, the precore mutant and mixed infection HBV variants. The results of the ACRS method on 30 HBV isolates revealed the TAG precore mutant in 50% (15/30), the TGG wild type variant in 30% (9/30) and the mixed infection in 20% (6/30). The sequencing data of these samples were in agreement with the ACRS results. The ACRS method is a rapid and cost-effective technique for detecting both the TGG wild type and the TAG HBV precore mutant variants. It can be carried out for follow-up of G1896A precore mutant variant in hepatitis B virus infected subjects at routine molecular diagnostic laboratories.
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37
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Bang G, Kim KH, Guarnieri M, Zoulim F, Kawai S, Li J, Wands J, Tong S. Effect of mutating the two cysteines required for HBe antigenicity on hepatitis B virus DNA replication and virion secretion. Virology 2005; 332:216-24. [PMID: 15661154 DOI: 10.1016/j.virol.2004.11.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 10/17/2004] [Accepted: 11/22/2004] [Indexed: 11/30/2022]
Abstract
Hepatitis B virus (HBV) variants with impaired expression of e antigen (HBeAg) frequently arise at the chronic stage of infection, as exemplified by precore and core promoter mutants. Since an intramolecular disulfide bond maintains the secondary structure of HBeAg, we explored effect of missense mutations of either cysteine codon. Consistent with earlier reports, substitution of each cysteine rendered HBeAg nearly undetectable. With underlying nucleotide changes at the loop of pregenome encapsidation signal, the C-7 mutants were severely impaired in pregenomic RNA packaging and hence DNA replication. Although none of the missense mutations at C61 reduced DNA replication, replacement with arginine, but not alanine, aspartic acid, phenylalanine, or serine, blocked virion secretion. Consistent with the detection of C61R genome from a patient serum, secretion block of the C61R mutant could be overcome by co-expression of wild-type core protein. In conclusion, point mutations of the C61 codon may generate viable HBeAg-negative variants.
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Affiliation(s)
- Genie Bang
- The Liver Research Center, Rhode Island Hospital and Brown Medical School, 55 Claverick Street, 4th Floor, Providence, RI 02903, USA
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38
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Tong S, Kim KH, Chante C, Wands J, Li J. Hepatitis B Virus e Antigen Variants. Int J Med Sci 2005; 2:2-7. [PMID: 15968333 PMCID: PMC1142218 DOI: 10.7150/ijms.2.2] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Accepted: 01/01/2005] [Indexed: 12/23/2022] Open
Abstract
More than 300 million people worldwide are chronically infected with hepatitis B virus (HBV). Considering the very short generation time for a virus, and the high error rate associated with the reverse transcription step of HBV replication, decades of HBV infection are probably equivalent to million years of human evolution. The most important selective force during the natural course of HBV infection appears to be the immune response. The development of anti-HBe antibody in hepatitis B patients usually correlates with reduction of HBV viremia. As a consequence, escape mutants of anti-HBe are selected. The core promoter mutants express less HBe antigen (HBeAg) through transcriptional down regulation, while precore mutants express truncated products. We recently identified additional mutations that modulate HBeAg translation initiation, proteolytic cleavage, and secondary structure maintenance through a disulfide bond. The core promoter mutants have been associated with the development of fulminant hepatitis during acute infection and liver cancer during chronic infection. Consistent with their enhanced pathogenicity, core promoter mutants were found to replicate at up to 10-fold higher levels in transfected human hepatoma cells than the wild-type virus. Moreover, some core promoter mutants are impaired in virion secretion due to missense mutations in the envelope gene. These virological properties may help explain enhanced pathogenicity of core promoter mutants in vivo.
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Affiliation(s)
- Shuping Tong
- 1. Liver Research Center, Rhode Island Hospital, Brown Medical School, Providence, RI 02903, USA
| | - Kyun-Hwan Kim
- 1. Liver Research Center, Rhode Island Hospital, Brown Medical School, Providence, RI 02903, USA
| | - Charles Chante
- 2. Cardinal Santos Medical Center, Metro Manila, 1500, Philippines
| | - Jack Wands
- 1. Liver Research Center, Rhode Island Hospital, Brown Medical School, Providence, RI 02903, USA
| | - Jisu Li
- 1. Liver Research Center, Rhode Island Hospital, Brown Medical School, Providence, RI 02903, USA
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Barros MF, Rodrigues PA, Matias SR, Carreira LM, Machado-Caetano JA. Detection of hepatitis B virus core mutants by PCR-RFLP in chronically infected patients. J Virol Methods 2004; 120:125-30. [PMID: 15288954 DOI: 10.1016/j.jviromet.2004.03.009] [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: 10/08/2003] [Revised: 03/15/2004] [Accepted: 03/16/2004] [Indexed: 10/26/2022]
Abstract
HBV chronic infection is an important health problem. The HBV core antigen carries several epitopes for T and B cell recognition and the immune response is crucial for determining the outcome of viral infection. Using PCR-RFLP several point mutations were detected in the HBV core ORF of HBV extracted from the serum of 140 chronically infected patients and 86 samples from another 37 patients followed-up in a longitudinal study. Mutations at position 2248 and 2147 (A3) and at 2038 (M2) were found most frequently. The wild type core genotype was found in about 50% of the samples. PCR-RFLP results were confirmed by direct sequencing of amplified products from HBV DNA present in chronically infected patients. The method is rapid and reliable and may be particularly useful for a rapid detection of viral mutants in a large number of patients.
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Affiliation(s)
- M F Barros
- Immunology Department, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo de Santana 130, 1169-056 Lisbon, Portugal.
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40
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Ahn SH, Kramvis A, Kawai S, Spangenberg HC, Li J, Kimbi G, Kew M, Wands J, Tong S. Sequence variation upstream of precore translation initiation codon reduces hepatitis B virus e antigen production. Gastroenterology 2003; 125:1370-8. [PMID: 14598253 DOI: 10.1016/j.gastro.2003.07.016] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND & AIMS Most South African hepatitis B virus strains harbor point mutations immediately upstream of the precore AUG codon. The aim of this study was to determine their effect on hepatitis B e antigen expression. METHODS The hepatitis B virus DNA sequence around the precore region was determined from sera of 45 black South Africans. The South African mutations were introduced into hepatitis B virus dimers of the same genotype, and hepatitis B e antigen was quantified from culture medium of transfected HepG2 or Huh7 cells. RESULTS The South African sequence changes were easily detectable in the acute, hepatitis B e antigen-positive phase of infection, suggesting that they were stable traits and were not selected by immune pressure. Triple mutations at the -5, -3, and -2 positions of the AUG codon severely impaired hepatitis B e antigen expression (P < 0.001). The frequent double mutation at the -5 and -2 positions moderately reduced hepatitis B e antigen levels (P < 0.001) to an extent comparable to that of the common core promoter mutations (1762(T)1764(A)). The presence of both South African and core promoter mutations diminished hepatitis B e antigen expression in an additive manner. It is interesting to note that the triple South African mutations enabled core protein translation from precore messenger RNA, which could rescue the replication defect of a hepatitis B virus genome with an ablated core gene. CONCLUSIONS We have identified a novel class of hepatitis B e antigen variants with reduced hepatitis B e antigen translation by a ribosomal leaky scanning mechanism. Reduction in hepatitis B e antigen expression may contribute to accelerated seroconversion from hepatitis B e antigen to its antibody in black South Africans infected with hepatitis B virus very early in life.
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Affiliation(s)
- Sang Hoon Ahn
- Liver Research Center, Rhode Island Hospital and Brown Medical School, 55 Claverick Street, Providence, RI 02903, USA
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41
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Norder H, Arauz-Ruiz P, Blitz L, Pujol FH, Echevarria JM, Magnius LO. The T(1858) variant predisposing to the precore stop mutation correlates with one of two major genotype F hepatitis B virus clades. J Gen Virol 2003; 84:2083-2087. [PMID: 12867638 DOI: 10.1099/vir.0.19034-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The precore mutation G(1896)-->A occurs frequently in anti-HBe-positive carriers of HBsAg with T(1858) in the stem of the encapsidation signal. Hepatitis B virus (HBV) genotype F, considered an Amerindian genotype, subdivides into two clades and the precore mutation occurs in Central American F strains. To investigate the relationship between substitutions at position 1858 and these clades, the precore and small S genes of 48 strains of HBV genotype F were subjected to phylogenetic analyses. Isolates of one clade, formed mainly of Central American strains, all had T(1858) and Thr(45) in the S gene, whereas in the other clade, formed mainly of South American strains and one strain from Polynesia, all had C(1858) and Leu(45). The latter strain was related to strains from Venezuela and Colombia, supporting an Amerindian contribution to the Polynesian population. The position of the Polynesian strain in the phylogenetic tree indicates that the two clades have resulted from an early split, showing a high degree of genetic stability of the stem of the HBsAg encapsidation signal.
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Affiliation(s)
- Heléne Norder
- Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden
| | - Patricia Arauz-Ruiz
- Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden
| | - Linda Blitz
- Laboratorio Regional de Referencia Virologica, Instituto de Investigaciones Clinicas, LUZ, Maracaibo, Venezuela
| | - Flor H Pujol
- Laboratorio de Virologia Molecular, CMBC, IVIC, Caracas, Venezuela
| | - José M Echevarria
- Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Lars O Magnius
- Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden
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Dumoulin FL, von dem Bussche A, Li J, Khamzina L, Wands JR, Sauerbruch T, Spengler U. Hepatitis C virus NS2 protein inhibits gene expression from different cellular and viral promoters in hepatic and nonhepatic cell lines. Virology 2003; 305:260-6. [PMID: 12573571 DOI: 10.1006/viro.2002.1701] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The mechanisms leading to viral persistence and hepatocarcinogenesis in hepatitis C virus (HCV) infection are not fully understood. Recently, evidence has been accumulated that HCV viral proteins might interfere with gene expression of host cells. Here, we demonstrate that the amino-terminal portion of HCV NS2 protein inhibits the expression of reporter genes driven by different promoters or enhancer elements and also inhibits hepatitis B virus (HBV) gene expression and HBV DNA replication. The inhibitory effect of HCV NS2 on liver and non-liver-specific promoters and enhancer elements might be relevant for the pathogenesis of chronic HCV infection.
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43
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Chen Y, Michitaka K, Matsubara H, Yamamoto K, Horiike N, Onji M. Complete genome sequence of hepatitis B virus (HBV) from a patient with fulminant hepatitis without precore and core promoter mutations: comparison with HBV from a patient with acute hepatitis infected from the same infectious source. J Hepatol 2003; 38:84-90. [PMID: 12480564 DOI: 10.1016/s0168-8278(02)00325-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND/AIMS There is a paucity of information regarding hepatitis B virus (HBV) from patients with fulminant hepatitis (FH) without precore (pre-C, nt 1896) and core promoter (CP, nt 1762, 1764) mutations. METHODS Pre-C and CP mutations were studied in eight patients with FH and 26 patients with acute hepatitis (AH) due to HBV. One patient with FH (FH1) was infected with HBV without these mutations. Interestingly, the sera of the infectious source (IS1) and of a patient with AH (AH1) infected from IS1 were available. Complete HBV genomes from these three patients were analyzed. RESULTS These mutations were found in seven of eight FH and five of 26 AH (P<0.01). HBV from FH1, IS1 and AH1 belonged to genotype D. Nucleotide difference between FH1 and AH1 was six of 3182 bases (nt 493, 998, 1173, 2928, 3067, and 3078). Two and five substitutions of deduced amino acid sequences were found in the pre-S1 and polymerase regions, respectively. The same nucleotide substitutions at nt 493, 1173, 2928 and 3067 were found in several patients with FH in our laboratory or GenBank. CONCLUSIONS These six nucleotide substitutions of HBV DNA could be candidates of mutations relating to FH.
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Affiliation(s)
- Yan Chen
- Third Department of Internal Medicine, Ehime University School of Medicine, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan
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44
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Zoulim F. A preliminary benefit-risk assessment of lamivudine for the treatment of chronic hepatitis B virus infection. Drug Saf 2002; 25:497-510. [PMID: 12093308 DOI: 10.2165/00002018-200225070-00004] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chronic hepatitis B virus (HBV) infection remains a major public health problem worldwide. Until recently, interferon (IFN)-alpha was the only approved drug for the treatment of chronic HBV infection. The recent registration of lamivudine, a dideoxycytidine analogue that inhibits both the HIV and HBV reverse transcriptases, has provided new perspectives for the treatment of chronic HBV infection. Lamivudine treatment for 12 months leads to a control of viral replication during therapy in the majority of the patients and to sustained anti-hepatitis B e (anti-HBe) seroconversion in 16 to 22% of the patients, associated with a biochemical and histological response. Further studies showed that extended lamivudine therapy increases the rate of anti-HBe seroconversion. However, long-term therapy is associated with the progressive emergence of drug resistant mutants. In most cases these mutants are not associated with a deterioration of the liver disease within the available follow-up. In the remaining patients and in particular settings such as liver transplantation, a severe exacerbation of the liver disease is observed and that requires add-on therapy. Lamivudine treatment of patients infected with a pre-core mutant also showed beneficial effect with the control of viral replication, and a biochemical and histological response in approximately 60% of the patients at 1 year. These patients face the same problem of drug resistant mutants, and the optimal duration of lamivudine treatment still needs to be determined in this clinical situation. Moreover, lamivudine therapy is the only therapeutic option in decompensated cirrhotic patients to allow liver transplantation, and in liver transplant patients with HBV recurrence following transplantation. Adverse effects of lamivudine therapy are comparable to those observed in placebo-treated patients. ALT flares have been observed mainly in relation to the re-occurrence of viral replication due to the rebound of viral replication after therapy withdrawal, or to the emergence of drug resistance mutants. Therefore, lamivudine provides a new treatment alternative for patients with chronic HBV infection. For each patient, its indication has to be weighed against the risk of developing viral resistance but also against the risk of natural history of the disease.
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45
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Lainé S, Salhi S, Rossignol JM. Overexpression and purification of the hepatitis B e antigen precursor. J Virol Methods 2002; 103:67-74. [PMID: 11906734 DOI: 10.1016/s0166-0934(02)00019-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Circumstantial evidence suggests that the secreted hepatitis B virus (HBV) e antigen (HBeAg) and/or its 22 kDa precursor (P22) have an essential role in the establishment of persistent infection. In order to identify cellular proteins that could interact with P22, large amounts of this protein are required to perform pull-down assays. A plasmid was constructed encoding a recombinant P22 with a Histidine-tag at its N-terminal extremity (P22r). The initial attempts to overexpress P22r in a conventional Escherichia coli strain failed, most likely due to the presence of rare AGA/AGG codon clusters in the 3' part of the gene. To overcome this difficulty, P22r was overexpressed in the Epicurian coli BL21-codonplus (DE3)-RIL strain, which possesses extra copies of the ArgU gene that encodes the tRNA(AGA/AGG). In this strain, P22r was overexpressed successfully and then purified in milligram quantities by metal affinity chromatography on Ni2+-chelated His-Bind resin. The purified recombinant protein P22r was able to interact with a cellular protein (P32), which had previously been shown to co-immunoprecipitate with native P22, indicating that at least some of the P22r molecules were folded correctly.
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Affiliation(s)
- Sébastien Lainé
- Laboratoire de Génétique des Virus, UPR 9053-CNRS, Avenue de la Terrasse, 91198, Gif sur Yvette, France
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46
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Affiliation(s)
- Fabien Zoulim
- INSERM U271 and Liver Unit Hotel Dieu Hospital, Lyon, France.
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47
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Chu CM, Yeh CT, Lee CS, Sheen IS, Liaw YF. Precore stop mutant in HBeAg-positive patients with chronic hepatitis B: clinical characteristics and correlation with the course of HBeAg-to-anti-HBe seroconversion. J Clin Microbiol 2002; 40:16-21. [PMID: 11773086 PMCID: PMC120083 DOI: 10.1128/jcm.40.1.16-21.2002] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
This study aimed to investigate the ratios of precore stop mutant (codon 28; TGG to TAG) to total viremia in 53 HBeAg-positive patients with chronic hepatitis B by amplification-created restriction site assays along the course of HBeAg-to-anti-HBe seroconversion. At baseline, 11% had exclusive wild-type hepatitis B virus (HBV), 15% had exclusively precore mutant, and 74% had mixed viral strains. Precore mutant ratios correlated little with age, sex, or HBV DNA levels (all P > 0.1), but correlated modestly with alanine aminotransferase (ALT) levels (P = 0.05). The intervals from presentation to anti-HBe seroconversion correlated significantly with ALT and precore mutant ratios in univariate analysis but with only precore mutant ratios in multivariate analysis (P = 0.003). Precore mutant ratios at baseline were significantly higher (P < 0.001) in six patients with persistent high viremia and ALT elevation after anti-HBe seroconversion (group 1) than in 47 with remission (group 2). All group 1 patients had exclusive precore mutant after anti-HBe seroconversion, as did only 14 (30%) of the group 2 patients (P = 0.003). Among group 2 patients, precore mutant ratios at baseline or after anti-HBe seroconversion showed no significant difference between 34 patients with sustained remission and 13 with relapse. Cirrhosis developed in 50% (5 of 10) of patients with precore mutant ratios >50% at baseline but only in 12% (5 of 43) of those with precore mutant ratios of <50% at baseline (P < 0.05). In conclusion, precore mutant of variable ratios was frequently detected in HBeAg-positive patients with chronic hepatitis B. Precore mutant ratios tended to correlate with ALT levels and anti-HBe seroconversion, but high precore mutant ratios were associated with persistent hepatitis after anti-HBe seroconversion and increased risk of cirrhosis.
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Affiliation(s)
- Chia-Ming Chu
- Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University, Taipei, Taiwan.
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48
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Parvez MK, Thakur V, Kazim SN, Guptan RC, Hasnain SE, Sarin SK. Base-pair alterations in the epsilon-lower stem due to a novel double substitution in the precore gene of HBV-e negative variant were recovered by secondary mutations. Virus Genes 2001; 23:315-20. [PMID: 11778699 DOI: 10.1023/a:1012525423754] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The HBe negative phenotype, a natural precore mutant (G1896A/G1897A) of HBV with aborted HBeAg expression is known to cause chronic hepatitis. The destabilized C : G base-pairing in the lower stem of epsilon-hairpin due to G1896A substitution is reportedly compensated by a second C1858T mutation and suggested to play an important role in enhanced selection of the HBe negative variant. We undertook to investigate presence of such compensatory mutations at other positions by analyzing epsilon-sequences (nts. 1847-1907) as well as to look for their effect(s), if any, on the consensus sequence of the overlapping core-initiator of HBe negative HBV variants in CLD patients. Three of the 5 HBe negative patients had classical G1896A mutation having a second compensatory mutation at nt. 1858. One patient showed an additional G1897A substitution, presenting as a novel precore stop codon mutation (UGG-->UAA), followed by a compensatory mutation at position 1857. In the third patient, a G1899A substitution was seen which compensated the impaired U at position 1855. Other substitution and deletion mutations were also observed in the remaining epsilon-hairpin, which however, did not produce any compensatory mutation. Further, all the precore variants showed a conserved G at position 1904, important for the optimal context of their core-initiator which however, remained impaired with A (nt. 1850). Our results suggest that the nts. 1851-1859 and nts. 1895-1904 in the lower stem, and restoration of authentic base-pairings therein, maintain the structural integrity and stability of the epsilon-hairpin. This may have a role in the enhanced selection of the HBe negative variants and persistence of HBV infection in chronic liver disease patients.
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Affiliation(s)
- M K Parvez
- Department of Gastroenterology, G.B. Pant Hospital, New Delhi, India
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49
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Sugauchi F, Mizokami M, Orito E, Ohno T, Kato H, Suzuki S, Kimura Y, Ueda R, Butterworth LA, Cooksley WGE. A novel variant genotype C of hepatitis B virus identified in isolates from Australian Aborigines: complete genome sequence and phylogenetic relatedness. J Gen Virol 2001; 82:883-892. [PMID: 11257194 DOI: 10.1099/0022-1317-82-4-883] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
There have been no reports of DNA sequences of hepatitis B virus (HBV) strains from Australian Aborigines, although the hepatitis B surface antigen (HBsAg) was discovered among them. To investigate the characteristics of DNA sequences of HBV strains from Australian Aborigines, the complete nucleotide sequences of HBV strains were determined and subjected to molecular evolutionary analysis. Serum samples positive for HBsAg were collected from five Australian Aborigines. Phylogenetic analysis of the five complete nucleotide sequences compared with DNA sequences of 54 global HBV isolates from international databases revealed that three of the five were classified into genotype D and were most closely related in terms of evolutionary distance to a strain isolated from a healthy blood donor in Papua New Guinea. Two of the five were classified into a novel variant genotype C, which has not been reported previously, and were closely related to a strain isolated from Polynesians, particularly in the X and Core genes. These two strains of variant genotype C differed from known genotype C strains by 5.9-7.4% over the complete nucleotide sequence and 4.0-5.6% in the small-S gene, and had residues Arg(122), Thr(127) and Lys(160), characteristic of serotype ayw3, which have not been reported previously in genotype C. In conclusion, this is the first report of the characteristics of complete nucleotide sequences of HBV from Australian Aborigines. These results contribute to the investigation of the worldwide spread of HBV, the relationship between serotype and genotype and the ancient common origin of Australian Aborigines.
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Affiliation(s)
- Fuminaka Sugauchi
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Masashi Mizokami
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Etsuro Orito
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Tomoyoshi Ohno
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Hideaki Kato
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Seiji Suzuki
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Yoshihide Kimura
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - Ryuzo Ueda
- Second Department of Internal Medicine1 and Laboratory Medicine2, Nagoya City University Medical School, Kawasumi, Mizuho, 467-8601 Nagoya, Japan
| | - L A Butterworth
- Royal Brisbane Hospital Research Foundation, Brisbane, Australia3
| | - W G E Cooksley
- Royal Brisbane Hospital Research Foundation, Brisbane, Australia3
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50
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Schories M, Peters T, Rasenack J. Isolation, characterization and biological significance of hepatitis B virus mutants from serum of a patient with immunologically negative HBV infection. J Hepatol 2000; 33:799-811. [PMID: 11097490 DOI: 10.1016/s0168-8278(00)80313-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND/AIM A low-titered hepatitis B virus infection without immunological markers was identified in a prospective study in the serum of a kidney transplant recipient by PCR. The aim of this study was to analyze HBV genomes and their biological significance. METHODS The genome was amplified in two overlapping fragments A and B. Sequencing of 22 clones of the A- and 12 clones of the B-fragment revealed a heterogeneous virus population. A consensus and a mutant sequence were computed, representing the complete sequence of the virus population. The two sequences were compared with 41 published genomes of the different HBV geno- and serotypes. RESULTS Ninety-five point mutations and two deletions were identified. Two mutations were observed in all clones and 17 other mutations in three or more clones. The deletions were found in ten and seven of 22 clones. They were located in the C-gene and led to stop codons yielding truncated e- and/or core proteins. In vitro transfection of DNA constructs containing these deletions demonstrated a stop of HBV replication and of HBeAg expression. Cotransfection experiments demonstrated a dominant negative effect of the mutants containing the deletions. In addition, we describe new variants of naturally occurring HBsAg mutants that may cause HBV infection less detectable by standard HBsAg measurement assays. They were characterized by two point mutations which were observed in 9 of 12 and 13 of 22 clones of the S-gene. They significantly reduced the HBsAg expression in in vitro transfection experiments. CONCLUSION We found a patient with low-titered HBV infection, with mutations of the 'a' epitope of the Santigen as well as with mutations leading to truncated core proteins which may cause a dominant negative effect.
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Affiliation(s)
- M Schories
- Department of Medicine II, Medizinische Universitätsklinik, Albert-Ludwig-Universität, Freiburg, Federal Republic of Germany
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