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Saeed U, Piracha ZZ, Alrokayan S, Hussain T, Almajhdi FN, Waheed Y. Immunoinformatics and Evaluation of Peptide Vaccines Derived from Global Hepatitis B Viral HBx and HBc Proteins Critical for Covalently Closed Circular DNA Integrity. Microorganisms 2023; 11:2826. [PMID: 38137971 PMCID: PMC10745757 DOI: 10.3390/microorganisms11122826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/07/2023] [Accepted: 11/17/2023] [Indexed: 12/24/2023] Open
Abstract
The Hepatitis B virus (HBV) HBx and HBc proteins play a crucial role in associating with covalently closed circular DNA (cccDNA), the primary factor contributing to intrahepatic viral persistence and a major obstacle in achieving a cure for HBV. The cccDNA serves as a reservoir for viral persistence. Targeting the viral HBc and HBx proteins' interaction with cccDNA could potentially limit HBV replication. In this study, we present epitopes identified from global consensus sequences of HBx and HBc proteins that have the potential to serve as targets for the development of effective vaccine candidates. Furthermore, conserved residues identified through this analysis can be utilized in designing novel, site-specific anti-HBV agents capable of targeting all major genotypes of HBV. Our approach involved designing global consensus sequences for HBx and HBc proteins, enabling the analysis of variable regions and highly conserved motifs. These identified motifs and regions offer potent sites for the development of peptide vaccines, the design of site-specific RNA interference, and the creation of anti-HBV inhibitors. The epitopes derived from global consensus sequences of HBx and HBc proteins emerge as promising targets for the development of effective vaccine candidates. Additionally, the conserved residues identified provide valuable insights for the development of innovative, site-specific anti-HBV agents capable of targeting all major genotypes of HBV from A to J.
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Affiliation(s)
- Umar Saeed
- Clinical and Biomedical Research Center (CBRC) and Multidisciplinary Laboratory (MDL), Foundation University Islamabad, Islamabad 44000, Pakistan;
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-749, Republic of Korea;
| | - Zahra Zahid Piracha
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-749, Republic of Korea;
- International Center of Medical Sciences Research (ICMSR), Islamabad 44000, Pakistan
| | - Salman Alrokayan
- Research Chair for Biomedical Application of Nanomaterials, Biochemistry Department, College of Sciences, King Saud University, Riyadh 11362, Saudi Arabia;
| | - Tajamul Hussain
- Research Chair for Biomedical Application of Nanomaterials, Biochemistry Department, College of Sciences, King Saud University, Riyadh 11362, Saudi Arabia;
- Center of Excellence in Biotechnology Research, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11451, Saudi Arabia
| | - Fahad N. Almajhdi
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia;
| | - Yasir Waheed
- Office of Research, Innovation, and Commercialization, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad 44000, Pakistan;
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos 1401, Lebanon
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Parikh N, Nonnemacher MR, Pirrone V, Block T, Mehta A, Wigdahl B. Substance abuse, HIV-1 and hepatitis. Curr HIV Res 2013; 10:557-71. [PMID: 22973853 DOI: 10.2174/157016212803306023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 07/16/2012] [Accepted: 09/05/2012] [Indexed: 02/06/2023]
Abstract
During the course of human immunodeficiency virus type 1 (HIV-1) disease, the virus has been shown to effectively escape the immune response with the subsequent establishment of latent viral reservoirs in specific cell populations within the peripheral blood (PB) and associated lymphoid tissues, bone marrow (BM), brain, and potentially other end organs. HIV-1, along with hepatitis B and C viruses (HBV and HCV), are known to share similar routes of transmission, including intravenous drug use, blood transfusions, sexual intercourse, and perinatal exposure. Substance abuse, including the use of opioids and cocaine, is a significant risk factor for exposure to HIV-1 and the development of acquired immune deficiency syndrome, as well as HBV and HCV exposure, infection, and disease. Thus, coinfection with HIV-1 and HBV or HCV is common and may be impacted by chronic substance abuse during the course of disease. HIV- 1 impacts the natural course of HBV and HCV infection by accelerating the progression of HBV/HCV-associated liver disease toward end-stage cirrhosis and quantitative depletion of the CD4+ T-cell compartment. HBV or HCV coinfection with HIV-1 is also associated with increased mortality when compared to either infection alone. This review focuses on the impact of substance abuse and coinfection with HBV and HCV in the PB, BM, and brain on the HIV-1 pathogenic process as it relates to viral pathogenesis, disease progression, and the associated immune response during the course of this complex interplay. The impact of HIV-1 and substance abuse on hepatitis virus-induced disease is also a focal point.
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Affiliation(s)
- Nirzari Parikh
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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3
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Cassino L, Laufer N, Giuliano SF, Bouzas M, Quarleri J. Short Communication: Hepatitis B Virus Harboring Nucleotide Deletions in the Basal Core Promoter in HBe-Positive HIV-Coinfected Patients Under Lamivudine Therapy. AIDS Res Hum Retroviruses 2011; 27:543-5. [PMID: 20919924 DOI: 10.1089/aid.2010.0096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The presence of HBV genomes with deletions at the basal core promoter (BCP) is associated with more aggressive liver disease. This 3-year longitudinal analysis of two HIV-HBV-coinfected patients allowed identification of three deletions with dissimilar abundance and permanence into the HBV quasispecies composition. These deletions may contribute to HBV pathogenesis in HIV-coinfected individuals.
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Affiliation(s)
- L. Cassino
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - N. Laufer
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Unidad de Enfermedades Infecciosas, Hospital Fernández, Buenos Aires, Argentina
| | - S. Fernández Giuliano
- Unidad de Virología, Hospital de Enfermedades Infecciosas “F.J. Muñiz,” Buenos Aires, Argentina
| | - M.B. Bouzas
- Unidad de Virología, Hospital de Enfermedades Infecciosas “F.J. Muñiz,” Buenos Aires, Argentina
| | - J. Quarleri
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
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Abstract
Although the prevalence of chronic hepatitis B virus (HBV) infection has declined in renal transplant recipients (RTRs), it remains a relevant clinical problem with high morbidity and mortality in long-term follow up. A thorough evaluation, including liver biopsy as well as assessment of HBV replication in serum (i.e. hepatitis B e antigen and/or HBV DNA) is required before transplantation. Interferon should not be used in this setting because of low efficacy and precipitation on acute allograft rejection. The advent of effective antiviral therapies offers the opportunity to prevent the progression of liver disease after renal transplantation. However, as far as we are aware, no studies have compared prophylactic and preemptive strategies. To date, the majority of RTRs with HBV-related liver disease have had a high virological and biochemical response to lamivudine use. However, lamivudine resistance is frequent with a prolonged course of therapy. Considering long-term treatment, antiviral agents with a high genetic barrier to resistance and lack of nephrotoxicity are suggested. The optimal strategy in RTRs with HBV infection remains to be established in the near future.
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Razanskas R, Sasnauskas K. A novel human protein is able to interact with hepatitis B virus core deletion mutant but not with the wild-type protein. Virus Res 2009; 146:130-4. [PMID: 19770013 DOI: 10.1016/j.virusres.2009.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 09/14/2009] [Accepted: 09/14/2009] [Indexed: 10/20/2022]
Abstract
Hepatitis B virus mutants with in-frame deletions in the central part of the core gene are associated with a severe course of infection in long-term immunosuppressed renal transplant recipients. In this study, yeast two-hybrid system was employed to investigate interaction capabilities of two core mutants with deleted 77-93 and 86-93 amino acids. The same mutant and wild-type (WT) protein pairs which form core-like particles inside bacterial cells were able to interact also in two-hybrid system. To find host proteins possibly involved in enhanced pathogenesis of the mutant variants, a human hepatocyte cDNA library was screened for proteins interacting with the mutant but not with the WT core protein. A human protein of unknown function FLJ20850 interacted specifically with the mutant proteins. An attempt to determine interacting regions revealed that FLJ20850 was unable to interact without significant parts of its C- or N-end, and introduced deletion in the central region conferred interaction capability to the WT core protein.
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Iser DM, Lewin SR. The pathogenesis of liver disease in the setting of HIV–hepatitis B virus coinfection. Antivir Ther 2009. [DOI: 10.1177/135965350901400207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There are many potential reasons for increased liver-related mortality in HIV–hepatitis B virus (HBV) coinfection compared with either infection alone. HIV infects multiple cells in the liver and might potentially alter the life cycle of HBV, although evidence to date is limited. Unique mutations in HBV have been defined in HIV–HBV-coinfected individuals and might directly alter pathogenesis. In addition, an impaired HBV- specific T-cell immune response is likely to be important. The roles of microbial translocation, immune activation and increased hepatic stellate cell activation will be important areas for future study.
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Affiliation(s)
- David M Iser
- Department of Medicine, The University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia
- Infectious Diseases Unit, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Sharon R Lewin
- Infectious Diseases Unit, The Alfred Hospital, Melbourne, Victoria, Australia
- Department of Medicine, Monash University, Melbourne, Victoria, Australia
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Revill PA, Littlejohn M, Ayres A, Yuen L, Colledge D, Bartholomeusz A, Sasaduesz J, Lewin SR, Dore GJ, Matthews GV, Thio CL, Locarnini SA. Identification of a novel hepatitis B virus precore/core deletion mutant in HIV/hepatitis B virus co-infected individuals. AIDS 2007; 21:1701-10. [PMID: 17690567 DOI: 10.1097/qad.0b013e32826fb305] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Although HAART has resulted in improved health outcomes for most HIV-infected individuals, liver failure has emerged as a major cause of morbidity and mortality in people co-infected with hepatitis B virus (HBV). In HBV mono-infected individuals, core deletion mutants are associated with more aggressive liver disease. As HIV accelerates HBV liver disease progression, we hypothesized that HIV-HBV co-infected individuals have increased frequency of core mutations including deletions. To test this hypothesis, we have analysed genome-length sequences of HBV DNA from patients both prior to and during antiviral therapy. SETTING Prospective HIV/HBV co-infected cohort study. METHODS Genomic length HBV DNA was amplified by PCR from the serum samples of ten HIV/HBV co-infected individuals and five HBV mono-infected individuals prior to the commencement of lamivudine therapy and again after nine to 74 months of treatment. The complete genomes were sequenced and in order to further analyse some mutations, their frequency was determined in additional HIV/HBV co-infected and HBV mono-infected individuals. RESULTS A novel -1G mutation was identified in the HBV precore and overlapping core genes that truncated the deduced precore/core proteins. The mutant genome was the dominant species in some HIV/HBV co-infected individuals and was more prevalent in HIV/HBV co-infected individuals than HBV mono-infected individuals. The mutation was also associated with high HBV DNA concentrations in HIV/HBV co-infected individuals. Additional mutations were identified in the core/precore and polymerase genes and regulatory regions. CONCLUSION Mutations in the HBV core and precore genes may be contributing to disease pathogenesis in HIV/HBV co-infected individuals.
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Affiliation(s)
- Peter A Revill
- Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia.
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Braun S, Zajakina A, Aleksejeva J, Sharipo A, Bruvere R, Ose V, Pumpens P, Garoff H, Meisel H, Kozlovska T. Proteasomal degradation of core protein variants from chronic hepatitis B patients. J Med Virol 2007; 79:1312-21. [PMID: 17607782 DOI: 10.1002/jmv.20939] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The accumulation of complex hepatitis B virus (HBV) variants with internal in-frame deletions in the C gene in immunosuppressed renal transplant recipients is associated with a severe course of the infection leading to end-stage liver disease (ESLD). A set of six HBV C genes with internal in-frame deletions corresponding to the pattern of HBV population in immunosuppressed patients has been expressed in two different eukaryotic cell lines. Synthesis and proteasomal degradation of HBV core (HBc) protein variants were compared with those of the wild-type HBc. In all cases, the steady-state level of internally deleted HBc proteins, predominantly with longer deletions, were considerably lower and turnover was significantly higher in comparison with those of the wild-type HBc, since all deletion variants were degraded rapidly via the proteasome pathway. Involvement and consequences of the proteasomal degradation machinery in the HBc protein turnover during HBV infection with complex HBV variants in the immunosuppressed patients are discussed.
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Affiliation(s)
- Sabine Braun
- Universitätsmedizin Berlin, Charité, Institut für Virologie, Campus Mitte, Charitéplatz 1, Berlin, Germany
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Enomoto M, Tamori A, Kohmoto MT, Morikawa H, Habu D, Sakaguchi H, Takeda T, Seki S, Kawada N, Shiomi S, Nishiguchi S. Mutational patterns of hepatitis B virus genome and clinical outcomes after emergence of drug-resistant variants during lamivudine therapy: Analyses of the polymerase gene and full-length sequences. J Med Virol 2007; 79:1664-70. [PMID: 17854034 DOI: 10.1002/jmv.20984] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It remains unclear whether mutational patterns of the hepatitis B virus (HBV) genome are associated with the development of severe hepatitis after the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) variants during lamivudine treatment. Thirty patients with chronic hepatitis B who had YMDD variants during lamivudine therapy and were followed up subsequently while receiving lamivudine alone for at least 6 months were examined retrospectively. The lamivudine resistant mutations in the HBV polymerase gene were detected by a line probe assay, and the full-length sequences of HBV DNA were determined in some patients. Between months 5 and 33 of therapy, mutations from methionine to isoleucine at rt204 (rtM204I) were detected in 18 patients, and mutations from methionine to valine at rt204 (rtM204V) were detected in 12. The rtM204V mutations were always accompanied by mutations from leucine to methionine at rt180 (rtL180M), while rtM204I mutations were not. Baseline characteristics, alanine aminotransferase (ALT) levels, and HBV DNA levels within 6 months after the emergence of YMDD variants did not differ significantly between patients with rtM204I alone and those with rtL180M/rtM204V. No specific mutation was identified on full-length sequence analysis in three patients with a hepatitis flare. During long term follow-up, the addition of rtL180M to rtM204I was found in four patients 7-31 months after detecting the change at rt204 and was linked to increased ALT levels. In conclusion, mutational patterns of HBV DNA at the time of emergence of YMDD variants were apparently unrelated to the clinical outcomes in Japanese patients with chronic hepatitis B during lamivudine therapy.
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Affiliation(s)
- Masaru Enomoto
- Department of Hepatology, Osaka City University Medical School, Asahimachi, Abeno-ku, Osaka, Japan
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Paik YH, Brenner DA. Immunosuppression, hepatitis B virus variants: Synergistic role in hepatic fibrogenesis. Gastroenterology 2006; 131:957-60. [PMID: 16952565 DOI: 10.1053/j.gastro.2006.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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11
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Affiliation(s)
- Stephan Günther
- Bernhard-Nocht-Institute of Tropical Medicine, Hamburg, Germany.
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12
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Abstract
Hepatitis B virus (HBV) is a major human health problem as approximately 8% of the world’s population are chronic carriers and there are over a million HBV-related deaths annually. Treatment of HBV is extremely difficult, as the unique viral replication strategy results in both a continual source of stable DNA molecules that are the template for viral replication and gene expression, and a pool of viral quasispecies from which different isolates may emerge as selection pressures alter. Although the use of antiviral therapies has improved outcomes significantly for many chronically infected individuals, the emergence of drug-resistant and immune/vaccine-escape viruses ensures there is a continuing need for the development of new and imaginative approaches to control and eventually eradicate HBV.
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Affiliation(s)
- Peter Revill
- Victorian Infectious Diseases Reference Laboratory, Research and Molecular Development, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia
| | - Stephen Locarnini
- Victorian Infectious Diseases Reference Laboratory, Research and Molecular Development, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia
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13
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Xiao X, Shao S, Ding Y, Huang Z, Chen X, Chou KC. An application of gene comparative image for predicting the effect on replication ratio by HBV virus gene missense mutation. J Theor Biol 2005; 235:555-65. [PMID: 15935173 DOI: 10.1016/j.jtbi.2005.02.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 12/13/2004] [Accepted: 02/09/2005] [Indexed: 11/26/2022]
Abstract
Hepatitis B viruses (HBVs) show instantaneous and high-ratio mutations when they are replicated, some sorts of which significantly affect the efficiency of virus replication through enhancing or depressing the viral replication, while others have no influence at all. The mechanism of gene expression is closely correlated with its gene sequence. With the rapid increase in the number of newly found sequences entering into data banks, it is highly desirable to develop an automated method for simulating the gene regulating function. The establishment of such a predictor will no doubt expedite the process of prioritizing genes and proteins identified by genomics efforts as potential molecular targets for drug design. Based on the power of cellular automata (CA) in treating complex systems with simple rules, a novel method to present HBV gene image has been introduced. The results show that the images thus obtained can very efficiently simulate the effects of the gene missense mutation on the virus replication. It is anticipated that CA may also serve as a useful vehicle for many other studies on complicated biological systems.
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Affiliation(s)
- Xuan Xiao
- Bio-Informatics Research Center, Donghua University, Shanghai 200051, China
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Gomes SA, de Castro L, Niel C, Santos EA. Uncommon mutation pattern of a hepatitis B virus isolate from genotype F infecting a patient with AIDS. J Infect 2004; 48:102-8. [PMID: 14667799 DOI: 10.1016/s0163-4453(03)00126-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE To study the genomic variations of a hepatitis B virus (HBV) isolate in a patient coinfected with human immunodeficiency virus type 1 (HIV-1) who developed severe hepatitis and died of AIDS. METHODS Two blood samples were collected, the first one during the asymptomatic phase of HIV-1 infection, and the other, 3 years later, few months before the death of the patient. Both samples were HBsAg and anti-HBe positive. Pre-S/S and precore-core genome regions were PCR amplified and analyzed. RESULTS The HBV isolate belonged to genotype F, cluster IV. A number of unique amino acid substitutions were found in the surface antigen gene and the overlapping polymerase coding region of HBV genomes derived from both samples. However, these substitutions reflected natural variations rather than mutations of clinical significance. The precore stop codon mutation A(1896) was present in both genomes. Furthermore, the HBV genome derived from the second, but not first sample, showed two out-of-frame core interval deletions, one and 103 nucleotides in length, respectively. CONCLUSIONS This is the first report of an HBV isolate from genotype F with core internal deletions. Our results suggest an association between specific core mutations and the severe hepatitis developed by the patient.
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Affiliation(s)
- S A Gomes
- Department of Virology, Oswaldo Cruz Institute, Rio de Janeiro, Brazil.
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Chua PK, Wen YM, Shih C. Coexistence of two distinct secretion mutations (P5T and I97L) in hepatitis B virus core produces a wild-type pattern of secretion. J Virol 2003; 77:7673-6. [PMID: 12805468 PMCID: PMC164791 DOI: 10.1128/jvi.77.13.7673-7676.2003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Unlike a Tokyo isolate of hepatitis B virus variants, we found a Shanghai isolate that secretes few virions with an immature genome despite its core I97L mutation. Core mutations P5T and I97L were found to be mutually compensatory in offsetting their respective distinct effects on virion secretion.
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Affiliation(s)
- Pong Kian Chua
- Center for Tropical Diseases, Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA
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Bock CT, Buerke B, Tillmann HL, Tacke F, Kliem V, Manns MP, Trautwein C. Relevance of hepatitis B core gene deletions in patients after kidney transplantation. Gastroenterology 2003; 124:1809-20. [PMID: 12806615 DOI: 10.1016/s0016-5085(03)00396-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND & AIMS Hepatitis B virus (HBV) infection is a major cause of death in the long-term follow-up after organ transplantation and immunosuppressive therapy. The selection pressure on the HBV genome in these patients is reduced. The aim was to analyze and characterize variations in the HBV core gene after organ transplantation and their impact for prognosis. METHODS In patients with chronic HBV infection after organ transplantation (liver, n = 60; heart, n = 50; kidney, n = 30) the HBV core gene was amplified by polymerase chain reaction (PCR). Core gene deletions were cloned into replication competent and expression vectors. The impact of these mutations on HBV replication and capsid formation was analyzed and correlated with disease progression. RESULTS Central core gene deletions only were detected in patients after kidney transplantation. Two types of core gene deletions--small and large--were found. Large core gene deletions showed no capsid formation and HBV replication, which resulted in nuclear core expression. The occurrence of large core gene deletions was associated with a severe course of liver disease. CONCLUSIONS Core gene deletions occur specifically after kidney transplantation. Only large core gene deletions resulted in impaired capsid formation and nuclear localization of the core protein. The presence of large core gene deletions was associated with progressive disease.
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Affiliation(s)
- C-Thomas Bock
- Department of Gastroenterology, Hepatology and Oncology, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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17
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Suk FM, Lin MH, Newman M, Pan S, Chen SH, Liu JD, Shih C. Replication advantage and host factor-independent phenotypes attributable to a common naturally occurring capsid mutation (I97L) in human hepatitis B virus. J Virol 2002; 76:12069-77. [PMID: 12414948 PMCID: PMC136898 DOI: 10.1128/jvi.76.23.12069-12077.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2002] [Accepted: 08/26/2002] [Indexed: 12/12/2022] Open
Abstract
Mutations of human hepatitis B virus (HBV) occur frequently within the capsid (core) protein in natural infections. The most frequent mutation of the core protein in HBV from Southeast Asia occurs at amino acid 97, changing an isoleucine (I) to a leucine (L). In our systematic study of virus-host interactions, we have examined the replication efficiency of a site-directed mutant, I97L, and its parental wild-type HBV in several different hepatoma cell lines. Interestingly, we found that this capsid variant replicated in human Huh7 hepatoma cells approximately 4.8-fold better than its parental wild-type HBV. A similar phenomenon was observed in another hepatoma cell line, J3. In addition, the level of encapsidated RNA pregenome in mutant I97L was about 5.7-fold higher than that of the wild-type HBV in Huh7 cells. Unlike Huh7 cells, no significant difference in viral DNA replication between the same I97L mutant and its parental wild-type HBV was observed in HepG2, a human hepatoblastoma cell line. This finding of a profound replication advantage for mutant I97L in Huh7 and J3 cells but not in HepG2 cells may have important implications for the emergence of this mutant in chronic HBV carriers. We speculate here that the mutation confers a host factor-independent growth advantage for the survival of HBV variants in gradually dedifferentiating hepatocytes and thus helps prolong viral persistence.
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Affiliation(s)
- Fat-Moon Suk
- Center for Tropical Diseases and Sealy Center for Vaccine Development, Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA
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Arauz-Ruiz P, Norder H, Robertson BH, Magnius LO. Genotype H: a new Amerindian genotype of hepatitis B virus revealed in Central America. J Gen Virol 2002; 83:2059-2073. [PMID: 12124470 DOI: 10.1099/0022-1317-83-8-2059] [Citation(s) in RCA: 534] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The complete genomes were sequenced for ten hepatitis B virus (HBV) strains. Two of them, from Spain and Sweden, were most similar to genotype D, although encoding d specificity. Five of them were from Central America and belonged to genotype F. Two strains from Nicaragua and one from Los Angeles, USA, showed divergences of 3.1-4.1% within the small S gene from genotype F strains and were recognized previously as a divergent clade within genotype F. The complete genomes of the two genotype D strains were found to differ from published genotype D strains by 2.8-4.6%. Their S genes encoded Lys(122), Thr(127) and Lys(160), corresponding to the putative new subtype adw3 within this genotype, previously known to specify ayw2, ayw3 or, rarely, ayw4. The complete genomes of the three divergent strains diverged by 0.8-2.5% from each other, 7.2-10.2% from genotype F strains and 13.2-15.7% from other HBV strains. Since pairwise comparisons of 82 complete HBV genomes of intratypic and intertypic divergences ranged from 0.1 to 7.4% and 6.8 to 17.1%, respectively, the three sequenced strains should represent a new HBV genotype, for which the designation H is proposed. In the polymerase region, the three strains had 16 unique conserved amino acid residues not present in genotype F strains. So far, genotype H has been encountered in Nicaragua, Mexico and California. Phylogenetic analysis of the complete genomes and subgenomes of the three strains showed them clustering with genotype F but forming a separate branch supported by 100% bootstrap. Being most similar to genotype F, known to be an Amerindian genotype, genotype H has most likely split off from genotype F within the New World.
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Affiliation(s)
- Patricia Arauz-Ruiz
- Louisiana State University-International Centre for Medical Research and Training, San José, Costa Rica2
- Department of Virology, Swedish Institute for Infectious Disease Control, SE-171 82 Stockholm, Sweden1
| | - Helene Norder
- Department of Virology, Swedish Institute for Infectious Disease Control, SE-171 82 Stockholm, Sweden1
| | - Betty H Robertson
- Laboratory Branch, Division of Viral Hepatitis, National Center for Infectious Diseases, Center for Disease Control and Prevention, Atlanta, GA 30333, USA3
| | - Lars O Magnius
- Department of Virology, Swedish Institute for Infectious Disease Control, SE-171 82 Stockholm, Sweden1
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19
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Kletzmayr J, Watschinger B. Chronic hepatitis B virus infection in renal transplant recipients. Semin Nephrol 2002. [DOI: 10.1053/snep.2002.33678] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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20
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Preikschat P, Günther S, Reinhold S, Will H, Budde K, Neumayer HH, Krüger DH, Meisel H. Complex HBV populations with mutations in core promoter, C gene, and pre-S region are associated with development of cirrhosis in long-term renal transplant recipients. Hepatology 2002; 35:466-77. [PMID: 11826424 DOI: 10.1053/jhep.2002.30698] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Long-term immunosuppressed renal transplant recipients with chronic hepatitis B virus (HBV) infection often develop liver cirrhosis (LC) and end-stage liver disease (ESLD). This study investigated accumulation and persistence of specific HBV mutants in relation to the clinical course in these patients (n = 38; mean follow-up, 3.5 years). HBV was analyzed longitudinally via length polymorphism of polymerase chain reaction (PCR) fragments (median, 6.5 serum samples per patient) as well as by cloning and partial sequencing of 346 full-length HBV genomes. Fourteen patients (group 1) developed LC or died from ESLD, whereas 24 patients (group 2) showed no evidence of LC during follow-up. Development of LC and ESLD was associated with persistence of HBV mutant populations characterized by deletions/insertions in core promoter plus deletions in the C gene and/or deletions in the pre-S region (86% of group 1 vs. 17% of group 2; P <.0001). HBV without these mutations or with core promoter mutations alone were predominantly found in group 2 (14% of group 1 vs. 75% of group 2). In patients infected with core promoter mutants, the additional appearance and persistence of deletions in the C gene and/or the pre-S region were accompanied or followed by development of LC and ESLD. The mutations were distributed on individual genomes in various combinations, leading to a high complexity of the virus population. In conclusion, these data suggest that accumulation and persistence of specific HBV populations characterized by mutations in 3 subgenomic regions play a role in pathogenesis of LC and ESLD in long-term renal transplant recipients.
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Affiliation(s)
- Petra Preikschat
- Institut für Virologie, Humboldt-Universität zu Berlin (Charité), Berlin, Germany
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21
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Abstract
Hepatitis B virus (HBV) is at the origin of severe liver diseases like chronic active hepatitis, liver cirrhosis and hepatocellular carcinoma. There are some groups of patients with high risk of generation of HBV mutants: infected infants, immunosuppressed individuals (including hemodialysis patients), patients treated with interferon and lamivudine for chronic HBV infection. These groups are the target for molecular investigations reviewed in this paper. The emergence of lamivudine- or other antiviral-resistant variants, rises concern regarding long term use of these drugs. Infection or immunization with one HBV subtype confers immunity to all subtypes. However, reinfection or reactivation of latent HBV infection with HBV mutants have been reported in patients undergoing transplant and those infected with HIV. Mutations of the viral genome which are not replicative incompetent can be selected in further course of infection or under prolonged antiviral treatment and might maintain the liver disease. Four open reading frames (ORF) which are called S-gene, C-gene, X-gene and P-gene were identified within the HBV genome. Mutations may affect each of the ORFs. Mutated S-genes were described to be responsible for HBV-infections in successfully vaccinated persons, mutated C-genes were found to provoke severe chronic liver diseases, mutated X-genes could cause serious medical problems in blood donors by escaping the conventional test systems and mutated P-genes were considered to be the reason for chemotherapeutic drug resistance. This paper reviews molecular, immunological and clinical aspects of the HBV mutants.
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Affiliation(s)
- C Kreutz
- International Technology for Evaluation of Clinical Pharmacology, Paris, France.
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22
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Kew MC. Hepatitis B virus in the etiology of hepatocellular carcinoma. VIRUSES AND LIVER CANCER 2002. [DOI: 10.1016/s0168-7069(02)06063-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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23
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Burda MR, Günther S, Dandri M, Will H, Petersen J. Structural and functional heterogeneity of naturally occurring hepatitis B virus variants. Antiviral Res 2001; 52:125-38. [PMID: 11672822 DOI: 10.1016/s0166-3542(01)00177-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Most organisms have developed sophisticated machineries to preserve their genomic integrity. On the contrary hepatitis B virus (HBV), like a lot of other viruses can undergo rapid and drastic sequence changes, especially if the virus has to cope with natural or therapy induced antiviral mechanisms in the host. Here, we try to summarize possible implications for the molecular pathogenesis of HBV based on the extensive research on the genetic variants of HBV.
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Affiliation(s)
- M R Burda
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Martinistr. 52, 20251 Hamburg, Germany
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24
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François G, Kew M, Van Damme P, Mphahlele MJ, Meheus A. Mutant hepatitis B viruses: a matter of academic interest only or a problem with far-reaching implications? Vaccine 2001; 19:3799-815. [PMID: 11427251 DOI: 10.1016/s0264-410x(01)00108-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- G François
- WHO Collaborating Centre for Prevention and Control of Viral Hepatitis, Department of Epidemiology and Social Medicine, Universiteit Antwerpen, Universiteitsplein 1, B-2610 Antwerpen, Belgium.
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25
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Lu M, Hilken G, Yang D, Kemper T, Roggendorf M. Replication of naturally occurring woodchuck hepatitis virus deletion mutants in primary hepatocyte cultures and after transmission to naive woodchucks. J Virol 2001; 75:3811-8. [PMID: 11264370 PMCID: PMC114872 DOI: 10.1128/jvi.75.8.3811-3818.2001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Woodchuck hepatitis virus (WHV) mutants with core internal deletions (CID) occur naturally in chronically WHV-infected woodchucks, as do hepatitis B virus mutants in humans. We studied the replication of WHV deletion mutants in primary woodchuck hepatocyte cultures and in vivo after transmission to naive woodchucks. By screening 14 wild-caught, chronically WHV-infected woodchucks, two woodchucks, WH69 and WH70, were found to harbor WHV CID mutants. Consistent with previous results, WHV CID mutants from both animals had deletions of variable lengths (90 to 135 bp) within the middle of the WHV core gene. In woodchuck WH69, WHV CID mutants represented a predominant fraction of the viral population in sera, normal liver tissues, and to a lesser extent, in liver tumor tissues. In primary hepatocytes of WH69, the replication of wild-type WHV and CID mutants was maintained at least for 7 days. Although WHV CID mutants were predominant in fractions of cellular WHV replicative intermediates, mutant covalently closed circular DNAs (cccDNAs) appeared to be a small part of cccDNA-enriched fractions. Analysis of cccDNA-enriched fractions from liver tissues of other woodchucks confirmed that mutant cccDNA represents only a small fraction of the total cccDNA pool. Four naive woodchucks were inoculated with sera from woodchuck WH69 or WH70 containing WHV CID mutants. All four woodchucks developed viremia after 3 to 4 weeks postinoculation (p.i.). They developed anti-WHV core antigen (WHcAg) antibody, lymphoproliferative response to WHcAg, and anti-WHV surface antigen. Only wild-type WHV, but no CID mutant, was found in sera from these woodchucks. The WHV CID mutant was also not identified in liver tissue from one woodchuck sacrificed in week 7 p.i. Three remaining woodchucks cleared WHV. Thus, the presence of WHV CID mutants in the inocula did not significantly change the course of acute self-limiting WHV infection. Our results indicate that the replication of WHV CID mutants might require some specific selective conditions. Further investigations on WHV CID mutants will allow us to have more insight into hepadnavirus replication.
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Affiliation(s)
- M Lu
- Institut für Virologie, Universitätsklinikum Essen, 45122 Essen, Germany.
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26
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Nakano T, Lu L, Hu X, Mizokami M, Orito E, Shapiro CN, Hadler SC, Robertson BH. Characterization of hepatitis B virus genotypes among Yucpa Indians in Venezuela. J Gen Virol 2001; 82:359-365. [PMID: 11161274 DOI: 10.1099/0022-1317-82-2-359] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The complete genome sequences of hepatitis B virus (HBV) from 12 HBV-infected Yucpa Indians of Venezuela, a group with highly endemic HBV, were amplified and sequenced. The 12 isolates were closely related to each other, with 98.6-100% nucleotide identity. A phylogenetic tree based on the complete genome indicated clearly that they were genotype F. Three individuals had evidence of infection with two different HBV deletion mutants. In two individuals, a three amino acid deletion was identified just prior to the 'a' determinant loop of the S region. A third individual was infected with virus that contained a complete core reading frame and a population that contained a deletion in the middle of the core region. These results indicate that genotype F HBV is present in the Venezuelan Yucpa Amerindians and the complete genome sequence allowed the identification of two unique deletion mutants in a limited set of samples.
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Affiliation(s)
- Tatsunori Nakano
- Second Department of Medicine, Nagoya City University Medical School, Nagoya 467-8601, Japan2
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
| | - Ling Lu
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
| | - Xiaolei Hu
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
| | - Masashi Mizokami
- Second Department of Medicine, Nagoya City University Medical School, Nagoya 467-8601, Japan2
| | - Etsuro Orito
- Second Department of Medicine, Nagoya City University Medical School, Nagoya 467-8601, Japan2
| | - Craig N Shapiro
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
| | - Stephan C Hadler
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
| | - Betty H Robertson
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA1
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27
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Botta A, Lu M, Zhen X, Kemper T, Roggendorf M. Naturally occurring woodchuck hepatitis virus (WHV) deletion mutants in chronically WHV-infected woodchucks. Virology 2000; 277:226-34. [PMID: 11080471 DOI: 10.1006/viro.1999.0127] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Deletion mutants of hepatitis B virus (HBV) are often found in chronically HBV-infected patients. It has not been possible to study the significance of such deletion mutants on liver diseases in a suitable animal model. In this study, we characterized naturally occurring deletion mutants of woodchuck hepatitis virus (WHV) in 11 chronically WHV-infected woodchucks. Deletions within the WHV preS region (nt 2992-338) had a length of 72 or 84 bp and were located in the amino terminal part of preS1. Internal deletions within the core gene (CID) had variable lengths (103 to 312 bp) and were identified within the center of this gene (nt 2021-2587). Four of seven CIDs were in-frame deletions, whereas the remaining three CIDs were out-of-frame deletions and led to the interruption of the reading frame. Sequence analysis of cloned PCR products of CIDs showed that heterogeneous WHV deletion mutants coexisted in single woodchucks. In addition, WHV genomes with double deletions in the preS1 and the core region could be found. We were unable to detect the expression of truncated core proteins in transfection experiments. The CID mutations led to a marked increase of the expression of the luciferase gene which was fused to the start codon of WHV polymerase, probably due to the shortening of the untranslated region or the removal of AUGs preceding the polymerase start codon. The characterization of naturally occurring WHV deletion mutants will allow us to study their biological and pathogenic properties in the woodchuck model in the future.
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Affiliation(s)
- A Botta
- Institut für Virologie, Universitätsklinikum Essen, Hufelandstrasse 55, 45122 Essen, Germany
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28
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Schläger F, Schaefer S, Metzler M, Gratzki N, Lampert F, Gerlich WH, Repp R. Quantitative DNA fragment analysis for detecting low amounts of hepatitis B virus deletion mutants in highly viremic carriers. Hepatology 2000; 32:1096-105. [PMID: 11050061 DOI: 10.1053/jhep.2000.19323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Many variants of hepatitis B virus (HBV) with deletions in the viral genome have been identified. Some of these variants are indicator or even effector of a more severe course of hepatitis. These deletion mutants contribute a variable and sometimes very low proportion to the viral population. For early detection of small amounts of deletion mutants among a large number of wild-type genomes, we applied a new screening method designated quantitative fragment analysis (QFA). By QFA the whole viral genome can be scanned for the presence of deletions or insertions of >/=3 nucleotides representing more than 2% of the viral population. Using QFA we showed that an often described deletion of 8 nucleotides is packaged in viral capsids and not a polymerase chain reaction (PCR) artifact. QFA was applied to study the emergence of deletion mutants in a group of 18 pediatric patients who had been infected from a common source while being under multidrug cancer chemotherapy. All patients had developed a highly viremic asymptomatic HBV carrier state. In 3 of these patients 3 different kinds of HBV deletion mutants were found by QFA: 8 bp deletions within the core promoter, core gene deletions from 8 to 86 bp, and large deletions of up to 1,989 bp spanning the precore/core and the preS/S reading frames. PCR primers that specifically amplify deletion variants enabled the detection of additional patients harboring the investigated variant.
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Affiliation(s)
- F Schläger
- Kinderheilkunde, Justus-Liebig-Universität, Giessen, Germany
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29
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Le Pogam S, Yuan TT, Sahu GK, Chatterjee S, Shih C. Low-level secretion of human hepatitis B virus virions caused by two independent, naturally occurring mutations (P5T and L60V) in the capsid protein. J Virol 2000; 74:9099-105. [PMID: 10982356 PMCID: PMC102108 DOI: 10.1128/jvi.74.19.9099-9105.2000] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The functional significance of naturally occurring variants of human hepatitis B virus (HBV) remains largely unknown. Previously, we reported an immature secretion phenotype caused by a highly frequent mutation at amino acid 97 of the HBV core (capsid) protein (HBcAg). This phenotype is characterized by a nonselective and excessive secretion of virions containing an immature genome of single-stranded viral DNA. To extend our study of virion secretion to other naturally occurring variants, we have characterized mutations at HBcAg codons 5, 38, and 60 via site-directed mutagenesis. Although the phenotype of the mutation at codon 38 is nearly identical to that for the wild-type virus, our study reveals that a single mutation at codon 5 or 60 exhibits a new extracellular phenotype with significantly reduced virion secretion yet maintains normal intracellular viral DNA replication. A complementation study indicates that the mutant core protein alone is sufficient for the "low-secretion" phenotype. Furthermore, the low-secretion phenotype of the codon 5 mutant appears to be induced by the loss of a parental proline residue, rather than by the gain of a new amino acid. Our study underscores the core protein as another crucial determinant in virion secretion, in addition to the known envelope proteins. Our present results suggest that a very precise structure of both alpha-helical and nonhelical loop regions of the entire HBcAg molecule is important for virion secretion. The low-secretion variants may contribute to the phenomenon of gradually decreasing viremia in chronic carriers during the late phase of persistent infection.
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Affiliation(s)
- S Le Pogam
- Center for Tropical Diseases, Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA
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30
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Günther S, Piwon N, Jung A, Iwanska A, Schmitz H, Will H. Enhanced replication contributes to enrichment of hepatitis B virus with a deletion in the core gene. Virology 2000; 273:286-99. [PMID: 10915599 DOI: 10.1006/viro.2000.0432] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Accumulation in immunosuppressed patients of hepatitis B virus (HBV) with a deletion in the C gene is associated with severe liver disease. The aim of this study was to determine the phenotype of such genomes in vitro. Four C gene fragments with different types of deletions were inserted in the context of a wild-type genome and tested by transfection into HuH7 cells. The deletions did not influence mRNA and surface protein levels. Truncated C gene translation products were expressed only from variants with in-frame deletions, whereas full-length polymerase was expressed from all variants at a similar or higher level than in wild-type virus. None of the variants was competent for autonomous replication; however, they produced 2- to 4.5-fold more progeny DNA than wild-type HBV when sufficiently complemented with wild-type core protein. Similarly, when variant and wild-type DNA were cotransfected in different ratios, the variants produced 2- to 5-fold more progeny DNA relative to the wild-type; this enrichment required the expression of the viral polymerase in cis. The mechanism of enrichment depended on the percentage of variant in the transfected DNA mixture. When the transfected DNA contained a small percentage of variant, enhanced replication of the variant accompanied by no or little suppression of wild-type replication was seen. Accordingly, overall production of progeny virus was slightly increased. At a high percentage of variant DNA, replication of both variant and wild-type decreased, probably due to a shortage of wild-type core protein. In conclusion, emergence of C gene deletion variants in vivo may be due to enhanced replication mediated at the level of encapsidation or reverse transcription. If the variants constitute a small part of the ccc DNA, they can be fully trans-complemented by wild-type virus which may increase the overall virus production.
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Affiliation(s)
- S Günther
- Bernhard-Nocht-Institut für Tropenmedizin, Hamburg, 20359, Federal Republic of Germany.
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31
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Preikschat P, Kazaks A, Dishlers A, Pumpens P, Krüger DH, Meisel H. Interaction of wild-type and naturally occurring deleted variants of hepatitis B virus core polypeptides leads to formation of mosaic particles. FEBS Lett 2000; 478:127-32. [PMID: 10922483 DOI: 10.1016/s0014-5793(00)01836-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The simultaneous presence of hepatitis B virus (HBV) genomes carrying wild-type (wt) and in-frame deleted variants of the HBV core gene has been identified as a typical feature of HBV-infected renal transplant patients with severe liver disease. To investigate possible interactions of wt and deleted core polypeptides a two-vector Escherichia coli expression system ensuring their concomitant synthesis has been developed. Co-expression of wt and a mutant core lacking 17 amino acid residues (77-93) within the immunodominant region led to the formation of mosaic particles, whereas the mutant alone was incapable of self-assembly.
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Affiliation(s)
- P Preikschat
- Institute of Virology, Humboldt University School of Medicine, Schumannstr, 20/21, D-10117, Berlin, Germany
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32
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Sommer G, van Bömmel F, Will H. Genotype-specific synthesis and secretion of spliced hepatitis B virus genomes in hepatoma cells. Virology 2000; 271:371-81. [PMID: 10860890 DOI: 10.1006/viro.2000.0331] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Hepatitis B virus-infected patients frequently have viral particles with DNA derived from differently spliced RNA. Which factors influence the synthesis of these splice variants is unclear. We analysed the type of splice variants produced from different genotypes and determined whether they are secreted as efficiently as wild-type virus. We demonstrate production of a single splice variant from genotypes D, C, and E as dominant species in two hepatoma cell lines. The type of minor splice variants synthesised varied between genotypes but was identical in both hepatoma cell lines. A novel splice variant with a deletion in the core gene was identified for genotype D. Viral DNA from intracellular compared with extracellular viral particles was spliced approximately five times more often than wild-type-sized genomes. A variable amount of the major splice variant was also identified in sera from patients infected with genotypes A, D, and C. These data indicate genotype A-, C-, D-, and E- as well as hepatoma cell line-independent synthesis of a dominant single splice variant and argue for a biological function of the corresponding splice sites. This study clearly demonstrates the intracellular accumulation of viral particles containing spliced genomes and offers a tool for the investigation of underlying mechanisms.
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Affiliation(s)
- G Sommer
- Heinrich-Pette Institut für Experimentelle Virologie und Immunologie, Universität Hamburg, Martinistrasse 52, Hamburg, 20251, Germany
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33
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Preikschat P, Meisel H, Will H, Günther S. Hepatitis B virus genomes from long-term immunosuppressed virus carriers are modified by specific mutations in several regions. J Gen Virol 1999; 80 ( Pt 10):2685-2691. [PMID: 10573161 DOI: 10.1099/0022-1317-80-10-2685] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is increasing evidence that hepatitis B virus (HBV) infection of an immunosuppressed host is associated with the appearance of virus mutants. To characterize the virus circulating in patients in detail, eleven full-length HBV genomes, isolated from the serum of five highly viraemic renal transplant recipients with liver disease, were cloned and sequenced. The genomes contained deletions in the C gene, deletions in the pre-S1/2 region frequently removing the pre-S2 initiation codon, premature termination codons in the pre-S1 or S region, and/or deletions/insertions in the X gene/core promoter. The mutations occurred at different positions and in various combinations; even mutant genomes circulating within a patient differed strikingly. It is concluded that long-term immunosuppression is associated with the occurrence of heterogeneous populations of partially defective HBV characterized by a specific mutation pattern. Efficient intracellular trans-complementation probably enables high virus replication in vivo.
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Affiliation(s)
- Petra Preikschat
- Institut für Medizinische Virologie der Charité, Humboldt-Universit ät zu Berlin, 10098 Berlin, Germany 1
| | - Helga Meisel
- Institut für Medizinische Virologie der Charité, Humboldt-Universit ät zu Berlin, 10098 Berlin, Germany 1
| | - Hans Will
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, 20251 Hamburg, Germany 2
| | - Stephan Günther
- Bernhard-Nocht-Institut für Tropenmedizin, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany 3
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34
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Yuan TT, Sahu GK, Whitehead WE, Greenberg R, Shih C. The mechanism of an immature secretion phenotype of a highly frequent naturally occurring missense mutation at codon 97 of human hepatitis B virus core antigen. J Virol 1999; 73:5731-40. [PMID: 10364324 PMCID: PMC112633 DOI: 10.1128/jvi.73.7.5731-5740.1999] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/1998] [Accepted: 03/29/1999] [Indexed: 01/12/2023] Open
Abstract
A very frequent missense mutation at codon 97 of human hepatitis B virus (HBV) core antigen (HBcAg) has been found in chronic carriers worldwide. Functional characterization of this mutant revealed one intracellular and two extracellular phenotypes in contrast to wild-type HBV: (i) a 6- to 12-fold decrease in the level of the full-length relaxed circular DNA, a 4- to 5-fold decrease in the plus-strand DNA, and an approximately 1.8-fold decrease in the minus-strand and overall DNA levels in the intracellular viral core particles; (ii) a 5.7-fold increase in the immature secretion of Dane particles, containing minus-strand, single-stranded virion DNA; and (iii) a significant reduction of nonenveloped core particles in the medium. The steady-state levels of mutant and wild-type core proteins expressed from the same vector appeared to be similar. Using a complementation assay and gradient centrifugation analysis, we demonstrated that this mutant core protein alone is necessary and sufficient for immature secretion. The decreased level of intracellular HBV DNA is caused by both the cis defect of the mutant genome and the trans defect of the mutant core protein. We have dissected further the relationship between the intracellular and extracellular phenotypes of mutant F97L. The pleiotropic effects of the HBcAg codon 97 mutation were observed consistently in several different experimental settings. The mechanism and biological significance of these findings are discussed.
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Affiliation(s)
- T T Yuan
- Departments of Pathology and of Microbiology and Immunology, Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA
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35
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Abstract
The existence of HBV as quasispecies is thought to be favoured by the infidelity of HBV RT, which would account for the emergence of the many natural mutants with point substitutions. RT infidelity may also underlie the hypermutation phenomenon. Indeed, the oft-reported point mutation in the preC gene that leads to failure of HBeAg synthesis may be driven by a hypermutation-related mechanism. The presence of mutants with deletions and insertions involving single nucleotides and oligonucleotides at specific positions in the genome, and of mutants with deletions of even longer stretches particularly in the C gene, suggests that other mutagenic mechanisms operate. Candidates include slippage during mispairing between template and progeny DNA strand, the action of cellular topoisomerase I, and gene splicing using alternative donor and acceptor sites. Natural substitutions, deletions or insertions involving the Cp/ENII locus in the X gene can significantly alter the extent of viral replicative activity. Similar mutations occurring at other locations of Cp/ENII, and at B-cell epitope sites of the S gene are associated with failure to detect serological markers of HBV infection. HBV variation can also arise from recombination between coinfecting strains. S gene mutations that become evident following HBIG administration and HBV vaccination are all point substitutions, as are mutations in functional RT domains of the P gene after treatment with viral RT-inhibitory drugs. Widespread and long-term use of prophylactic and therapeutic agents may potentially generate serologically occult HBV variants that might become difficult to eradicate.
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Affiliation(s)
- S L Ngui
- Section of Hepatology, Rush-Presbyterian-St. Luke's Medical Centre, 1725 West Harrison, Chicago, Illinois 60612, USA
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36
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Günther S, Fischer L, Pult I, Sterneck M, Will H. Naturally occurring variants of hepatitis B virus. Adv Virus Res 1999; 52:25-137. [PMID: 10384235 DOI: 10.1016/s0065-3527(08)60298-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S Günther
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Universität Hamburg, Federal Republic of Germany.
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37
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Pumpens P, Grens E. Hepatitis B core particles as a universal display model: a structure-function basis for development. FEBS Lett 1999; 442:1-6. [PMID: 9923592 DOI: 10.1016/s0014-5793(98)01599-3] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Because it exhibits a remarkable capability to accept mutational intervention and undergo correct folding and self-assembly in all viable prokaryotic and eukaryotic expression systems, hepatitis B core (HBc) protein has been favored over other proposed particulate carriers. Structurally, the unusual alpha-helical organization of HBc dimeric units allows introduction of foreign peptide sequences into several areas of HBc shells, including their most protruding spikes. Progress toward full resolution of the spatial structure as well as accumulation of chimeric HBc-based structures has brought closer the knowledge-based design of future vaccines, gene therapy tools and other artificial particulate objects.
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Affiliation(s)
- P Pumpens
- Biomedical Research and Study Centre, University of Latvia, Riga.
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38
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Tsubota A, Kumada H, Takaki K, Chayama K, Kobayashi M, Kobayashi M, Suzuki Y, Saitoh S, Arase Y, Murashima N, Ikeda K. Deletions in the hepatitis B virus core gene may influence the clinical outcome in hepatitis B e antigen-positive asymptomatic healthy carriers. J Med Virol 1998; 56:287-93. [PMID: 9829631 DOI: 10.1002/(sici)1096-9071(199812)56:4<287::aid-jmv1>3.0.co;2-p] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
To address the significance of mutations within the hepatitis B virus (HBV) core gene in chronic HBV infection, we followed prospectively HBe-antigen-positive asymptomatic healthy carriers, documented the onset of their disease based on serum alanine transaminase (ALT) concentrations, and analyzed sequentially serum samples from a quiescent phase through to an active phase of the chronic infection. In three female carriers, the first flare-up was documented during the follow-up period. Serial analysis by polymerase chain reaction, cloning, and sequencing of the HBV precore/core open reading frame genome demonstrated that clones with core gene deletions emerged during the quiescent phase and persisted subsequently during the active phase in two patients, who failed to seroconvert to anti-HBe and had persistently increased ALT levels despite interferon (IFN) therapy. The deletions were various, overlapping, and located in the mid-core region ranging from amino acid (aa) position 64 to 128. The remaining patient, who seroconverted with IFN therapy, did not have a core-gene-deletion HBV variant during follow-up, but had aa substitutions clustered in some restricted core regions. Two control asymptomatic carriers, who had no change in biochemical or virologic markers over a 15- to 19-year period, had no core-gene-deletion variants and few aa changes. These findings indicate that the mid-portion of the core gene is subject to deletion even during the quiescent phase. Thus, the immunologic interaction between the host and virus may occur insidiously, and the emergence of a core-gene-deletion HBV variant during the quiescent phase may be involved in the onset of hepatitis and the subsequent outcome of chronic infection.
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Affiliation(s)
- A Tsubota
- Department of Gastroenterology, Toranomon Hospital, Tokyo, Japan
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39
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Sällberg M, Hughes J, Javadian A, Ronlov G, Hultgren C, Townsend K, Anderson CG, O'Dea J, Alfonso J, Eason R, Murthy KK, Jolly DJ, Chang SM, Mento SJ, Milich D, Lee WT. Genetic immunization of chimpanzees chronically infected with the hepatitis B virus, using a recombinant retroviral vector encoding the hepatitis B virus core antigen. Hum Gene Ther 1998; 9:1719-29. [PMID: 9721082 DOI: 10.1089/hum.1998.9.12-1719] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cytotoxic T lymphocyte (CTL) activity and CD4+ helper T cell responses to the hepatitis B virus (HBV) core antigen (HBcAg) have been implicated in clearance of acute and chronic HBV infections. We showed that intramuscular injections of a novel recombinant retroviral vector expressing an HBcAg-neomycin phosphotransferase II (HBc-NEO) fusion protein induces HBc/eAg-specific antibodies and CD4+ and CD8+ T cell responses in mice and rhesus monkeys. We have now immunized three chronically infected chimpanzees, each with 10(10) CFU of nonreplicating retroviral vector particles expressing the HBc-NEO fusion protein. Of two immunized chimpanzees examined for CTL responses, one developed HBcAg-specific CTLs and showed marginal, transient elevations of alanine aminotransferase (ALT) levels following injection. However, both chimpanzees remained positive for serum HBeAg, negative for anti-HBe antibody by conventional assays, and displayed no change in HBV viral load throughout the study. In contrast, the third chimpanzee exhibited a traditional seroconversion evidenced by a loss of serum HBeAg and the subsequent emergence of anti-HBe antibodies within 24 weeks after the first injection. Simultaneously, two transient ALT flares and a significant decrease in the serum HBV DNA levels were noted. Despite its limitations, the present study demonstrates (1) the safety of treatment with high titers of retroviral vector in chimpanzees, (2) the capability of a retroviral vector expressing HBcAg to stimulate immune responses in HBV chronic carrier chimpanzees, and (3) that retroviral vector immunization may be therapeutically beneficial in the treatment of chronic HBV infection.
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Affiliation(s)
- M Sällberg
- Chiron Technologies Center for Gene Therapy, San Diego, CA 92121-1204, USA
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40
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Ulrich R, Nassal M, Meisel H, Krüger DH. Core particles of hepatitis B virus as carrier for foreign epitopes. Adv Virus Res 1998; 50:141-82. [PMID: 9520999 DOI: 10.1016/s0065-3527(08)60808-8] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To be effective as vaccines, most monomeric proteins and peptides either require chemical coupling to high molecular weight carriers or application together with adjuvants. More recently, recombinant DNA techniques have been used to insert foreign epitopes into proteins with inherent multimerization capacity, such as particle-forming viral capsid or envelope proteins. The core protein of hepatitis B virus (HBcAg), because of its unique structural and immunological properties, has gained widespread interest as a potential antigen carrier. Foreign sequences of up to approximately 40 amino acid residues at the N terminus, 50 or 100 amino acids in the central immunodominant c/e 1 epitope region of HBcAg, and up to 100 or even more residues at the C terminus, did not interfere with particle formation. The humoral immunogenicity of inserted epitopes is determined by the immunogenicity of the peptide itself and its surface exposure, and is influenced by the route of application. The probably flexible and surface-exposed c/e1 region emerged as the most promising insertion site. When applied together with adjuvants approved for human and veterinary use, or even without adjuvants, such chimeric particles induced B and T cell immune responses against the inserted epitopes. In some cases neutralizing antibodies, cytotoxic T cells and protection against challenge with the intact pathogen were demonstrated. Major factors for the potentiated immune response against the foreign epitopes are the multimeric structure of chimeric HBcAg that results in a high epitope density per particle, and the provision of T cell help by the carrier moiety. Beyond its use as subunit vaccine, chimeric HBcAg produced in attenuated Salmonella strains may be applicable as live vaccine.
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Affiliation(s)
- R Ulrich
- Charité Medical School, Humboldt University, Berlin, Germany
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41
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Blum HE. Hepatitis viruses: genetic variants and clinical significance. INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH 1998; 27:213-24. [PMID: 9506264 DOI: 10.1007/bf02912461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Variants of hepatitis B, C, and delta virus have been identified in patients both with acute and chronic infections. In the hepatitis B virus genome, naturally occurring mutations have been found in all viral genes, most notably in the genes coding for the structural envelope and nucleocapsid proteins. In the hepatitis C virus genome, the regions coding for the structural envelope proteins E1 and E2, as well as the 3'-contiguous non-structural region NS1, were found to be hypervariable. Viral variants may be associated with a specific clinical course of the infection, e.g., acute, fulminant or chronic hepatitis. Specific mutations may reduce viral clearance by immune mechanisms ('vaccine escape' and 'immune escape'), response to antiviral therapy ('therapy escape'), as well as detection ('diagnosis escape'). The exact contribution, however, of specific mutations to the pathogenesis and natural course of hepatitis B, C, or delta virus infection, including hepatocellular carcinoma development, and the response to antiviral treatment remains to be established.
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Affiliation(s)
- H E Blum
- Department of Internal Medicine II, University of Freiburg, Germany
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42
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Yuan TT, Lin MH, Qiu SM, Shih C. Functional characterization of naturally occurring variants of human hepatitis B virus containing the core internal deletion mutation. J Virol 1998; 72:2168-76. [PMID: 9499073 PMCID: PMC109512 DOI: 10.1128/jvi.72.3.2168-2176.1998] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/1997] [Accepted: 11/12/1997] [Indexed: 02/06/2023] Open
Abstract
Naturally occurring variants of human hepatitis B virus (HBV) containing the core internal deletion (CID) mutation have been found frequently in HBV carriers worldwide. Despite numerous sequence analysis reports of CID variants in patients, in the past decade, CID variants have not been characterized functionally, and thus their biological significance to HBV infection remains unclear. We report here two different CID variants identified from two patients that are replication defective, most likely due to the absence of detectable core protein. In addition, we were unable to detect the presence of the precore protein and e antigen from CID variants. However, the production of polymerase appeared to be normal. The replication defect of the CID variants can be rescued in trans by complementation with wild-type core protein. The rescued CID variant particles, which utilize the wild-type core protein, presumably are enveloped properly since they can be secreted into the medium and band at a position similar to that of mature wild-type Dane particles, as determined by gradient centrifugation analysis. Our results also provide an explanation for the association of CID variants with helper or wild-type HBV in nature. The significance of CID variants in HBV infection and pathogenesis is discussed.
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Affiliation(s)
- T T Yuan
- Department of Pathology, Center for Tropical Diseases, University of Texas Medical Branch, Galveston 77555-0609, USA
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Günther S, Sommer G, Von Breunig F, Iwanska A, Kalinina T, Sterneck M, Will H. Amplification of full-length hepatitis B virus genomes from samples from patients with low levels of viremia: frequency and functional consequences of PCR-introduced mutations. J Clin Microbiol 1998; 36:531-8. [PMID: 9466771 PMCID: PMC104572 DOI: 10.1128/jcm.36.2.531-538.1998] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To facilitate the investigation of hepatitis B virus (HBV) sequence variation, we recently established a method for functional analysis of PCR-amplified full-length HBV genomes. This study aimed at estimating the number of mutations introduced during amplification of genomes from samples from patients with low levels of viremia and their influence on replication and antigen expression. Wild-type HBV DNA template molecules in concentrations like those present in samples from patients with very low levels of viremia were amplified, sequenced (30 kb total), and functionally tested. We found that Taq polymerase and a Taq-Pwo polymerase mixture introduced an average of 5.7 and 3.1 mutations per genome, respectively, corresponding to polymerase error rates of 12.1 x 10(-5) and 6.0 x 1(0-5). One of 8 genomes (12%) amplified with Taq polymerase, but 7 of 17 genomes amplified with Taq-Pwo polymerases (41%), remained replication competent. All replication-competent genomes expressed HBs and HBe antigens and had an average of only 0.9 mutations per genome. In contrast, replication-defective genomes had an average of 5.4 mutations, which frequently also disturbed viral antigen expression. From these data we conclude that many of the replication-competent HBV genomes from a clinical specimen will retain their replication and antigen expression phenotypes even after extensive amplification with Taq-Pwo polymerases. Because replication competence is highly sensitive to random mutations, it is the best marker for the identification of HBV genomes with few or no PCR-introduced mutations.
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Affiliation(s)
- S Günther
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Federal Republic of Germany.
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44
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Sommer G, Günther S, Sterneck M, Otto S, Will H. A new class of defective hepatitis B virus genomes with an internal poly(dA) sequence. Virology 1997; 239:402-12. [PMID: 9434730 DOI: 10.1006/viro.1997.8898] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sequence heterogeneity of hepatitis B virus (HBV) is increasingly recognized to play a role in virus-host interaction. We have used a recently established method for HBV full-length genome amplification to search for novel types of HBV variants and to investigate further the sequence heterogeneity of HBV genome populations. Using this method, a substantial fraction of HBV genomes much shorter than wildtype size was found in some sera and liver biopsies from infected patients. Cloning and sequencing of a number of these HBV genomes as well as hybridization studies revealed a new minor class of HBV genomes with an internal poly(dA) sequence approximately 60 to more than 100 nucleotides long in 4 of 10 patients. The 5'-ends of the internal poly(dA) sequences are located at positions corresponding to the authentic processing/polyadenylation sites of the RNA pregenome, whereas the positions of the 3'-ends are variable due to different sizes of adjacent deletions. These data suggest that the poly(A) tail of the pregenomic RNA is occasionally reverse transcribed by the HBV P-protein and during this process a deletion seems to be introduced into the DNA minus strand. We propose a mechanism by which this could be accomplished during DNA minus strand synthesis.
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Affiliation(s)
- G Sommer
- Heinrich-Pette-Institut für experimentalle Virologie und immunologie an, Universität Hamburg, Germany
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45
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Abstract
BACKGROUND/AIMS Little is known about the persistence and risk of infection with hepatitis B viruses (HBV) containing mutations in the pre-C and pre-S region. The aim of this study was to study the long-term persistence and the risk of intrafamilial spreading of these variants. METHODS Serological markers were analyzed immunologically and pre-C and pre-S sequences of HBV DNA in sera from several members of five families by DNA amplification and direct sequencing. RESULTS In most HBV-DNA positive individuals of each family, either the dominant HBV population or a subpopulation had a stop codon in the pre-C region which prevented expression of e-antigen. The pre-S region of the dominant virus populations of 8/15 HBV-DNA positive sera showed different deletions or a pre-S2 translation initiation codon mutation in addition to various point mutations. Selection for pre-C and pre-S mutant viruses from a predominant "wildtype" virus population was observed in three individuals during the natural course of infection. Persistence of a pre-C/pre-S double mutant virus as a stable strain for 6 years was found in one patient. CONCLUSIONS These data indicate extensive intrafamilial clustering of HBV variants with mutations in the pre-C and pre-S regions due to patient-specific selection mechanisms and long-term persistence of some mutants as stable strains. The type of viruses found suggests that occasionally virus subpopulations are selectively transmitted or become a dominant virus population after selection.
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Affiliation(s)
- T Santantonio
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Universität Hamburg, Germany
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