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Panasiuk YV, Vlasenko NV, Churilova NS, Klushkina VV, Dubodelov DV, Kudryavtseva EN, Korabelnikova MI, Rodionova ZS, Semenenko TA, Kuzin SN, Akimkin VG. [Modern views on the role of X gene of the hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) in the pathogenesis of the infection it causes]. Vopr Virusol 2022; 67:7-17. [PMID: 35293184 DOI: 10.36233/0507-4088-84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 11/05/2022]
Abstract
The review presents information on the role of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) (HBV) X gene and the protein it encodes (X protein) in the pathogenesis of viral hepatitis B. The evolution of HBV from primordial to the modern version of hepadnaviruses (Hepadnaviridae), is outlined as a process that began about 407 million years ago and continues to the present. The results of scientific works of foreign researchers on the variety of the influence of X protein on the infectious process and its role in the mechanisms of carcinogenesis are summarized. The differences in the effect of the X protein on the course of the disease in patients of different ethnic groups with regard to HBV genotypes are described. The significance of determining the genetic variability of X gene as a fundamental characteristic of the virus that has significance for the assessment of risks of hepatocellular carcinoma (HCC) spread among the population of the Russian Federation is discussed.
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Affiliation(s)
- Y V Panasiuk
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - N V Vlasenko
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - N S Churilova
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - V V Klushkina
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - D V Dubodelov
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - E N Kudryavtseva
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - M I Korabelnikova
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - Z S Rodionova
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - T A Semenenko
- FSBI «National Research Centre for Epidemiology and Microbiology named after the honorary academician N.F. Gamaleya» of the Ministry of Health of Russia
| | - S N Kuzin
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
| | - V G Akimkin
- FSBI «Central Research Institute for Epidemiology» of the Federal Service for Supervision of Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor)
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2
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Niedźwiedzka-Rystwej P, Grywalska E, Hrynkiewicz R, Wołącewicz M, Becht R, Roliński J. The Double-Edged Sword Role of Viruses in Gastric Cancer. Cancers (Basel) 2020; 12:cancers12061680. [PMID: 32599870 PMCID: PMC7352989 DOI: 10.3390/cancers12061680] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/14/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023] Open
Abstract
Due to its high morbidity and mortality, gastric cancer is a topic of a great concern throughout the world. Major ways of treatment are gastrectomy and chemotherapy, unfortunately they are not always successful. In a search for more efficient therapy strategies, viruses and their potential seem to be an important issue. On one hand, several oncogenic viruses have been noticed in the case of gastric cancer, making the positive treatment even more advantageous, but on the other, viruses exist with a potential therapeutic role in this malignancy.
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Affiliation(s)
- Paulina Niedźwiedzka-Rystwej
- Institute of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland; (R.H.); (M.W.)
- Correspondence:
| | - Ewelina Grywalska
- Department of Clinical Immunology and Immunotherapy, Medical University of Lublin, 20-093 Lublin, Poland; (E.G.); (J.R.)
| | - Rafał Hrynkiewicz
- Institute of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland; (R.H.); (M.W.)
| | - Mikołaj Wołącewicz
- Institute of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland; (R.H.); (M.W.)
| | - Rafał Becht
- Clinical Department of Oncology, Chemotherapy and Cancer Immunotherapy, Pomeranian Medical University of Szczecin, 70-204 Szczecin, Poland;
| | - Jacek Roliński
- Department of Clinical Immunology and Immunotherapy, Medical University of Lublin, 20-093 Lublin, Poland; (E.G.); (J.R.)
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Minarovits J, Niller HH. Truncated oncoproteins of retroviruses and hepatitis B virus: A lesson in contrasts. INFECTION GENETICS AND EVOLUTION 2019; 73:342-357. [DOI: 10.1016/j.meegid.2019.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 05/27/2019] [Indexed: 02/07/2023]
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4
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Jo WK, Pfankuche VM, Petersen H, Frei S, Kummrow M, Lorenzen S, Ludlow M, Metzger J, Baumgärtner W, Osterhaus A, van der Vries E. New Avian Hepadnavirus in Palaeognathous Bird, Germany. Emerg Infect Dis 2018; 23:2089-2091. [PMID: 29148393 PMCID: PMC5708223 DOI: 10.3201/eid2312.161634] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
In 2015, we identified an avian hepatitis B virus associated with hepatitis in a group of captive elegant-crested tinamous (Eudromia elegans) in Germany. The full-length genome of this virus shares <76% sequence identity with other avihepadnaviruses. The virus may therefore be considered a new extant avian hepadnavirus.
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Mitra B, Guo H. Hepatitis B virus X protein crosses out Smc5/6 complex to maintain covalently closed circular DNA transcription. Hepatology 2016; 64:2246-2249. [PMID: 27639252 PMCID: PMC5115954 DOI: 10.1002/hep.28834] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/03/2016] [Accepted: 08/17/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Bidisha Mitra
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
| | - Haitao Guo
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN
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6
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Suh A, Weber CC, Kehlmaier C, Braun EL, Green RE, Fritz U, Ray DA, Ellegren H. Early mesozoic coexistence of amniotes and hepadnaviridae. PLoS Genet 2014; 10:e1004559. [PMID: 25501991 PMCID: PMC4263362 DOI: 10.1371/journal.pgen.1004559] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 06/24/2014] [Indexed: 12/16/2022] Open
Abstract
Hepadnaviridae are double-stranded DNA viruses that infect some species of birds and mammals. This includes humans, where hepatitis B viruses (HBVs) are prevalent pathogens in considerable parts of the global population. Recently, endogenized sequences of HBVs (eHBVs) have been discovered in bird genomes where they constitute direct evidence for the coexistence of these viruses and their hosts from the late Mesozoic until present. Nevertheless, virtually nothing is known about the ancient host range of this virus family in other animals. Here we report the first eHBVs from crocodilian, snake, and turtle genomes, including a turtle eHBV that endogenized >207 million years ago. This genomic “fossil” is >125 million years older than the oldest avian eHBV and provides the first direct evidence that Hepadnaviridae already existed during the Early Mesozoic. This implies that the Mesozoic fossil record of HBV infection spans three of the five major groups of land vertebrates, namely birds, crocodilians, and turtles. We show that the deep phylogenetic relationships of HBVs are largely congruent with the deep phylogeny of their amniote hosts, which suggests an ancient amniote–HBV coexistence and codivergence, at least since the Early Mesozoic. Notably, the organization of overlapping genes as well as the structure of elements involved in viral replication has remained highly conserved among HBVs along that time span, except for the presence of the X gene. We provide multiple lines of evidence that the tumor-promoting X protein of mammalian HBVs lacks a homolog in all other hepadnaviruses and propose a novel scenario for the emergence of X via segmental duplication and overprinting of pre-existing reading frames in the ancestor of mammalian HBVs. Our study reveals an unforeseen host range of prehistoric HBVs and provides novel insights into the genome evolution of hepadnaviruses throughout their long-lasting association with amniote hosts. Viruses are not known to leave physical fossil traces, which makes our understanding of their evolutionary prehistory crucially dependent on the detection of endogenous viruses. Ancient endogenous viruses, also known as paleoviruses, are relics of viral genomes or fragments thereof that once infiltrated their host's germline and then remained as molecular “fossils” within the host genome. The massive genome sequencing of recent years has unearthed vast numbers of paleoviruses from various animal genomes, including the first endogenous hepatitis B viruses (eHBVs) in bird genomes. We screened genomes of land vertebrates (amniotes) for the presence of paleoviruses and identified ancient eHBVs in the recently sequenced genomes of crocodilians, snakes, and turtles. We report an eHBV that is >207 million years old, making it the oldest endogenous virus currently known. Furthermore, our results provide direct evidence that the Hepadnaviridae virus family infected birds, crocodilians and turtles during the Mesozoic Era, and suggest a long-lasting coexistence of these viruses and their amniote hosts at least since the Early Mesozoic. We challenge previous views on the origin of the oncogenic X gene and provide an evolutionary explanation as to why only mammalian hepatitis B infection leads to hepatocellular carcinoma.
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Affiliation(s)
- Alexander Suh
- Department of Evolutionary Biology (EBC), Uppsala University, Uppsala, Sweden
- * E-mail:
| | - Claudia C. Weber
- Department of Evolutionary Biology (EBC), Uppsala University, Uppsala, Sweden
| | - Christian Kehlmaier
- Museum of Zoology, Senckenberg Research Institute and Natural History Museum, Dresden, Germany
| | - Edward L. Braun
- Department of Biology and Genetics Institute, University of Florida, Gainesville, Florida, United States of America
| | - Richard E. Green
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Uwe Fritz
- Museum of Zoology, Senckenberg Research Institute and Natural History Museum, Dresden, Germany
| | - David A. Ray
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, Mississippi, United States of America
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Hans Ellegren
- Department of Evolutionary Biology (EBC), Uppsala University, Uppsala, Sweden
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Wang Y, Li Y, Yang C, Hui L, Han Q, Ma L, Wang Q, Yang G, Liu Z. Development and application of a universal Taqman real-time PCR for quantitation of duck hepatitis B virus DNA. J Virol Methods 2013; 191:41-7. [PMID: 23557670 DOI: 10.1016/j.jviromet.2013.03.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/08/2013] [Accepted: 03/14/2013] [Indexed: 11/18/2022]
Abstract
To develop a quantitative assay for universal detection of duck hepatitis B virus (DHBV) DNA, a Taqman real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) assay was developed using primers and probes based on genomic sequences located at nucleotide 241-414 of the DHBV Core region which possesses the highest homology among the 44 DHBV genomes available in Genbank. The DHBV Core gene cloned in pGEM-T was used to generate DHBV DNA standard. The assay had a lowest detection limit of 10(3) copies/ml and a good linear standard curve (Y=-3.989X+49.086, r(2)=0.9993) over a wide range of input DHBV DNA (10(3) to 10(10) copies/ml). The standard deviation of intra- and inter-assay was 0.01-0.06 and 0.05-0.16, respectively, and the coefficient of variation was 1.3-1.8%. The specificity of the assay was validated using duck hepatitis virus type 1, hepatitis B virus, and E. coli DNA. Comparison of ABI 7300 and Bio-Rad iQ5 PCR instruments yielded highly consistent results. The assay showed a positive rate of 63.8% (51/80) DHBV DNA in peripheral blood and liver tissue from ducks from Xi'an, China. The FQ-PCR developed is highly sensitive, specific, reproducible and versatile, and may be used to universally detect DHBV DNA of different DHBV strains.
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Affiliation(s)
- Yawen Wang
- Department of Laboratory Medicine, First Affiliated Hospital, School of medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi, China
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8
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Piasecki T, Harkins GW, Chrząstek K, Julian L, Martin DP, Varsani A. Avihepadnavirus diversity in parrots is comparable to that found amongst all other avian species. Virology 2013; 438:98-105. [PMID: 23411008 DOI: 10.1016/j.virol.2013.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/12/2013] [Accepted: 01/17/2013] [Indexed: 12/15/2022]
Abstract
Avihepadnaviruses have previously been isolated from various species of duck, goose, stork, heron and crane. Recently the first parrot avihepadnavirus was isolated from a Ring-necked Parakeet in Poland. In this study, 41 psittacine liver samples archived in Poland over the last nine years were tested for presence of Parrot hepatitis B virus (PHBV). We cloned and sequenced PHBV isolates from 18 birds including a Crimson Rosella, an African grey parrot and sixteen Ring-necked Parakeets. PHBV isolates display a degree of diversity (>78% genome wide pairwise identity) that is comparable to that found amongst all other avihepadnaviruses (>79% genome wide pairwise identity). The PHBV viruses can be subdivided into seven genetically distinct groups (tentatively named A-G) of which the two isolated of PHBV-G are the most divergent sharing ∼79% genome wide pairwise identity with all their PHBVs. All PHBV isolates display classical avihepadnavirus genome architecture.
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Affiliation(s)
- Tomasz Piasecki
- Department of Epizootiology with Clinic of Birds and Exotic Animals, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, 50-360 Wrocław, Poland
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9
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Piasecki T, Kurenbach B, Chrząstek K, Bednarek K, Kraberger S, Martin DP, Varsani A. Molecular characterisation of an avihepadnavirus isolated from Psittacula krameri (ring-necked parrot). Arch Virol 2011; 157:585-90. [DOI: 10.1007/s00705-011-1197-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 12/07/2011] [Indexed: 02/08/2023]
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10
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Jitendra S, Nanda A, Kaur S, Singh M. A comprehensive molecular interaction map for Hepatitis B virus and drug designing of a novel inhibitor for Hepatitis B X protein. Bioinformation 2011; 7:9-14. [PMID: 21904432 PMCID: PMC3163926 DOI: 10.6026/97320630007009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 12/17/2022] Open
Abstract
Hepatitis B virus (HBV) infection is a leading source of liver diseases such as hepatitis, cirrhosis and hepatocellular carcinoma. In this study, we use computation methods in order to improve our understanding of the complex interactions that occur between molecules related to Hepatitis B virus (HBV). Due to the complexity of the disease and the numerous molecular players involved, we devised a method to construct a systemic network of interactions of the processes ongoing in patients affected by HBV. The network is based on high-throughput data, refined semi-automatically with carefully curated literature-based information. We find that some nodes in the network that prove to be topologically important, in particular HBx is also known to be important target protein used for the treatment of HBV. Therefore, HBx protein is the preferential choice for inhibition to stop the proteolytic processing. Hence, the 3D structure of HBx protein was downloaded from PDB. Ligands for the active site were designed using LIGBUILDER. The HBx protein's active site was explored to find out the critical interactions pattern for inhibitor binding using molecular docking methodology using AUTODOCK Vina. It should be noted that these predicted data should be validated using suitable assays for further consideration.
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Affiliation(s)
- Singh Jitendra
- Department of Bioinformatics, ADI Biosolution, Mohali, Punjab, India-160059
| | - Ashina Nanda
- Department of Bioinformatics, Hans Raj Mahila Mahavidyalaya, Jalandhar, Punjab, India
| | - Satveer Kaur
- Department of Bioinformatics, Hans Raj Mahila Mahavidyalaya, Jalandhar, Punjab, India
| | - Maneet Singh
- Department of Bioinformatics, ADI Biosolution, Mohali, Punjab, India-160059
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Ying C, Tan S, Cheng YC. Helioxanthin analogue 8-1 inhibits duck hepatitis B virus replication in cell culture. Antivir Chem Chemother 2011; 21:97-103. [PMID: 21107018 DOI: 10.3851/imp1686] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Current approved anti-HBV treatment cannot completely eliminate HBV infection, and emergence of resistant virus is an important treatment issue. Effective anti-HBV agents with different mechanisms of action on novel target sites are needed for the treatment of HBV infection and for combating the resistant virus, alone or in combination with current anti-HBV strategies. Helioxanthin analogue 8-1 displayed potent anti-HBV activity in human HBV in vitro and in animal models, with a unique antiviral mechanism. Its antiviral activity in other HBV system needs further study. METHODS The anti-duck hepatitis B virus (DHBV) activity of 8-1, an analogue of a natural product, helioxanthin, was studied in the DHBV inducible cell line, dstet5, in comparison to and in combination with the nucleoside analogue, lamivudine (3TC). RESULTS Helioxanthin analogue 8-1 exhibited anti-DHBV activity as demonstrated by quantification of viral DNA, RNA, covalently closed circular DNA and protein synthesis. Analogue 8-1 did not affect the stability of cellular macromolecules and did not have a sustained antiviral effect after drug removal. When DHBV replication was induced, virus-harbouring cells were more susceptible to the cytotoxicity of 8-1 than non-induced cells. CONCLUSIONS 8-1 exhibited effective inhibition on DHBV replication. The combination of 8-1 with 3TC resulted in additional anti-DHBV activity. Viral induced cells displayed higher susceptibility to 8-1 treatment than non-induced cells. HBV X protein might not be an essential factor in the initiation of the biological activity of 8-1, as demonstrated by its absence in DHBV. These findings warrant further development of 8-1 for the treatment of chronic hepatitis B and its associated diseases.
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Affiliation(s)
- Chunxiao Ying
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
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12
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Lizzano RA, Yang B, Clippinger AJ, Bouchard MJ. The C-terminal region of the hepatitis B virus X protein is essential for its stability and function. Virus Res 2010; 155:231-9. [PMID: 20969903 DOI: 10.1016/j.virusres.2010.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/10/2010] [Accepted: 10/12/2010] [Indexed: 02/06/2023]
Abstract
More than 350 million people worldwide are chronically infected with the human hepatitis B virus (HBV). Chronic HBV infections are associated with the development of hepatocellular carcinoma. While the mechanism of HBV-associated carcinoma remains undefined, it is thought to involve a combination of a continuous inflammatory response to HBV-infected hepatocytes and activities of HBV proteins such as the HBV X protein (HBx). HBx stimulates HBV replication; however, the mechanism by which HBx stimulates HBV replication remains incompletely understood. Studies performed with the woodchuck hepatitis virus (WHV) in woodchucks demonstrated that a C-terminally truncated mutant of the WHV X protein could not stimulate WHV replication. However, whether the C-terminus of HBx is important for HBx-stimulation of HBV replication is unclear. We have constructed C-terminal truncation mutants of HBx and have demonstrated that the C-terminus of HBx impacts HBx stability, HBx activation of transcription, and HBx stimulation of HBV replication. These observations highlight the impact of the HBx C-terminus on HBx activities and the importance of directly analyzing HBx expression and functions in HBV-associated tumors that contain chromosomal integrants of HBV with truncations of the HBx gene.
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Affiliation(s)
- Rebecca A Lizzano
- Graduate Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19102, United States
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13
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Pre-P is a secreted glycoprotein encoded as an N-terminal extension of the duck hepatitis B virus polymerase gene. J Virol 2008; 83:1368-78. [PMID: 19004940 DOI: 10.1128/jvi.01263-08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The duck hepatitis B virus (DHBV) pregenomic RNA is a bicistronic mRNA encoding the core and polymerase proteins. Thirteen AUGs (C2 to C14) and 10 stop codons (S1 to S10) are located between the C1 AUG for the core protein and the P1 AUG that initiates polymerase translation. We previously found that the translation of the DHBV polymerase is initiated by ribosomal shunting. Here, we assessed the biosynthetic events after shunting. Translation of the polymerase open reading frame was found to initiate at the C13, C14, and P1 AUGs. Initiation at the C13 AUG occurred through ribosomal shunting because translation from this codon was cap dependent but was insensitive to blocking ribosomal scanning internally in the message. C13 and C14 are in frame with P1, and translation from these upstream start codons led to the production of larger isoforms of P. We named these isoforms "pre-P" by analogy to the pre-C and pre-S regions of the core and surface antigen open reading frames. Pre-P was produced in DHBV16 and AusDHBV-infected duck liver and was predicted to exist in 80% of avian hepadnavirus strains. Pre-P was not encapsidated into DHBV core particles, and the viable strain DHBV3 cannot make pre-P, so it is not essential for viral replication. Surprisingly, we found that pre-P is an N-linked glycoprotein that is secreted into the medium of cultured cells. These data indicate that DHBV produces an additional protein that has not been previously reported. Identifying the role of pre-P may improve our understanding of the biology of DHBV infection.
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14
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Clippinger AJ, Bouchard MJ. Hepatitis B virus HBx protein localizes to mitochondria in primary rat hepatocytes and modulates mitochondrial membrane potential. J Virol 2008; 82:6798-811. [PMID: 18448529 PMCID: PMC2446973 DOI: 10.1128/jvi.00154-08] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 04/22/2008] [Indexed: 12/20/2022] Open
Abstract
Over 350 million people are chronically infected with hepatitis B virus (HBV), and a significant number of chronically infected individuals develop primary liver cancer. HBV encodes seven viral proteins, including the nonstructural X (HBx) protein. The results of studies with immortalized or transformed cells and with HBx-transgenic mice demonstrated that HBx can interact with mitochondria. However, no studies with normal hepatocytes have characterized the precise mitochondrial localization of HBx or the effect of HBx on mitochondrial physiology. We have used cultured primary rat hepatocytes as a model system to characterize the mitochondrial localization of HBx and the effect of HBx expression on mitochondrial physiology. We now show that a fraction of HBx colocalizes with density-gradient-purified mitochondria and associates with the outer mitochondrial membrane. We also demonstrate that HBx regulates mitochondrial membrane potential in hepatocytes and that this function of HBx varies depending on the status of NF-kappaB activity. In primary rat hepatocytes, HBx activation of NF-kappaB prevented mitochondrial membrane depolarization; however, when NF-kappaB activity was inhibited, HBx induced membrane depolarization through modulation of the mitochondrial permeability transition pore. Collectively, these results define potential pathways through which HBx may act in order to modulate mitochondrial physiology, thereby altering many cellular activities and ultimately contributing to the development of HBV-associated liver cancer.
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Affiliation(s)
- Amy J Clippinger
- Graduate Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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15
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Abstract
Hepatitis B viruses are small enveloped DNA viruses referred to as Hepadnaviridae that cause transient or persistent (chronic) infections of the liver. This family is divided into two genera, orthohepadnavirus and avihepadnavirus, which infect mammals or birds as natural hosts, respectively. They possess a narrow host range determined by the initial steps of viral attachment and entry. Hepatitis B virus is the focus of biomedical research owing to its medical significance. Approximately 2 billion people have serological evidence of hepatitis B, and of these approximately 350 million people have chronic infections (World Health Organisation, Fact Sheet WHO/204, October 2000). Depending on viral and host factors, the outcomes of infection with hepatitis B virus vary between acute hepatitis, mild or severe chronic hepatitis or cirrhosis. Chronic infections are associated with an increased risk for the development of hepatocellular carcinoma.
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Affiliation(s)
- Hans-Jürgen Netter
- Monash University, Department of Microbiology, Clayton Campus, Victoria 3800, Australia
| | - Shau-Feng Chang
- Industrial Technology Research Institute, Biomedical Engineering Laboratories, 300 Hsinchu, Taiwan
| | - Michael Bruns
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, 20251 Hamburg, Germany
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16
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Cheng B, Lin ST, Yang YZ, Li PY. Establishment of gene-transfected cell strain L02/HBx and effect of HBx on the cell cycles. Shijie Huaren Xiaohua Zazhi 2007; 15:1488-1493. [DOI: 10.11569/wcjd.v15.i13.1488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To establish gene-transfected cell strain L02/HBx and study its cell cycle changes.
METHODS: Effectene transfection and G418 selection were used to obtain the positive clones of L02/HBx cells. Then HBx mRNA and protein expression were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. Finally, MTT assay and flow cytometry were adopted to measure the proliferation, apoptosis and cell cycles of L02/HBx cells.
RESULTS: RT-PCR and Western blot analysis showed that the positive clones had HBx expression at mRNA and protein level. MTT assay demonstrated that the proliferation of L02/HBx cells had been accelerated. Flow cytometry found that the apoptosis rates of L02/HBx cells were at a lower level (0.09% ± 0.13% vs 3.74% ± 1.29%, P < 0.05), and the proportion of L02/HBx cells fell G1 phase (61.35% ± 0.82% vs 67.80% ± 6.84%, P < 0.05) but rose in S phase (36.59% ± 2.54% vs 22.37% ± 2.17%, P < 0.05). After co-culture with adriamycin, L02/HBx cells manifested a higher apoptosis rate (34.91% ± 5.85% vs 0.09% ± 0.13%, P < 0.05), and the proportion of G1-phase cells was significantly increased (82.81% ± 6.48% vs 61.35% ± 0.82%, P < 0.05), but still lower than that in the non-transfected group (82.81% ± 6.48% vs 87.19% ± 1.92%, P < 0.05). However, the percentage of S-phase cells was markedly decreased (13.84% ± 6.16% vs 36.59% ± 2.54%, P < 0.05), but still higher than that in the non-transfected group (13.84% ± 6.16% vs 2.22% ± 1.26%, P < 0.05).
CONCLUSION: L02/HBx cell strain stably expressing HBx is established successfully. HBx can accelerate the cell cycles and improve the growth instead of facilitating the apoptosis. L02/HBx cells can be easily affected by the apoptotic factors, indicating that HBx may increase the susceptibility of normal liver cells to the apoptosis-inducing factors.
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17
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Funk A, Mhamdi M, Will H, Sirma H. Avian hepatitis B viruses: Molecular and cellular biology, phylogenesis, and host tropism. World J Gastroenterol 2007; 13:91-103. [PMID: 17206758 PMCID: PMC4065881 DOI: 10.3748/wjg.v13.i1.91] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The human hepatitis B virus (HBV) and the duck hepatitis B virus (DHBV) share several fundamental features. Both viruses have a partially double-stranded DNA genome that is replicated via a RNA intermediate and the coding open reading frames (ORFs) overlap extensively. In addition, the genomic and structural organization, as well as replication and biological characteristics, are very similar in both viruses. Most of the key features of hepadnaviral infection were first discovered in the DHBV model system and subsequently confirmed for HBV. There are, however, several differences between human HBV and DHBV. This review will focus on the molecular and cellular biology, evolution, and host adaptation of the avian hepatitis B viruses with particular emphasis on DHBV as a model system.
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Affiliation(s)
- Anneke Funk
- Department of General Virology, Heinrich-Pette-Institut fur experimentelle Virologie und Immunologie an der Universitat Hamburg, PO Box 201652, Hamburg 20206, Germany
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18
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Abstract
Hepatocellular carcinoma (HCC) is one of the most common cancers in the world with an annual incidence of more than 500 000 in the year 2000. Its incidence is rising in many countries. Recently, it has been estimated that about 53% of HCC cases in the world are related to hepatitis B virus (HBV). The epidemiological association of HBV with HCC is well established. In recent studies, it was revealed that HBsAg carriers have a 25-37 times increased risk of developing HCC as compared to non-infected people. At present, HBV-associated carcinogenesis can be seen as a multi-factorial process that includes both direct and indirect mechanisms that might act synergistically. The integration of HBV DNA into the host genome occurs at early steps of clonal tumor expansion. The integration has been shown in a number of cases to affect a variety of cancer-related genes and to exert insertional mutagenesis. The permanent liver inflammation, induced by the immune response, resulting in a degeneration and regeneration process confers to the accumulation of critical mutations in the host genome. In addition to this, the regulatory proteins HBx and the PreS2 activators that can be encoded by the integrate exert a tumor promoter-like function resulting in positive selection of cells producing a functional regulatory protein. Gene expression profiling and proteomic techniques may help to characterize the molecular mechanisms driving HBV-associated carcinogenesis, and thus potentially identify new strategies in diagnosis and therapy.
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Affiliation(s)
- Joachim Lupberger
- University of Freiburg, Department of Internal Medicine II, Hugstetter Strasse 55, Freiburg D-79106, Germany
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19
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Fiedler N, Quant E, Fink L, Sun J, Schuster R, Gerlich WH, Schaefer S. Differential effects on apoptosis induction in hepatocyte lines by stable expression of hepatitis B virus X protein. World J Gastroenterol 2006; 12:4673-82. [PMID: 16937438 PMCID: PMC4087832 DOI: 10.3748/wjg.v12.i29.4673] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: Hepatitis B virus protein X (HBx) has been shown to be weakly oncogenic in vitro. The transforming activities of HBx have been linked with the inhibition of several functions of the tumor suppressor p53. We have studied whether HBx may have different effects on p53 depending on the cell type.
METHODS: We used the human hepatoma cell line HepG2 and the immortalized murine hepatocyte line AML12 and analyzed stably transfected clones which expressed physiological amounts of HBx. P53 was induced by UV irradiation.
RESULTS: The p53 induction by UV irradiation was unaffected by stable expression of HBx. However, the expression of the cyclin kinase inhibitor p21waf/cip/sdi which gets activated by p53 was affected in the HBx transformed cell line AML12-HBx9, but not in HepG2. In AML-HBx9 cells, p21waf/cip/sdi-protein expression and p21waf/cip/sdi transcription were deregulated. Furthermore, the process of apoptosis was affected in opposite ways in the two cell lines investigated. While stable expression of HBx enhanced apoptosis induced by UV irradiation in HepG2-cells, apoptosis was decreased in HBx transformed AML12-HBx9. P53 repressed transcription from the HBV enhancer I, when expressed from expression vectors or after induction of endogenous p53 by UV irradiation. Repression by endogenous p53 was partially reversible by stably expressed HBx in both cell lines.
CONCLUSION: Stable expression of HBx leads to deregulation of apoptosis induced by UV irradiation depending on the cell line used. In an immortalized hepatocyte line HBx acted anti-apoptotic whereas expression in a carcinoma derived hepatocyte line HBx enhanced apoptosis.
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Affiliation(s)
- Nicola Fiedler
- Abt. Virologie, Institut fur Medizinische Mikrobiologie, Schillingallee 70, Universitat Rostock, D-18055 Rostock, Germany
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20
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Bouchard MJ, Wang L, Schneider RJ. Activation of focal adhesion kinase by hepatitis B virus HBx protein: multiple functions in viral replication. J Virol 2006; 80:4406-14. [PMID: 16611900 PMCID: PMC1472019 DOI: 10.1128/jvi.80.9.4406-4414.2006] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The hepatitis B virus (HBV) X protein (HBx) is a multifunctional regulator of cellular signal transduction and transcription pathways and has a critical role in HBV replication. Much of the cytoplasmic signal transduction activity associated with HBx expression and its stimulation of viral replication is attributable to HBx-induced activation of calcium signaling pathways involving Pyk2 and Src tyrosine kinases. To further characterize upstream signal transduction pathways that are required for HBx activity, including activation of Src and mitogen-activated protein kinase (MAPK) cascades, we determined whether focal adhesion kinase (FAK), a known regulator of Src family kinases and the other member of the Pyk2/FAK kinase family, is activated by HBx. We report that HBx activates FAK and that FAK activation is important for multiple HBx functions. Dominant inhibiting forms of FAK blocked HBx activation of Src kinases and downstream signal transduction, HBx stimulation of NF-kappaB and AP-1-dependent transcription, and HBV DNA replication. We also demonstrate that HBx-induced activation of FAK is dependent on cellular calcium signaling, which is modulated by HBx. Moreover, prolonged expression of HBx increases both FAK activity and its level of expression. FAK activation may play a role in cellular transformation and cancer progression. HBx stimulation of FAK activity and abundance may also be relevant as a potential cofactor in HBV-associated hepatocellular carcinoma.
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Affiliation(s)
- Michael J Bouchard
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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21
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Cao F, Tavis JE. Suppression of mRNA accumulation by the duck hepatitis B virus reverse transcriptase. Virology 2006; 350:475-83. [PMID: 16563457 DOI: 10.1016/j.virol.2006.02.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 02/09/2006] [Accepted: 02/14/2006] [Indexed: 01/12/2023]
Abstract
Hepadnaviruses establish chronic liver infections, but the mechanisms of persistence and immune evasion are poorly understood. We previously found that the duck hepatitis B virus (DHBV) and hepatitis B virus reverse transcriptases (P protein) unexpectedly accumulate in the cytoplasm where they could affect function(s) beyond viral DNA synthesis, such as gene expression. Therefore, we measured effects of DHBV P on gene expression from reporter constructs and the viral genome. P reduced reporter expression at the mRNA level to approximately 30-40%, independent of reporter tested. Accumulation of the viral pregenomic RNA from its native promoter was suppressed three-to four-fold by P, and accumulation of the capsid protein and intracellular core particles was similarly suppressed because the pregenomic RNA encodes the capsid protein. Therefore, suppression of the pregenomic RNA by DHBV P creates a negative feedback loop to limit viral antigen accumulation and replication, possibly contributing to maintenance of chronic infection.
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Affiliation(s)
- Feng Cao
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., St. Louis, MO 63104, USA.
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22
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Guo H, Mason WS, Aldrich CE, Saputelli JR, Miller DS, Jilbert AR, Newbold JE. Identification and characterization of avihepadnaviruses isolated from exotic anseriformes maintained in captivity. J Virol 2005; 79:2729-42. [PMID: 15708992 PMCID: PMC548436 DOI: 10.1128/jvi.79.5.2729-2742.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Five new hepadnaviruses were cloned from exotic ducks and geese, including the Chiloe wigeon, mandarin duck, puna teal, Orinoco sheldgoose, and ashy-headed sheldgoose. Sequence comparisons revealed that all but the mandarin duck viruses were closely related to existing isolates of duck hepatitis B virus (DHBV), while mandarin duck virus clones were closely related to Ross goose hepatitis B virus. Nonetheless, the S protein, core protein, and functional domains of the Pol protein were highly conserved in all of the new isolates. The Chiloe wigeon and puna teal hepatitis B viruses, the two new isolates most closely related to DHBV, also lacked an AUG start codon at the beginning of their X open reading frame (ORF). But as previously reported for the heron, Ross goose, and stork hepatitis B viruses, an AUG codon was found near the beginning of the X ORF of the mandarin duck, Orinoco, and ashy-headed sheldgoose viruses. In all of the new isolates, the X ORF ended with a stop codon at the same position. All of the cloned viruses replicated when transfected into the LMH line of chicken hepatoma cells. Significant differences between the new isolates and between these and previously reported isolates were detected in the pre-S domain of the viral envelope protein, which is believed to determine viral host range. Despite this, all of the new isolates were infectious for primary cultures of Pekin duck hepatocytes, and infectivity in young Pekin ducks was demonstrated for all but the ashy-headed sheldgoose isolate.
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Affiliation(s)
- Haitao Guo
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111, USA
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23
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Schultz U, Grgacic E, Nassal M. Duck hepatitis B virus: an invaluable model system for HBV infection. Adv Virus Res 2005; 63:1-70. [PMID: 15530560 DOI: 10.1016/s0065-3527(04)63001-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ursula Schultz
- Department of Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106 Freiburg, Germany
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24
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25
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Affiliation(s)
- Michael J Bouchard
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
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26
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Mangisa NP, Smuts HE, Kramvis A, Linley CW, Skelton M, Tucker TJ, De La M Hall P, Kahn D, Jilbert AR, Kew MC. Molecular characterization of duck hepatitis B virus isolates from South African ducks. Virus Genes 2004; 28:179-86. [PMID: 14976417 DOI: 10.1023/b:viru.0000016856.56499.32] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The objective of the study was to characterize the genome of duck hepatitis B virus (DHBV) isolates from South African Pekin ducks. Duck serum and liver samples were collected from two commercial duck farms from geographically distinct regions of South Africa. In total, 498 duck serum samples were tested for the presence of DHBV DNA using either sub-genomic or full-length polymerase chain reaction (PCR) assays. The overall prevalence of DHBV infection in South African ducks was 47%. In addition, 30% of 59 liver tissues tested were DHBV DNA-positive. Six randomly selected serum or liver samples were used to clone and sequence the genomes of the South African DHBV strains. All six isolates had DHBV genomes of 3,021 nucleotides with three characteristic overlapping reading frames encoding the polymerase, surface and core gene products. No X-like gene with a traditional start codon was found. Following phylogenetic analysis, the South African DHBV isolates clustered with DHBV isolates from other "Western" countries, including United States of America, Canada, Germany and India. On translation of the open reading frames, the South African isolates were found to share signature amino acids in the polymerase and surface genes with the "Western" country isolates as opposed to those of Chinese DHBV isolates.
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MESH Headings
- Animals
- Base Sequence
- Cloning, Molecular
- DNA, Viral/blood
- DNA, Viral/genetics
- Ducks/virology
- Hepadnaviridae Infections/veterinary
- Hepadnaviridae Infections/virology
- Hepatitis B Virus, Duck/classification
- Hepatitis B Virus, Duck/genetics
- Hepatitis B Virus, Duck/isolation & purification
- Hepatitis, Viral, Animal/virology
- Nucleic Acid Conformation
- Phylogeny
- Poultry Diseases/virology
- RNA, Viral/chemistry
- RNA, Viral/genetics
- South Africa
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Affiliation(s)
- Nomathibane P Mangisa
- MRC/CANSA/University Molecular Hepatology Research Unit and Department of Medicine, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, South Africa
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27
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Gao LF, Sun WS, Ma CH, Liu SX, Wang XY, Zhang LN, Cao YL, Zhu FL, Liu YG. Establishment of mice model with human viral hepatitis B. World J Gastroenterol 2004; 10:841-6. [PMID: 15040029 PMCID: PMC4727006 DOI: 10.3748/wjg.v10.i6.841] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To establish a mice model of hepatitis B by using HBV-transgenic mice, and to transfer HBV-specific cytotoxic T lymphocytes (CTL) induced from syngeneic BALB/c mice immunized by a eukaryotic expression vector containing HBV complete genome DNA.
METHODS: HBV DNA was obtained from digested pBR322-2HBV and ligated with the vector pcDNA3. Recombinant pcDNA3-HBV was identified by restriction endonuclease assay and transfected into human hepatoma cell line HepG2 with lipofectin. ELISA was used to detect the expression of HBsAg in culture supernatant, and RT-PCR to determine the existence of HBV PreS1 mRNA. BALB/c mice were immunized with pcDNA3-HBV or pcDNA3 by intramuscular injection. ELISA was used to detect the expression of HBsAb in serum. MTT assay was used to measure non-specific or specific proliferation ability and specific killing activity of spleen lymphocytes. Lymphocytes from immunized mice were transferred into HBV-transgenic mice (2.5 × 107 per mouse). Forty-eight hours later, the level of serum protein and transaminase was detected with biochemical method, liver and kidney were sectioned and stained by HE to observe the pathological changes.
RESULTS: By enzyme digestion with Eco RI, Xho I and Hind III, the recombinant pcDNA3-HBV was verified to contain a single copy of HBV genome, which was inserted in the positive direction. HepG2 cells transfected with the recombinant could stably express PreS1 mRNA and HBsAg. After immunized by pcDNA3-HBV for 4 weeks, HBsAb was detected in the serum of BALB/c mice. The potential of spleen lymphocytes for both non-specific and specific proliferation and the specific killing activity against target cells were enhanced. The transgenic mice in model group had no significant changes in the level of serum protein but had an obvious increase of ALT and AST. The liver had obvious pathological changes, while the kidney had no evident damage.
CONCLUSION: A eukaryotic expression vector pcDNA3-HBV containing HBV complete genome is constructed successfully. HepG2 cells transfected with the recombinant can express PreS1 mRNA and HBsAg stably. Specific cellular immune response can be induced in mice immunized by pcDNA3-HBV. A mice model of acute hepatitis with HBV has been established.
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Affiliation(s)
- Li-Fen Gao
- Institute of Immunology, Medical College, Shandong University, Jinan 250012, Shandong Province, China
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28
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Meier P, Scougall CA, Will H, Burrell CJ, Jilbert AR. A duck hepatitis B virus strain with a knockout mutation in the putative X ORF shows similar infectivity and in vivo growth characteristics to wild-type virus. Virology 2004; 317:291-8. [PMID: 14698667 DOI: 10.1016/j.virol.2003.08.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hepadnaviruses including human hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) express X proteins, HBx and DHBx, respectively. Both HBx and DHBx are transcriptional activators and modulate cellular signaling in in vitro assays. To test whether the DHBx protein plays a role in virus infection, we compared the in vivo infectivity and growth characteristics of a DHBV3 strain with a stop codon in the X-like ORF (DHBV3-X-K.O.) to those of the wild-type DHBV3 strain. Here we report that the two strains showed no significant difference in (i). their ability to induce infection that resulted in stable viraemia measured by serum surface antigen (DHBsAg) and DHBV DNA, and detection of viral proteins and replicative DNA intermediates in the liver; (ii). the rate of spread of infection in liver and extrahepatic sites after low-dose virus inoculation; and (iii). the ability to produce transient or persistent infection under balanced age/dose conditions designed to detect small differences between the strains. Thus, none of the infection parameters assayed were detectably affected by the X-ORF knockout mutation, raising the question whether DHBx expression plays a physiological role during in vivo infection with wild-type DHBV.
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Affiliation(s)
- P Meier
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia.
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29
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Prassolov A, Hohenberg H, Kalinina T, Schneider C, Cova L, Krone O, Frölich K, Will H, Sirma H. New hepatitis B virus of cranes that has an unexpected broad host range. J Virol 2003; 77:1964-76. [PMID: 12525630 PMCID: PMC140978 DOI: 10.1128/jvi.77.3.1964-1976.2003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
All hepadnaviruses known so far have a very limited host range, restricted to their natural hosts and a few closely related species. This is thought to be due mainly to sequence divergence in the large envelope protein and species-specific differences in host components essential for virus propagation. Here we report an infection of cranes with a novel hepadnavirus, designated CHBV, that has an unexpectedly broad host range and is only distantly evolutionarily related to avihepadnaviruses of related hosts. Direct DNA sequencing of amplified CHBV DNA as well a sequencing of cloned viral genomes revealed that CHBV is most closely related to, although distinct from, Ross' goose hepatitis B virus (RGHBV) and slightly less closely related to duck hepatitis B virus (DHBV). Phylogenetically, cranes are very distant from geese and ducks and are most closely related to herons and storks. Naturally occurring hepadnaviruses in the last two species are highly divergent in sequence from RGHBV and DHBV and do not infect ducks or do so only marginally. In contrast, CHBV from crane sera and recombinant CHBV produced from LMH cells infected primary duck hepatocytes almost as efficiently as DHBV did. This is the first report of a rather broad host range of an avihepadnavirus. Our data imply either usage of similar or identical entry pathways and receptors by DHBV and CHBV, unusual host and virus adaptation mechanisms, or divergent evolution of the host genomes and cellular components required for virus propagation.
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Affiliation(s)
- Alexej Prassolov
- Heinrich Pette Institute of Experimental Virology and Immunology, Hamburg. Institute of Zoo and Wildlife Research, Berlin, Germany
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30
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Lara-Pezzi E, Moreno-Otero R, López-Cabrera M. Implicación de la proteína HBx del virus de la hepatitis B en la respuesta inmune y la progresión tumoral. GASTROENTEROLOGIA Y HEPATOLOGIA 2003; 26:552-61. [PMID: 14642243 DOI: 10.1016/s0210-5705(03)70412-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- E Lara-Pezzi
- Unidad de Biología Molecular, Hospital Universitario de La Princesa, Madrid, España
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31
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Schuster R, Hildt E, Chang SF, Terradillos O, Pollicino T, Lanford R, Gerlich WH, Will H, Schaefer S. Conserved transactivating and pro-apoptotic functions of hepadnaviral X protein in ortho- and avihepadnaviruses. Oncogene 2002; 21:6606-13. [PMID: 12242658 DOI: 10.1038/sj.onc.1205916] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2001] [Revised: 07/01/2002] [Accepted: 07/25/2002] [Indexed: 01/12/2023]
Abstract
Two established activities of the multifunctional human hepatitis B virus X-protein are its transactivating and pro-apoptotic potential. We analysed whether X-proteins from other orthohepadnaviruses and the newly discovered avihepadnaviral X-proteins have similar functions as HBx. Previously, we have shown that HBx suppresses oncogenic transformation of primary rat embryo fibroblasts (REF) by induction of apoptosis. Using this system, we found that the wildtype X-proteins of woodchuck, ground squirrel, arctic squirrel and woolly monkey hepatitis B virus exhibit similar levels of pro-apoptotic activity as HBx, whereas mutants with carboxyterminal deletions were severely impaired in this activity. A strong correlation between the pro-apoptotic and transactivating abilities of the mammalian X-proteins was found. The newly discovered avihepadnaviral X-like proteins showed similar and Raf-MAPK pathway-dependent transactivating abilities and induced apoptosis in the REF-assay. Our data indicate that the transactivating and pro-apoptotic activities reside in the carboxyterminal half of orthohepadnaviral X and are conserved in avihepadnaviral X-proteins.
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32
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Interaction of hepatitis B virus X protein with damaged DNA-binding protein p127: Structural analysis and identification of antagonists. J Biomed Sci 2002. [DOI: 10.1007/bf02254999] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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33
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Abstract
In 1988, it was reported that the full nucleotide sequences of 18 hepatitis B virus (HBV) strains clustered into four genetic groups (A to D) with more than 8% divergence between the groups. This classification of strains in terms of genome sequence has since proven to be an important tool in the understanding of HBV epidemiology and evolution and has been expanded to include three more genotypes. In parallel with the HBV genotypes described in humans, HBV strains isolated from different primates and hepadnaviruses found in woodchucks, ground squirrels, ducks and herons have been studied. Sequence differences between HBV genotypes can lead to structural differences at the level of the pregenome and can also lead to dramatic differences at the translational level when specific and commonly occurring mutations occur. There is increasing evidence that the clinical picture, the response to treatment and the long-term prognosis may differ depending on which genotype has infected the patient. The consideration of traditional serological patterns in a patient must therefore take the genotype of the infecting strain into account. Nucleotide variability between HBV strains has been used in several studies to trace routes of transmission and, since it is becoming increasingly clear that the differences between HBV genotypes are important, the need for reliable and easy methods of differentiating HBV genotypes has arisen. This review summarizes the knowledge of HBV genotypes with regard to their genetic, structural and clinically significant differences and their origin and evolution in the context of the hepadnaviruses in general.
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Affiliation(s)
| | - Yuzo Miyakawa
- Miyakawa Memorial Research Foundation, Tokyo 107-0062, Japan2
| | - Alistair H Kidd
- Department of Virology, University of Umeå, SE-901 85 Umeå, Sweden3
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34
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Zhang Z, Torii N, Hu Z, Jacob J, Liang TJ. X-deficient woodchuck hepatitis virus mutants behave like attenuated viruses and induce protective immunity in vivo. J Clin Invest 2001. [PMID: 11714744 DOI: 0.1172/jci13787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The X protein (HBX) of the hepatitis B virus (HBV) has been shown to be important for the establishment of HBV infection in vivo. Our previous studies suggested that interaction of HBX with the proteasome complex may underlie the pleiotropic functions of HBX. In this study, we generated a series of woodchuck hepatitis virus (WHV) X mutants, including mutants of the domain interacting with the proteasome, and studied their infectivity in woodchucks. Many of the mutants were defective in transactivation but none of them were completely replication defective in vitro. In vivo, all the wild-type and some X mutant-transfected animals demonstrated evidence of infection with anti-WHc and/or anti-WHs seroconversion. Most of the wild-type- and X mutant-transfected animals had transient viremia. Some animals were later challenged with infectious WHV. Animals inoculated with X mutants, including those with no serologic evidence of infection, were protected from the challenge, suggesting previous infection with resulting protective immunity. Our study demonstrates that the previously described functional domains of HBX are biologically important and the X-defective mutants, possibly as attenuated viruses, are not completely replication defective in vivo.
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Affiliation(s)
- Z Zhang
- Liver Diseases Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1800, USA
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35
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Zhang Z, Torii N, Hu Z, Jacob J, Liang TJ. X-deficient woodchuck hepatitis virus mutants behave like attenuated viruses and induce protective immunity in vivo. J Clin Invest 2001. [DOI: 10.1172/jci200113787] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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36
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Zhang Z, Torii N, Hu Z, Jacob J, Liang TJ. X-deficient woodchuck hepatitis virus mutants behave like attenuated viruses and induce protective immunity in vivo. J Clin Invest 2001; 108:1523-31. [PMID: 11714744 PMCID: PMC209423 DOI: 10.1172/jci13787] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The X protein (HBX) of the hepatitis B virus (HBV) has been shown to be important for the establishment of HBV infection in vivo. Our previous studies suggested that interaction of HBX with the proteasome complex may underlie the pleiotropic functions of HBX. In this study, we generated a series of woodchuck hepatitis virus (WHV) X mutants, including mutants of the domain interacting with the proteasome, and studied their infectivity in woodchucks. Many of the mutants were defective in transactivation but none of them were completely replication defective in vitro. In vivo, all the wild-type and some X mutant-transfected animals demonstrated evidence of infection with anti-WHc and/or anti-WHs seroconversion. Most of the wild-type- and X mutant-transfected animals had transient viremia. Some animals were later challenged with infectious WHV. Animals inoculated with X mutants, including those with no serologic evidence of infection, were protected from the challenge, suggesting previous infection with resulting protective immunity. Our study demonstrates that the previously described functional domains of HBX are biologically important and the X-defective mutants, possibly as attenuated viruses, are not completely replication defective in vivo.
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Affiliation(s)
- Z Zhang
- Liver Diseases Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-1800, USA
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37
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Lipoprotein lipase mediates an increase in selective uptake of HDL-associated cholesteryl esters by cells in culture independent of scavenger receptor BI. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)31500-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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38
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Pult I, Netter HJ, Bruns M, Prassolov A, Sirma H, Hohenberg H, Chang SF, Frölich K, Krone O, Kaleta EF, Will H. Identification and analysis of a new hepadnavirus in white storks. Virology 2001; 289:114-28. [PMID: 11601923 DOI: 10.1006/viro.2001.1115] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We identified, cloned, and functionally characterized a new avian hepadnavirus infecting storks (STHBV). STHBV has the largest DNA genome of all avian hepadnaviruses and, based on sequence and phylogenetic analysis, is most closely related to, but distinct from, heron hepatitis B virus (HHBV). Unique for STHBV among the other avian hepadnaviruses is a potential HNF1 binding site in the preS promoter. In common only with HHBV, STHBV has a myristylation signal on the S and not the preS protein, two C terminally located glycosylation sites on the precore/core proteins and lacks the phosphorylation site essential for the transcriptional transactivation activity of duck-HBV preS protein. The cloned STHBV genomes were competent in gene expression, replication, and viral particle secretion. STHBV infected primary duck hepatocytes very inefficiently suggesting a restricted host range, similar to other hepadnaviruses. This discovery of stork infections unravels novel evolutionary aspects of hepadnaviruses and provides new opportunities for hepadnavirus research.
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Affiliation(s)
- I Pult
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistrasse 52, 20251 Hamburg, Germany
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