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Hepatology International Nov 2017Hepatitis B virus is a member of the Hepadnaviridae family and responsible for causing acute and chronic hepatitis in humans. The current estimates of people chronically... (Review)
Review
Hepatitis B virus is a member of the Hepadnaviridae family and responsible for causing acute and chronic hepatitis in humans. The current estimates of people chronically infected with the virus are put at 250 million worldwide. Immune-mediated liver damage in these individuals may lead to the development of cirrhosis and hepatocellular carcinoma later in life. This review deals with our current understanding of the virology, molecular biology, life cycle and cell-to-cell spread of this very important pathogen, all of which are considered essential for current and future approaches to antiviral treatment.
Topics: Animals; Hepatitis B virus; Hepatitis B, Chronic; Humans; Life Cycle Stages; Protein Biosynthesis; Transcription, Genetic; Virus Assembly; Virus Attachment; Virus Internalization; Virus Physiological Phenomena; Virus Release; Virus Uncoating
PubMed: 29098564
DOI: 10.1007/s12072-017-9829-7 -
Journal of Cellular Biochemistry Nov 2018Curcumin is a yellow-orange powder derived from the Curcuma longa plant. Curcumin has been used extensively in traditional medicine for centuries. This component is... (Review)
Review
Curcumin is a yellow-orange powder derived from the Curcuma longa plant. Curcumin has been used extensively in traditional medicine for centuries. This component is non-toxic and shown different therapeutic properties such as anti-inflammatory, anti-cancer, antiviral, anti-bacterial, anti-fungal, anti-parasites, and anti-oxidant. Hepatitis B virus (HBV) is a small DNA member of the genus Orthohepadnavirus (Hepadnaviridae family) which is a highly contagious blood-borne viral pathogen. HBV infection is a major public health problem with 2 billion people infected throughout the world and 350 million suffering from chronic HBV infection. Increasing evidence indicated that curcumin as a natural product could be employed in the treatment of HBV patients. It has been showed that curcumin exerts its therapeutic effects on HBV patients via targeting a variety of cellular and molecular pathways such as Wnt/β-catenin, Ap1, STAT3, MAPK, and NF-κB signaling. Here, we summarized the therapeutic effects of curcumin on patients who infected with HBV. Moreover, we highlighted main signaling pathways (eg, NF-κB, AP1, and Wnt/β-catenin signaling) which affected by curcumin in HBV infections.
Topics: Animals; Cell Proliferation; Curcumin; Hepatitis B virus; Humans; NF-kappa B; Signal Transduction; Transcription Factor AP-1; Wnt Signaling Pathway; beta Catenin
PubMed: 29923222
DOI: 10.1002/jcb.26829 -
Viruses Apr 2017Hepatitis B X protein (HBx) plays an essential role in the hepatitis B virus (HBV) replication cycle, but the function of HBx has been elusive until recently. It was... (Review)
Review
Hepatitis B X protein (HBx) plays an essential role in the hepatitis B virus (HBV) replication cycle, but the function of HBx has been elusive until recently. It was recently shown that transcription from the HBV genome (covalently-closed circular DNA, cccDNA) is inhibited by the structural maintenance of chromosome 5/6 complex (Smc5/6), and that a key function of HBx is to redirect the DNA-damage binding protein 1 (DDB1) E3 ubiquitin ligase to target this complex for degradation. By doing so, HBx alleviates transcriptional repression by Smc5/6 and stimulates HBV gene expression. In this review, we discuss in detail how the interplay between HBx and Smc5/6 was identified and characterized. We also discuss what is known regarding the repression of cccDNA transcription by Smc5/6, the timing of HBx expression, and the potential role of HBx in promoting hepatocellular carcinoma (HCC).
Topics: Cell Cycle Proteins; Chromosomal Proteins, Non-Histone; Hepatitis B virus; Host-Pathogen Interactions; Humans; Trans-Activators; Viral Regulatory and Accessory Proteins; Virus Replication
PubMed: 28368357
DOI: 10.3390/v9040069 -
Annals of the New York Academy of... 1980Hepatitis B virus (HBV) of man has several characteristics that distinguish it from viruses of other groups. These include its ultrastructure, viral DNA size and... (Review)
Review
Hepatitis B virus (HBV) of man has several characteristics that distinguish it from viruses of other groups. These include its ultrastructure, viral DNA size and structure, a virion DNA polymerase which repairs a single-stranded region in the viral DNA, liver tropism, character of persistent infection, and association with hepatitis and hepatocellular carcinoma. Recently three other viruses have been found in other animal species that appear to share these characteristics although the viruses are not identical. HBV, Woodchuck hepatitis virus (WHV), ground squirrel hepatitis virus (GSHV), and duck hepatitis virus (DHV) appear to be members of a new virus group that might be designated the Hepadna virus group. Genetic variation among hepatitis B viruses includes the antigenic variation in the surface antigen (HBsAg) which constitutes the known HBsAg subtypes. There is also frequent variation in DNA base sequence among HBVs isolated from different patients.
Topics: Animals; Base Sequence; DNA, Viral; DNA-Directed DNA Polymerase; Genetic Variation; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis Viruses; Marmota; Sciuridae
PubMed: 7013620
DOI: 10.1111/j.1749-6632.1980.tb27978.x -
Viruses Mar 2017Hepatitis B virus (HBV) is a para-retrovirus or retroid virus that contains a double-stranded DNA genome and replicates this DNA via reverse transcription of a RNA... (Review)
Review
Hepatitis B virus (HBV) is a para-retrovirus or retroid virus that contains a double-stranded DNA genome and replicates this DNA via reverse transcription of a RNA pregenome. Viral reverse transcription takes place within a capsid upon packaging of the RNA and the viral reverse transcriptase. A major characteristic of HBV replication is the selection of capsids containing the double-stranded DNA, but not those containing the RNA or the single-stranded DNA replication intermediate, for envelopment during virion secretion. The complete HBV virion particles thus contain an outer envelope, studded with viral envelope proteins, that encloses the capsid, which, in turn, encapsidates the double-stranded DNA genome. Furthermore, HBV morphogenesis is characterized by the release of subviral particles that are several orders of magnitude more abundant than the complete virions. One class of subviral particles are the classical surface antigen particles (Australian antigen) that contain only the viral envelope proteins, whereas the more recently discovered genome-free (empty) virions contain both the envelope and capsid but no genome. In addition, recent evidence suggests that low levels of RNA-containing particles may be released, after all. We will summarize what is currently known about how the complete and incomplete HBV particles are assembled. We will discuss briefly the functions of the subviral particles, which remain largely unknown. Finally, we will explore the utility of the subviral particles, particularly, the potential of empty virions and putative RNA virions as diagnostic markers and the potential of empty virons as a vaccine candidate.
Topics: Hepatitis B virus; Humans; Virion; Virus Assembly; Virus Replication
PubMed: 28335554
DOI: 10.3390/v9030056 -
Journal of Clinical Virology : the... Dec 2008In sub-Saharan Africa, genotype E is the predominant genotype throughout a vast region spanning from Senegal to Namibia and extending to the Central African Republic in... (Review)
Review
BACKGROUND
In sub-Saharan Africa, genotype E is the predominant genotype throughout a vast region spanning from Senegal to Namibia and extending to the Central African Republic in the East. Despite its wide geographic distribution and the high prevalence throughout this genotype E crescent, this genotype has a very low genetic diversity.
OBJECTIVES
Here we review our current understanding of genotype E reanalysing all currently available sequences of the S gene and the complete genome.
RESULTS
Phylogenetic analysis of the complete genome sequences confirmed a previously suggested South-West/Central African cluster and several lineages of West African sequences. The overall mean genetic distance was 1.71%, with the more Southern countries of the genotype E crescent exhibiting lower distances than the Northern countries.
CONCLUSIONS
Genotype E seems to have a longer natural history in the Northern part of the genotype E crescent than in the Southern countries. As genotype E is essentially absent from the Americas despite the Afro-American slave trade until at least the beginning of the 19th century, genotype E strains may have been introduced into the general African population only within the past 200 years. How the virus may have spread throughout the genotype E crescent warrants further investigation.
Topics: Africa; DNA, Viral; Genome, Viral; Genotype; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Phylogeny; Sequence Homology
PubMed: 18922739
DOI: 10.1016/j.jcv.2008.08.018 -
World Journal of Gastroenterology Sep 2014Hepatitis B virus (HBV) has killed countless lives in human history. The invention of HBV vaccines in the 20(th) century has reduced significantly the rate of the viral... (Review)
Review
Hepatitis B virus (HBV) has killed countless lives in human history. The invention of HBV vaccines in the 20(th) century has reduced significantly the rate of the viral infection. However, currently there is no effective treatment for chronic HBV carriers. Newly emerging vaccine escape mutants and drug resistant strains have complicated the viral eradication program. The entire world is now facing a new threat of HBV and human immunodeficiency virus co-infection. Could phage display provide solutions to these life-threatening problems? This article reviews critically and comprehensively the innovative and potential applications of phage display in the development of vaccines, therapeutic agents, diagnostic reagents, as well as gene and drug delivery systems to combat HBV. The application of phage display in epitope mapping of HBV antigens is also discussed in detail. Although this review mainly focuses on HBV, the innovative applications of phage display could also be extended to other infectious diseases.
Topics: Animals; Antiviral Agents; Cell Surface Display Techniques; Drug Design; Epitope Mapping; Gene Expression Regulation, Viral; Genotype; Hepatitis B Vaccines; Hepatitis B virus; Hepatitis B, Chronic; Humans; Molecular Targeted Therapy; Mutation; Predictive Value of Tests
PubMed: 25206271
DOI: 10.3748/wjg.v20.i33.11650 -
Frontiers in Bioscience (Landmark... Jan 2010The Hepatitis B virus (HBV) can induces severe liver diseases as chronic hepatitis and hepatocellular carcinoma. Actually, apoptosis can play an important role in the... (Review)
Review
The Hepatitis B virus (HBV) can induces severe liver diseases as chronic hepatitis and hepatocellular carcinoma. Actually, apoptosis can play an important role in the progress of these diseases. As apoptosis goes through various extrinsic or intrinsic pathways, with activation of caspases and the possible involvement of mitochondria, HBV proteins can interfere with the various apoptosis processes. So far, four HBV proteins were reported to have such effect: the Large envelope protein, a truncated form of the Middle envelope protein, the HBx protein and HBSP, a protein generated from a spliced mRNA. In addition, our recent results suggest that indirectly the precore protein could have a function in apoptosis. This review focuses on the putative roles of HBV proteins as pro- or anti-apoptotic factors and the relationship which could exist with the HBV life cycle.
Topics: Animals; Apoptosis; Hepatitis B virus; Hepatocytes; Host-Pathogen Interactions; Humans; Liver; Models, Biological; Viral Proteins
PubMed: 20036802
DOI: 10.2741/3602 -
World Journal of Gastroenterology Nov 2007Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically... (Review)
Review
Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection (SOI). The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection (POI) where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.
Topics: Animals; Disease Models, Animal; Disease Progression; Hepatitis B; Hepatitis B Virus, Woodchuck; Hepatitis B virus; Humans
PubMed: 17963292
DOI: 10.3748/wjg.v13.i43.5682 -
Infection, Genetics and Evolution :... Jun 2013Hepatitis B virus (HBV) has evolved into phylogenetically separable genotypes and subgenotypes. Accurately assigning the subgenotype for an HBV strain is of clinical and... (Review)
Review
Hepatitis B virus (HBV) has evolved into phylogenetically separable genotypes and subgenotypes. Accurately assigning the subgenotype for an HBV strain is of clinical and epidemiological significance. In this paper, we review the recommendations currently employed for HBV subgenotyping, the history of HBV subgenotyping, the effects of recombination on HBV subgenotyping, misclassifications in HBV subgenotyping, and suggestions are made to correct the misclassifications. Finally, proposals are made to guide future HBV subgenotyping.
Topics: Genotyping Techniques; Hepatitis B; Hepatitis B virus; Humans; Recombination, Genetic
PubMed: 23538336
DOI: 10.1016/j.meegid.2013.03.021