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Comparative Immunology, Microbiology... Dec 2021Hepatitis B virus (HBV) is the prototype of the Orthohepadnavirus genus and represents an important cause of chronic hepatitis, liver cirrhosis, and hepatic cancer in...
Hepatitis B virus (HBV) is the prototype of the Orthohepadnavirus genus and represents an important cause of chronic hepatitis, liver cirrhosis, and hepatic cancer in humans worldwide. To verify the occurrence and genetic variability of orthohepadnavirus among neotropical bats, we tested 81 liver samples of New World bats from São Paulo State, Southeastern Brazil, collected during 2012. PCR, sequencing, and phylogenetic analysis of Surface/Polymerase and Core viral genes confirmed the occurrence of the first isolate of bat orthohepadnavirus detected in South America. These results may contribute to subsequent studies of the origin, variability, host species, and evolution of bat orthohepadnaviruses in South America.
Topics: Animals; Brazil; Chiroptera; Hepatitis B virus; Orthohepadnavirus; Phylogeny
PubMed: 34634750
DOI: 10.1016/j.cimid.2021.101713 -
Trends in Microbiology Jan 2018Hepatitis B virus (HBV) chronically infects 250 million people worldwide, resulting in nearly one million deaths annually. Studies in recent years have significantly... (Review)
Review
Hepatitis B virus (HBV) chronically infects 250 million people worldwide, resulting in nearly one million deaths annually. Studies in recent years have significantly improved our knowledge on the mechanisms of HBV persistence. HBV uses multiple pathways to harness host innate immunity to enhance its replication. It can also take advantage of the developing immune system and the not-yet-stabilized gut microbiota of young children to facilitate its persistence, and use maternal viral e antigen to educate immunity of the offspring to support its persistence after vertical transmission. The knowledge gained from these recent studies paves the way for the development of new therapies for the treatment of chronic HBV infection, which has so far been very challenging.
Topics: Age Factors; Child; Gastrointestinal Microbiome; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Host-Pathogen Interactions; Humans; Immunity, Innate; Infectious Disease Transmission, Vertical; Life Cycle Stages; Maternal Inheritance; Microbiota; Viral Load
PubMed: 28823759
DOI: 10.1016/j.tim.2017.07.006 -
Trends in Microbiology Apr 2018This infographic about hepatitis B virus explores its replication cycle, natural history of infection and pathogenesis, and how this can be controlled and treated....
This infographic about hepatitis B virus explores its replication cycle, natural history of infection and pathogenesis, and how this can be controlled and treated. Hepatitis B virus (HBV) is a common worldwide blood-borne pathogen. Chronic hepatitis B can progress to an inactive carrier state, and then, in some patients, give rise to cirrhosis and cancer of the liver, leading to death. An HBV surface-antigen vaccine is effective, but treatments are currently not curative. HBV replicates via reverse transcription. Its covalently closed circular (ccc) DNA in the nucleus encodes a pregenomic RNA (pgRNA), which can be encapsidated by HBV polymerase. Reverse transcription occurs in the capsids by using the pgRNA as a template for the synthesis of single-stranded linear and then partially double-stranded relaxed circular (rc) DNA. Capsids containing a mature rc DNA genome target to the nucleus for ccc DNA synthesis. Persistent HBV infection is caused mainly by ccc DNA and immune tolerance to HBV antigens in the liver. Unlike acute infection, chronic carriers contain only a low level of HBV core-antigen-specific T cell activity, contributing to the lack of viral clearance.
Topics: Animals; Antigens, Viral; Disease Models, Animal; Hepatitis B; Hepatitis B Vaccines; Hepatitis B virus; Humans; Nucleocapsid; Vaccines, Synthetic; Virion
PubMed: 29500037
DOI: 10.1016/j.tim.2018.01.009 -
Hepatology (Baltimore, Md.) Jul 2021
Topics: DNA; Hepatitis B virus; RNA
PubMed: 33368408
DOI: 10.1002/hep.31689 -
Viruses Mar 2019New technologies enable viral discovery in a diversity of hosts, providing insights into viral evolution. We used one such approach, the virome capture sequencing for...
New technologies enable viral discovery in a diversity of hosts, providing insights into viral evolution. We used one such approach, the virome capture sequencing for vertebrate viruses (VirCapSeq-VERT) platform, on 21 samples originating from six dead Maxwell's duikers () from Taï National Park, Côte d'Ivoire. We detected the presence of an orthohepadnavirus in one animal and characterized its 3128 bp genome. The highest viral copy numbers were detected in the spleen, followed by the lung, blood, and liver, with the lowest copy numbers in the kidney and heart; the virus was not detected in the jejunum. Viral copy numbers in the blood were in the range known from humans with active chronic infections leading to liver histolytic damage, suggesting this virus could be pathogenic in duikers, though many orthohepadnaviruses appear to be apathogenic in other hosts, precluding a formal test of this hypothesis. The virus was not detected in 29 other dead duiker samples from the Côte d'Ivoire and Central African Republic, suggesting either a spillover event or a low prevalence in these populations. Phylogenetic analysis placed the virus as a divergent member of the mammalian clade of orthohepadnaviruses, though its relationship to other orthohepadnaviruses remains uncertain. This represents the first orthohepadnavirus described in an artiodactyl. We have tentatively named this new member of the genus (family ), Taï Forest hepadnavirus. Further studies are needed to determine whether it, or some close relatives, are present in a broader range of artiodactyls, including livestock.
Topics: Animals; Antelopes; Cote d'Ivoire; Genetic Variation; Genome, Viral; Orthohepadnavirus; Parks, Recreational; Phylogeny
PubMed: 30893858
DOI: 10.3390/v11030279 -
International Journal of Molecular... Mar 2024causes chronic hepatitis in a broad range of mammals, including primates, cats, woodchucks, and bats. Hepatitis B virus (HBV) X protein inhibits type-I interferon (IFN)...
causes chronic hepatitis in a broad range of mammals, including primates, cats, woodchucks, and bats. Hepatitis B virus (HBV) X protein inhibits type-I interferon (IFN) signaling, thereby promoting HBV escape from the human innate immune system and establishing persistent infection. However, whether X proteins of viruses in other species display a similar inhibitory activity remains unknown. Here, we investigated the anti-IFN activity of 17 X proteins derived from various hosts. We observed conserved activity of X proteins in inhibiting TIR-domain-containing adaptor protein inducing IFN-β (TRIF)-mediated IFN-β signaling pathway through TRIF degradation. X proteins from domestic cat hepadnavirus (DCH), a novel member of , inhibited mitochondrial antiviral signaling protein (MAVS)-mediated IFNβ signaling pathway comparable with HBV X. These results indicate that inhibition of IFN signaling is conserved in X proteins.
Topics: Humans; Animals; Cats; Orthohepadnavirus; Signal Transduction; Adaptor Proteins, Vesicular Transport; Chiroptera; Interferon Type I; Marmota
PubMed: 38612565
DOI: 10.3390/ijms25073753 -
Hepatology (Baltimore, Md.) Aug 2019
Topics: Hepatitis B virus; Hepatocytes; Humans; Nucleotides, Cyclic
PubMed: 30991445
DOI: 10.1002/hep.30663 -
Alimentary Pharmacology & Therapeutics Oct 2019This article is linked to Jiang et al papers. To view these articles, visit https://doi.org/10.1111/apt.15381 and https://doi.org/10.1111/apt.15452.
This article is linked to Jiang et al papers. To view these articles, visit https://doi.org/10.1111/apt.15381 and https://doi.org/10.1111/apt.15452.
Topics: Hepatitis B virus; Humans
PubMed: 31591767
DOI: 10.1111/apt.15428 -
Archives of Virology Jan 2015Bats in Myanmar, Gabon, and Panama have been found to harbor diverse hepadnaviruses. Here, we report a novel hepadnavirus in 4 of 20 pomona roundleaf bats from Yunnan...
Bats in Myanmar, Gabon, and Panama have been found to harbor diverse hepadnaviruses. Here, we report a novel hepadnavirus in 4 of 20 pomona roundleaf bats from Yunnan province, China. This virus contains 3,278 nucleotides (nt) in the full circularized genome, with four predicted open frames (ORFs) reading in the same direction. Full genomic sequence comparisons and evolutionary analysis indicate that this virus is a member of a new species within the genus Orthohepadnavirus.
Topics: Animals; Biological Evolution; China; Chiroptera; Genetic Variation; Hepadnaviridae Infections; Hepatitis, Viral, Animal; Orthohepadnavirus; Phylogeny
PubMed: 25193071
DOI: 10.1007/s00705-014-2222-0 -
Voprosy Virusologii Mar 2022The achievement of the goal of the World Health Organization to eliminate viral hepatitis B by 2030 seems to be problematic partly due to the presence of escape mutants...
INTRODUCTION
The achievement of the goal of the World Health Organization to eliminate viral hepatitis B by 2030 seems to be problematic partly due to the presence of escape mutants of its etiological agent, hepatitis B virus (HBV) (<i>Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus</i>), that are spreading mainly in the risk groups. Specific routine diagnostic assays aimed at identification of HBV escape mutants do not exist.The study aimed the evaluation of the serological fingerprinting method adapted for routine detection of escape mutations in 143 and 145 aa positions of HBV surface antigen (HBsAg).
MATERIAL AND METHODS
HBV DNA from 56 samples of HBsAg-positive blood sera obtained from donors, chronic HBsAg carriers and oncohematology patients has been sequenced. After the identification of mutations in HBsAg, the samples were tested in the enzyme-linked immunosorbent assay (ELISA) kit «Hepastrip-mutant-3K».
RESULTS AND DISCUSSION
Escape mutations were detected mainly in patients with hematologic malignancies. Substitutions in 143 and 145 aa were found in 10.81% and in 8.11% of such patients, respectively. The G145R mutation was recognized using ELISA kit in almost all cases. The kit specifically recognized the S143L substitution in contrast to the S143T variant. The presence of neighbor mutation D144E can be assumed due to it special serological fingerprint.
CONCLUSION
ELISA-based detection of escape mutations S143L, D144E and G145R can be used for routine diagnostics, especially in the risk groups. The diagnostic parameters of the kit can be refined in additional studies. This immunoassay and methodology are applicable for the development and quality control of vaccines against escape mutants.
Topics: DNA, Viral; Enzyme-Linked Immunosorbent Assay; Hepadnaviridae; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Mutation; Orthohepadnavirus
PubMed: 35293188
DOI: 10.36233/0507-4088-91