scholarly journals A Divergent Hepatitis D-Like Agent in Birds

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 720 ◽  
Author(s):  
Michelle Wille ◽  
Hans Netter ◽  
Margaret Littlejohn ◽  
Lilly Yuen ◽  
Mang Shi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Hepatitis B Virus ◽  
Sequence Analysis ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Amino Acid Similarity ◽  
Hepatitis D ◽  
Delta Antigen ◽  
B Virus ◽  
Delta Virus

Hepatitis delta virus (HDV) is currently only found in humans and is a satellite virus that depends on hepatitis B virus (HBV) envelope proteins for assembly, release, and entry. Using meta-transcriptomics, we identified the genome of a novel HDV-like agent in ducks. Sequence analysis revealed secondary structures that were shared with HDV, including self-complementarity and ribozyme features. The predicted viral protein shares 32% amino acid similarity to the small delta antigen of HDV and comprises a divergent phylogenetic lineage. The discovery of an avian HDV-like agent has important implications for the understanding of the origins of HDV and sub-viral agents.

scholarly journals A divergent hepatitis D-like agent in birds

2018 ◽  
Author(s):  
Michelle Wille ◽  
Hans J. Netter ◽  
Margaret Littlejohn ◽  
Lilly Yuen ◽  
Mang Shi ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Amino Acid Similarity ◽  
Hepatitis Delta ◽  
Hepatitis D ◽  
Delta Antigen ◽  
B Virus ◽  
Severe Liver Disease ◽  
Delta Virus

AbstractHepatitis delta virus (HDV) is currently only found in humans, and is a satellite virus that depends on hepatitis B virus (HBV) envelope proteins for assembly, release and entry. Using meta-transcriptomics, we identified the genome of a novel HDV-like agent in ducks. Sequence analysis revealed secondary structures that were shared with HDV, including self-complementarity and ribozyme features. The predicted viral protein shares 32% amino acid similarity to the small delta antigen of HDV and comprises a divergent phylogenetic lineage. The discovery of an avian HDV-like agent has important implications for the understanding of the origins of HDV and subviral agents.ImportanceHepatitis delta virus (HDV) is currently only found in humans, and coinfections of HDV and Hepatitis B virus (HBV) in humans result in severe liver disease. There are a number of hypotheses for the origin of HDV, although a key component of all is that HDV only exists in humans. Here, we describe a novel deltavirus-like agent identified in wild birds. Although this agent is genetically divergent, it exhibits important similarities to HDV, such as the presence of ribosymes and self-complementarity. The discovery of an avian HDV-like agent challenges our understanding of both the origin and the co-evolutionary relationships of subviral agents with helper viruses.

scholarly journals Hepatitis Delta Antigen Regulates mRNA and Antigenome RNA Levels during Hepatitis Delta Virus Replication

2019 ◽  
Vol 93 (8) ◽  
Author(s):  
Kaneemozhe Harichandran ◽  
Yiran Shen ◽  
Susannah Stephenson Tsoris ◽  
See-Chi Lee ◽  
John L. Casey
Keyword(s):  
Liver Disease ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
B Virus ◽  
Hepatitis Delta Antigen ◽  
Infected Cells ◽  
Delta Virus

ABSTRACTHepatitis delta virus (HDV) is a satellite of hepatitis B virus that increases the severity of acute and chronic liver disease. HDV produces three processed RNAs that accumulate in infected cells: the circular genome; the circular antigenome, which serves as a replication intermediate; and lesser amounts of the mRNA, which encodes the sole viral protein, hepatitis delta antigen (HDAg). The HDV genome and antigenome RNAs form ribonucleoprotein complexes with HDAg. Although HDAg is required for HDV replication, it is not known how the relative amounts of HDAg and HDV RNA affect replication, or whether HDAg synthesis is regulated by the virus. Using a novel transfection system in which HDV replication is initiated usingin vitro-synthesized circular HDV RNAs, HDV replication was found to depend strongly on the relative amounts of HDV RNA and HDAg. HDV controls these relative amounts via differential effects of HDAg on the production of HDV mRNA and antigenome RNA, both of which are synthesized from the genome RNA template. mRNA synthesis is favored at low HDAg levels but becomes saturated at high HDAg concentrations. Antigenome RNA accumulation increases linearly with HDAg and dominates at high HDAg levels. These results provide a conceptual model for how HDV antigenome RNA production and mRNA transcription are controlled from the earliest stage of infection onward and also demonstrate that, in this control, HDV behaves similarly to other negative-strand RNA viruses, even though there is no genetic similarity between them.IMPORTANCEHepatitis delta virus (HDV) is a satellite of hepatitis B virus that increases the severity of liver disease; approximately 15 million people are chronically infected worldwide. There are no licensed therapies available. HDV is not related to any known virus, and few details regarding its replication cycle are known. One key question is whether and how HDV regulates the relative amounts of viral RNA and protein in infected cells. Such regulation might be important because the HDV RNA and protein form complexes that are essential for HDV replication, and the proper stoichiometry of these complexes could be critical for their function. Our results show that the relative amounts of HDV RNA and protein in cells are indeed important for HDV replication and that the virus does control them. These observations indicate that further study of these regulatory mechanisms is required to better understand replication of this serious human pathogen.

scholarly journals Analysis of Multiple Liver Explant Pieces Reveals that Levels of Hepatitis Delta Virus RNA Are Independent of Hepatitis B Virus Expression

2021 ◽  
Author(s):  
Kasthuri Prakash ◽  
Simon B. Larsson ◽  
Gustaf E. Rydell ◽  
Johan Ringlander ◽  
Catarina Skoglund ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Hepatitis Delta ◽  
Virus Rna ◽  
B Virus ◽  
Virus Expression ◽  
Delta Virus

Occurrence of Hepatitis Delta Virus Infection in Hepatitis B Virus-Infected Patients with Different Serum Patterns of PreS Gene-Encoded Proteins

Digestion ◽  
1993 ◽  
Vol 54 (1) ◽  
pp. 9-14
Author(s):  
Nicola Napoli ◽  
Giorgio Fiore ◽  
Giacomo Fera ◽  
Angela Modugno ◽  
Gianluigi Giannelli ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Virus Infection ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Hepatitis Delta ◽  
Hepatitis Delta Virus Infection ◽  
B Virus ◽  
Encoded Proteins ◽  
Delta Virus
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