Metabolism and function of hepatitis B virus cccDNA: Implications for the development of cccDNA-targeting antiviral therapeutics.
Persistent hepatitis B virus (HBV) infection relies on the stable maintenance and proper functioning of a nuclear episomal form of the viral genome called covalently closed circular (ccc) DNA. One of the major reasons for the failure of currently available antiviral therapeutics to achieve a cure of chronic HBV infection is their inability to eradicate or inactivate cccDNA. In this review article, we summarize our current understanding of cccDNA metabolism in hepatocytes and the modulation of cccDNA by host pathophysiological and immunological cues. Perspectives on the future investigation of cccDNA biology, as well as strategies and progress in therapeutic elimination and/or transcriptional silencing of cccDNA through rational design and phenotypic screenings, are also discussed. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."
Baruch S. Blumberg Institute, Hepatitis B Foundation, Doylestown, PA 18902, USA. Electronic address: ju-tao.guo@bblumberg.org.
Ju-Tao
JT
Guo
Department of Microbiology and Immunology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA. Electronic address: haitguo@iupui.edu.
Haitao
H
Guo
D000998:Antiviral Agents / Q000494:pharmacology* / Q000627:therapeutic use; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism*; D006515:Hepatitis B virus / Q000235:genetics* / Q000378:metabolism*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D022781:Hepatocytes / Q000821:virology*; D006801:Humans; D014779:Virus Replication
D000998:Antiviral Agents; D004270:DNA, Circular
Antiviral; DNA repair; Hepatitis B virus; Innate immunity; cccDNA