Research Article
HBx relieves chromatin-mediated transcriptional repression of hepatitis B viral cccDNA involving SETDB1 histone methyltransferase- Lise Rivière1, 2,
- Laetitia Gerossier3,
- Aurélie Ducroux1, 2, 4,
- Sarah Dion5,
- Qiang Deng5, 6,
- Marie-Louise Michel5,
- Marie-Annick Buendia7,
- Olivier Hantz3,
- Christine Neuveut1, 2, ,
- 1 Unité des Hépacivirus et Immunité Innée, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France
- 2 UMR CNRS 3569, 28 rue du Dr. Roux, 75015 Paris, France
- 3 Inserm U1052, CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Université de Lyon, F-69000 Lyon, France
- 4 Institute for Experimental Virology, Group Innate Immunity and Viral Evasion, 30625 Hannover, Germany†
- 5 Laboratoire de Pathogenèse des Virus de l’Hépatite B, Département de Virologie, Institut Pasteur, 75015 Paris, France
- 6 Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China†
- 7 Inserm Unit U785, University Paris-Sud, Paul Brousse Hospital, 12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
Received 4 March 2015, Revised 16 June 2015, Accepted 24 June 2015, Available online 2 July 2015
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doi:10.1016/j.jhep.2015.06.023Get rights and content
Background & AimsMaintenance of the covalently closed circular HBV DNA (cccDNA) that serves as a template for HBV transcription is responsible for the failure of antiviral therapies. While studies in chronic hepatitis patients have shown that high viremia correlates with hyperacetylation of cccDNA-associated histones, the molecular mechanisms controlling cccDNA stability and transcriptional regulation are still poorly understood. This study aimed to decipher the role of chromatin and chromatin modifier proteins on HBV transcription. MethodsWe analyzed the chromatin structure of actively transcribed or silenced cccDNA by infecting primary human hepatocytes and differentiated HepaRG cells with wild-type virus or virus deficient (HBVX-) for the expression of hepatitis B virus X protein (HBx), that is required for HBV expression. ResultsIn the absence of HBx, HBV cccDNA was transcriptionally silenced with the concomitant decrease of histone 3 (H3) acetylation and H3K4me3, increase of H3 di- and tri-methylation (H3K9me) and the recruitment of heterochromatin protein 1 factors (HP1) that correlate with condensed chromatin. SETDB1 was found to be the main histone methyltransferase responsible for the deposition of H3K9me3 and HBV repression. Finally, full transcriptional reactivation of HBVX- upon HBx re-expression correlated with an increase of histone acetylation and H3K4me3, and a concomitant decrease of HP1 binding and of H3K9me3 on the cccDNA. ConclusionUpon HBV infection, cellular mechanisms involving SETDB1-mediated H3K9me3 and HP1 induce silencing of HBV cccDNA transcription through modulation of chromatin structure. HBx is able to relieve this repression and allow the establishment of active chromatin.
Graphical abstract
Abbreviations- HBV, Hepatitis B Virus;
- pgRNA, pre-genomic RNA;
- RC-DNA, relaxed-circular HBV DNA;
- cccDNA, covalently closed circular HBV DNA;
- CBP, CREB-binding protein;
- PCAF, p300/CREB-binding Protein-associated Factor;
- H3, H4, histone 3, histone 4;
- HDAC1, histone deacetylase 1;
- PRC2, Polycomb Repressive Complex 2;
- HBx, Hepatitis B Virus X protein;
- H3K9me, histone 3 methylated on lysine 9;
- AcH3, acetylated histone 3;
- HKMT, histone lysine methyl transferase;
- SETDB1, SET domain bifurcated 1;
- HP1, heterochromatin protein 1;
- vp, viral particles;
- MOI, multiplicity of infection;
- dHepaRG, differentiated HepaRG;
- PHH, primary human hepatocytes;
- HBeAg, hepatitis B virus e antigen;
- TSA, trichostatin A;
- MNase, Micrococcal Nuclease;
- CCNA2, cyclin A2;
- HBc, HBV core protein;
- ERV, endogenous retrovirus;
- mESC, mouse embryonic stem cell;
- hCMV, human cytomegalovirus
Keywords- HBV;
- cccDNA regulation;
- Epigenetic;
- SETDB1;
- HBx;
- HP1
Corresponding author. Address: Unité des Hépacivirus et Immunité Innée, URA CNRS 3015, Institut Pasteur, 28 rue du Dr. Roux, 75015 Paris, France. Tel.: +33 1 45 68 87 76; fax: +33 1 40 61 30 12.†Present address.
Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier Ireland Ltd. All rights reserved. |
发表于 2015-11-2 19:43
