Hepatitis B virus polymerase inhibits RIG-I- and Toll-like receptor 3-mediated beta interferon induction in human hepatocytes through interference with interferon regulatory factor 3 activation and dampening of the interaction between TBK1/IKKepsilon and DDX3.
Hepatitis B virus (HBV) infection remains one of the most serious health problems worldwide. Whilst studies have shown that HBV impairs interferon (IFN) production from dendritic cells in chronic hepatitis B patients, it remains unknown whether HBV inhibits IFN production in human hepatocytes. Using transient transfection assays in a primary human hepatocyte cell line (PH5CH8), this study demonstrated that HBV polymerase inhibits IFN-beta promoter activity induced by Newcastle disease virus, Sendai virus or poly(I : C) in a dose-dependent manner, whilst ectopic expression of the HBV core and X proteins had no effect on IFN-beta promoter activity. In addition, HBV polymerase blocked cellular IFN-beta expression and consequent antiviral immunity revealed by an infection protection assay. Furthermore, overexpression of key molecules on the IFN-beta induction axis, together with HBV polymerase, resulted in a block of IFN-beta promoter activity triggered by RIG-I, IPS-1, TRIF, TBK1 and IKKepsilon, but not by an IFN regulatory factor 3 dominant-positive mutant (IRF3-5D), suggesting that HBV polymerase prevents IFN-beta expression at the TBK1/IKKepsilon level. Further studies showed that HBV polymerase inhibited phosphorylation, dimerization and nuclear translocation of IRF3, in response to Sendai virus infection. Finally, it was shown that HBV polymerase-mediated dampening of the interaction between TBK1/IKKepsilon and DDX3 may be involved in the inhibitory effect on IFN-beta induction. Taken together, these findings reveal a novel role of HBV polymerase in HBV counteraction of IFN-beta production in human hepatocytes.
Yu
Shiyan
S
Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.|Key Laboratory of Medical Molecular Virology, Ministry of Education and Public Health, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
Chen
Jieliang
J
Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.|Key Laboratory of Medical Molecular Virology, Ministry of Education and Public Health, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
Wu
Min
M
Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.
Chen
Hui
H
Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.|Key Laboratory of Medical Molecular Virology, Ministry of Education and Public Health, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
Kato
Nobuyuki
N
Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.
Yuan
Zhenghong
Z
Department of Tumour Virology, Okayama University, Okayama 700-8558, Japan.|Shanghai Public Health Clinical Center affiliated to Fudan University, Shanghai 201508, PR China.|Key Laboratory of Medical Molecular Virology, Ministry of Education and Public Health, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
D002460:Cell Line; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000276:immunology* / Q000378:metabolism; D015684:Gene Products, pol / Q000502:physiology*; D006515:Hepatitis B virus / Q000276:immunology / Q000472:pathogenicity*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D050838:Interferon Regulatory Factor-3 / Q000037:antagonists & inhibitors*; D016899:Interferon-beta / Q000096:biosynthesis*; D009522:Newcastle disease virus / Q000276:immunology; D011070:Poly I-C / Q000276:immunology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011971:Receptors, Immunologic; D029082:Sendai virus / Q000276:immunology; D051196:Toll-Like Receptor 3 / Q000276:immunology*; D014162:Transfection; D037521:Virulence Factors / Q000502:physiology*
D015684:Gene Products, pol; C494232:IRF3 protein, human; D050838:Interferon Regulatory Factor-3; C066027:P protein, Hepatitis B virus; D011971:Receptors, Immunologic; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D037521:Virulence Factors; D016899:Interferon-beta; D017346:Protein Serine-Threonine Kinases; C403191:TBK1 protein, human; D051550:I-kappa B Kinase; C119332:DDX3X protein, human; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D011070:Poly I-C