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

J Gen Virol. 2010 Aug;91(Pt 8):2080-2090. doi: 10.1099/vir.0.020552-0. Epub 2010 Apr 7.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases / immunology*
  • DEAD-box RNA Helicases / metabolism
  • Gene Products, pol / physiology*
  • Hepatitis B virus / immunology
  • Hepatitis B virus / pathogenicity*
  • Hepatocytes / virology
  • Humans
  • I-kappa B Kinase / metabolism
  • Interferon Regulatory Factor-3 / antagonists & inhibitors*
  • Interferon-beta / biosynthesis*
  • Newcastle disease virus / immunology
  • Poly I-C / immunology
  • Protein Serine-Threonine Kinases / metabolism
  • Receptors, Immunologic
  • Sendai virus / immunology
  • Toll-Like Receptor 3 / immunology*
  • Transfection
  • Virulence Factors / physiology*

Substances

  • Gene Products, pol
  • IRF3 protein, human
  • Interferon Regulatory Factor-3
  • P protein, Hepatitis B virus
  • Receptors, Immunologic
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Virulence Factors
  • Interferon-beta
  • Protein Serine-Threonine Kinases
  • TBK1 protein, human
  • I-kappa B Kinase
  • DDX3X protein, human
  • RIGI protein, human
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases
  • Poly I-C