Regulation of CXCL-8 (interleukin-8) induction by double-stranded RNA signaling pathways during hepatitis C virus infection

J Virol. 2007 Jan;81(1):309-18. doi: 10.1128/JVI.01411-06. Epub 2006 Oct 11.

Abstract

Hepatitis C virus (HCV) infection induces the alpha-chemokine interleukin-8 (CXCL-8), which is regulated at the levels of transcription and mRNA stability. In the current study, CXCL-8 regulation by double-stranded (ds)RNA pathways was analyzed in the context of HCV infection. A constitutively active mutant of the retinoic acid-inducible gene I (RIG-I), RIG-N, activated CXCL-8 transcription. Promoter mutagenesis experiments indicated that NF-kappaB and interferon (IFN)-stimulated response element (ISRE) binding sites were required for the RIG-N induction of CXCL-8 transcription. IFN-beta promoter stimulator 1 (IPS-1) expression also activated CXCL-8 transcription, and mutations of the ISRE and NF-kappaB binding sites reduced and abrogated CXCL-8 transcription, respectively. In the presence of wild-type RIG-I, transfection of JFH-1 RNA or JFH-1 virus infection of Huh7.5.1 cells activated the CXCL-8 promoter. Expression of IFN regulatory factor 3 (IRF-3) stimulated transcription from both full-length and ISRE-driven CXCL-8 promoters. Chromatin immunoprecipitation assays demonstrated that IRF-3 and NF-kappaB bound directly to the CXCL-8 promoter in response to virus infection and dsRNA transfection. RIG-N stabilized CXCL-8 mRNA via the AU-rich element in the 3' untranslated region of CXCL-8 mRNA, leading to an increase in its half-life following tumor necrosis factor alpha induction. The data indicate that HCV infection triggers dsRNA signaling pathways that induce CXCL-8 via transcriptional activation and mRNA stabilization and define a regulatory link between innate antiviral and inflammatory cellular responses to virus infection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / metabolism
  • Gene Expression Regulation
  • Hepacivirus / immunology*
  • Humans
  • Interferon Regulatory Factor-3 / metabolism
  • Interferon Regulatory Factor-3 / physiology
  • Interleukin-8 / biosynthesis
  • Interleukin-8 / genetics*
  • Mutation
  • Promoter Regions, Genetic
  • RNA, Double-Stranded / metabolism*
  • RNA, Messenger / metabolism
  • Receptors, Immunologic
  • Signal Transduction*
  • Transcription, Genetic

Substances

  • Interferon Regulatory Factor-3
  • Interleukin-8
  • RNA, Double-Stranded
  • RNA, Messenger
  • Receptors, Immunologic
  • RIGI protein, human
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases