Cutting Edge: Influenza A virus activates TLR3-dependent inflammatory and RIG-I-dependent antiviral responses in human lung epithelial cells

J Immunol. 2007 Mar 15;178(6):3368-72. doi: 10.4049/jimmunol.178.6.3368.

Abstract

Influenza A virus (IAV) triggers a contagious acute respiratory disease that causes considerable mortality annually. Recently, we established a role for the pattern-recognition TLR3 in the response of lung epithelial cells to IAV-derived dsRNA. However, additional nucleic acid-recognition proteins have lately been implicated as key viral sensors, including the RNA helicases retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene (MDA)-5. In this study, we investigated the respective role of TLR3 vs RIG-I/MDA-5 signaling in human respiratory epithelial cells infected by IAV using BEAS-2B cells transfected with vectors encoding either a dominant-negative form of TLR3 or of mitochondrial antiviral signaling protein (MAVS; a signaling intermediate of RIG-I and MDA-5), or with plasmids overexpressing functional RIG-I or MDA-5. We demonstrate that the sensing of IAV by TLR3 primarily regulates a proinflammatory response, whereas RIG-I (but not MDA-5) mediates both a type I IFN-dependent antiviral signaling and a proinflammatory response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • DEAD-box RNA Helicases / immunology
  • Epithelial Cells / immunology*
  • Epithelial Cells / virology
  • Humans
  • Inflammation / genetics
  • Inflammation / immunology
  • Influenza A Virus, H3N2 Subtype
  • Influenza, Human / genetics
  • Influenza, Human / immunology*
  • Interferon Type I / immunology
  • Interferon-Induced Helicase, IFIH1
  • Lung / immunology*
  • Mitochondrial Proteins / immunology
  • RNA Helicases
  • RNA, Double-Stranded / immunology
  • RNA, Viral / immunology
  • Receptors, Retinoic Acid / immunology*
  • Signal Transduction / genetics
  • Signal Transduction / immunology*
  • Toll-Like Receptor 3 / genetics
  • Toll-Like Receptor 3 / immunology*

Substances

  • Interferon Type I
  • Mitochondrial Proteins
  • PLAAT4 protein, human
  • RNA, Double-Stranded
  • RNA, Viral
  • Receptors, Retinoic Acid
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • IFIH1 protein, human
  • DEAD-box RNA Helicases
  • Interferon-Induced Helicase, IFIH1
  • RNA Helicases