Critical role for interferon regulatory factor 3 (IRF-3) and IRF-7 in type I interferon-mediated control of murine norovirus replication

J Virol. 2012 Dec;86(24):13515-23. doi: 10.1128/JVI.01824-12. Epub 2012 Oct 3.

Abstract

Human noroviruses (HuNoV) are the major cause of epidemic, nonbacterial gastroenteritis in the world. The short course of HuNoV-induced symptoms has implicated innate immunity in control of norovirus (NoV) infection. Studies using murine norovirus (MNV) confirm the importance of innate immune responses during NoV infection. Type I alpha and beta interferons (IFN-α/β) limit HuNoV replicon function, restrict MNV replication in cultured cells, and control MNV replication in vivo. Therefore, the cell types and transcription factors involved in antiviral immune responses and IFN-α/β-mediated control of NoV infection are important to define. We used mice with floxed alleles of the IFNAR1 chain of the IFN-α/β receptor to identify cells expressing lysozyme M or CD11c as cells that respond to IFN-α/β to restrict MNV replication in vivo. Furthermore, we show that the transcription factors IRF-3 and IRF-7 work in concert to initiate unique and overlapping antiviral responses to restrict MNV replication in vivo. IRF-3 and IRF-7 restrict MNV replication in both cultured macrophages and dendritic cells, are required for induction of IFN-α/β in macrophages but not dendritic cells, and are dispensable for the antiviral effects of IFN-α/β that block MNV replication. These studies suggest that expression of the IFN-α/β receptor on macrophages/neutrophils and dendritic cells, as well as of IRF-3 and IRF-7, is critical for innate immune responses to NoV infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • DNA Primers
  • Dendritic Cells / immunology
  • Immunity, Innate
  • Interferon Regulatory Factor-3 / physiology*
  • Interferon Regulatory Factor-7 / physiology*
  • Interferon Type I / physiology*
  • Macrophages / immunology
  • Mice
  • Norovirus / immunology
  • Norovirus / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Virus Replication / physiology*

Substances

  • DNA Primers
  • Interferon Regulatory Factor-3
  • Interferon Regulatory Factor-7
  • Interferon Type I
  • Irf3 protein, mouse
  • Irf7 protein, mouse