NOD1 contributes to mouse host defense against Helicobacter pylori via induction of type I IFN and activation of the ISGF3 signaling pathway
Tomohiro Watanabe, … , Atsushi Kitani, Warren Strober
Tomohiro Watanabe, … , Atsushi Kitani, Warren Strober
Published April 12, 2010
Citation Information: J Clin Invest. 2010;120(5):1645-1662. https://doi.org/10.1172/JCI39481.
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Research Article Immunology

NOD1 contributes to mouse host defense against Helicobacter pylori via induction of type I IFN and activation of the ISGF3 signaling pathway

Abstract

Nucleotide-binding oligomerization domain 1 (NOD1) is an intracellular epithelial cell protein known to play a role in host defense at mucosal surfaces. Here we show that a ligand specific for NOD1, a peptide derived from peptidoglycan, initiates an unexpected signaling pathway in human epithelial cell lines that results in the production of type I IFN. Detailed analysis revealed the components of the signaling pathway. NOD1 binding to its ligand triggered activation of the serine-threonine kinase RICK, which was then able to bind TNF receptor–associated factor 3 (TRAF3). This in turn led to activation of TANK-binding kinase 1 (TBK1) and IκB kinase ε (IKKε) and the subsequent activation of IFN regulatory factor 7 (IRF7). IRF7 induced IFN-β production, which led to activation of a heterotrimeric transcription factor complex known as IFN-stimulated gene factor 3 (ISGF3) and the subsequent production of CXCL10 and additional type I IFN. In vivo studies showed that mice lacking the receptor for IFN-β or subjected to gene silencing of the ISGF3 component Stat1 exhibited decreased CXCL10 responses and increased susceptibility to Helicobacter pylori infection, phenotypes observed in NOD1-deficient mice. These studies thus establish that NOD1 can activate the ISGF3 signaling pathway that is usually associated with protection against viral infection to provide mice with robust type I IFN–mediated protection from H. pylori and possibly other mucosal infections.

Authors

Tomohiro Watanabe, Naoki Asano, Stefan Fichtner-Feigl, Peter L. Gorelick, Yoshihisa Tsuji, Yuko Matsumoto, Tsutomu Chiba, Ivan J. Fuss, Atsushi Kitani, Warren Strober

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Figure 5

ISGF3-dependent production of IP-10 in HT-29.

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ISGF3-dependent production of IP-10 in HT-29. (A) Expression of Stat1, S...
(A) Expression of Stat1, Stat2, and IRF-9 in whole cell extracts of HT-29 cells. Middle and right panels show immunoblots from HT-29 cells not treated with IFN-γ and treated with IFN-γ, respectively. Extracts from cells treated with IFN-β were used as positive controls. (B) Nuclear translocation of ISGF3 by NOD1 activation. Nuclear extracts were prepared from IFN-γ–untreated (left 2 blots) or IFN-γ–treated (middle) HT-29 cells stimulated with iE-DAP. Nuclear extracts from IFN-γ–treated HT-29 cells 2 hours after stimulation with iE-DAP were used for Supershift assays (right). White arrowheads indicate position of the ISGF3 complex. Black arrowheads indicate position of supershifted complexes. (C) Expression of Stat1 in nuclear extracts was determined by Transfactor assay. HT-29 cells pre-incubated or not with IFN-γ were stimulated with iE-DAP for 4 hours, at which point nuclear extracts were prepared. **P < 0.01 compared with cells without stimulation. (D) Production of IP-10 and IFN-β by HT-29 cells transfected with Stat1 or Stat2 siRNA. HT-29 cells were transfected with control vector, Stat1 siRNA–expressing vector, or Stat2 siRNA–expressing vector and then stimulated with iE-DAP in the absence of IFN-γ. Cells were then lysed, and the whole lysates obtained were subjected to Western blot analysis. Production of IP-10 and IFN-β by HT-29 cells transfected with Stat1 or Stat2 siRNA is shown in the graphs. Results are expressed as mean ± SD. **P < 0.01 compared with cells transfected with control vector. Results shown are representative of 2 similar studies.