Interleukin-1 (IL-1) signaling in intestinal stromal cells controls KC/ CXCL1 secretion, which correlates with recruitment of IL-22- secreting neutrophils at early stages of Citrobacter rodentium infection

Infect Immun. 2015 Aug;83(8):3257-67. doi: 10.1128/IAI.00670-15.

Abstract

Attaching and effacing pathogens, including enterohemorrhagic Escherichia coli in humans and Citrobacter rodentium in mice, raise serious public health concerns. Here we demonstrate that interleukin-1 receptor (IL-1R) signaling is indispensable for protection against C. rodentium infection in mice. Four days after infection with C. rodentium, there were significantly fewer neutrophils (CD11b+ Ly6C+ Ly6G+) in the colons of IL-1R−/− mice than in wild-type mice. Levels of mRNA and protein of KC/CXCL1 were also significantly reduced in colon homogenates of infected IL-1R−/− mice relative to wild-type mice. Of note, infiltrated CD11b+ Ly6C+ Ly6G+ neutrophils were the main source of IL-22 secretion after C. rodentium infection. Interestingly, intestinal stromal cells isolated from IL-1R−/− mice secreted lower levels of KC/CXCL1 than stromal cells from wild-type mice during C. rodentium infection. Similar effects were found when mouse intestinal stromal cells and human nasal polyp stromal cells were treated with IL-1R antagonists (i.e., anakinra) in vitro. These results suggest that IL-1 signaling plays a pivotal role in activating mucosal stromal cells to secrete KC/CXCL1, which is essential for infiltration of IL-22-secreting neutrophils upon bacterial infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chemokine CXCL1 / genetics
  • Chemokine CXCL1 / metabolism*
  • Citrobacter rodentium / physiology*
  • Enterobacteriaceae Infections / genetics
  • Enterobacteriaceae Infections / metabolism*
  • Enterobacteriaceae Infections / microbiology
  • Female
  • Humans
  • Interleukin-1 / genetics
  • Interleukin-1 / metabolism*
  • Interleukin-22
  • Interleukins / genetics
  • Interleukins / metabolism*
  • Intestinal Mucosa / metabolism*
  • Intestines / microbiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neutrophils / metabolism*
  • Receptors, Interleukin-1 / genetics
  • Receptors, Interleukin-1 / immunology
  • Signal Transduction
  • Stromal Cells / metabolism*

Substances

  • Chemokine CXCL1
  • Cxcl1 protein, mouse
  • Interleukin-1
  • Interleukins
  • Receptors, Interleukin-1