Ezrin links CFTR to TLR4 signaling to orchestrate anti-bacterial immune response in macrophages

Sci Rep. 2017 Sep 7;7(1):10882. doi: 10.1038/s41598-017-11012-7.

Abstract

Macrophages (MΦs) with mutations in cystic fibrosis transmembrane conductance regulator (CFTR) have blunted induction of PI3K/AKT signaling in response to TLR4 activation, leading to hyperinflammation, a hallmark of cystic fibrosis (CF) disease. Here, we show that Ezrin links CFTR and TLR4 signaling, and is necessary for PI3K/AKT signaling induction in response to MΦ activation. Because PI3K/AKT signaling is critical for immune regulation, Ezrin-deficient MΦs are hyperinflammatory and have impaired Pseudomonas aeruginosa phagocytosis, phenocopying CF MΦs. Importantly, we show that activated CF MΦs have reduced protein levels and altered localization of the remaining Ezrin to filopodia that form during activation. In summary, we have described a direct link from CFTR to Ezrin to PI3K/AKT signaling that is disrupted in CF, and thus promotes hyper-inflammation and weakens phagocytosis.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / pathology*
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism*
  • Cytoskeletal Proteins / metabolism*
  • Disease Models, Animal
  • Macrophage Activation*
  • Macrophages / immunology*
  • Mice
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Pseudomonas Infections / pathology
  • Pseudomonas aeruginosa / immunology
  • Signal Transduction*
  • Toll-Like Receptor 4 / metabolism*

Substances

  • Cytoskeletal Proteins
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • ezrin
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Proto-Oncogene Proteins c-akt