STING-dependent sensing of self-DNA drives silica-induced lung inflammation

Nat Commun. 2018 Dec 6;9(1):5226. doi: 10.1038/s41467-018-07425-1.

Abstract

Silica particles induce lung inflammation and fibrosis. Here we show that stimulator of interferon genes (STING) is essential for silica-induced lung inflammation. In mice, silica induces lung cell death and self-dsDNA release in the bronchoalveolar space that activates STING pathway. Degradation of extracellular self-dsDNA by DNase I inhibits silica-induced STING activation and the downstream type I IFN response. Patients with silicosis have increased circulating dsDNA and CXCL10 in sputum, and patients with fibrotic interstitial lung disease display STING activation and CXCL10 in the lung. In vitro, while mitochondrial dsDNA is sensed by cGAS-STING in dendritic cells, in macrophages extracellular dsDNA activates STING independent of cGAS after silica exposure. These results reveal an essential function of STING-mediated self-dsDNA sensing after silica exposure, and identify DNase I as a potential therapy for silica-induced lung inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chemokine CXCL10 / metabolism
  • DNA / genetics
  • DNA / metabolism*
  • Dendritic Cells / metabolism
  • Humans
  • Macrophages / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Pneumonia / genetics
  • Pneumonia / metabolism*
  • Silicon Dioxide / chemistry
  • Silicon Dioxide / metabolism*
  • Silicosis / metabolism
  • Sputum / metabolism

Substances

  • Chemokine CXCL10
  • Membrane Proteins
  • STING1 protein, human
  • Sting1 protein, mouse
  • Silicon Dioxide
  • DNA