Title

Silica crystals and aluminum salts activate the NALP3 inflammasome through phagosomal destabilization

UMMS Affiliation

Department of Medicine, Division of Infectious Diseases and Immunology; Department of Pathology

Date

7-8-2008

Document Type

Article

Subjects

Aluminum Compounds; Animals; Carrier Proteins; Inflammation; Inflammation Mediators; Macrophages; Mice; Mice, Inbred C57BL; Silicon Dioxide; Silicosis

Abstract

Inhalation of silica crystals causes inflammation in the alveolar space. Prolonged exposure to silica can lead to the development of silicosis, an irreversible, fibrotic pulmonary disease. The mechanisms by which silica and other crystals activate immune cells are not well understood. Here we demonstrate that silica and aluminum salt crystals activated inflammasomes formed by the cytoplasmic receptor NALP3. NALP3 activation required phagocytosis of crystals, and this uptake subsequently led to lysosomal damage and rupture. 'Sterile' lysosomal damage (without crystals) also induced NALP3 activation, and inhibition of either phagosomal acidification or cathepsin B activity impaired NALP3 activation. Our results indicate that the NALP3 inflammasome senses lysosomal damage as an endogenous 'danger' signal.

Rights and Permissions

Citation: Nat Immunol. 2008 Aug;9(8):847-56. Epub 2008 Jul 11. Link to article on publisher's site

Related Resources

Link to Article in PubMed

PubMed ID

18604214