First Author | Case CL | Year | 2013 |
Journal | Proc Natl Acad Sci U S A | Volume | 110 |
Issue | 5 | Pages | 1851-6 |
PubMed ID | 23307811 | Mgi Jnum | J:211694 |
Mgi Id | MGI:5575933 | Doi | 10.1073/pnas.1211521110 |
Citation | Case CL, et al. (2013) Caspase-11 stimulates rapid flagellin-independent pyroptosis in response to Legionella pneumophila. Proc Natl Acad Sci U S A 110(5):1851-6 |
abstractText | A flagellin-independent caspase-1 activation pathway that does not require NAIP5 or NRLC4 is induced by the intracellular pathogen Legionella pneumophila. Here we demonstrate that this pathway requires caspase-11. Treatment of macrophages with LPS up-regulated the host components required for this caspase-11 activation pathway. Activation by Legionella differed from caspase-11 activation using previously described agonists in that Legionella caspase-11 activation was rapid and required bacteria with a functional type IV secretion system called Dot/Icm. Legionella activation of caspase-11 induced pyroptosis by a mechanism independent of the NAIP/NLRC4 and caspase-1 axis. Legionella activation of caspase-11 stimulated activation of caspase-1 through NLRP3 and ASC. Induction of caspase-11-dependent responses occurred in macrophages deficient in the adapter proteins TRIF or MyD88 but not in macrophages deficient in both signaling factors. Although caspase-11 was produced in macrophages deficient in the type-I IFN receptor, there was a severe defect in caspase-11-dependent pyroptosis in these cells. These data indicate that macrophages respond to microbial signatures to produce proteins that mediate a capsase-11 response and that the caspase-11 system provides an alternative pathway for rapid detection of an intracellular pathogen capable of evading the canonical caspase-1 activation system that responds to bacterial flagellin. |