| First Author | Van Opdenbosch N | Year | 2014 |
| Journal | Nat Commun | Volume | 5 |
| Pages | 3209 | PubMed ID | 24492532 |
| Mgi Jnum | J:244194 | Mgi Id | MGI:5912973 |
| Doi | 10.1038/ncomms4209 | Citation | Van Opdenbosch N, et al. (2014) Activation of the NLRP1b inflammasome independently of ASC-mediated caspase-1 autoproteolysis and speck formation. Nat Commun 5:3209 |
| abstractText | Despite its clinical importance in infection and autoimmunity, the activation mechanisms of the NLRP1b inflammasome remain enigmatic. Here we show that deletion of the inflammasome adaptor ASC in BALB/c mice and in C57BL/6 macrophages expressing a functional NLRP1b prevents anthrax lethal toxin (LeTx)-induced caspase-1 autoproteolysis and speck formation. However, ASC(-/-) macrophages undergo normal LeTx-induced pyroptosis and secrete significant amounts of interleukin (IL)-1beta. In contrast, ASC is critical for caspase-1 autoproteolysis and IL-1beta secretion by the NLRC4, NLRP3 and AIM2 inflammasomes. Notably, LeTx-induced inflammasome activation is associated with caspase-1 ubiquitination, which is unaffected in ASC-deficient cells. In vivo, ASC-deficient mice challenged with LeTx produce significant levels of IL-1beta, IL-18 and HMGB1 in circulation, although caspase-1 autoproteolysis is abolished. As a result, ASC(-/-) mice are sensitive to rapid LeTx-induced lethality. Together, these results demonstrate that ASC-driven caspase-1 autoprocessing and speck formation are dispensable for the activation of caspase-1 and the NLRP1b inflammasome. |
