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Clostridium difficile toxin-induced inflammation and intestinal injury are mediated by the inflammasome.

Authors :
Ng J
Hirota SA
Gross O
Li Y
Ulke-Lemee A
Potentier MS
Schenck LP
Vilaysane A
Seamone ME
Feng H
Armstrong GD
Tschopp J
Macdonald JA
Muruve DA
Beck PL
Source :
Gastroenterology [Gastroenterology] 2010 Aug; Vol. 139 (2), pp. 542-52, 552.e1-3. Date of Electronic Publication: 2010 Apr 13.
Publication Year :
2010

Abstract

Background & Aims: Clostridium difficile-associated disease (CDAD) is the leading cause of nosocomial diarrhea in the United States. C difficile toxins TcdA and TcdB breach the intestinal barrier and trigger mucosal inflammation and intestinal damage. The inflammasome is an intracellular danger sensor of the innate immune system. In the present study, we hypothesize that TcdA and TcdB trigger inflammasome-dependent interleukin (IL)-1beta production, which contributes to the pathogenesis of CDAD.<br />Methods: Macrophages exposed to TcdA and TcdB were assessed for IL-1beta production, an indication of inflammasome activation. Macrophages deficient in components of the inflammasome were also assessed. Truncated/mutated forms of TcdB were assessed for their ability to activate the inflammasome. The role of inflammasome signaling in vivo was assessed in ASC-deficient and IL-1 receptor antagonist-treated mice.<br />Results: TcdA and TcdB triggered inflammasome activation and IL-1beta secretion in macrophages and human mucosal biopsy specimens. Deletion of Nlrp3 decreased, whereas deletion of ASC completely abolished, toxin-induced IL-1beta release. TcdB-induced IL-1beta release required recognition of the full-length toxin but not its enzymatic function. In vivo, deletion of ASC significantly reduced toxin-induced inflammation and damage, an effect that was mimicked by pretreatment with the IL-1 receptor antagonist anakinra.<br />Conclusions: TcdA and TcdB trigger IL-1beta release by activating an ASC-containing inflammasome, a response that contributes to toxin-induced inflammation and damage in vivo. Pretreating mice with the IL-1 receptor antagonist anakinra afforded the same level of protection that was observed in ASC-/- mice. These data suggest that targeting inflammasome or IL-1beta signaling may represent new therapeutic targets in the treatment of CDAD.<br /> (Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Details

Language :
English
ISSN :
1528-0012
Volume :
139
Issue :
2
Database :
MEDLINE
Journal :
Gastroenterology
Publication Type :
Academic Journal
Accession number :
20398664
Full Text :
https://doi.org/10.1053/j.gastro.2010.04.005