Anthrax toxin induces macrophage death by p38 MAPK inhibition but leads to inflammasome activation via ATP leakage.

Autor: Ali SR; Laboratory of Signal Transduction, Department of Pharmacology, University of California, San Diego, La Jolla, California, USA., Timmer AM, Bilgrami S, Park EJ, Eckmann L, Nizet V, Karin M
Jazyk: angličtina
Zdroj: Immunity [Immunity] 2011 Jul 22; Vol. 35 (1), pp. 34-44. Date of Electronic Publication: 2011 Jun 16.
DOI: 10.1016/j.immuni.2011.04.015
Abstrakt: Detection of microbial constituents by membrane associated and cytoplasmic pattern recognition receptors is the essence of innate immunity, leading to activation of protective host responses. However, it is still unclear how immune cells specifically respond to pathogenic bacteria. Using virulent and nonvirulent strains of Bacillus anthracis, we have shown that secretion of ATP by infected macrophages and the sequential activation of the P2X7 purinergic receptor and nucleotide binding oligomerization domain (NOD)-like receptors are critical for IL-1-dependent host protection from virulent B. anthracis. Importantly, lethal toxin produced by virulent B. anthracis blocked activation of protein kinases, p38 MAPK and AKT, resulting in opening of a connexin ATP release channel and induction of macrophage death. Prevention of cell death or ATP release through constitutive p38 or AKT activation interfered with inflammasome activation and IL-1β production, thereby compromising antimicrobial immunity.
(Copyright © 2011 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE