Open AccessMaturation modulates caspase‐1‐independent responses of dendritic cells to Anthrax Lethal Toxin
Author(s) -
Reig Núria,
Jiang Aimin,
Couture Rachael,
Sutterwala Fayyaz S.,
Ogura Yasunori,
Flavell Richard A.,
Mellman Ira,
Van Der Goot F. Gisou
Publication year - 2008
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2008.01121.x
Subject(s) - biology , inflammasome , bacillus anthracis , immune system , innate immune system , microbiology and biotechnology , programmed cell death , caspase 1 , caspase , apoptosis , toxin , caspase 8 , immunology , inflammation , genetics , bacteria
Summary Anthrax lethal toxin (LT) contributes to the immune evasion strategy of Bacillus anthracis by impairing the function of cells of the immune system, such as macrophages and dendritic cells (DCs). Macrophages from certain inbred mice strains undergo rapid death upon LT treatment mediated by caspase‐1 activation dependent on Nalp1b, an inflammasome component. Rapid LT‐induced death is however, not observed in macrophages from human and many mouse strains. Here, we focused on the responses of various murine DCs to LT. Using a variety of knockout mice, we found that depending on the mouse strain, death of bone marrow‐derived DCs and macrophages was mediated either by a fast Nalp1b and caspase‐1‐dependent, or by a slow caspase‐1‐independent pathway that was triggered by the impairment of MEK1/2 pathways. Caspase‐1‐independent death was observed in cells of different genetic backgrounds and interestingly occurred only in immature DCs. Maturation, triggered by different types of stimuli, led to full protection of DCs. These studies illustrate that the cellular damage inflicted by LT depends not only on the innate responses but also on the maturation stage of the cell, which modulates the more general caspase‐1‐independent responses.