Salmonella virulence factor SipB induces activation and release of IL-18 in human dendritic cells
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Date
2002Author
Dreher, Donatus
Kok, Menno
Obregon, Carolina
Kiama, S G
Gehr, Peter
Nicod, Laurent P.
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Interleukin-18 (IL-18) plays an important
role in innate and acquired immunity, in particular
against intracellular pathogens. However,
little is known about the microbial factors that
trigger IL-18 secretion by dendritic cells (DCs). To
determine the influence of bacterial virulence factors
on the activation and release of IL-18, we
infected human monocyte-derived DCs with virulence
mutants of the facultative intracellular pathogen
Salmonella typhimurium. Our results show that
infection by S. typhimurium causes caspase-1-dependent
activation of IL-18 and triggers the release
of IL-18 in human DCs. The secretion of
IL-18 by the DCs was closely correlated with the
ability of the S. typhimurium strains to induce apoptosis.
We demonstrate that activation and release
of IL-18 are blocked by mutations in the
Salmonella sipB gene, which encodes a virulence
factor that activates caspase-1 to induce apoptosis.
These findings indicate that the activation and release
of IL-18 induced by bacterial virulence factors
may represent one component of innate immunity
against the intracellular bacteria. J. Leukoc.
Biol. 72: 743–751; 2002.
Publisher
Division of Pneumology, University Hospital of Geneva, Switzerland Department of Genetics and Microbiology Department of Medical Biochemistry, University of Geneva, Switzerland Institute of Anatomy, University of Berne, Switzerland Department of Veterinary Anatomy, University of Nairobi, Kenya