IFN regulatory factor 3-dependent induction of type I IFNs by intracellular bacteria is mediated by a TLR- and Nod2-independent mechanism.

Autor: Stockinger S; Max F. Perutz Laboratories, University Department at the Vienna Biocenter, Department of Microbiology and Genetics, University of Vienna, Austria., Reutterer B, Schaljo B, Schellack C, Brunner S, Materna T, Yamamoto M, Akira S, Taniguchi T, Murray PJ, Müller M, Decker T
Jazyk: angličtina
Zdroj: Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2004 Dec 15; Vol. 173 (12), pp. 7416-25.
DOI: 10.4049/jimmunol.173.12.7416
Abstrakt: Like viruses, intracellular bacteria stimulate their host cells to produce type I IFNs (IFN-alpha and IFN-beta). In our study, we investigated the signals and molecules relevant for the synthesis of and response to IFN by mouse macrophages infected with Listeria monocytogenes. We report that IFN-beta is the critical immediate-early IFN made during infection, because the synthesis of all other type I IFN, expression of a subset of infection-induced genes, and the biological response to type I IFN was lost upon IFN-beta deficiency. The induction of IFN-beta mRNA and the IFN-beta-dependent sensitization of macrophages to bacteria-induced death, in turn, was absolutely dependent upon the presence of the transcription factor IFN regulatory factor 3 (IRF3). IFN-beta synthesis and signal transduction occurred in macrophages deficient for TLR or their adaptors MyD88, TRIF, or TRAM. Expression of Nod2, a candidate receptor for intracellular bacteria, increased during infection, but the protein was not required for Listeria-induced signal transduction to the Ifn-beta gene. Based on our data, we propose that IRF3 is a convergence point for signals derived from structurally unrelated intracellular pathogens, and that L. monocytogenes stimulates a novel TLR- and Nod2-independent pathway to target IRF3 and the type I IFN genes.
Databáze: MEDLINE