Interferons direct an effective innate response to Legionella pneumophila infection.
Legionella pneumophila remains an important opportunistic pathogen of human macrophages. Its more limited ability to replicate in murine macrophages has been attributed to redundant innate sensor systems that detect and effectively respond to this infection. The current studies evaluate the role of one of these innate response systems, the type I interferon (IFN-I) autocrine loop. The ability of L. pneumophila to induce IFN-I expression was found to be dependent on IRF-3, but not NF-kappaB. Secreted IFN-Is then in turn suppress the intracellular replication of L. pneumophila. Surprisingly, this suppression is mediated by a pathway that is independent of Stat1, Stat2, Stat3, but correlates with the polarization of macrophages toward the M1 or classically activated phenotype.
Plumlee
Courtney R
CR
Department of Biological Sciences, Columbia University, New York, New York 10032, USA.
Lee
Carolyn
C
Beg
Amer A
AA
Decker
Thomas
T
Shuman
Howard A
HA
Schindler
Christian
C
D000818:Animals; D019898:Autocrine Communication / Q000276:immunology; D002478:Cells, Cultured; D007113:Immunity, Innate; D007370:Interferon Type I / Q000276:immunology*; D007372:Interferons / Q000276:immunology*; D016952:Legionella pneumophila / Q000502:physiology; D007877:Legionnaires' Disease / Q000276:immunology*; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D051379:Mice; D016328:NF-kappa B; D050791:STAT Transcription Factors
D007370:Interferon Type I; D016328:NF-kappa B; D050791:STAT Transcription Factors; D007372:Interferons