Gene expression induced by Toll-like receptors in macrophages requires the transcription factor NFAT5.
Toll-like receptors (TLRs) engage networks of transcriptional regulators to induce genes essential for antimicrobial immunity. We report that NFAT5, previously characterized as an osmostress responsive factor, regulates the expression of multiple TLR-induced genes in macrophages independently of osmotic stress. NFAT5 was essential for the induction of the key antimicrobial gene Nos2 (inducible nitric oxide synthase [iNOS]) in response to low and high doses of TLR agonists but is required for Tnf and Il6 mainly under mild stimulatory conditions, indicating that NFAT5 could regulate specific gene patterns depending on pathogen burden intensity. NFAT5 exhibited two modes of association with target genes, as it was constitutively bound to Tnf and other genes regardless of TLR stimulation, whereas its recruitment to Nos2 or Il6 required TLR activation. Further analysis revealed that TLR-induced recruitment of NFAT5 to Nos2 was dependent on inhibitor of κB kinase (IKK) β activity and de novo protein synthesis, and was sensitive to histone deacetylases. In vivo, NFAT5 was necessary for effective immunity against Leishmania major, a parasite whose clearance requires TLRs and iNOS expression in macrophages. These findings identify NFAT5 as a novel regulator of mammalian anti-pathogen responses.
Immunology Unit, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), 08003 Barcelona, Spain.
Maria
M
Buxadé
Giulia
G
Lunazzi
Jordi
J
Minguillón
Salvador
S
Iborra
Rosa
R
Berga-Bolaños
Margarita
M
Del Val
José
J
Aramburu
Cristina
C
López-Rodríguez
D000818:Animals; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000235:genetics; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D053263:Gene Regulatory Networks / Q000235:genetics / Q000276:immunology*; D051550:I-kappa B Kinase / Q000378:metabolism; D015151:Immunoblotting; D015850:Interleukin-6 / Q000378:metabolism; D007891:Leishmania / Q000276:immunology; D008156:Luciferases; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D046228:Microarray Analysis; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D051193:Toll-Like Receptors / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D017931:DNA Primers; D015850:Interleukin-6; C492200:Nfat5 protein, mouse; D009573:Nitrites; D051193:Toll-Like Receptors; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D008156:Luciferases; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D051550:I-kappa B Kinase