title: Inhibition of interleukin-12 p40 transcription and NF-kappaB activation by nitric oxide in murine macrophages and dendritic cells.
abstract: Nitric oxide (NO), an important effector molecule of the innate immune system, can also regulate adaptive immunity. In this study, the molecular effects of NO on the toll-like receptor signaling pathway were determined using interleukin-12 (IL-12) as an immunologically relevant target gene. The principal conclusion of these experiments is that NO inhibits IL-1 receptor-associated kinase (IRAK) activity and attenuates the molecular interaction between tumor necrosis factor receptor-associated factor-6 and IRAK. As a consequence, the NO donor S-nitroso-N-acetylpenicillamine (SNAP) inhibits lipopolysaccharide (LPS)-induced IL-12 p40 mRNA expression, protein production, and promoter activity in murine macrophages, dendritic cells, and the murine macrophage cell line RAW 264.7. Splenocytes from inducible nitric-oxide synthase-deficient mice demonstrate markedly increased IL-12 p40 protein and mRNA expression compared with wild type splenocytes. The inhibitory action of NO on IL-12 p40 is independent of the cytokine IL-10. The effects of NO can be directly attributed to inhibition of NF-kappaB activation through IRAK-dependent pathways. Accordingly, SNAP strongly reduces LPS-induced NF-kappaB DNA binding to the p40 promoter and inhibits LPS-induced IkappaB phosphorylation. Similarly, NO attenuates IL-1beta-induced NF-kappaB activation. These experiments provide another example of how an innate immune molecule may have a profound effect on adaptive immunity.
authors.affiliation: Immunobiology Center, The Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: Huabao
authors.initials: H
authors.lastname: Xiong
authors.forename: Chen
authors.initials: C
authors.lastname: Zhu
authors.forename: Fengling
authors.initials: F
authors.lastname: Li
authors.forename: Refaat
authors.initials: R
authors.lastname: Hegazi
authors.forename: Kaili
authors.initials: K
authors.lastname: He
authors.forename: Mark
authors.initials: M
authors.lastname: Babyatsky
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Bauer
authors.forename: Scott E
authors.initials: SE
authors.lastname: Plevy
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism; D002460:Cell Line; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases; D018664:Interleukin-12 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053762:Interleukin-12 Subunit p40; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D021122:Protein Subunits / Q000037:antagonists & inhibitors*; D011506:Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology; D048029:TNF Receptor-Associated Factor 6; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D004791:Enzyme Inhibitors; D053762:Interleukin-12 Subunit p40; D016328:NF-kappa B; D020030:Nitric Oxide Donors; D021122:Protein Subunits; D011506:Proteins; D012333:RNA, Messenger; D048029:TNF Receptor-Associated Factor 6; D018664:Interleukin-12; D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D011494:Protein Kinases; D053592:Interleukin-1 Receptor-Associated Kinases