Inhibition of interleukin-12 p40 transcription and NF-kappaB activation by nitric oxide in murine macrophages and dendritic cells.
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.
Xiong
Huabao
H
Immunobiology Center, The Mount Sinai School of Medicine, New York, New York 10029, USA.
Zhu
Chen
C
Li
Fengling
F
Hegazi
Refaat
R
He
Kaili
K
Babyatsky
Mark
M
Bauer
Anthony J
AJ
Plevy
Scott E
SE
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
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