Inhibition of IFN-gamma-induced janus kinase-1-STAT1 activation in macrophages by vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide.
The vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating polypeptide (PACAP), two immunomodulatory neuropeptides that affect both innate and acquired immunity, down-regulate IL-12 p40 and inducible NO synthase expression in LPS/IFN-gamma-stimulated macrophages. We showed previously that VIP/PACAP inhibit NF-kappaB nuclear translocation through the stabilization of IkappaB and reduce IFN regulatory factor-1 (IRF-1) binding to the regulatory elements found in the IL-12 p40 and inducible NO synthase promoters. In this paper we studied the molecular mechanisms involved in the VIP/PACAP regulation of IRF-1 transactivating activity. Our studies indicate that the inhibition in IRF-1 binding correlates with a reduction in IRF-1 protein and mRNA in IFN-gamma-treated Raw 264.7 macrophages. In agreement with the described Janus kinase (Jak)1/Jak2/STAT1/IRF-1 activation pathway, VIP/PACAP inhibit Jak1/Jak2, STAT1 phosphorylation, and the binding of STAT1 to the GAS sequence motif in the IRF-1 promoter. The effects of VIP/PACAP are mediated through the specific VIP/PACAP receptor-1 and the cAMP/protein kinase A (PKA) transduction pathway, but not through the induction of suppressor of cytokine signaling-1 or suppressor of cytokine signaling-3. Because IFN-gamma is a major stimulator of innate immune responses in vivo, the down-regulation of IFN-gamma-induced gene expression by VIP and PACAP could represent a significant element in the regulation of the inflammatory response by endogenous neuropeptides.
Delgado
M
M
Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA.
Ganea
D
D
D000818:Animals; D001667:Binding, Competitive / Q000276:immunology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism; D004789:Enzyme Activation / Q000276:immunology; D050856:Interferon Regulatory Factor-1; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000502:physiology*; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D008262:Macrophage Activation / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000201:enzymology* / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009479:Neuropeptides / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism; D010766:Phosphorylation; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011401:Promoter Regions, Genetic / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000378:metabolism; D018005:Receptors, Vasoactive Intestinal Peptide / Q000502:physiology; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D012097:Repressor Proteins; D050794:STAT1 Transcription Factor; D015398:Signal Transduction / Q000276:immunology*; D000071222:Suppressor of Cytokine Signaling 1 Protein; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014157:Transcription Factors; D014660:Vasoactive Intestinal Peptide / Q000502:physiology*
C495402:Adcyap1 protein, mouse; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D050856:Interferon Regulatory Factor-1; C494258:Irf1 protein, mouse; D009479:Neuropeptides; D010750:Phosphoproteins; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D018005:Receptors, Vasoactive Intestinal Peptide; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D012097:Repressor Proteins; D050794:STAT1 Transcription Factor; C491590:Socs1 protein, mouse; C491411:Socs3 protein, mouse; C494080:Stat1 protein, mouse; D000071222:Suppressor of Cytokine Signaling 1 Protein; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D014660:Vasoactive Intestinal Peptide; D007371:Interferon-gamma; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D011505:Protein-Tyrosine Kinases; C507905:Jak1 protein, mouse; C507926:Jak2 protein, mouse; D053613:Janus Kinase 1; D053614:Janus Kinase 2