CpG-ODN-induced nitric oxide production is mediated through clathrin-dependent endocytosis, endosomal maturation, and activation of PKC, MEK1/2 and p38 MAPK, and NF-kappaB pathways in avian macrophage cells (HD11).
We have characterized the nitric oxide (NO) induction by CpG oligodeoxydinucleotide (CpG-ODN) and lipopolysaccharide (LPS) in an avian macrophage cell line (HD11) and evaluated signal transduction pathways by using selective inhibitors. Our results indicate that while CpG-ODN and LPS both stimulate inducible NO synthase (iNOS) to produce NO through common signalling pathways involving activation of protein kinase C (PKC), mitogen-activated protein kinases (p38 MAPK and MEK1/2) and transcription factor NF-kappaB; CpG-ODN inducing NO production distinctively requires a clathrin-dependent endocytosis and subsequent endosomal maturation. Inhibitors of clathrin-dependent endocytosis such as monodansylcadaverine and hyperosmolar sucrose completely abolished CpG-ODN stimulated NO production by HD11 cells, but have no or less effect on LPS-induced NO production. The endosomal maturation is also critical for stimulation of NO induction by CpG-ODN, but not by LPS. Our findings are the first to demonstrate cellular signalling pathways that mediate CpG-ODN immunostimulatory activity in cells from non-mammalian species.
He
Haiqi
H
USDA-ARS-SPARC, 2881 F&B Road, College Station, TX 77845, USA. he@ffsru.tamu.edu
Kogut
Michael H
MH
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002645:Chickens / Q000276:immunology* / Q000378:metabolism; D002966:Clathrin / Q000502:physiology; D004705:Endocytosis; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D004789:Enzyme Activation; D008070:Lipopolysaccharides / Q000494:pharmacology; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000502:physiology; D052002:NF-kappa B p50 Subunit; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases
D000276:Adjuvants, Immunologic; C408982:CPG-oligonucleotide; D002966:Clathrin; D008070:Lipopolysaccharides; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D009838:Oligodeoxyribonucleotides; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases