Abstract
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.
MeSH terms
-
Adjuvants, Immunologic / pharmacology*
-
Animals
-
Cell Line
-
Chickens / immunology*
-
Chickens / metabolism
-
Clathrin / physiology
-
Endocytosis*
-
Endosomes / drug effects
-
Endosomes / metabolism
-
Enzyme Activation
-
Lipopolysaccharides / pharmacology
-
MAP Kinase Kinase 1
-
MAP Kinase Kinase 2
-
Macrophages / drug effects
-
Macrophages / enzymology
-
Macrophages / metabolism*
-
Mitogen-Activated Protein Kinase Kinases / metabolism
-
Mitogen-Activated Protein Kinases / metabolism
-
NF-kappa B / physiology
-
NF-kappa B p50 Subunit
-
Nitric Oxide / biosynthesis*
-
Nitric Oxide Synthase / metabolism
-
Oligodeoxyribonucleotides / pharmacology*
-
Protein Kinase C / metabolism
-
Protein-Tyrosine Kinases / metabolism
-
Signal Transduction*
-
p38 Mitogen-Activated Protein Kinases
Substances
-
Adjuvants, Immunologic
-
CPG-oligonucleotide
-
Clathrin
-
Lipopolysaccharides
-
NF-kappa B
-
NF-kappa B p50 Subunit
-
Oligodeoxyribonucleotides
-
Nitric Oxide
-
Nitric Oxide Synthase
-
Protein-Tyrosine Kinases
-
Protein Kinase C
-
Mitogen-Activated Protein Kinases
-
p38 Mitogen-Activated Protein Kinases
-
MAP Kinase Kinase 1
-
MAP Kinase Kinase 2
-
Mitogen-Activated Protein Kinase Kinases