Immunostimulation by the synthetic lipopeptide P3CSK4: TLR4-independent activation of the ERK1/2 signal transduction pathway in macrophages.

Abstract

Synthetic lipopeptides based on bacterial lipoprotein are efficient activators for monocytes/macrophages inducing the release of interleukin (IL)-1, IL-6, tumour necrosis factor-alpha (TNF-alpha), reactive oxygen/nitrogen intermediates, and the translocation of nuclear factor kappaB (NFkappaB). In this report we investigate the signal transduction pathways involved in leucocyte activation by the synthetic lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R,S)-propyl]-(R)-cysteinyl-seryl-(lysyl)3-lysine (P3CSK4). We show that P3CSK4 activates mitogen-activated protein (MAP)-kinases ERK1/2 and MAP kinase (MAPK)-kinases MEK1/2 in bone-marrow-derived macrophages (BMDM) and in the macrophage cell line RAW 264.7. Additionally, we could detect differences between the P3CSK4 and lipopolysaccharide (LPS)-induced phosphorylation of MAP kinases: Different levels in phosphorylation were found both in kinetics and dose-response using RAW 264.7 cells or BMDM from BALB/c and LPS responder mice (C57BL/10ScSn) or LPS non-responder mice (C57BL/10ScCr). The lipopeptide activated the MAPK-signalling cascade in both LPS responder and non-responder macrophages, whereas LPS induced the MAPK signalling pathway only in macrophages derived from LPS responder mice. An approximately 70% decrease of lipopeptide induced NFkappaB translocation and an about 50% reduction of nitric oxide (NO) release was observed in the presence of anti-CD14. These data correspond to the reduction of phosphorylation of ERK1/2 after stimulation with P3CSK4 in the presence of anti-CD14 antibodies. Inhibition of MEK1/2 by PD98059 completely reduced the lipopeptide-induced phosphorylation of ERK1/2 indicating that MEK1/2 are solely responsible for the phosphorylation of the downstream-located MAP kinases ERK1/2.

• Authors: M R Müller, S D Pfannes, M Ayoub, P Hoffmann, W G Bessler, K Mittenbühler
• Journal: Immunology (Immunology) Vol. 103 Issue 1 Pg. 49-60 (May 2001) ISSN: 0019-2805 [Print] England
• PMID: 11380692 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Drosophila Proteins
• Enzyme Inhibitors
• Flavonoids
• Lipopolysaccharide Receptors
• Lipopolysaccharides
• Lipoproteins
• Membrane Glycoproteins
• NF-kappa B
• Receptors, Cell Surface
• Toll-Like Receptor 4
• Toll-Like Receptors
• N-palmitoyl-S-(2,3-bis(palmitoyloxy)propyl)cysteinyl-seryl-lysyl-lysyl-lysyl-lysine
• Nitric Oxide
• Mitogen-Activated Protein Kinase 1
• Mitogen-Activated Protein Kinase 3
• Mitogen-Activated Protein Kinases
• Mitogen-Activated Protein Kinase Kinases
• 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one

Topics

• Animals
• Bone Marrow (immunology)
• Cell Line
• Drosophila Proteins
• Enzyme Inhibitors (pharmacology)
• Flavonoids (pharmacology)
• Lipopolysaccharide Receptors (immunology)
• Lipopolysaccharides (immunology)
• Lipoproteins (immunology)
• Macrophage Activation (immunology)
• Membrane Glycoproteins (immunology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Mitogen-Activated Protein Kinase 1 (immunology)
• Mitogen-Activated Protein Kinase 3
• Mitogen-Activated Protein Kinase Kinases (metabolism)
• Mitogen-Activated Protein Kinases (immunology, metabolism)
• NF-kappa B (genetics)
• Nitric Oxide (metabolism)
• Phosphorylation
• Receptors, Cell Surface (immunology)
• Signal Transduction (immunology)
• Toll-Like Receptor 4
• Toll-Like Receptors
• Translocation, Genetic