Toll-like receptor agonists stimulate human neutrophil migration via activation of mitogen-activated protein kinases.
Human neutrophil migratory responses to Toll-like receptor (TLR) agonists were studied using videomicroscopy. When challenged with lipopolysaccharide (LPS, TLR4 agonist) or N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-(R)-cysteinyl-seryl-(lysyl)(3)-lysine (P3CSK4, TLR2 agonist), neutrophils displayed enhanced motility, which was found to reflect increased random migration but not directed migration (chemotaxis). Enhanced neutrophil motility was detected within 10 min after stimulation with LPS or P3CSK4, and was sustained for more than 80 min. Stimulation of neutrophils with LPS or P3CSK4 resulted in the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), which preceded neutrophil migration. TLR-mediated neutrophil migration was strongly suppressed by pretreatment of cells with U0126 (MAPK/ERK kinase inhibitor) but not with U0124 (an inactive analogue of U0126) or SB203580 (a p38 MAPK inhibitor), and was almost completely abolished by pretreatment of cells with U0126 and SB203580 in combination. Randomly migrating neutrophils in response to LPS or P3CSK4 displayed directed migration when further challenged with gradient concentrations of N-formyl-methionyl-leucyl-phenylalanine (FMLP) or platelet-activating factor (PAF). These findings indicate that TLR agonists stimulate human neutrophil migration via the activation of ERK and p38 MAPK, and FMLP- or PAF-induced neutrophil chemotaxis is not affected by the pre-exposure of cells to TLR agonists.
Department of Physiology, Osaka City University Graduate School of Medicine, Ashai-machi, Abeno-ku, Osaka, Japan.
Kazuki
K
Aomatsu
Takayuki
T
Kato
Hisakazu
H
Fujita
Fumihiko
F
Hato
Nobuhide
N
Oshitani
Noriko
N
Kamata
Tomohiko
T
Tamura
Tetsuo
T
Arakawa
Seiichi
S
Kitagawa
D002070:Butadienes / Q000276:immunology; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D004789:Enzyme Activation / Q000276:immunology; D004791:Enzyme Inhibitors / Q000276:immunology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000276:immunology; D006801:Humans; D007093:Imidazoles / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008074:Lipoproteins / Q000276:immunology; D020928:Mitogen-Activated Protein Kinases / Q000276:immunology*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000276:immunology; D009504:Neutrophils / Q000276:immunology*; D009570:Nitriles / Q000276:immunology; D010766:Phosphorylation; D010972:Platelet Activating Factor / Q000276:immunology; D011725:Pyridines / Q000276:immunology; D051193:Toll-Like Receptors / Q000819:agonists*; D048051:p38 Mitogen-Activated Protein Kinases / Q000276:immunology
D002070:Butadienes; D004791:Enzyme Inhibitors; D007093:Imidazoles; D008070:Lipopolysaccharides; D008074:Lipoproteins; D009570:Nitriles; D010972:Platelet Activating Factor; D011725:Pyridines; D051193:Toll-Like Receptors; C113580:U 0126; C061108:N-palmitoyl-S-(2,3-bis(palmitoyloxy)propyl)cysteinyl-seryl-lysyl-lysyl-lysyl-lysine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580