Toll-like receptor agonists stimulate human neutrophil migration via activation of mitogen-activated protein kinases

• Published in: Immunology 2008-02, Vol.123 (2), p.171-180
• Main Authors: Aomatsu, Kazuki, Kato, Takayuki, Fujita, Hisakazu, Hato, Fumihiko, Oshitani, Nobuhide, Kamata, Noriko, Tamura, Tomohiko, Arakawa, Tetsuo, Kitagawa, Seiichi
• Format: Article
• Language: English
• Subjects: Butadienes - immunology; Chemotaxis, Leukocyte - immunology; Dose-Response Relationship, Immunologic; Enzyme Activation - immunology; Enzyme Inhibitors - immunology; Extracellular Signal-Regulated MAP Kinases - immunology; extracellular signal‐regulated kinase; Humans; Imidazoles - immunology; lipopolysaccharide; Lipopolysaccharides - immunology; Lipoproteins - immunology; mitogen-activated protein kinase; Mitogen-Activated Protein Kinases - immunology; N-Formylmethionine Leucyl-Phenylalanine - immunology; Neutrophils - immunology; Nitriles - immunology; Original; p38; p38 Mitogen-Activated Protein Kinases - immunology; P3CSK4; Phosphorylation; Platelet Activating Factor - immunology; Pyridines - immunology; P₃CSK; Toll-Like Receptors - agonists
• ISSN: 0019-2805; 1365-2567
• DOI: 10.1111/j.1365-2567.2007.02684.x

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.