Source: Annual Congress 2002 - Cellular reactions in allergy in humans and animals
Disease area: Airway diseases

Abstract

Rationale: The signal transduction pathways that lead to chemotaxis of human eosinophils are incompletely understood but are believed to involve protein tyrosine kinase(s) but not protein kinase C. We investigated a possible role for phosphatidylinositol 3-kinase (PI-3K) using the inhibitor wortmannin on human eosinophils stimulated with platelet activating factor (PAF) and eotaxin. Methods: Eosinophils were isolated from the blood of atopic, non-asthmatic individuals and chemotaxis was evaluated in a fluorescence-based 96-well blind chamber assay. Calcein-labelled eosinophils (200,000) were pre-incubated for 30 min at 37[degree]C with medium or wortmannin (0.1-100 nM) and placed in the upper wells of the chemotaxis chamber; migration through 8-μm pore-size PVP-coated polycarbonate filters in response to PAF or eotaxin (both at 30 nM in the lower wells) was measured after 1 h as cell-associated fluorescence (λ_ex=485 nm, λ_em=530 nm) in the lower wells. Results: PAF and eotaxin caused chemotaxis of eosinophils (geometric mean 24,590 [95% c.i. 15,070-40,180] and 39,290 [12,620-122,460] cells/well, respectively, above the background level of migration). Wortmannin caused concentration-dependent inhibition of PAF-induced eosinophil chemotaxis (IC₅₀=1.24 nM [0.092-16.6 nM], n=6), with significant inhibition observed at 1 nM (p<0.0001). Responses to eotaxin were inhibited less potently (IC₅₀=16.1 nM [0.27-964 nM], n=5), with significant inhibition observed only at 100 nM (p<0.05). Conclusions: Both PAF and eotaxin are able to induce chemotaxis of human eosinophils. PAF-induced chemotaxis in human eosinophils is likely to involve PI-3K in the signal transduction cascade, while PI-3K plays a less important role in eotaxin-induced chemotaxis.

Rating:

Share or cite this content

Citations should be made in the following way:
R. K. Mishra, B. C. Gray, R. Djukanovic, G. Dent (Southampton, United Kingdom). Differential inhibition of PAF- and eotaxin-induced human eosinophil chemotaxis by wortmannin. Eur Respir J 2002; 20: Suppl. 38, 311

Member's Comments

No comment yet.

Related content which might interest you: Ionomycin stimulates a synergistic effect of IL-8 and induced sputum on PMN chemotaxis during COPD Source: Annual Congress 2010 - COPD and asthma: models and human studies Year: 2010 Montelukast inhibits both resting and GM-CSF-stimulated eosinophil adhesion to VCAM-1 under flow conditions Source: Eur Respir J 2006; 28: Suppl. 50, 433s Year: 2006 Differential actions of phosphatidyinositol 3-kinase inhibitors on respiratory burst and leukotriene C4 generation in PAF-stimulated human eosinophils Source: Eur Respir J 2003; 22: Suppl. 45, 547s Year: 2003 A CXCR2 antagonist inhibits polyI:C-induced airway neutrophil, but not lymphocyte infiltrate Source: Annual Congress 2011 - Anti-inflammatory strategies in acute lung injury Year: 2011 GB001 potently inhibits PGD2 metabolite-induced DP2-mediated cell signaling and eosinophil activation Source: Virtual Congress 2020 – Asthma science: novel targets and mechanisms Year: 2020 Inhibition of LPS-induced neutrophil recruitment in the lungs correlates with modulation of neutrophil CD11b expression using the selective CXCR2 receptor antagonist SB-656933 Source: Eur Respir J 2004; 24: Suppl. 48, 218s Year: 2004 Inhibition of eosinophil migration by montelukast, a cysteinyl leukotriene receptor antagonist, through down regulation of plasmin activity Source: Eur Respir J 2004; 24: Suppl. 48, 36s Year: 2004 Fluvastatin and lovastatin inhibit human eosinophil, but not neutrophil, adhesion to ICAM-1 under flow conditions Source: Annual Congress 2008 - Novel therapeutic approaches and immunological mechanisms in airway cell pathobiology Year: 2008 Effects of N-acetylcysteine and salbutamol on neutrophil migration and release of interleukin-8 and elastase by neutrophils in vitro Source: Eur Respir J 2004; 24: Suppl. 48, 579s Year: 2004 Inhibition of basophil activation by adenosine and its agonists Source: Eur Respir J 2001; 18: Suppl. 33, 532s Year: 2001 The selective phosphodiesterase 4 inhibitor, cilomilast, inhibits interleukin-8-induced pulmonary neutrophil accumulation in the rabbit Source: Eur Respir J 2001; 18: Suppl. 33, 35s Year: 2001 Roflumilast potently inhibits CXCL1 mediated neutrophil migration in COPD patients Source: Annual Congress 2011 - COPD: clinical studies and animal cell models Year: 2011 Neutrophil activation by FMLP and IL-8: differences in involvement of RhoA Source: Eur Respir J 2001; 18: Suppl. 33, 161s Year: 2001 The selective CXCR2 receptor antagonist SB-656933 inhibits CXCL1-induced neutrophil CD11b expression in human whole blood Source: Eur Respir J 2004; 24: Suppl. 48, 218s Year: 2004 Synergistic inhibition of salmeterol with fluticasone propionate or rolipram on stimulated eosinophil binding of β2-integrin to ICAM-1 and cytosolic gIV-phospholipase A2 activation Source: Eur Respir J 2003; 22: Suppl. 45, 455s Year: 2003 Platelet-induced 5-LOX activity is associated with ROS-dependent ASMC proliferation Source: Annual Congress 2007 - Inflammatory cell biology Year: 2007 The PDE4-inhibitors roflumilast and rolipram modulate fibroblast collagen-gel contraction and chemotaxis mediated by autocrine PGE2 synthesis induced by TGF-β1 Source: Eur Respir J 2005; 26: Suppl. 49, 214s Year: 2005 N-Acetylcysteine inhibits eotaxin and MCP-1 release in human airway smooth muscle cells in vitro through the inhibition of ROS production, resulting in a decrease of p38 MAP kinase activation Source: Eur Respir J 2002; 20: Suppl. 38, 170s Year: 2002 Dexamethasone potently induces human basophil apoptosis Source: Eur Respir J 2002; 20: Suppl. 38, 29s Year: 2002 Carbachol-stimulated primary bronchial epithelial cells induce neutrophil chemokinesis Source: Eur Respir J 2007; 30: Suppl. 51, 218s Year: 2007