Eosinophil Trans-Basement Membrane Migration Induced by Interleukin-8 and Neutrophils

Abstract

Neutrophilic inflammation observed with severe asthma is often associated with interleukin-8 (IL-8). Neutrophils can secrete a variety of mediators that may augment the migration of eosinophils. We have reported a positive correlation between the concentrations of neutrophils and eosinophils in sputum from subjects with severe asthma, suggesting a possible role of neutrophils in regulating eosinophilic inflammation. The aim of this study was to investigate whether neutrophils stimulated with IL-8 modify the trans-basement membrane migration (TBM) of eosinophils. Eosinophils and neutrophils were isolated from peripheral blood drawn from healthy donors or subjects with mild asthma. The TBM of eosinophils in response to IL-8 was evaluated in the presence or absence of neutrophils using the chambers with a Matrigel-coated transwell insert. Neither IL-8 alone nor the presence of neutrophils alone induced the TBM of eosinophils. However, when eosinophils were coincubated with neutrophils and stimulated with IL-8, the TBM of eosinophils was significantly augmented. This augmented TBM of eosinophils was inhibited by a matrix metalloproteinase-9 inhibitor, a leukotriene B4 receptor antagonist, platelet-activating factor antagonists, or an anti-TNF-alpha monoclonal antibodies. These results suggest that neutrophils migrated in response to IL-8 may lead eosinophils to accumulate in the airways of asthma and possibly aggravate this disease.

Trans-Basement Membrane Migration of Eosinophils Induced By LPS-Stimulated Neutrophils from Human Peripheral Blood in Vitro

“…We also confirmed that the amount of IL-8 protein in induced sputum is higher in severe asthmatics than in mild asthmatics [7]. Furthermore, we reported that, even in the absence of chemoattractant for eosinophils, neutrophils stimulated by IL-8 are capable of inducing the trans-basement membrane migration (TBM) of eosinophils [8], suggesting that IL-8-stimulated neutrophils lead eosinophils to accumulate in the airways of asthmatic patients. The mechanism of upregulation of IL-8 in severe asthma remains to be elucidated.…”

“…Neutrophils and eosinophils were prepared as previously described [8]. Both types of cells were isolated from the peripheral blood of the same donors, collected from nonatopic healthy volunteers whose eosinophil content was <5% of their peripheral leukocytes (14 subjects (nine males and five females, ranging in age from 24 to 40 years)) or from severe asthmatics (four patients (one male and three females, ranging in age from 42 to 87 years)), respectively.…”

“…The TBM of neutrophils and eosinophils was examined using a modified Boyden's chamber method as previously described [8]. Eosinophils (1×10 5 cells) were placed into the upper compartment of a Matrigel-coated Transwell (3 μm; Becton Dickinson Labware, Franklin Lakes, NJ, USA).…”

“…Eosinophils (1×10 5 cells) were placed into the upper compartment of a Matrigel-coated Transwell (3 μm; Becton Dickinson Labware, Franklin Lakes, NJ, USA). Neutrophils (2×10 4 cells) and LPS (10 µg·mL −1 ) were placed into the lower compartment of the chamber and incubated for 120 min in 5% CO 2 at 37°C, according to the findings that eosinophil TBM by IL-8-stimulated neutrophils mainly occurred 15-60 min after the initiation of reaction and reached plateau at 90-120 min (data not shown) [8]. The peroxidase activity of migrated eosinophils in the lower compartment of the chamber was evaluated.…”

Association analysis of DTD1 gene variations with aspirin-intolerance in asthmatics

“…Previous studies have demonstrated the association between an IL-8 polymorphism and respiratory syncytial virus (rSV) bronchiolitis, a condition that may progress to bronchial asthma (34,35). In addition, IL-8 has been implicated in neutrophilic inflammation associated with severe asthma (36,37), whereas EMAP II has been known to stimulate the production of tumor necrosis factor-α (TNFα) (38), an AIA-susceptibility gene (39). Given the indirect role of DTD1 in AIA susceptibility by interacting with tyrRS and catalyzing the formation of d-amino acids, we investigated the association of DTD1 genetic variants with the risk of AIA in a korean population.…”