title: Trans-basement membrane migration of eosinophils induced by LPS-stimulated neutrophils from human peripheral bloodin vitro.
abstract: In the airways of severe asthmatics, an increase of neutrophils and eosinophils is often observed despite high-dose corticosteroid therapy. We previously reported that interleukin-8-stimulated neutrophils induced trans-basement membrane migration (TBM) of eosinophils, suggesting the link between neutrophils and eosinophils. Concentrations of lipopolysaccharide (LPS) in the airway increase in severe asthma. As neutrophils express Toll-like receptor (TLR)4 and can release chemoattractants for eosinophils, we investigated whether LPS-stimulated neutrophils modify eosinophil TBM. Neutrophils and eosinophils were isolated from peripheral blood of healthy volunteers and severe asthmatics. Eosinophil TBM was examined using a modified Boyden's chamber technique. Eosinophils were added to the upper compartment, and neutrophils and LPS were added to the lower compartment. Migrated eosinophils were measured by eosinophil peroxidase assays. LPS-stimulated neutrophils induced eosinophil TBM (about 10-fold increase), although LPS or neutrophils alone did not. A leukotriene B4receptor antagonist, a platelet-activating factor receptor antagonist or an anti-TLR4 antibody decreased eosinophil TBM enhanced by LPS-stimulated neutrophils by almost half. Neutrophils from severe asthmatics induced eosinophil TBM and lower concentrations of LPS augmented neutrophil-induced eosinophil TBM. These results suggest that the combination of neutrophils and LPS leads eosinophils to accumulate in the airways, possibly involved the pathogenesis of severe asthma.
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Fuyumi
authors.initials: F
authors.lastname: Nishihara
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakagome
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Takehito
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Noguchi
authors.affiliation: Community Health Science Center, Saitama Medical University, Saitama, Japan.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Araki
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Uchida
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Soma
authors.affiliation: Dept of Respiratory Medicine and Allergy Center, Saitama Medical University, Saitama, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nagata