title: Down modulation of L-Selectin expression on eosinophils recovered from bronchoalveolar lavage fluid after allergen provocation.
abstract: In allergic asthma eosinophils infiltrate into the lung after allergen challenge. The mechanism of this cellular infiltration is not fully understood. L-Selectin is involved in leucocyte-endothelial cell recognition and participates in homing of leucocytes into sites of inflammation. To find indications for a role of L-Selectin in the migration of eosinophils to the bronchoalveolar space we measured L-Selectin expression on eosinophils in peripheral blood and bronchoalveolar lavage fluid (BAL) 4 hr after the early allergic reaction after allergen challenge. Nine patients with allergic asthma participated in the study. An eosinophil specific high depolarization signal enabled us to measure L-Selectin expression on eosinophils in a FACS analysis without isolation of these cells. Eosinophils recovered from BAL showed a strong decrease of L-Selectin expression compared to blood eosinophils. This decrease in L-Selectin expression can be induced in vitro by activation of eosinophils with PMA or FMLP whereas priming of eosinophils during several hours with GM-CSF did not influence L-Selectin expression. Our results are a first indication that L-Selectin may play a role during homing of eosinophils in the lung in asthma after allergen challenge. Moreover, the low expression of L-Selectin on eosinophils in the lung is a further indication that these cells exhibit an activated phenotype.
authors.affiliation: Department of Pulmonary Diseases, University Hospital, Utrecht, The Netherlands.
authors.forename: H J
authors.initials: HJ
authors.lastname: Mengelers
authors.forename: T
authors.initials: T
authors.lastname: Maikoe
authors.forename: B
authors.initials: B
authors.lastname: Hooibrink
authors.forename: T W
authors.initials: TW
authors.lastname: Kuypers
authors.forename: J
authors.initials: J
authors.lastname: Kreukniet
authors.forename: J W
authors.initials: JW
authors.lastname: Lammers
authors.forename: L
authors.initials: L
authors.lastname: Koenderman
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000502:physiology; D002469:Cell Separation; D002478:Cells, Cultured; D015536:Down-Regulation; D004804:Eosinophils / Q000737:chemistry / Q000502:physiology*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D019041:L-Selectin; D008297:Male
chemical_list: D015815:Cell Adhesion Molecules; D019041:L-Selectin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor