title: House dust mite allergen activates human eosinophils via formyl peptide receptor and formyl peptide receptor-like 1.
abstract: The objective was to evaluate which receptors house dust mite (HDM) and birch pollen extracts engage to activate human eosinophils. Chemotaxis and degranulation were studied in eosinophils pretreated with pertussis toxin and other antagonists of G protein-coupled receptors, e.g. the formyl peptide receptor (FPR), CC chemokine receptor 3 (CCR3) and leukotriene receptor B4 (LTB(4)R). Inhibition of the FPR as well as desensitization of the receptor rendered eosinophils anergic to activation by the allergens. Blockade of CCR3 or LTB(4)R did not affect eosinophilic reactivity. It was determined by PCR that human eosinophils express the FPR family members FPR and FPR-like 1 (FPRL1). HDM, unlike birch pollen, evoked calcium fluxes in HL-60 cells transfected with FPR or FPRL1. Although both allergens gave rise to calcium transients in neutrophils, which also express FPR and FPRL1, only the HDM response was decreased by the FPR antagonist. Moreover, neutrophils migrated toward HDM but not to birch pollen. Eosinophils pretreated with inhibitors of MAPK p38, ERK1/2 or protein kinase C exhibited diminished responsiveness to the aeroallergens. This study indicates that FPR and FPRL1 mediate the activation of eosinophils by HDM, whereas birch pollen employs other pathways shared with FPR to activate human eosinophils.
authors.affiliation: Department of Clinical Bacteriology, Göteborg University, Göteborg, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Svensson
authors.forename: Elin
authors.initials: E
authors.lastname: Redvall
authors.forename: Camilla
authors.initials: C
authors.lastname: Björn
authors.forename: Jennie
authors.initials: J
authors.lastname: Karlsson
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Bergin
authors.forename: Marie-Josèphe
authors.initials: MJ
authors.lastname: Rabiet
authors.forename: Claes
authors.initials: C
authors.lastname: Dahlgren
authors.forename: Christine
authors.initials: C
authors.lastname: Wennerås
mesh_terms: D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D029662:Betula / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D011058:Pollen / Q000276:immunology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D054397:Receptors, CCR3; D019707:Receptors, Chemokine / Q000276:immunology / Q000378:metabolism; D044042:Receptors, Formyl Peptide / Q000276:immunology* / Q000378:metabolism; D018102:Receptors, Leukotriene B4 / Q000276:immunology / Q000378:metabolism; D044067:Receptors, Lipoxin / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D014162:Transfection
chemical_list: D039741:Antigens, Dermatophagoides; C515350:CCR3 protein, human; C105101:FPR2 protein, human; C513240:LTB4R protein, human; D012333:RNA, Messenger; D054397:Receptors, CCR3; D019707:Receptors, Chemokine; D044042:Receptors, Formyl Peptide; D018102:Receptors, Leukotriene B4; D044067:Receptors, Lipoxin; D002118:Calcium