title: Allergen-induced increases in bone marrow T lymphocytes and interleukin-5 expression in subjects with asthma.
abstract: Inhaled allergen challenge of subjects with atopic asthmatic increases bone marrow eosinophil progenitor cells. Interleukin-5 (IL-5) specifically induces growth and maturation of eosinophils. This study examined the effect of allergen challenge on the number of bone marrow total and CD3+ cells expressing IL-5 protein and IL-5 mRNA in subjects with asthma who developed either allergen-induced isolated early responses, or early and late asthmatic responses (dual responders). At 24 hours after allergen challenge, dual responders had significantly greater blood and airway eosinophilia compared with early responders. There were significant increases in the percentage of bone marrow CD3+ cells (p < 0.005) in both groups. However, there were significant differences in the increases in bone marrow IL-5 mRNA+ (p < 0.005), CD3+ (p < 0.005), and IL-5 mRNA+ CD3+ (p < 0.005) cells between the dual and early responder groups. These results suggest that, in subjects with atopic asthma, inhaled allergen causes trafficking of T lymphocytes to the bone marrow, and that in subjects who develop late responses and greater blood and airway eosinophilia after inhalation of allergen, there is a significant increase in the ability of bone marrow cells, particularly T lymphocytes, to produce IL-5.
authors.affiliation: Asthma Research Group, Firestone Institute for Respiratory Health, St. Joseph's Hospital and the Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Lorna J
authors.initials: LJ
authors.lastname: Wood
authors.forename: Roma
authors.initials: R
authors.lastname: Sehmi
authors.forename: Sandra
authors.initials: S
authors.lastname: Dorman
authors.forename: Qutayba
authors.initials: Q
authors.lastname: Hamid
authors.forename: Meri K
authors.initials: MK
authors.lastname: Tulic
authors.forename: Richard M
authors.initials: RM
authors.lastname: Watson
authors.forename: Ronan
authors.initials: R
authors.lastname: Foley
authors.forename: Parveen
authors.initials: P
authors.lastname: Wasi
authors.forename: Judah A
authors.initials: JA
authors.lastname: Denburg
authors.forename: Gail
authors.initials: G
authors.lastname: Gauvreau
authors.forename: Paul M
authors.initials: PM
authors.lastname: O'Byrne
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000175:diagnosis / Q000276:immunology*; D001854:Bone Marrow Cells / Q000276:immunology*; D001985:Bronchial Provocation Tests; D017252:CD3 Complex; D003627:Data Interpretation, Statistical; D004804:Eosinophils; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D015848:Interleukin-5 / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D012882:Skin Tests; D013147:Spirometry; D013183:Sputum / Q000166:cytology; D013234:Stem Cells / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D000485:Allergens; D017252:CD3 Complex; D015848:Interleukin-5; D012333:RNA, Messenger