title: IL-13-producing BLT1-positive CD8 cells are increased in asthma and are associated with airway obstruction.
abstract: BACKGROUND
  The role of CD8 T lymphocytes in the pathogenesis of asthma is not well understood. We investigated whether a subset of IL-13-producing BLT1-positive CD8 T lymphocytes are present in asthmatic airways and are associated with impaired lung function.
  
  
  METHODS
  Bronchoalveolar lavage (BAL) cells were obtained from asthmatic (n = 39) and healthy control (n = 28) subjects. Cells were stimulated with phorbol ester and ionomycin in the presence of brefeldin A and stained for CD8, BLT1, and intracellular IL-13. The frequency of IL-13-producing BLT1-positive CD8 T lymphocytes was compared between the two groups and related to lung function, serum IgE levels, and reticular basement membrane (RBM) thickness.
  
  
  RESULTS
  A subset of CD8 T lymphocytes expressing BLT1 and producing IL-13 were detected in the airways of all asthmatic subjects. The frequency of this subset among recovered lymphocytes was significantly higher in the airways of asthmatic subjects compared with controls (mean ± SEM: 16.2 ± 1.4 vs 5.3 ± 0.5, respectively, P < 0.001) and correlated positively with serum IgE levels and RBM thickness. More importantly, the frequency of CD8 T lymphocytes co-expressing BLT1 and IL-13 was inversely related to FEV1 and FEF[25-75] percent predicted values (P < 0.001).
  
  
  CONCLUSIONS
  A subset of CD8 T lymphocytes expressing BLT1 and producing IL-13 is present in the airways of asthmatics. The accumulation of these cells is associated with airway obstruction, suggesting that they may play a significant pathogenic role in bronchial asthma.
authors.affiliation: Department of Pediatrics, National Jewish Health, Denver, CO 80014, USA. DakhamaA@NJHealth.org
authors.forename: A
authors.initials: A
authors.lastname: Dakhama
authors.forename: M L
authors.initials: ML
authors.lastname: Collins
authors.forename: H
authors.initials: H
authors.lastname: Ohnishi
authors.forename: E
authors.initials: E
authors.lastname: Goleva
authors.forename: D Y M
authors.initials: DY
authors.lastname: Leung
authors.forename: R
authors.initials: R
authors.lastname: Alam
authors.forename: E R
authors.initials: ER
authors.lastname: Sutherland
authors.forename: R J
authors.initials: RJ
authors.lastname: Martin
authors.forename: E W
authors.initials: EW
authors.lastname: Gelfand
mesh_terms: D000293:Adolescent; D000328:Adult; D000402:Airway Obstruction / Q000276:immunology* / Q000378:metabolism*; D001249:Asthma / Q000276:immunology* / Q000378:metabolism* / Q000503:physiopathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018793:Interleukin-13 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D018102:Receptors, Leukotriene B4 / Q000378:metabolism*; D012129:Respiratory Function Tests; D055815:Young Adult
chemical_list: D018793:Interleukin-13; C513240:LTB4R protein, human; D018102:Receptors, Leukotriene B4