title: Increased frequency of dual-positive TH2/TH17 cells in bronchoalveolar lavage fluid characterizes a population of patients with severe asthma.
abstract: BACKGROUND
  TH2 cells can further differentiate into dual-positive TH2/TH17 cells. The presence of dual-positive TH2/TH17 cells in the airways and their effect on asthma severity are unknown.
  
  
  OBJECTIVE
  We sought to study dual-positive TH2/TH17 cells in bronchoalveolar lavage (BAL) fluid from asthmatic patients, examine their response to glucocorticoids, and define their relevance for disease severity.
  
  
  METHODS
  Bronchoscopy and lavage were performed in 52 asthmatic patients and 25 disease control subjects. TH2 and TH2/TH17 cells were analyzed by using multicolor flow cytometry and confocal immunofluorescence microscopy. Cytokines were assayed by means of ELISA.
  
  
  RESULTS
  Dual-positive TH2/TH17 cells were present at a higher frequency in BAL fluid from asthmatic patients compared with numbers seen in disease control subjects. High-level IL-4 production was typically accompanied by high-level IL-17 production and coexpression of GATA3 and retinoic acid receptor-related orphan receptor γt. Increased presence of TH2/TH17 cells was associated with increased IL-17 production in lavage fluid. TH2/TH17 cell counts and IL-17 production correlated with PC20 for methacholine, eosinophil counts, and FEV1. TH2/TH17 cells, unlike TH2 cells, were resistant to dexamethasone-induced cell death. They expressed higher levels of mitogen-activated protein-extracellular signal-regulated kinase kinase 1, a molecule that induces glucocorticoid resistance. On the basis of the dominance of BAL fluid TH2 or TH2/TH17 cells, we identified 3 subgroups of asthma: TH2(predominant), TH2/TH17(predominant), and TH2/TH17(low). The TH2/TH17(predominant) subgroup manifested the most severe form of asthma, whereas the TH2/TH17(low) subgroup had the mildest asthma.
  
  
  CONCLUSIONS
  Asthma is associated with a higher frequency of dual-positive TH2/TH17 cells in BAL fluid. The TH2/TH17(predominant) subgroup of asthmatic patients manifested glucocorticoid resistance in vitro. They also had the greatest airway obstruction and hyperreactivity compared with the TH2(predominant) and TH2/TH17(low) subgroups.
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo.
authors.forename: Chaoyu
authors.initials: C
authors.lastname: Irvin
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo.
authors.forename: Iram
authors.initials: I
authors.lastname: Zafar
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo; School of Medicine, University of Colorado at Denver, Denver, Colo.
authors.forename: James
authors.initials: J
authors.lastname: Good
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo; School of Medicine, University of Colorado at Denver, Denver, Colo.
authors.forename: Donald
authors.initials: D
authors.lastname: Rollins
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo.
authors.forename: Christina
authors.initials: C
authors.lastname: Christianson
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo; School of Medicine, University of Colorado at Denver, Denver, Colo.
authors.forename: Magdalena M
authors.initials: MM
authors.lastname: Gorska
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo; School of Medicine, University of Colorado at Denver, Denver, Colo.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Martin
authors.affiliation: Department of Medicine, Division of Allergy & Immunology, and Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, Colo; School of Medicine, University of Colorado at Denver, Denver, Colo. Electronic address: alamr@njhealth.org.
authors.forename: Rafeul
authors.initials: R
authors.lastname: Alam
mesh_terms: D001249:Asthma / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D018893:Bronchoalveolar Lavage; D001999:Bronchoscopy / Q000379:methods; D003907:Dexamethasone / Q000008:administration & dosage; D005260:Female; D005434:Flow Cytometry; D050990:GATA3 Transcription Factor; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D020381:Interleukin-17 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D058504:Th17 Cells / Q000276:immunology* / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology* / Q000473:pathology
chemical_list: D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D005938:Glucocorticoids; C508598:IL4 protein, human; D020381:Interleukin-17; D015847:Interleukin-4; D003907:Dexamethasone
keywords: Dual-positive T(H)2/T(H)17 cells; MEK; asthma; bronchoalveolar lavage; glucocorticoid resistance