title: Disruption of th17/treg balance in the sputum of patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Amplified inflammation persists in the airways of patients with chronic obstructive pulmonary disease (COPD); however, the underlying mechanism is still unclear. Th17/T regulatory cells (Treg) imbalance may exist in the airways and contribute to this abnormal inflammation.
  
  
  METHODS
  This study involved 21 patients with COPD, 21 healthy smokers (HS), and 21 healthy nonsmokers (HNS). We investigated receptor-related orphan receptor (RORC2) and forkhead box P3 (FOXP3) mRNA expression in induced sputum by real-time polymerase chain reaction and assayed IL-17, IL-10, TGF-β and IL-6 by enzyme-linked immunosorbent assay. Th17 and Treg cells in peripheral blood were analyzed by flow cytometry.
  
  
  RESULTS
  The level of sputum FOXP3 mRNA in both COPD and HNS was lower than that in HS (PCOPD = 0.017; PHNS = 0.009). In contrast, the level of RORC2 mRNA was markedly higher in COPD than in either HS or HNS (PHS = 0.005; PHNS < 0.001). There was a correspondingly elevated ratio of sputum RORC2 to FOXP3 mRNA in COPD. Concentrations of IL-17, TGF-β and IL-6 were elevated in COPD sputum. In peripheral blood, both Th17 and Treg cells were elevated in COPD.
  
  
  CONCLUSIONS
  A compartmental imbalance of Th17 over Treg exists in the airways of patients with COPD, suggesting a defect in anti-inflammatory homeostasis in COPD.
authors.affiliation: Department of Cadre Health Care (HL), Qilu Hospital, Shandong University, Jinan, Shandong; Physical Examination Office (HL), Health Department of Shandong Province, Jinan, China; and Departments of Respiratory Disease (QL, YJ, YIZ, WX), and Obstetrics and Gynecology (YAZ), Qilu Hospital, Shandong University, Jinan, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Li
authors.forename: Qixiao
authors.initials: Q
authors.lastname: Liu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
mesh_terms: D000368:Aged; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D016753:Interleukin-10 / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D057093:Orphan Nuclear Receptors / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D012129:Respiratory Function Tests; D012137:Respiratory System / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D012907:Smoking / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D013183:Sputum / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D058504:Th17 Cells / Q000378:metabolism*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D020381:Interleukin-17; D057093:Orphan Nuclear Receptors; D016753:Interleukin-10