title: CD4-regulatory cells in COPD patients.
abstract: BACKGROUND
  The numbers of airway CD8 and B lymphocytes are increased in COPD patients, suggesting an autoimmune process. CD4-regulatory T cells control autoimmunity but have not been studied in patients with COPD.
  
  
  OBJECTIVE
  To compare T-regulatory cell numbers in the BAL from COPD patients, smokers with normal lung function, and healthy nonsmokers (HNS).
  
  
  METHODS
  BAL and peripheral blood mononuclear cell (PBMC) samples were obtained from 26 COPD patients, 19 smokers, and 8 HNS. Flow cytometry was performed for regulatory phenotypic markers.
  
  
  RESULTS
  COPD patients had increased BAL CD8 numbers compared to smokers and HNS. CD4 numbers were similar between groups. There was increased BAL CD4CD25(bright) expression in smokers (median 28.8%) and COPD patients (median 23.1%) compared to HNS (median 0%). Increased FoxP3 expression was confirmed in BAL CD4CD25(bright) cells. BAL CD4CD25 cells expressed less CD27 compared to PBMCs, suggesting weaker functional regulatory ability.
  
  
  CONCLUSIONS
  Chronic cigarette smoke exposure up-regulates airway CD4 regulatory cell numbers. Their function may be to control pulmonary inflammation.
authors.affiliation: North West Lung Centre, University of Manchester, South Manchester University Hospitals Trust, Manchester, UK. ljcsmyth@yahoo.co.uk
authors.forename: Lucy J C
authors.initials: LJ
authors.lastname: Smyth
authors.forename: Cerys
authors.initials: C
authors.lastname: Starkey
authors.forename: Jorgen
authors.initials: J
authors.lastname: Vestbo
authors.forename: Dave
authors.initials: D
authors.lastname: Singh
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism; D017252:CD3 Complex / Q000235:genetics / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000235:genetics / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism; D037181:Lectins, C-Type; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D039921:Neuropilins / Q000235:genetics / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology* / Q000473:pathology*; D012907:Smoking / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000235:genetics / Q000378:metabolism; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016827:CD8 Antigens; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D037181:Lectins, C-Type; D017493:Leukocyte Common Antigens; D039921:Neuropilins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D000099192:CD69 Antigens; C418974:FOXP3 protein, human