title: Cigarette smoke increases TLR4 and TLR9 expression and induces cytokine production from CD8(+) T cells in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Cigarette smoke is a major risk factor for chronic obstructive pulmonary disease (COPD), an inflammatory lung disorder. COPD is characterized by an increase in CD8(+) T cells within the central and peripheral airways. We hypothesized that the CD8(+) T cells in COPD patients have increased Toll-like receptor (TLR) expression compared to control subjects due to the exposure of cigarette smoke in the airways.
  
  
  METHODS
  Endobronchial biopsies and peripheral blood were obtained from COPD patients and control subjects. TLR4 and TLR9 expression was assessed by immunostaining of lung tissue and flow cytometry of the peripheral blood. CD8(+) T cells isolated from peripheral blood were treated with or without cigarette smoke condensate (CSC) as well as TLR4 and TLR9 inhibitors. PCR and western blotting were used to determine TLR4 and TLR9 expression, while cytokine secretion from these cells was detected using electrochemiluminescence technology.
  
  
  RESULTS
  No difference was observed in the overall expression of TLR4 and TLR9 in the lung tissue and peripheral blood of COPD patients compared to control subjects. However, COPD patients had increased TLR4 and TLR9 expression on lung CD8(+) T cells. Exposure of CD8(+) T cells to CSC resulted in an increase of TLR4 and TLR9 protein expression. CSC exposure also caused the activation of CD8(+) T cells, resulting in the production of IL-1β, IL-6, IL-10, IL-12p70, TNFα and IFNγ. Furthermore, inhibition of TLR4 or TLR9 significantly attenuated the production of TNFα and IL-10.
  
  
  CONCLUSIONS
  Our results demonstrate increased expression of TLR4 and TLR9 on lung CD8(+) T cells in COPD. CD8(+) T cells exposed to CSC increased TLR4 and TLR9 levels and increased cytokine production. These results provide a new perspective on the role of CD8(+) T cells in COPD.
authors: Meakins-Christie Laboratories, Faculty of Medicine, McGill University, Montreal, Qc, Canada.
authors: Jessica
authors: J
authors: Nadigel
authors: David
authors: D
authors: Préfontaine
authors: Carolyn J
authors: CJ
authors: Baglole
authors: François
authors: F
authors: Maltais
authors: Jean
authors: J
authors: Bourbeau
authors: David H
authors: DH
authors: Eidelman
authors: Qutayba
authors: Q
authors: Hamid
mesh_terms: D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology* / Q000473:pathology; D013638:Tars / Q000494:pharmacology*; D051197:Toll-Like Receptor 4 / Q000276:immunology*; D051217:Toll-Like Receptor 9 / Q000276:immunology*; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
chemical_list: D016207:Cytokines; C495345:TLR4 protein, human; C495371:TLR9 protein, human; D013638:Tars; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; C024746:tobacco tar