title: Blunted expression of miR-199a-5p in regulatory T cells of patients with chronic obstructive pulmonary disease compared to unaffected smokers.
abstract: Chronic obstructive pulmonary disease (COPD) is characterized by an abnormal regulatory T cell (T(reg)) response and increases in T helper type 1 (Th1) and Th17 cell responses. It is unclear if dysregulation of microRNAs (miRNA) within T(reg) cells contributes to the abnormal inflammatory response in COPD. In this study, we aimed to compare the miRNA profile of COPD T(reg) cells with that of healthy controls and to explore the function of differentially expressed miRNAs. We first obtained T(reg) and T effector cells (Teff ) from peripheral blood of non-smokers, unaffected current smokers and COPD current smokers. Then, we assessed their miRNA expression by microarray analysis followed by real-time reverse transcription-polymerase chain reaction (RT-PCR) validation of particular miRNAs. Six and 96 miRNAs were expressed differentially in COPD T(reg) cells versus T(reg) cells of healthy non-smokers and healthy smokers, whereas no differences were found in miRNA expression in T(eff) cells. We found that miR-199a-5p was repressed by approximately fourfold in T(reg) cells of COPD patients compared to healthy smokers (P < 0·05). In addition, miR-199a-5p was over-expressed in T(reg) cells compared to Teff cells (P < 0·001) and had significant over-representation of its target genes in the T(reg) transcriptome, being associated with the transforming growth factor (TGF)-β activation pathway (P < 0·01). We also confirmed the function of miR-199a5p in an in-vitro loss-of-function cell model running TaqMan® arrays of the human TGF-β pathway. These findings suggest that the abnormal repression of miR-199a-5p in patients with COPD compared to unaffected smokers may be involved in modulating the adaptive immune balance in favour of a Th1 and Th17 response.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Temple University School of Medicine, Philadelphia, PA, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Chatila
authors.forename: G J
authors.initials: GJ
authors.lastname: Criner
authors.forename: W W
authors.initials: WW
authors.lastname: Hancock
authors.forename: T
authors.initials: T
authors.lastname: Akimova
authors.forename: B
authors.initials: B
authors.lastname: Moldover
authors.forename: J-K
authors.initials: JK
authors.lastname: Chang
authors.forename: W
authors.initials: W
authors.lastname: Cornwell
authors.forename: M
authors.initials: M
authors.lastname: Santerre
authors.forename: T J
authors.initials: TJ
authors.lastname: Rogers
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D002908:Chronic Disease; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D046228:Microarray Analysis; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology*; D015398:Signal Transduction; D012907:Smoking / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D016212:Transforming Growth Factor beta; C531408:mirn199 microRNA, human
keywords: FoxP3; T cells; miR-199a-5p; microRNAs; smoking