Clinical and experimental immunology
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Clin. Exp. Immunol. · Jul 2014
Blunted expression of miR-199a-5p in regulatory T cells of patients with chronic obstructive pulmonary disease compared to unaffected smokers.
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. ⋯ 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.