The Changes Of Regulatory T Cells In Different Periods Of COPD

Objective To investigate the changes of regulatory T cells in different periods of chronic obstructive pulmonary disease (COPD) and the expression of relevant cytokines on acute exacerbations of COPD.Methods 21 patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and 23 patients with stable COPD and 20 normal controls were enrolled in this study. The patients of stable COPD inhaled Tiotropium Bromide 18ug daily for 3 months. Their peripheral blood samples were collected. Three-color labeled monoclonal antibodies flow cytometry was used to detect the quantity and percentage of CD₄⁺T cell, CD₄⁺CD₂5⁺T cell, CD₄⁺CD₂5⁺Foxp3⁺T cell (CD₄⁺Treg), CD₈⁺CD₂5⁺T cell, CD₈⁺CD₂5⁺Foxp3⁺T cell(CD₈⁺Treg), respectively. The expression of TGF-β, TNF-α, IL-9, IL-10 and IL-17 were detected by ELISA on acute exacerbation of COPD.Results The percentages of CD₄⁺T cell and CD₈⁺T cell in peripheral blood were not significantly different among acute exacerbation of COPD (AECOPD) patients, stable COPD patients and normal controls(F=0.74,P=-0.48). The percentages of CD₄⁺CD₂5⁺T cell among acute exacerbation of COPD (AECOPD), stable COPD patients and normal controls were significantly different(F=33.08,P<0.01) and it increased most in AECOPD patients. The percentages of CD₄⁺Treg in AECOPD and stable COPD patients were significantly decreased compare with normal controls. However, the number of CD₄⁺Treg was increased in AECOPD compared to stable COPD and normal controls, but the number of CD₄⁺Treg in stable COPD was not significantly different compared to normal controls. Compare with stable COPD and normal controls, the percentage of CD₈⁺CD₂5⁺T cell and the number of CD₈⁺Treg in AECOPD were significantly increased, but the percentage of CD₈⁺ Treg was significantly decreased. The total number of Treg and the percentage of Treg/L in AECOPD were significantly increased compare with stable COPD and normal controls. The percentage of CD₈⁺Treg was increased but CD₄⁺CD₂5⁺ T cell was decreased after inhalation of muscarinic cholinergic receptor antagonists (tiotropium bromide) for three months in stable COPD patients. The cytokines TGF-β, TNF-α, IL-9, IL-10 and IL-17 in AECOPD patients were all increased compared to normal controls. The expression of CD₄⁺ Treg was negative correlated with white blood cells and neutrophils but positive with lymphocytes. The expression of CD₈⁺Treg was negative correlated with smoking index. The level of IL-10 was positive correlated with white blood cells and negative correlated with smoking index. The expression of IL-9 was negative correlated with the expression of IL-17 in AECOPD patients, but the expression of IL-10 was positive correlated with expression of IL-17 in normal controls.Conclusions Regulatory T cells and cytokines play important role in pathogenesis of COPD. Pathogenic factors in COPD reduce the response of regulatory T cells so that regulatory T cells cannot prohibit inflammation enough. Moreover, muscarinic receptor has complex affect on regulatory T cells.