tailieunhanh - Báo cáo y học: " Expansion of CD4+CD25+ helper T cells without regulatory function in smoking and COPD"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: " Expansion of CD4+CD25+ helper T cells without regulatory function in smoking and COPD. | Roos-Engstrand et al. Respiratory Research 2011 12 74 http content 12 1 74 RESPIRATORY RESEARCH RESEARCH Open Access Expansion of CD4 CD25 helper T cells without regulatory function in smoking and COPD Ester Roos-Engstrand1 Jamshid Pourazar1 Annelie F Behndig1 Anders Bucht1 2 and Anders Blomberg1 Abstract Background Regulatory T cells have been implicated in the pathogenesis of COPD by the increased expression of CD25 on helper T cells along with enhanced intracellular expression ofFoxP3 and low absent CD127 expression on the cell surface. Method Regulatory T cells were investigated in BALF from nine COPD subjects and compared to fourteen smokers with normal lung function and nine never-smokers. Results In smokers with normal lung function the expression of CD25 CD4 was increased whereas the proportions of FoxP3 and CD127 were unchanged compared to never-smokers. Among CD4 cells expressing high levels of CD25 the proportion of FoxP3 cells was decreased and the percentage of CD127 was increased in smokers with normal lung function. CD4 CD25 cells with low absent CD127 expression were increased in smokers with normal lung function but not in COPD when compared to never smokers. Conclusion The reduction of FoxP3 expression in BALF from smokers with normal lung function indicates that the increase in CD25 expression is not associated with the expansion of regulatory T cells. Instead the high CD127 and low FoxP3 expressions implicate a predominantly non-regulatory CD25 helper T-cell population in smokers and stable COPD. Therefore we suggest a smoking-induced expansion of predominantly activated airway helper T cells that seem to persist after COPD development. Keywords Bronchoalveolar lavage BAL CD25bright CD127 FoxP3 lymphocyte subsets Introduction Chronic obstructive pulmonary disease COPD is characterized by progressive airway obstruction and airway inflammation. Tobacco smoking is the main risk factor for COPD. Smoking causes an .