摘要
目的探讨CD8^＋CD28-T细胞在哮喘发病机制中的作用及地塞米松对该细胞的影响。方法30只BALB／c小鼠随机分为哮喘组、地塞米松组、正常对照组，各10只。哮喘组和地塞米松组给予卵白蛋白致敏后雾化吸入卵白蛋白溶液，地塞米松组每次雾化吸入前腹腔注射地塞米松1mg／kg，各组分别于末次雾化激发后测定小鼠的气道反应性；对支气管肺泡灌洗液（BALF）行细胞总数、嗜酸性粒细胞（EOS）计数；取肺组织作HE染色病理切片；测BALF中IgE含量；流式细胞仪检测小鼠血、BALF中CD8^＋CD28-T细胞占淋巴细胞百分比；分析BALF中IgE、EOS计数与血液中CD8^＋CD28-T细胞百分比的相关性。结果哮喘组、地塞米松组气道反应性明显高于正常对照组。哮喘组BALF中细胞总数和EOS计数分别为（5．56±4．06）×10^2／L和（3．29±2．23）×10^2／L，均明显高于地塞米松组[（2．59±1．69）×10^2／L，P=0．044和（1．11±0．73）×10^2／L，P=0．008]及正常对照组[（0．91±0．65）×10^2／L，P=0．003和（0．43±0．37）×10^2／L，P=0．001）]；而后两组之间差异均无统计学意义（均P〉0．05）。哮喘组、地塞米松组、正常对照组BALF中IgE含量分别为（23．85±5．97）g/L、（13．15±2．22）g／L、（6．54±1．03）g／L，三组间差异有统计学意义（F=38．558，P=0．000）。哮喘组、地塞米松组、正常对照组CD8^＋CD28-T细胞百分比在外周血中分别为（18．68±4．12）％、（13．43±2．90）％、（8．43±4．60）％；在BALF中分别为（1．25±0．40）％、（0．66±0．49）％、（0．21±0．19）％，组间差异均有统计学意义（F=11．837，P=0．001；F=12．885，P=0．000）。哮喘组BALF中IgE含量和EOS计数与外周血中CD8^＋CD28-T细胞百分比均呈正相关（r=0．864，P=0．012和r=0．804，P=0．029）。结论CD8^＋CD28-T细胞数量与哮喘小鼠气道炎症有明显相关性，地塞米松可有效抑制哮喘气道炎症并可能抑制了CD8^＋CD28-T细胞的表达和功能。
Objective To explore whether or not CD8 ^＋ CD28 - T cell play a pathogenic role in asthma and detect the effects of dexamethasone （ DXM ）. Methods A total of 30 mice were randomly divided into 3 groups： asthmatic group, DXM group and control group （n = 10 each）. The asthmatic and DXM groups were sensitized twice and inhaled ovalbumin. The DXM Group received an intraperitoneal injection of DXM 1mg/kg before inhaling ovalbumin. After successful modeling, 3 mice were selected randomly from each group to measure the airway responsiveness. Also a bronchoalveolar lavage cytological study was performed and lung tissue sections were prepared for histopathologic examination to evaluate the airway inflammation. The content of IgE in bronehoaleolar lavage fluid （BALF） was detected with a murine IgE ELISA kit. And the fractions of CD8^＋ CD28 ^- T cell of peripheral blood and BALF were tested by flow eytometry to analyze the correlation between IgE, eosinophils （EOS） of BALF and CD8 ^＋ CD28^ - T cell of blood. Results The airway hyperresponsiveness in asthmatic and DXM groups were significantly higher than that in the control group. The number of total cells and EOS of BALF in the asthmatic group [（5.56±4.06）×10^2/L; （3.29±2.23）×10^2/L] were significantly higher than that in control group [（0.91±0.65）×10^2/L,P=0.003; （0.43±0.37）×10^2/L,P=0.001）] and DXM group [ （2.59±1.69）×10^2/L,P=0.044; （1.11±0.73）×10^2/L,P=0.008] ; while the DXM group was insignificantly higher than the control group （ P = 0. 234, P = 0. 363 ）. There were significant differences in the contents of lgE of BALF for the asthmatic, DXM and control groups [ （23.85±5.97）g/L、（13.15±2.22）g/L、（6.54±1.03）g/L, F =38.558, P =0.000]. The percentages of CD8^ ＋ CD28^-T cell in peripheral blood in asthmatic and DXM groups [ （ 18. 68 ± 4. 12 ） % and （ 13.43 ±2. 91 ） %] were significantly higher than those in control mice [ （8. 43 ± 4. 60） %, both P 〈 0. 05 ]. The percentages of CD8 ^＋ CD28^ - T cell of BALF in asthmatic group and DXM group [ （ 1.25±0.40）% and （0. 66 ±0.49）% ] were also significantly higher than those in control mice [ （0. 21±0. 19）%, both P 〈 0.05]. The percentages of CD8^ ＋ CD28^-T cell of blood and BALF in the DXM mice were significantly lower than those in asthmatic group. The correlations betweenlgE （r =0.864, P =0.012）, EOS （r =0.804, P =0.029） and CD8^ ＋ CD28^- T cell were significant. Coneluslon The fraction of CD8 ＋ CD28 - T cell is closely correlated with the inflammation of asthmatic airway. The airway hyperresponsiveness and inflammation in asthmatic mice may be relieved by DXM through its effect of inhibiting the expression of CD8 ^＋ CD28^ - T cell.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2011年第26期1861-1865,共5页
National Medical Journal of China
基金
广东省自然科学基金（8151051501000060）
