特异性免疫治疗对哮喘大鼠转化生长因子-β1和CD4＋CD25＋调节性T细胞的影响

Effect of specific immunotherapy on TGF-β1 and CD4＋CD25＋ regulatory T Cells in asthmatic rats

目的 探讨特异性免疫治疗（specific immunotherapy,SIT）对哮喘大鼠转化生长因子-β1（TGF-β1）和CD4＋CD25＋调节性T细胞（CD4＋CD25＋Tr）的影响.方法 40只健康雄性清洁级Wistar大鼠随机分为哮喘组、正常对照组、SIT对照组和SIT治疗组4组,每组10只.通过卵蛋白（OVA）雾吸减敏的方法对致敏大鼠进行SIT,观察各组支气管肺泡灌洗液（BALF）中细胞分类及计数结果、血清和BALF中TGF-β1水平及外周血CD4＋CD25＋Tr百分率变化.结果 哮喘组血清和BALF中TGF-β1水平分别高于正常对照组（均P＜0.01）和SIT治疗组（P＜0.05或0.01）;正常对照组外周血CD4＋CD25＋Tr百分率显著高于哮喘组（P＜0.01）和SIT治疗组（P＜0.01）,而SIT治疗组CD4＋CD25＋Tr百分率高于哮喘组（P＜0.05）.结论 特异性免疫治疗可下调哮喘大鼠体内TGF-β1水平和纠正调节性T细胞的缺失状态.

Objective To examine the effect of specific immunotherapy on TGF- β1 and CD4^＋CD25^＋ regulatory T cells （CD4^＋CD25^＋Tr） in asthmatic rats. Methods Forty Wistar rats were randomly divided into 4 groups： control group, asthma group, control of specific immunotherapy group （SIT control） and specific immunotherapy group （SIT） with 10 rats in each group. The asthma model was induced by the ovalbumin （OVA） challenge methods and the SIT group received specific immunotherapy by repeated inhaling different doses of OVA. The percentage of cells in bronchoalveolar lavage fluid （BALF）, the serum and BALF concentration of TGF- β 1 and the percentage of CD4^＋CD25^＋Tr in peripheral blood was measured respectively. Results The concentration of TGF- β1 in BALF of asthma group was significantly higher than that of control group （P 〈 0.01） or SIT group （P 〈 0.01）. The concentration of TGF- β 1 in serum of asthma group was higher than that of control group （P〈 0.01） or SIT group （P〈 0.05）. The percentage of CD4＋CD25＋Tr in peripheral blood of control group was significantly higher than that of asthma group （P〈 0.01） or SIT group （P〈 0.01）. The percentage of CD4^＋CD25^＋Tr in peripheral blood of SIT group was higher than that of asthma group （P 〈0.05）. Conclusion CD4^＋CD25^＋Tr and TGF-β1 may be involved in pathogenesis of asthma in rats. Specific im- munotherapy can prevent the airway inflammation and increase CD4＋CD25＋Tr in asthmatic rats.