条件免疫反应对小鼠支气管哮喘的作用机制研究

Mechanism of conditioned immune response in curing bronchial asthma in mice

目的探讨条件免疫反应对小鼠支气管哮喘的机制。方法选4—6周龄的雌性BALB／C小鼠，用卵清蛋白（OVA）腹膜下注射致敏，OVA雾化吸入激发，建立支气管哮喘模型，健康对照组用磷酸盐缓冲溶液进行相同操作。将模型小鼠随机分为7组，每组15只：（1）条件免疫反应1组（CIR1）组，以声音为条件刺激，布地奈德加沙丁胺醇雾化吸人为非条件刺激，两者结合7次（7d）后可建立条件免疫反应，此后每日再现条件刺激，每周条件刺激再与非条件刺激结合1次，共20周；（2）CIR：组，以糖精水为条件刺激，其余操作同CIR，组；（3）常规治疗组，给予布地奈德和沙丁胺醇雾化吸入治疗，1次／d，共20周；（4）常规治疗减量组，给予布地奈德和沙丁胺醇雾化吸入，1次／d，共7d，之后1次／周，共20周；（5）单纯声音刺激组，单纯给声音刺激20周；（6）单纯糖精水刺激组，单纯给糖精水刺激20周；（7）空白对照组，PBS雾化吸入20周。以上7组每天给予哮喘激发1次，各治疗组在治疗间隔1h以后给予激发；（8）健康对照组，用PBS激发20周。治疗20周后，分离小鼠脾脏单个核细胞，加入CD4＋磁珠，利用分选器、分离柱分选出CD4＋T淋巴细胞，经PMA、离子霉素和莫能霉素刺激培养6h后，流式细胞技术检测CD4＋T细胞胞膜上烟碱型乙酰胆碱受体胡（nAChRα7）与胞浆内IL-4、IFN-1及IL-17表达量，分析nAChRot7与IL-4、IFN-γ及IL-17的相关性。结果（1）CIR1组（8．7±1．2）、CIR2组（9．1±1．0）、常规治疗组（8．4±1．1）及健康对照组（0．8±0．7）比空白对照组（16．2±1．3）肺泡灌洗液中嗜酸性粒细胞占白细胞的百分数均明显减少（P〈0．01），在CIR，组、CIR2组及常规治疗组之间差异无统计学意义（P〉0．05）。（2）CIR1组、CIR2组、常规治疗组及健康对照组与空白对照组相比较，CD4’T淋巴细胞表达nAChRα7、IL-4及IL-17明显降低（P〈0．01），IFN-γ增高（P〈0．01）；除nAChRα7外其他各因子在CIR，组、CIR：组及常规治疗组之间差异无统计学意义（P〉0．05）。nAChRα7与IL-4表达呈正相关（r=0．76，P〈0．01），与IL-17呈正相关（r=0．46，P〈0．01），与IFN-γ表达呈负相关（r=0．69，P〈0．01）。（3）常规治疗减量组、单纯声音刺激组、单纯糖精水刺激组及空白对照组与健康对照组相比，气道上皮增厚，管腔狭窄，管壁周围有大量炎症细胞浸润，胶原纤维显著增多；CIR1组、CIR2组及常规治疗组经治疗后气道上皮及炎性浸润情况明显改善，胶原纤维减少。结论以声音或糖精水为条件刺激，以布地奈德加沙丁胺醇雾化吸入为非条件刺激建立起的条件免疫反应，可以通过下调CD4＋T淋巴细胞上nAChRα7的表达，调节CD4＋T淋巴细胞的免疫功能。

Objective To understand the mechanism of effect of conditioned immune response in curing bronchial asthma. Methods An experimental asthma modal was produced on healthy BALB/C mice （female, 4-6 weeks old） by sensitization and stimulation with ovalbumin （OV A）. Totally 105 mice were divided into 7 groups randomly with 15 in each and treated differently： in group CIR1 , noise was used as conditioned stimulus （CS） and budesonide and salbutamol as unconditioned stimulus （UCS） respectively, a conditioned immune response model of mice with asthma was established by the combination of CS and UCS 7 times （7 days）, then the mice were given CS only, and the combination were given once a week for 20 weeks. In group CIR2 saccharin （SAC） was taken as CS, and the other treatments were the same as the group CIR1. In the group of conventional therapy, the mice were given inhation of nebulized budesonide and salbutamol only for 20 weeks. In the group of lower dose conventional therapy, the mice were given nebulized inhalation of budesonide and salbutamol for the first 7 days, then once a week for 20 weeks. In the noise group the mice were given noise only everyday for 20 weeks. In SAC group the mice were treated with SAC only everyday for 20 weeks. In the blank control group the mice were treated with placebo for 20 weeks. The mice in all the groups were stimulated with OVA once a day. The mice in the healthy control group were given PBS inhalation for 20 weeks. After 20 weeks therapy, the bronchoalveolar lavage fluid （BALF） was taken for eosinophils （EOS） counting. The spleens were taken to obtain CD4＋ T lymphocytes and the expression of neuronal acetylcholine receptor alpha 7 （nAChRα7） , IL-4, IFN-γand IL-17 were detected by flow cytometry. Results （ 1 ） The percent of EOS of groups CIR1 , CIR2, conventional therapy and healthy control was much lower than that of blank control （P 〈 0. 01 ）, and there was no significant difference among groups CIR1, CIR2 and conventional therapy（P 〉0. 05）. （2） The expression of nAChRα7, IL-4 and IL-17 of groups CIR1 , CIR,, conventional therapy and healthy control was much lower than that in blank control group, IFN-γwas much higher（P 〈 0.01 ）, and no significant difference was found among groups CIR,, CIR2 and conventional therapy（P 〉 0. 05 ）. There was a positive correlation between nAChRα7 and IL-4 （r = 0. 76 ,P 〈 0. 01 ）, nAChRα7 and IL-17 （ r = 0. 46, P 〈 0. 01 ）. There was a negative correlation between nAChRα7 and IFN-γ （r = 0. 69, P 〈 0. 01 ）. （3） In the groups treated with lower dose of conventional therapy, noise, SAC and blank control, the epithelial tissue of airway were much thicker, the lumens were much narrower, and inflammatory cells and collagen fibers were much more than in the healthy control group, and after therapy, the inflammation in groups CIR1 , CIR2 and conventional therapy was significantly improved. Conclusion The conditioned immune response models established by both noise and SAC as CS and budesonide and salbutamol as UCS can downregulate nAChRα7 on CD4＋ T lymphocytes, regulate the function of CD4＋ T lymphocytes, and achieve the same therapeutic efficacy in treatment of asthma.