胃内灌服卡介苗对哮喘小鼠外周血Th1/Th2平衡的影响

Effects of Oral Intragastric Administration of Bacillus Calmette-Guerin on Th1/Th2 Balance in Mouse Model of Asthma

目的探讨胃内灌服卡介苗(BCG)对哮喘小鼠Th1/Th2平衡的影响。方法32只BABL/c小鼠分为正常对照组、哮喘组、皮内注射卡介苗+哮喘组、胃内灌服卡介苗+哮喘组,以卵蛋白(OVA)致敏激发建立哮喘模型。用ELISA方法测定外周血中IL-4和IFN-γ水平,并采用三色流式细胞法测定外周血Th1/Th2细胞之比。结果哮喘组及外周血中IL-4较正常对照组明显升高,而IFN-γ水平明显降低(P均<0.05);与哮喘组相比,卡介苗皮内注射组与胃内灌服卡介苗组外周血中IL-4水平明显下降,IFN-γ水平明显升高(P均<0.05);而卡介苗干预两组之间无明显差异(P>0.05);哮喘组外周血Th1/Th2比值(0.69±0.39)较正常对照组(1.23±0.29)明显下降(P<0.05);与哮喘组比较,皮内注射卡介苗组(1.84±0.50)与胃内灌服卡介苗组(1.60±0.39)明显升高,差异具有显著性(P均<0.05);而卡介苗干预两组外周血Th1/Th2比值无显著性差异(P>0.05)。同时Tc1/Tc2比值哮喘组(0.64±0.36)较正常对照组(1.16±0.45)明显下降(P<0.05);与哮喘组比较,皮内注射卡介苗组(1.34±0.55)与胃内灌服卡介苗组(1.26±0.48)明显升高,差异具有显著性(P均<0.05);而卡介苗干预两组外周血Tc1/Tc2比值无明显差异(P>0.05)。结论Th1/Th2失平衡是哮喘发病的重要机理,小鼠胃内灌服卡介苗操作简单、方便、副作用小,并且能够获得与皮内注射相同的免疫效力。

Objective To explore effects of intragastric administration of BCG on Th1/Th2 balance in mouse model of asthma. Methods 32 BABL/c mouses were divided into four groups： control group, ovalbumin-sensitized group, intradermal-injection intragastric administration of BCG＋ ovalbumin-sensitized group, oral BCG＋ ovalbumin-sensitized group. Mouses were sensitized and challenged with ovalbumin （OVA）to established an asthmatic model. Then IL-4 and IFN-γ in the peripheral blood were analysed by ELISA, and the peripheral blood Th1/Th2 ratio was detected by using three-color flow cytometry method. Results Compared with the control group,ovalbumin-sensitized group has higher IL-4 level and lower IFN-γ level in the peripheral blood,P〈0.05. Compared with ovalbumin-sensitized group, intradermal injection group and intragastric administration of BCG group have lower IL-4 level and higher IFN-γ level in the peripheral blood,P〈0.05. Blood Th1/Th2 cells ratio in the ovalbumin--sensitized group（0.69±0.39） was lower compared with control group（1.234±0.29）,P（0.05. Compared with ovalbumin-sensitized group, intradermal injection group（1.84 ± 0. 50） and intragastric administration of BCG group（1.60±0.39）, P〈0.05, intragastric administration of BCG group as well as intraderma｜ injection group,P〉0.05. Also the blood Tc1/Tc2 cells ratio in the ovalbumin-sensitized group（0.64±0.36） was lower compared with control grourp （1. 16±0. 45）, P〈0. 05. Compared with ovalbumin-sensitized group,intradermal injection group （1.34 ± 0. 55） and intragastric administration of BCG group（1.26±0.48） ,P〈0.05. Intragastric administration of BCG group as well as intradermal injection group,P〉0.05. Conclusion The immune imbalance of Th1/Th2 is a important role in asthmatic morbidity mechanism,intragastric administration of BCG have manipulation simpler, convenient, little adverse reaction of advantages. Intragastric administration of BCG could correct the imbalance of Th1/Th2 which were smiliar effects with injecton BCG.