黄芪甲苷Ⅳ对卵清蛋白诱导的哮喘小鼠CD_4^+T细胞亚型Th1、Th2免疫活性的抑制作用

Inhibitory effect of astragaloside Ⅳ on the immunocompetent of spleen-derived CD_4^+T cell subtype Th1, Th2 in the ovalbumin-induced asthma mice

目的:探讨黄芪甲苷Ⅳ(ASTⅣ)对卵清蛋白(OVA)诱导的哮喘模型小鼠Th1/Th2平衡的免疫调节作用。方法:Balb/c小鼠随机分为4组:对照组、OVA组、ASTⅣ组、地塞米松(Dex)组,每组10只。ASTⅣ组小鼠灌胃ASTⅣ溶液,Dex组小鼠灌胃Dex溶液,对照组和OVA组灌胃等体积无菌0.9%氯化钠溶液。酶联免疫法检测上清液中各细胞因子水平,采用流式细胞仪检测脾细胞悬液中Th1(T-bet)和Th2(GATA-3)细胞比例情况,采用q RT-PCR分析转录因子mRNA的表达水平。结果:与OVA组比较,Dex组和ASTⅣ组小鼠Th2细胞因子(IL-4、IL-13、TNF-α)、GATA-3 mRNA明显降低(P<0.05),Th1细胞因子(IFN-γ)、T-bet mRNA表达明显升高(P<0.05)。OVA组小鼠CD_4^+GATA-3+细胞明显高于对照组(P<0.05)。而Dex组和ASTⅣ组小鼠CD_4^+GATA-3+细胞明显降低(P<0.05),CD_4^+T-bet+细胞占比明显升高(P<0.05)。结论:ASTⅣ可以纠正OVA诱导的哮喘模型小鼠中Th1/Th2的不平衡,表明该药物可能抑制哮喘的发展和严重程度。

Objective： To determine whether astragaloside Ⅳ（AST Ⅳ） has immuno-regulatory effects on the Th1/Th2 balance in ovalbumin（OVA）-induced asthma model mice. Methods： Balb/c rats were randomly divided into the control group, OVA group, AST IV group and dexamethasone（Dex） group. The ASTⅣgroup was administered with ASTⅣsolution daily by intragastrical gavage, the Dex group was given Dex solution, and the control group and OVA group were given 0.9% sterile sodium chloride solution of equal volume. The ratio of Th1（T-bet） and Th2（GATA-3） cells in spleen suspension was detected by flow cytometer, and the expression level of transcription factor mRNA was analyzed by q RT-PCR. Results： Compared with OVA group, IL-4, IL-13, TNF-α and the mRNA expression of GATA-3 in Dex group and ASTⅣ group were significantly decreased（P〈0.05）, but INF-γ and the mRNA expression of T-bet was significantly increased（P〈0.05）. Compared with the control group, the percentage of CD4^＋ GATA-3＋ cells in the OVA group was significantly increased（P〈0.05）, but that in the Dex group and ASTⅣ group was significantly decreased（P〈0.05）, and the proportion of CD4^＋T-bet＋ cells was increased in the Dex group and ASTⅣ group（P〈0.05）. Conclusion： ASTⅣ could correct the imbalance of Th1/Th2 in OVA-induced asthma model mice, which indicates that this medicine may inhibit the development and severity of asthma.