阻断Dll4-Notch信号通路对哮喘小鼠Th17细胞分化的影响

摘要

目的:探讨哮喘小鼠体内Delta样配体4(Delta-like ligand 4, Dll4)-Notch信号通路阻断对辅助性T细胞17(Th17细胞)分化的影响.方法:30只雄性BALB/c小鼠随机分为正常对照组、生理盐水对照组、哮喘模型组、Dll4单克隆抗体干预组和IgG对照组.肺组织切片进行免疫组织化学染色,定性分析Dll4的表达.流式细胞术分析各组小鼠脾脏Th17细胞在CD4+ T淋巴细胞中的比例.采用Western blot法检测小鼠脾脏分离淋巴细胞中维甲酸相关孤儿受体γt(retinoid-related orphan receptor γt,RORγt)的蛋白表达.应用酶联免疫吸附实验(enzyme-linked immunosorbent assay,ELISA)检测各组小鼠血清中白细胞介素17(interleukin 17,IL-17)的含量.结果:与哮喘模型组比较,Dll4单克隆抗体干预组Dll4表达存在明显差异.与哮喘模型组比较,Dll4单克隆抗体干预组脾脏分离CD4+T淋巴细胞中Th17细胞的比例和RORγt表达水平均存在统计学显著性(P<0.05).Dll4单克隆抗体干预组小鼠血清IL-17的表达与哮喘模型组之间的差异也存在统计学显著性(P<0.01).结论:阻断Dll4-Notch信号通路对哮喘小鼠Th17细胞分化起到抑制作用.%AIM:To explore the effect of Delta-like ligand 4 (Dll4)-Notch signaling pathway blockade on the development of Thelper 17(Th17) cells in the asthmatic mice.METHODS:Male BALB/c mice were randomly divided into 5 groups:control group, asthma group, normal saline group, anti-Dll4 antibody group, and immunoglobulin G group.The protein expression of Dll4 was detected by immunohistochemical staining.The proportion of Th17 cells in mouse spleen isolated CD4+ T cells was measured by flow cytometry.The protein expression of Th17 transcription factor retinoid-related orphan receptor γt (RORγt) was determined by Western blot.The serum level of interleukin (IL)-17 was measured by enzyme-linked immunosorbent assay (ELISA).RESULTS:The expression of Dll4 in the lung tissues from asthma group significantly increased as compared with anti-Dll4 antibody group.The proportion of Th17 cells in CD4+ T cells was significantly down-regulated, and the protein expression of RORγt in the lung tissues was significantly reduced in anti-Dll4 antibody group compared with asthma group (P<0.05).Moreover, the serum level of IL-17 in anti-Dll4 antibody group was significantly reduced compared with asthma group (P<0.01).CONCLUSION:The blockade of Dll4-Notch signaling pathway inhibits the differentiation of Th17 cells in asthmatic mice.