【摘要】 目的观察肺炎链球菌3型多糖(T3P)对支气管哮喘小鼠气道炎症以及Treg/Th17细胞的影响,探讨T3P对哮喘小鼠的免疫调节作用。方法 BALB/c小鼠随机分成对照组、哮喘组和T3P组,每组8只。哮喘组以卵清蛋白(OVA)致敏、气道激发建立哮喘模型,对照组以PBS代替,T3P组在OVA致敏前皮下注射T3P进行干预。观察小鼠肺组织病理改变,对支气管肺泡灌洗液(BALF)进行细胞计数及分类,ELISA法检测血清OVA特异性IgE(OVA-IgE)以及BALF中白介素4(IL-4)、干扰素γ(IFN-γ)、IL-10、IL-17浓度,实时荧光定量PCR法检测肺组织中转录因子Foxp3和RORγt mRNA表达水平,流式细胞术检测Treg和Th17细胞占CD4~+细胞百分比。结果 T3P组小鼠肺组织炎症反应程度弱于哮喘组,血清OVA-IgE,BALF中细胞总数、嗜酸粒细胞比例以及IL-4、IL-17浓度均低于哮喘组(P<0.05),IFN-γ、IL-10浓度高于哮喘组(P<0.05),小鼠肺组织Foxp3 mRNA表达水平及Treg占CD4~+细胞百分比均高于哮喘组(P<0.05),RORγt mRNA表达水平和Th17细胞占CD4~+细胞百分比均低于哮喘组(P<0.05)。哮喘组和T3P组小鼠肺组织Foxp3-mRNA/RORγt-mRNA比值及Treg/Th17细胞比例与BALF中嗜酸粒细胞数量呈负相关。结论 T3P可以通过抑制过敏原特异性IgE表达调节Th1/Th2、Treg/Th17细胞平衡,抑制气道炎症。更多还原

【Abstract】 Objective To investigate the effects of type-3-polysaccharide(T3P) on airway inflammation and Treg/Th17 cells in bronchial asthmatic mice,so as to explore the immunoregulation mechanism of T3P in asthmatic mice. Methods BALB/c mice were randomly divided into 3 groups,with 8 mice in each group.The control group received PBS treatment,the asthma group were sensitized and challenged with ovalbumin(OVA),and the T3P group received a pretreatment with T3P by subcutaneous injection before sensitization with OVA.The pulmonary histological changes were observed and differential cell counts in bronchoalveolar lavage fluid(BALF) were performed.Serum OVA-IgE and IFN-γ,IL-4,IL-17 and IL-10 levels in the BALF were detected by enzyme-linked immunosorbent assay(ELISA).The levels of Foxp3 and RORyt mRNA expression were measured by real-time fluorescence-based quantitative PCR.The proportions of Treg and Th17 cells in CD4 cells were assessed by flow cytometric analysis.Results The inflammatory degree of pulmonary tissue,serum OVA-IgE, and total cell number,proportion of eosinophils,and IL-4,IL-17 levels in BALF were significantly lower in T3P group than in the asthma group(P<0.05).The BALF levels of IFN-γand IL-10,Foxp3 mRNA expression and proportion of Treg cells among CD4~+ cells were significantly higher in the T3P group than in the asthma group(P<0.05),while RORyt mRNA expression and the proportion of Th17 cells among CD4~+ cells were significantly lower than in the asthma group(P<0.05). The count of BALF eosinophils was negatively correlated with the ratios of Foxp3-mRNA/RORγt-mRNA and Treg/Th17 in asthma and T3P groups(P<0.05).Conclusion T3P may inhibit airway inflammation by inhibiting OVA-IgE and regulating Thl/Th2 and Treg/Th17 cell balance in asthmatic mouse model.更多还原