胸腺基质淋巴细胞生成素受体剔降的未成熟树突状细胞调节哮喘小鼠Thl/Th2失衡的研究

Immature dendritic cells treated by TSLPR knock-down regulate Thl/Th2 balance in asthmatic mice

目的树突细胞疫苗是治疗哮喘的新途径,文中探讨经鼻滴注基质淋巴细胞生成素(thymic stromal lymphopoetin,TSLP)受体剔降的未成熟树突状细胞(immature dendritic cell,imDC)对哮喘模型小鼠过敏性气道炎症及Th1/Th2免疫失衡的影响,为免疫调节治疗哮喘提供理论和实验基础。方法36只C57BL/6小鼠随机分为胸腺TSLP受体剔降的imDC治疗组(A组)、imDC治疗组(B组)和哮喘组(C组)。以卵蛋白(ovalbumin,OVA)、氢氧化铝免疫建立哮喘模型,A组和B组分别于激发前气道内滴注100μl的细胞悬液,分别含有1×106TSLPR剔降的imDC、imDC,C组气道内滴注100μl的PBS;各组激发后肺泡灌洗分析细胞组份,分离肺淋巴细胞测定细胞因子分泌水平,以流式细胞仪检测CD4+干扰素-γ(interferonγ,IFN-γ)+、CD4+白细胞介素-4(interleukin-4,IL-4)+百分比及IFN-γ+/IL-4+比值,比较各组肺组织学改变。结果TSLP受体剔降的imDC治疗组与其他组比较:①可明显抑制OVA抗原激发后气道内嗜酸性粒细胞的浸润(P<0.01);②明显抑制肺淋巴细胞产生IL-4、IL-5,增加了IFN-γ的产生;③肺淋巴细胞CD4+IFN-γ+百分比及IFN-γ+/IL-4+明显升高(P<0.01),而CD4+IL-4+百分比则明显下降(P<0.01);④明显抑制哮喘鼠气道内及肺泡内的过敏性炎症反应。结论激发前经鼻滴注TSLP受体剔降的imDC对哮喘小鼠过敏性气道炎症有明显的防治作用,其机制可能与抑制树突细胞TSLP-TSLP受体信号通路,调整Thl/Th2失衡有关。

Objective The use of dendritic vaccine is a new approach to the treatment of asthma.This study investigated the effect of immature dendritic cells（imDC） treated by thymic stromal lymphopoetin receptor（TSLPR） knock-down on the antigen-induced airway allergic inflammatory reaction and Th1/Th2 imbalance in mice with asthma,so as to provide a theoretical and experimental foundation for the treatment of asthma by immune modulation.Methods Thirty-six C57BL/6 mice were randomly divided into a TSLPR-knocked-down imDC treatment group（group A）,an imDC treatment group（group B）,and an asthma group（group C）.The asthma model was established in the C57BL/6 mice by immunization with ovalbumin（OVA） and Al（OH）3.The mice in the three groups were given intranasal instillation of 100 μl cell suspension containing 1×106 TSLPR-knocked-down imDC,imDC,and phosphate buffer saline（PBS）,respectively.The cellular composition of the bronchoalveolar lavage fluid was analyzed after challenge in every group.The lung lymphocytes were isolated for detection of cytokine secretion and FCM analysis of intracellular IFNγ and IL-4 positive T cells.Histological changes in the lung were compared among the three groups.Results Compared with groups B and C,administration of TSLPR-knocked-down imDC markedly inhibited eosinophilia in the lung（P〈0.01）,suppressed IL-4 and IL-5 production and enhanced IFNγ production in the pulmonary T cells.The percentage of CD4＋ IFNγ＋ pulmonary T cells and the ratio of IFNγ＋ to IL/4 ＋ lung lymphocytes were significantly increased（P〈0.01）,but the percentage of CD4＋ IL-4＋ pulmonary T cells obviously decreased（P〈0.01）.Allergic inflammatory reaction was remarkably inhibited in the airway and lung tissues of the asthma mice.Conclusion Intranasal instillation of TSLPR-knocked-down imDC can significantly inhibit antigen-induced airway allergic inflammatory reaction,the mechanism of which may involve its regulation of Th1/Th2 imbalance by inhibiting TSLP-TSLPR signal transduction.