呼吸道菌群失调加重小鼠过敏性呼吸道炎症反应

发布时间：2018-09-13 14:57

【摘要】：【目的】探讨呼吸道菌群失调对小鼠过敏性呼吸道疾病发病的影响。【方法】C57BL/6雌性小鼠给予万古霉素雾化吸入10 d后处死,应用16S rRNA高通量测序技术分析支气管肺泡灌洗液(BALF)菌群组成,探索建立小鼠呼吸道菌群失调模型的方法。建模成功后,应用相同的方法建立小鼠呼吸道菌群失调模型,在此基础上,通过腹腔注射致敏及雾化吸入卵清蛋白(OVA)激发,诱导小鼠过敏性呼吸道炎症反应,计数擦鼻频率,检测BALF中细胞总数及嗜酸性粒细胞百分比,肺组织病理分析炎症反应及杯状细胞增生情况,ELISA法检测血清中IgE水平,BALF中IFN-γ、IL-4、IL-5水平,血清、BALF及肠组织中IL-33水平,从而分析呼吸道菌群失调对过敏性呼吸道炎症反应的影响。【结果】万古霉素雾化吸入使小鼠呼吸道Bradyrhizobium、Sphingopyxis、Cupriavidus、Pelomonas等菌属增加,而Akkermansia及Prevotella_6等菌属显著降低,发生明显的菌群失调。利用此动物模型进一步研究发现,呼吸道菌群失调加重了卵清蛋白诱导的过敏性呼吸道炎症反应,表现为擦鼻频率增加,BALF中细胞渗出增加、嗜酸性粒细胞百分比增高,肺组织炎症及杯状细胞增生加重,血清中IgE水平增加。另外,与卵清蛋白组相比,菌群失调联合卵清蛋白组小鼠BALF中Th1型细胞因子IFN-γ水平降低,Th2型细胞因子IL-4、IL-5水平升高,发生更为严重的Th1/Th2平衡失调;BALF中IL-33水平增加,而血清及肠组织中IL-33水平差异无统计学意义,表明呼吸道菌群失调仅影响局部IL-33的产生。【结论】应用万古霉素雾化吸入成功建立了小鼠呼吸道菌群失调模型。呼吸道菌群失调可能通过增加局部IL-33产生,激活Th2及固有样淋巴细胞(ILC),诱发Th1/Th2平衡失调,从而促进过敏性呼吸道疾病发病。
[Abstract]:[objective] to investigate the effect of respiratory tract flora disorder on allergic respiratory diseases in mice. [methods] female C57BL/6 mice were killed by vancomycin aerosol inhalation for 10 days. The composition of (BALF) flora in bronchoalveolar lavage fluid (BALF) was analyzed by 16s rRNA high-throughput sequencing technique. After the successful establishment of the model, the same method was used to establish the model of respiratory tract dysbacteriosis in mice. On this basis, the allergic respiratory inflammation was induced by intraperitoneal injection of ovalbumin (OVA) and atomized inhalation of ovalbumin, and the frequency of nasal rubbing was counted. The total number of cells and the percentage of eosinophils in BALF were detected. The inflammatory reaction and goblet cell proliferation in lung tissue were analyzed. The levels of IgE in serum and IFN- 纬 -IL-4 / IL-5 in BALF and IL-33 in intestinal tissue were detected by Elisa. The results showed that vancomycin atomized inhalation increased the number of Bradyrhizobium,Sphingopyxis,Cupriavidus,Pelomonas in respiratory tract of mice, while Akkermansia and Prevotella_6 decreased significantly, resulting in obvious dysbacteriosis. Using this animal model, we found that the respiratory tract bacterial imbalance aggravated the allergic respiratory inflammation induced by ovalbumin, which showed that the frequency of nasal rubbing increased the exudation of cells and the percentage of eosinophilic granulocytes in BALF, and the percentage of eosinophilic granulocytes in BALF was increased. Pulmonary inflammation and goblet cell proliferation increased, and serum IgE level increased. In addition, compared with ovalbumin group, the level of Th1 type cytokine IFN- 纬 in BALF of mice with dysbacteriosis combined with ovalbumin group decreased, and the level of IL-4,IL-5 of Th2 type cytokines increased, and the IL-33 level in Th1/Th2 balance disorder increased in BALF. However, there was no significant difference in the levels of IL-33 in serum and intestinal tissue, indicating that the respiratory tract flora disorder only affected the production of local IL-33. [conclusion] the model of respiratory tract bacterial flora disorder was successfully established by vancomycin aerosol inhalation in mice. Respiratory dysbacteriosis may promote the pathogenesis of allergic respiratory diseases by increasing the production of local IL-33, activating Th2 and (ILC), of inherent lymphocytes to induce Th1/Th2 imbalance.
【作者单位】：暨南大学医学院微生物与免疫学系;
【基金】：广东省自然科学基金(2014A030313370) 暨南大学科研培育与创新基金(21615420)
【分类号】：R56

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