哮喘疫苗重组BCG与肠道黏膜细胞相互作用的信号传导

In the previous researches, we have prepared the asthma vaccine-house dust mite allergen (Der p2) recombinant BCG, and observed that immunization from oral administration of this vaccine can stimulate allergen-specific Th1-edge response, and we also strengthened its adhesion function through Campylobacter bacteria outer membrane antigen PEB1, which makes the vaccine used for immunotherapy of murine asthma model effectively.However, the mechanism of its interaction with the intestinal mucosal cells and submucosal immune system is unclear. For this reason, the project will use cellular and animal experiments, and directly observe the mutual recognition and interaction between the vaccine and intestinal M cells through electron microscopy. We will determine the molecular changes of cell surface and interior induced by interaction between M cells and vaccine through histochemistry, immunochemistry and molecular biology methods. Then we will intervene the key molecule of the Toll-like receptor signaling pathway through the siRNA technology and TLR2-/- knockout mice, and observe the signal transduction pathway of immunocyte stimulated by vaccine. And finally we will determine the change of inflammatory factors and cytokines through the cells immunological methods. By illuminating the mechanism of the co-recognization and interaction between the vaccine and intestinal mucosal immune system, the project will complement and improve the theory that rBCG as an oral vaccine can regulate immune.

我们前期的工作制备了哮喘疫苗屋尘螨过敏原（Der p2）重组BCG，观察到口服免疫后可激发过敏原特异性的Th1优势应答，利用空肠弯曲菌外膜抗原PEB1对疫苗的黏附功能进行了强化，有效用于小鼠哮喘模型的免疫治疗。但其与肠道黏膜细胞和黏膜下免疫系统相互作用的机制尚不清楚。为此，本项目通过细胞水平和动物试验，拟利用电镜技术直接观察疫苗与肠道M细胞间的相互识别、相互作用；利用组织化学、免疫化学和分子生物学手段，测定M细胞与疫苗相互作用引发的细胞表面和内部的分子改变；利用siRNA技术和TLR2-/-基因敲除小鼠，干预胞浆内Toll样受体信号通路中的关键分子，探察疫苗刺激后免疫细胞内部发生的信号转导途径；利用细胞免疫学方法，测定疫苗刺激后所引发的炎症因子和细胞因子改变。阐明疫苗和肠道黏膜免疫系统相互识别、相互作用的机制，以补充和完善rBCG作为口服疫苗调节免疫的理论。