Der f1/f2融合基因重组乳酸菌治疗实验性哮喘小鼠及其免疫调节作用研究

Asthma is a commonly and frequently encountered disease in the world, and the allergen-specific immunotherapy is the only etiological treatment method, but now the immune effect of simple allergen therapy is not excellent. Lactic acid bacterial is intestinal symbiotic bacteria which be widely used in food, and it is a good immune adjuvant for its strong immune function. This research will transform the house dust mite main allergen Der f1 and Der f2 fusion gene into lactic acid bacteria to construct recombination engineering bacteria vaccine, after immune treatment asthma mice and vaccination normal and defect mice, we will detect the two group mice's serum specific IgE, IgG2a, IgG4 and IL-4, IL-10, IFN-gamma, the Th17, Treg, and eosinophil cell changes, and airway responsiveness, and lung pathology change. The mouse's splenic T cells and bone marrow DC cells will be Isolated in pretherapy and post vaccination, and co-culture with the recombination strain's pyrolysis products, then detecting the IL-4, IL-10, IFN-gamma of T-cell group, the TLR-9, CD86 of DC-cell group.By in vitro and in vivo experiments, the immunoregulation and its mechanism will be studied of dust mite asthmatic mice by Der f1 recombination lactic acid bacteria, and this will provided new ideas for the prophylaxis and immunotherapy of allergic asthma.

尘螨性哮喘是世界范围内的常见病和多发病，变应原特异性免疫治疗是迄今惟一的病因治疗方法，目前单纯的变应原治疗免疫效果不佳。乳酸菌是肠道共生菌，对人体安全，且免疫调节作用强，是效果良好的生物免疫佐剂。本研究拟将尘螨主要变应原Der f1和Der f2融合基因转化乳酸菌，构建重组工程菌，免疫治疗哮喘小鼠，并预防接种正常和缺陷小鼠，考察接种前后小鼠血清特异性IgE、IgG2a、IgG4和IL-4、IL-10、IFN-γ等水平，Th17、Treg、嗜酸性粒细胞变化，以及气道反应性、肺组织病理改变等。分离治疗前和预防接种后小鼠脾T细胞、骨髓DC细胞，与重组菌株裂解产物共培养，检测T细胞组IL-4、IL-10、IFN-γ等水平，DC细胞组TLR-9、CD86等表达。通过体内、体外实验，研究Der f1重组乳酸菌对尘螨性哮喘小鼠模型的免疫调节作用及机制，将为过敏性哮喘免疫预防及免疫治疗提供新思路。

尘螨性哮喘是世界范围内的常见病和多发病，变应原特异性免疫治疗是迄今惟一的病因治疗方法，目前单纯的变应原治疗免疫效果不佳。乳酸菌是肠道共生菌，对人体安全，且免疫调节作用强，是效果良好的生物免疫佐剂。我们将尘螨主要变应原Der f1和Der f2融合基因，连接到表达质粒pNZ8149，转化食品级乳酸菌，构建重组工程菌，以活的重组乳酸菌鼻腔接种行免疫治疗，观察免疫治疗后哮喘小鼠状态、气道反应性，并在末次免疫治疗24h后，收集血清、肺组织，检测血清IL-4、IL-10、IFN-γ等细胞因子水平，以及肺组织病理改变等，初步认为该重组乳酸菌对哮喘小鼠的症状有所改善。