Bla g 7多肽疫苗免疫治疗小鼠过敏性气道炎症的研究

Study on the therapeutical effect of chitosan nano-particles used as a Bla g 7 polypeptide antigen in the sensitized mice

目的观察以壳聚糖(CS)材料为佐剂制备的德国小蠊变应原Bla g 7多肽纳米疫苗对小鼠过敏性气道炎症的疗效,探讨其免疫机制。方法用CS包裹Bla g 7多肽制成纳米疫苗;25只BALB/c小鼠用蟑螂粗提液致敏、激发,随机分为阴性对照组(A组)、模型组(B组)、Bla g 7多肽治疗组(C组)、Bla g 7多肽+CS治疗组(D组)、CS对照(E组)。通过HE染色观察小鼠肺部炎症;观察支气管肺泡灌洗液(BALF)中细胞总数和细胞分类;气道高反应仪监测治疗前后小鼠气道高反应性的变化。结果成功制备Bla g 7多肽纳米疫苗;D组与A组相比肺部病理改变不明显,BALF中的细胞总数、EOS计数均显著低于模型组(P<0.01),而C组和E组对致敏小鼠无明显疗效。气道高反应数值治疗前后变化差别有统计学意义(P<0.05)。结论Bla g 7多肽壳聚糖纳米疫苗对致敏小鼠具有免疫治疗作用,是一种新型的治疗蟑螂过敏性气道炎症的缓释制剂,为脱敏疫苗的研究提供了理论基础。

To investigate the therapeutical effect of the chitosan （CS） nana-paritclessingle administration of Bla g 7 poly peptide - CS nanoparticles used as a BLa g7 polypeptide antigen in the sensitized mice and to explore its immune mechanism, the polypeptide Bla g 7 was enclosed into CS to develop the Bla g 7 polypeptide entrapped CS nano-particles. In the present experiment, 25 BALB/c mice were divided randomly into the Bla g 7 polypeptide treated group（group A , n= 5） , Bla g 7 polypep tide plus CS treated group（group B , n= 5） , CS=control group （group C , n= 5）,model group （group D , n= 5） and negative control group （group E, n= 5）, After sensitization by intraperitoneal route and challenged by intranasal instillation with crude extracts of German cockroach , the inflammatory changes in the mouse lung tissues were observed after the lung tissues were fixed and stained with haematoxylin and eosin（H＆E）. The total cell number and the cellular composition of bronchoalveolar lavage fluid （BALF） were detected; and the changes of the mouse airway hyper-reactivity were determined by the whole body plethysmograohy pre-and post-treatments. In these ways, the Bla g7 peptide CS nano-particel vaccine was successfully developed. It was found that the pathological changes in mouse lungs in group D were not so prominent in comparison with those of group A of mice sensitized with crude extract of German cockroach, in which the development of eosinophil infiltration in the airway of mice in D group could be demonstrated. The lung inflammatory reactions and the mucus secretion in lungs of D group were significantly alleviated than those of the B group, but there was no therapeutical effect for the mice fed with the isodoses of Bla g 7 polypeptide or CS. It was also shown that the airway hyper-reactivity of mice was depressed after treatment （P〈 0.05）. It is evident that CS nano-particles show definite therapeutical effect and may serve as a powerful vehicle to improve the tolerance effect of the Bla g 7 polypeptide CS nanoparticle vaccine, and a single administration of Bla g 7 polypeptide-CS nanop article vaccine may hold promise as a new strategy to desensitize the Bla g 7 sensitized disease.