尘螨Ⅱ类改组变应原对哮喘小鼠免疫治疗的效果

目的 探讨以改组尘螨Ⅱ类变应原基因Der f2和Der p2后表达的蛋白为变应原，对小鼠哮喘模型的特异性免疫治疗效果。方法 随机将160只清洁级BALB/c小鼠分为PBS组（阴性对照组），Der f2和Der p2免疫治疗组（阳性对照组），哮喘组，改组变应原免疫治疗M01、M03、M08、M10蛋白治疗组。用尘螨提取液于0、7、14d腹腔注射致敏激发BALB/c小鼠，第21天雾化吸入激发，连续7d，其中各免疫治疗组于第25～27天雾化前30min分别用Der f2、Der p2和改组变应原进行特异性免疫治疗，PBS组则用PBS进行腹腔注射和雾化吸入。最后1次雾化24h后，引颈处死。分别观察肺组织病理变化、支气管肺泡灌洗液（BLAF）白细胞计数，酶联免疫吸附试验（ELISA）测定BLAF和脾细胞培养上清液细胞因子IL-4、IL-17和IFN γ的含量及血清中特异性IgG1、IgE抗体水平变化。结果 与哮喘组比较，改组变应原免疫治疗组和阳性治疗组肺部炎症显著减轻， BALF中的总细胞数及嗜酸性粒细胞数，血清中抗原特异性IgG1、IgE抗体均显著降低；免疫治疗组（包括阳性对照）的BALF和脾细胞培养上清液中的细胞因子IL-4、IL-17均明显降低，IFN-γ含量显著升高。结论 通过基因改组获得的尘螨Ⅱ类变应原改组疫苗免疫治疗小鼠哮喘，可有效降低尘螨引起的小鼠肺部炎症。

Effect of immunotherapy on asthma mice with chimeric allergens derived from the major allergen group 2 genes of dust mites

Objective To explore the effect of specific immunotherapy with chimeric allergens in murine asthma models, which were derived from the major allergen group 2 genes, Der f 2 and Der p 2, from dust mites. Methods One hundred and sixty BALB∕c mice were randomly divided into 8 groups, namely PBS group(negative control group), Der f 2 and Der p 2 immunotherapy group (positive control group), asthma group and chimeric allergen immunotherapy groups (divided into four groups: M01, M03, M08 and M10). BALB/c mice were treated with dust mite extract on 0, 7 and 14 day by intraperitoneal injection of allergens and inhaled aerosol on day 21 for 7 days; Before inhalation in immunotherapy groups (including positive controls) in the 25d- 27 d, specific allergen immunotherapy were performed using Der f 2, Der p 2 and chimeric allergens. PBS group were treated with PBS all the time. Twenty-four hours after the last challenge, mice in every group were sacrificed. The lungs were made into slices stained by hematoxylin and eosin in order to observe the pathologic changes in lungs. The bronchoalveolar lavage fluid (BALF) was collected to determine the number of the total cells, neutrophils, lymphocytes and eosinophils by Liu’s staining. ELISA was used to assay the level of cytokines (IL-4, IL-17and IFN-γ) in BALF and in the supernatant of splenocyte culture (SSCC) and the level of allergen-specific IgE, IgG1 in sera. Results Compared with those in the asthma group, the lung allergic inflammation changes in positive and experimental groups were significantly alleviated. The number of total cells and eosinophils in the above groups greatly decreased, while the level of allergen-specific IgE and IgG1 in sera was significantly lower in the immunotherapy groups (including positive groups) than that in the asthma group. The level of IL-4, IL-17 released from BALF and SSCC in the immunotherapy groups significantly decreased compared with that in the asthma group, and the level of IFN-γ in the immunotherapy groups was significantly higher than that in the asthma group. Conclusion The chimeric allergens obtained from major allergen group 2 of dust mites can effectively reduce the dust mite-induced lung inflammation in murine asthma models.