尘螨主要变应原DNA疫苗对其提取液诱导小鼠肺部变应性炎症的免疫保护作用

目的　探讨尘螨主要变应原DNA疫苗对尘螨提取液诱导的小鼠肺部变应性炎症的免疫治疗作用。方法　分别构建表达Derp1和Derp 2的真核表达质粒pCMV Derp 1和pDerp 2 IRES Derp1。 30只BALB/c小鼠随机分为正常组 (6只 )、对照组 (12只 )、单质粒组 (6只 )和混合组 (6只 )。后三组分别用空白质粒、pDerp 2 IRES Derp 1或混合的pDerp 2 IRES Derp 1和pCMV Derp 1免疫 ,4周后用尘螨提取液致敏、激发 ,观察肺部炎症、计分、肺泡灌洗液 (BALF)细胞总数和分类计数 ;酶联免疫吸附法 (ELISA)检测BALF中白细胞介素 4 (IL 4 )和γ干扰素 (IFN γ)水平。结果　细胞总数和嗜酸细胞(EOS)计数 :混合组 (6± 4 )× 10 5/ml、0 0 5± 0 0 4 ]和对照组 (2 1± 13)× 10 5/L、1 80± 1 39]比较差异有显著性 (P <0 0 5 ) ;IL 4水平 :混合组 (16 8± 2 33)g/L]与对照组 (5 38± 2 5 6 )g/L]比较差异有显著性 (P<0 0 5 ) ,各组间IFN γ比较差异无显著性 (P >0 0 5 )。结论　尘螨主要变应原的DNA疫苗可有效抑制尘螨提取液诱导的肺部变应性炎症 ,能表达两个主要变应原的DNA疫苗其抑制变应性炎症效果优于只表达一种变应原的疫苗。

The immunotherapeuftc effect of DNA vaccine of mite major allergen on mite extract triggered allergic pulmonary diseases

OBJECTIVE: To assess the effects of DNA vaccine of mite major allergens on murine pulmonary allergic inflammation triggered by mite extract. METHODS: Two eukarycyte expression plasmids of Derp 1 and Derp 2 (pDerp 2-IRES-Derp 1 and pCMV-Derp 1) were constructed. BALB/c mice were divided into four groups: normal group, control group, mono-plasmid group and mixture immunization group. The latter three groups were immunized with blank plasmid, pDerp 2-IRES-Derp 1 and mixture of both pDerp 2-IRES-Derp 1 and pCMV-Derp 1, respectively. The mice were sensitized and challenged with mite extract 4 weeks later. Pathological scores, bronchoalveolar lavage (BAL) total cell count and differentiation were studied. IL-4 and IFN-gamma levels in BAL fluid (BALF) were detected by ELISA. RESULTS: Total cell count and eosinophil count in the mixture immunization group (6 +/- 4) x 10(5)/ml], 0.05 +/- 0.04 were significantly lower than those in the control group (21 +/- 13)10(5)/ml], 1.80 +/- 1.39, (P < 0.05). IL-4 in BALF in the mixture immunization (168 +/- 233) g/L] group was significantly lower than that in the control group (538 +/- 256) g/L], (P < 0.05). IFN-gamma showed no significant changes among different groups (P > 0.05). CONCLUSIONS: DNA vaccine of mite major allergens showed inhibitory effect on pulmonary allergic inflammation induced by mite extract, and this effect was more prominent in the DNA vaccine expressing two allergens than that expressing only one allergen.