白介素12基因治疗对变应性鼻炎小鼠嗜酸粒细胞及白介素5的影响

目的 探讨经鼻局部给予脂质体包裹的白细胞介素(interleukin,IL)12基因治疗对变应性鼻炎(allergic rhinitis,AR)小鼠模型鼻黏膜、外周血和骨髓中嗜酸粒细胞(eosinophils,EOS)的调节作用及相关因子IL-5的影响.方法 采用6～8周雄性BALB/C小鼠,随机分成AR组、基因治疗组和健康对照组,每组12只.卵清蛋白(ovalbumin,OVA)致敏激发建立AR模型,治疗组激发前经鼻给予脂质体包裹的pGEG.m IL-12,对照组用生理盐水代替.三组分别用HE染色计数鼻黏膜中EOS的数量,用瑞氏染色计数骨髓涂片中EOS数,以流式细胞仪检测外周血中的EOS数;免疫组化染色检测鼻黏膜和骨髓中IL-5的表达,以ELISA方法检测血清中的IL-5含量.采用单因素方差分析进行统计学处理.结果 三组小鼠中,各检测指标在各组之间的差异均有统计学意义(P值均<0.01).两两比较发现,基因治疗组鼻黏膜EOS数为(4.6±2.6)个/高倍镜视野,低于AR组的(26.5±9.8)个/高倍镜视野,差异有统计学意义(P<0.05);IL-5阳性细胞数[(3.0±1.3)个/高倍镜视野]也低于AR组[(17.6±6.4)个/高倍镜视野],差异有统计学意义(P<0.05);骨髓涂片中EOS(0.040±0.029)低于AR组(0.086±0.014),差异有统计学意义(P<0.05),IL-5阳性细胞数(0.035±0.012)也低于AR组(0.083±0.025),差异有统计学意义(P<0.05).基因治疗组外周血中EOS(0.124±0.031)低于AR组(0.184±0.079),差异有统计学意义(P<0.05),IL-5[(29.51±6.68)pg/ml]也低于AR组[(56.58±16.80)pg/ml],差异有统计学意义(P<0.05).结论 经鼻局部给予脂质体包裹的pGEG.m IL-12能够通过降低骨髓、外周血和鼻黏膜中IL-5的表达,进而减少骨髓、外周血和鼻黏膜中EOS的数量,IL-12基因治疗可能为呼吸道变应性炎症开辟一种新的治疗途径.

Effect of intranasal IL-12 gene therapy on the mice eosinophils and IL-5 in the murine model of allergic rhinitis

Objective To evaluate the effect of intranasal liposome-mediated IL-12 gene therapy on the eosinophils and IL-5 in the murine model of allergic rhinitis. Methods Thirty-six BALB/C mice were randomly divided into allergic rhinitis (AR) group, gene therapy group and control group. Allergic rhinitis group were sensitized and stimulated by ovalbumin(OVA), and gene therapy group were administered with hposome-mediated pGEG. m IL-12 transnasally before stimulated. The eosinophiis in bone marrow were counted by Wright's staining, and the eosinophils in nasal mucosa were counted by HE staining. The eosinophils of peripheral blood were detected by flow cytometry. The expression of IL-5 in bone marrow and nasal mucosa was examined by immunohistochemistry. The IL-5 in serum was detected by ELISA. Results Among the three groups, the difference of all data was statistically significant (P<0.01). Multiple Comparison showed that the ratio of eosinophils to white cells and the mount of IL-5 positive cells in nasal mucosa and bone marrow of gene therapy group was significantly lower than that of AR group (P<0.05).The ratio of eosinophils to granulocyte(0.124±0.031) and the expression level of IL-5[(29. 51±6. 68) pg /ml]in peripheral blood [0.184±0. 079 and (56. 58±16. 80) pg/ml] were significantly lower in gene therapy group than in AR group (P<0.05). Conclusions Transnasal administration of liposome- mediated pGEG. mIL-12 could depress the expression of IL-5 in bone marrow, peripheral blood, and nasal mucosa, to influence the proliferation and differentiation of eosinophils and decrease the delivery and transference of eosinophils to peripheral blood and nasal mucosa. It may be a new treatment for respiratory tract allergic inflammation.