IL-4RA基因转染对哮喘模型气道STAT6的干预作用

Interference of IL-4RA transfection to express level of STAT6 in airways

目的:观察呼吸道转染IL-4RA基因对哮喘模型气道STAT6的干预作用。方法:BALB/c小鼠被随机分为五组,空白对照组、哮喘模型组、空载体干预组、激素治疗组、目的基因干预组。除空白对照组外其他各组小鼠在试验第1天和第7天和第14天通过腹腔注射0.2ml混有40mg氢氧化铝和10μg OVA的pH7.4 PBS致敏,空载体干预组和基因干预组在试验第12天连续给药三天,激素治疗组在激发的同时给予激素雾化吸入一周,在试验第15天用5%的OVA对小鼠进行雾化激发,连续一周。在最后一次激发后24小时放血杀死小鼠,检测血浆IgE水平和血中嗜酸细胞计数,留取肺组织标本做进一步的分析:肺组织用10%的甲醛固定,通过免疫组化的方法对STAT6的表达进行检测。结果:逆转录病毒载体携带目的基因IL-4RA成功地整合到了宿主基因组中,通过逆转录病毒转染的IL-4RA的基因高表达成功地阻止在哮喘模型鼠气道由IL-4和IL-13诱发的气道嗜酸细胞浸润,另外,逆转录病毒介导的IL-4RA在气道的表达明显地阻止了哮喘相关的气道STAT6水平,因此基因治疗可能会成为治疗慢性哮喘气道炎症和哮喘症状的极有潜力的药物。结论:IL-4RA基因转染阻止了哮喘模型气道STAT6的产生。

Objective： To study the effect of airway IL-4RA gene transfer on asthma-associated expression of STAT6 in the mice of allergic asthma. Methods： Forty BALB/c mice were randomly divided into four groups： blank control, asthma model, asthma model administered by pLNC-laz, and asthma model administered by glucocorticoid and pLNC-IL-4RA. The ten mice in each groups were sensitized by i. p. injection of 10μg of OVA emulsified in 40 mg of aluminum hydroxide in a total volume of 200 kd on the days of 1st,7th and 14th. On the 15th day, the mice were challenged via airways with OVA for 7 days, 20 min a day, blank control were sensitized by i. p. injection of 200μl pH = 7.4 PBS on days 7 and 14. Asthma model was administered by pLNC-laz or pLNC-IL-4RA for 3 days beginning at the 12^th day. The mice of the group with glucocorticoid was administered with glucocorticoid on the 15^th day for 7 days. 24 hours after the last challenge, the mice were sacrificed by bloodletting. Serum OVA-specific IgE and blood Eosinophils were measured. The lungs were fixed by immersion in 10% formalin. Expression of STAT6 was identified by immunohistochemistry. Results：It was shown that pLNC-IL-4RA was integrated to the genomic DNA of pneumonic tissues. Retrovirus-mediated delivery of IL-4RA to airways of the asthma mice weakened airway eosinophilia triggered by either IL-13 or IL-4. Furthermore, IL-4RA delivered by retroviras was expressed in airways of the mice with allergen sensitization, resulting in significiant reduction of expressing level of asthma-associated STAT6 in the experimental mice of allergic asthma. Conclusion： Retrovirus mediated delivery of IL-4RA to airways reduces expression of STAT6 in pneumonic tissues of asthmatic mice. Thus, the gene theraphy can be a potential therapeutic option to treat and control chronic airway inflammation and asthmatic symptoms.