使用交链孢霉建立小鼠过敏性哮喘模型

Establishment of a Mouse Model of Alternaria-allergic Asthma

目的探讨使用交链孢霉过敏原建立小鼠过敏性哮喘模型的可行性。方法 24只Balb/c小鼠随机分为对照组与实验组,每组12只;实验组用交链孢霉提取液在乙醚麻醉下滴鼻致敏与激发,交链孢霉致敏浓度25μg/ml,100μl分两次滴鼻,激发浓度为50μg/ml,操作同前。观察3 d后,在第4、5、6、7天连续4 d致敏,第18、19、20天及第36、37、38天进行激发;对照组用生理盐水代替。通过观察末次激发后小鼠的活动表现,检测小鼠气道反应性,肺泡灌洗液细胞分类计数,血清总Ig E和特异性Ig E水平,肺泡灌洗液中白介素(interleukin,IL)-4、IL-10、干扰素(interferon,IFN)-γ水平,肺组织中IL-25 m RNA与IL-33 m RNA表达水平及肺组织病理切片以验证模型的有效性。结果与对照组相比,实验组小鼠末次激发后均出现抓耳挠腮、呼吸急促、焦躁不安或安静少动等异常表现,并且需要更久的时间恢复正常;实验组小鼠气道阻力增加[(0.87±0.17)、(2.96±0.24)、(10.57±2.33)、(13.26±5.79)、(16.40±6.52)cm H2O/(ml·s),P<0.05或P<0.01]、气道顺应性降低[(0.280±0.160)、(0.150±0.092)、(0.053±0.031)、(0.046±0.022)、(0.037±0.009)ml/cm H2O,P<0.05或P<0.01],肺泡灌洗液的细胞总数[(21.28±4.58)×105/ml]和嗜酸性粒细胞比例(68.33%±17.80%)明显增多(P<0.01),血清总Ig E[(883.94±122.33)ng/ml]和特异性Ig E[(65.76±15.56)ng/ml]及肺泡灌洗液的IL-4[(109.14±42.51)pg/ml]水平明显偏高(P<0.05或P<0.01),IFN-γ[(93.42±51.26)pg/ml]的水平偏低(P<0.01),肺组织中IL-33 m RNA表达水平(2.21±0.58)亦明显增高(P<0.01);IL-25 m RNA表达水平在实验组与对照组均未检测出。结论交链孢霉致敏Balb/c小鼠的实验结果符合过敏性哮喘模型的变化。

Objective To investigate the feasibility of establishment of a mouse allergic asthma model by using Alternaria extract.Methods 24 Balb/c mice were divided into control and experimental group randomly,12 in each group.The mice were given intranasal administration of Alternaria extract(25μg/ml,50μl)twice in experimental group or saline in control group under ether anesthesia at Day 4,5,6 and 7 in sensitization phase.Intranasal challenge was performed with Alternaria extract(50μg/ml)at Day 18,19,20 and Day 36,37,38 in experimental group and with saline in control group in the same procedure in challenge phase.The activity of mice was observed after last challenge.Airway responsiveness,total and differential cell count in bronchoalveolar lavage fluid(BALF),serum total IgE and Alternaria specific IgE level,IL-4,IL-10 and IFN-γlevel in BALF and IL-25 mRNA,IL-33 mRNA expression in lung tissue were also detected after last challenge.The pathological changes of lung tissues were evaluated.Results The abnormal activities such as scratching,shortness of breath or restless were observed among mice in experimental group after challenge and recovery delayed,compared to the mice in control group.The airway resistance increased[(0.87±0.17),(2.96±0.24),(10.57±2.33),(13.26±5.79),(16.40±6.52)cm H 2O/(ml·s),P<0.05 or P<0.01]and the airway compliance decreased[(0.280±0.160),(0.150±0.092),(0.053±0.031),(0.046±0.022),(0.037±0.009)ml/cm H 2O,P<0.05 or P<0.01]in experimental group.The total cell count[(21.28±4.58)×10 5/ml],the percentage of eosinophils(68.33%±17.80%),serum total IgE[(883.94±122.33)ng/ml],specific IgE[(65.76±15.56)ng/ml]and IL-4[(109.14±42.51)pg/ml]level in BALF and the expression level of IL-33 mRNA(2.21±0.58)in lung tissue was higher(P<0.05 or P<0.01),while the IFN-γ[(93.42±51.26)pg/ml]level was lower(P<0.01)in experimental group.The expression of IL-25 mRNA was not detectable both in experimental and control group.Conclusion Balb/c mouse model of Alternaria-allergic asthma was successfully established,basing on the allergic inflammation profile shown in experimental group.