咪喹莫特对哮喘小鼠BALF中IL-12、IL-13及血IgE水平的影响

摘要

目的 研究雾化吸入一定浓度的咪喹莫特对哮喘小鼠支气管肺泡灌洗液(BALF)中IL-12、IL-13及血清中IgE水平的影响.方法 将30只小鼠随机分为正常组、哮喘组、咪喹莫特组,每组10只.哮喘组和咪喹莫特组均用卵蛋白(OVA)腹腔注射与雾化吸入建立哮喘模型,咪喹莫特组在吸入OVA前30分钟雾化吸入眯喹莫特混悬液.OVA雾化结束后24h,每组小鼠摘除眼球采血收集血清,采用酶联免疫吸附(ELISA)法测定血清IgE水平;收集BALF进行细胞计数和分类并采用ELISA法测定其IL-12和IL-13的水平;HE染色观察肺组织炎症变化.结果 (1)哮喘组小鼠HE染色可见其小气道管壁增厚,分泌物增多,上皮细胞脱落,排列紊乱,黏膜下有大量的炎症细胞浸润,主要以淋巴细胞为主.而咪喹莫特组小鼠的炎症程度比哮喘组小鼠减轻.(2)哮喘组小鼠BALF中细胞总数及各种炎症细胞较正常组明显增加,咪喹莫特治疗组中的嗜酸性粒细胞和淋巴细胞比哮喘组显著减少(P＜0.05).(3)哮喘组小鼠BALF中的IL-12水平较正常组降低,咪喹莫特治疗组中IL-12水平较哮喘组升高而血清中IgE水平降低,IL-12与IgE呈负相关(r=-0.802,P＜0.05);而哮喘组小鼠BALF中的IL-13和血清中的IgE水平较正常组增加,IL-13与IgE呈正相关(r=0.774,P＜0.05),咪喹莫特治疗组较哮喘组降低,较正常组增加(P＜0.05).结论 雾化吸入咪喹莫特能上调IL-12水平,下调IL-13水平;并能显著降低外周血IgE水平,提示咪喹莫特可能在一定程度上减轻哮喘的气道炎症.%Objective To observe the effects of aerosol imiquimod on the level of Interleukin-12 (IL-12) and interleukin-13 (IL-13) in bronchial alveolar lavage fluid(BALF) and serum immunoglobulin E(IgE) level in mouse asthma models.Methods Thirty BALB/c mice were divided into 3 groups, control group, asthma group and imiquimod group, ten in each group.The asthma group and imiquimod group were established by sensitization and challenge with ovalbumin (OVA) ,imiquimod group was interfered with aerosol imiquimod 30 min before challenge.Serum in each group was collected by excising eyeball 24 h after the last challenge.The level of IgE in serum was measured by ELISA.Bronchoalveolar lavage fluid (BALF) was performed, and total cell counts,cell differential were examined.The level of IL-12 and IL-13 in BALF was measured by ELISA and total cell counts, cell differential were examined in BALF.The inflammation changes of lung was observed by HE staining.Results (1) By hematoxylin-eosin (HE) staining, the result of asthma mice were small airway wall thickening ,secretion increased, epithelial cells fall off, arranging disorderly, and submucosal had plenty of inflammatory cells infiltration, mainly with lymphocytes.But imquimod group attenuated the airway inflammation of asthmatic mice.(2) Total cell counts and all kinds of inflammatory cells of asthma group were increased greatly compared with normal group;Eosinophil and lymphocyte cells were much lower in imquimod group than those in asthma group (P ＜0.05).(3) The level of IL-13 in BALF and the level of IgE in serum in imiquimod group was obviously higher than that in control group,IL-13 level were positively correlated with IgE level(r =0.774 ,P ＜ 0.05), but imiquimod group was greatly decreased compared with control group and increased in comparison with that in group A;The level of IL-12 in asthma group was reduced and the level of IgE was increased compared with normal group.IL-12 level in imiquimod group was evidently higher and IgE level was lower than that in asthma group.IL-12 level negatively correlated with IgE level(r =-0.802, P ＜ 0.05).Conclusion Imiquimod aerosol inhalation may up-regulate the level of Th1 chemokine IL-12,down-regulates the level of Th2 chemokine IL-13 and decrease the level of IgE in serum so that it may suppress antigen-induced airway inflammation.