颗粒性过敏原对致敏小鼠肥大细胞生成干扰素的影响研究

Particulate Allergens Enhance Production of IFN-γ in Mast Cells of Mice

目的研究颗粒过敏原诱导过敏性哮喘反应中重要的效应细胞肥大细胞生成干扰素IFN-γ的能力以及可能的作用机制。方法为模拟环境中附着有过敏原成分的可吸入性颗粒物,将模式过敏原蛋白三硝基苯基结合的卵清蛋白(OVA-TNP)共价偶联于大小均一的微球上形成颗粒状过敏原。肥大细胞首先用识别TNP的IgE致敏,然后用颗粒过敏原进行刺激。以Real-time PCR方法测定肥大细胞活化后IFN-γ的基因表达水平。采用同等剂量的以可溶形式存在的OVA/TNP作为可溶过敏原,比较颗粒过敏原刺激肥大细胞生成干扰素的能力。采用三种骨架蛋白抑制剂(Latrunculin B,cytochalasin D和Jasplakinolinde)观察阻断Actin的功能。结果与可溶过敏原相比,颗粒过敏原刺激IgE致敏的肥大细胞的IFN-γ的基因表达水平上升。肥大细胞IFN-γ基因表达的峰值出现在过敏原刺激后1 h。骨架蛋白抑制剂降低过敏原刺激肥大细胞IFN-γ的基因表达水平。结论当过敏原以颗粒形式存在时可以刺激致敏的肥大细胞生成更高水平的Th1型细胞因子干扰素IFN-γ,但作用机制与已知颗粒过敏原增强肥大细胞生成Th2型细胞因子的机制不同。

Objective To study the capacity of particulate allergens to induce production of IFN-γ in mast cells,which was critical effector cells in allergic asthma.The underlying mechanisms were also investigated.Methods To mimic the natural particulate allergens which were formed by adherence of environmental allergen proteins on ambient inhalable particles,the model allergen protein OVA-TNP was covalently conjugated on the surface of uni-sized polystyrene microspheres.Real-time PCR was used to analyze the synthesis of IFN-γ in IgE sensitized mast cells exposed to particulate allergens.Equal amount of OVA-TNP was used as soluble allergens for comparison with particulate allergens.Three actin inhibitors,Latrunculin B,cytochalasin D,and Jasplakinolinde were used to block the function of actin.Results Compared with soluble allergens,particulate allergens enhanced the production of IFN-γ in sensitized mast cells,and the peak time was at one hour.The pretreatment of actin inhibitors on sensitized mast cells reduced the production of IFN-γ in sensitized mast cells exposed to allergens.Conclusion Particulate form of allergens can stimulate stronger production of IFN-γ,the Th1 type cytokine,in mast cells.However,the functioning mechanism may be different with which particulate allergens used to regulate the production of Th2 type cytokines.