牛奶中高分子质量蛋白致敏作用的初步研究

Preliminary Research on the Milk Allergy Induced by High Molecular Weight Protein

目的探讨牛奶中高分子质量蛋白在牛奶过敏过程中的致敏作用。方法选取牛奶过敏患者血清30例,皮肤点刺试验阳性,血清特异性Ig E(s Ig E)检测结果均为阳性且≥1+。健康对照血清1例,血清s Ig E检测阴性,无过敏史。空腹采血,收集血清于-20℃冻存备用。利用Sephadex G200凝胶层析获得牛奶高分子质量蛋白,通过蛋白免疫印迹法(Wetern blot)和酶联免疫吸附测定(ELISA)检测高分子质量蛋白与牛奶过敏患者血清s Ig E的结合活性。结果 SDS-PAGE显示Sephadex G200凝胶层析纯化得到的高分子质量蛋白主要包括3条带,分子质量约为67、80和160 ku,推断其可能是牛血清白蛋白、乳铁蛋白和免疫球蛋白。经Western blot分析,3种高分子质量蛋白与牛奶过敏患者血清均能反应,并且在67 ku附近条带最明显。经ELISA分析,高分子质量蛋白与牛奶过敏患者血清的阳性反应率比β-乳球蛋白略高(分别是46.7%、43.3%)。结论牛奶中高分子质量蛋白组分能够诱导特异性抗体产生,这些组分在牛奶过敏过程中具有重要的致敏作用。

Objective To investigate the allergization of milk high molecular weight proteins. Methods Thirty cases of patients with serum allergic to milk were selected. Their skin prick tests were positive. Results of serum specific IgE （sIgE） test were positive and≥1＋. One case of healthy control with negative sIgE test and without history of allertgy, was included in this study. The serum samples were collected and frozen at-20℃. Sephadex G200 gel chromatography was used to obtain milk high molecular weight proteins. Western blot and ELISA methods were used to detect milk high molecular weight proteins and the activity of serum sIgE. Results Results of SDS-PAGE showed that high molecular weights proteins displayed by Sephadex G200 gel chromatography, mainly including three bands, the molecular weight of 67 ku, 80 ku and 160 ku. Western blot analysis showed that three kinds of high molecular weights proteins can react with milk allergy serum, and the most obvious appeared near the molecular weight 67 ku band. ELISA analysis showed that the positive response rate of high molecular weight proteins with milk allergic patient’s serum was slightly higher than that ofβ-lactoglobulin （46.7%and 43.3%, respectively）. Conclusion The milk high molecular weight protein components can induce specific IgE antibod？ies, which have important sensitization in the process of milk allergy.