基于动物模型的大豆球蛋白诱导肠黏膜过敏反应机理研究

目的:探究大豆球蛋白诱导小鼠肠黏膜过敏反应的调控机理。方法:以大豆球蛋白和β-伴球蛋白为试验材料,Balb/c小鼠为受试动物,采用连续灌胃的方式建立肠道过敏动物模型。研究了小鼠小肠绒毛T、B淋巴细胞的数量、肠细胞凋亡率和固有层IgA+浆细胞的数量及小肠液中sIgA的含量。结果:与对照组相比,大豆球蛋白组小肠绒毛固有层淋巴细胞CD3^+、CD4^+数量显著高于对照组(P<0.01);大豆β-伴球蛋白组小肠绒毛固有层及肠上皮细胞中CD3^+、CD8^+、CD4^+及整合素α4β7的数量均显著高于对照。高倍镜下观察显示试验组小鼠小肠固有层中可见大量浆细胞及淋巴细胞等炎性细胞浸润;试验组小鼠小肠固有层IgA+浆细胞呈现明显的阳性染色。结论:大豆球蛋白可以介导细胞免疫为主的过敏反应发生,肠黏膜上皮细胞凋亡亢进是造成肠道通透性加强,进而破坏肠黏膜屏障功能的重要原因。

Studies on Mechanism of Mucosal Immune-mediated Intestinal Allergic Reaction Induced by Soybean Protein Based on Animal Model

Soybean glycinin andβ-conglycinin represent up to one third of protein in the soybean.Previous studies indicated that glycinin andβ-conglycinin have been characterized as major soybean allergens involved in food allergy.To elucidate the mechanism of mucosal immune-mediated gut allergic reaction induced by soybean glycinin andβ-conglyinin,and offered reasons for outcome or preventing of food allergic reactions in susceptible individuals.Balb/c mice were sensitized by gavages with 1 mg/d of glycinin orβ-conglycinin for 5 weeks,and T lymphocytes andα4β7 integrin in the intestinal lamina propria and epithelium were counted by immunohistochemistry.Apoptotic lymphocytes in the small intestinal mucosa were analyzed using the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL)assay,Intestinal secretory-IgA was measured by ELISA.The results showed that increased counts of CD3^+,CD4^+,CD8^+T cells andα4β7 integrin as well as sIgA level were observed in mice dosed with 1 mg/d soybean protein.