抗线粒体抗体M2抗原诱导小鼠原发性胆汁性肝硬化模型的建立

Establishment of a mouse model of primary biliary cirrhosis by AMA M2 autoantigen injection

目的用抗线粒体抗体M2抗原免疫C57BL／6小鼠,建立原发性胆汁性肝硬化实验动物模型。方法将纯化的抗线粒体抗体M2抗原与完全弗氏佐剂,每只小鼠腹腔1次注射200μl。对照组免疫原用牛血清白蛋白与完全弗氏佐剂。免疫后第66周,检测小鼠血清M2抗体、碱性磷酸酶、丙氨酸氢基转移酶和总胆红素,并对小鼠肝脏、肾脏、胃和肌肉组织进行病理学检查。结果 M2抗原免疫小鼠诱导出M2 抗体。模型组小鼠碱性磷酸酶显著升高,而丙氨酸氨基转移酶与总胆红素无显著变化。模型组小鼠汇管区有明显单个核细胞浸润,小叶间胆管损伤或增生。在其他组织器官如肾脏、胃和肌肉中未见明显病理变化。结论 M2抗原诱导C57BL／6小鼠,建立原发性胆汁性肝硬化模型,其生化和病理特征与人类原发性胆汁性肝硬化早期相似。

Objective To establish a primary biliary cirrhosis （PBC） model by AMAM2 autoantigen injection into C57BL/6 mice. Methods Mice of the model group were immunized intraperitonealy with 200μl of purified recombinant AMAM2 autoantigen in complete Freund＇s adjuvant （CFA）. Mice immunized with bovine serum albumin and CFA in the same way were used as negative controls. Sixty-six weeks later, mice were sacrificed and their sera were collected. Sera samples were assayed for AMAM2 autoantibody, alkaline phosphatase （ALP）, ALT and total bilirubin （TBil）. Their liver, stomach, muscle and kidney tissues were sectioned and stained using HE to observe the pathological changes. Results Antibodies to AMAM2 autoantigen were readily induced in the model group. The mice in the model group had no significant changes in the level of serum ALT and TBil but had an obvious increase of ALP （P 〈 0.05）. The stomach, muscle and kidney tissues showed no evident damage while the livers had obvious pathological changes, including bile duct degeneration or proliferation, and mononuclear cell infiltration. Conclusion The AMAM2 autoaotigeninduced PBC animal model was successfully established in C57BL/6 mice in our experiment and its characteristic biochemical and pathology are quite similar to that in the early stage of human PBC. This model may provide a useful experimental approach for further study of the pathogenesis and clinical treatment of human PBC.