HBeAg的B细胞线性表位预测及鉴定

Prediction and identification of B-cell linear epitopes of hepatitis B e antigen

目的预测并鉴定乙型肝炎病毒e抗原(HBeAg)的B细胞线性表位,为乙型肝炎的诊断和治疗提供新的依据。方法采用生物信息学分析技术,利用NCBI数据库和免疫表位数据库提供的相应软件预测HBeAg的B细胞线性表位,采用人工合成法合成相应表位肽并分别将与血蓝蛋白(KLH)偶联,作为免疫原,免疫大白兔制备抗HBeAg抗原表位抗体,ELISA法鉴定抗体的特异性。结果发现了1MDIDPYKEFG10、37LYREALESPEHCSP50、74SNLEDPAS81、127RTPPAYRPPNAPIL140等4条新的HBeAg蛋白B细胞线性表位肽,其与KLH的偶联物作为免疫原免疫大白兔,获得特异性高效价抗体,抗体滴度大于1∶512000,ELISA实验证实上述抗体均可与HBeAg发生特异性免疫反应。结论采用生物信息学技术成功确认了4个HBeAg蛋白B细胞线性表位肽,为深入研究HBeAg的功能和作用以及乙型肝炎的治疗提供了新依据。

Objective To predict and identify B-cell linear epitopes of hepatitis B e antigen （HBeAg）. Methods The B-cell linear epitopes of HBeAg were predicted using the software provided by NCBI Database and Immune Epitope Database （IEDB） and synthesized by a solid-phase method followed by conjugation with keyhole limpet hemocyanin （KLH）. The KLH conjugates were used for immunization of New Zealand white rabbits, and the immune response of the rabbits was monitored by direct ELISA using a bovine serum albumin conjugate of the predicted epitopes. Results Four new B-cell linear epitopes of HBeAg were identified, namely 1MDIDPYKEFG^10, 37LYREALESPEHCSP^50, ^74SNLEDPAS^81 and IVRTPPAYRPPNAPIL^140. The rabbits immunized with the KLH conjugate showed an antibody titer over 1 ： 512 000. The antisera of B-cell linear epitopes collected could specifically react with HBeAg as shown by ELISA. Conclusion Four B-cell linear epitopes of HBeAg have been confirmed using bioinformatics methods, which provides new evidence for further functional studies of HBeAg in hepatitis B.