丙型肝炎病毒核心蛋白人源抗独特型单链抗体在大肠杆菌中的表达

目的 在大肠杆菌中表达丙型肝炎病毒核心蛋白人源抗独特型单链抗体。方法 采用噬菌体表面展示技术，将丙型肝炎病毒(HCV)核心蛋白单克隆抗体固相包被于Nunc板。从人源噬菌体单链可变区抗体库中经过3轮“吸附-洗脱-扩增”的筛选，获得结合活性较强的人源HCV核心蛋白抗独特型(抗-Id)scFv阳性克隆。从阳性克隆中提取质粒，经SfiI／Not I酶切鉴定后，亚克隆到pCANTAB5E载体，转化大肠杆菌XL1-Blue，应用异丙基硫代-β-D-半乳糖苷(IPTG)诱导表达可溶性的HCV核心蛋白抗独特型单链可变区抗体。酶联免疫吸附法(ELISA)证实表达的HCV核心蛋白抗-Id scFv具有与HCV核心蛋白单克隆抗体反应的特异性。对转化的大肠杆菌XL1-Blue上清中表达的HCV核心蛋白抗-Id scFv进行硫酸铵沉淀，并进行SDS-PAGE电泳。结果 筛选得到的HCV核心蛋白抗-Id scFv片段基因由774bp组成。SDS-PAGE电泳表明，大肠杆菌XL1-Blue中表达的可溶性HCV核心蛋白抗-Id scFv分子量约28kD。结论 HCV核心蛋白抗-Id scFv与HCV核心蛋白抗-Id scFv单克隆抗体具有较强的结合活性和特异性。HCV核心蛋白抗-Id scFv的筛选和表达成功，为今后HCV核心蛋白抗-Id scFv的研究和应用奠定了基础。

Expression of soluble human anti-idiotypic single chain Fv antibody to hepatitis C core protein in E.coli

Objective To express soluble human anti-idiotypic single chain Fv to hepatitis C core protein in E.coli. Methods Using phage display technique, the semisynthetic phage library was panned by HCV core monoclonal antibody which was coated in a microtiter plate. After three rounds of biopanning, 53 clones were identified specific to HCV core antibody. The specificity of anti-idiotypic scFv was determined by ELISA. After digested with Sfi/Not, the selected HCV core anti-idiotypic scFv positive clone was subcloned into the vector pCANTAB5E for the expression of E-tagged soluble anti-idiotypic scFv. The E.coli XL1-Blue was transformed and induced by IPTG. The specificity of anti-Id scFv was evaluated with ELISA. Results HCV core anti-Id scFv DNA digestion and sequence data showed that the scFv gene was composed of 774bp. ELISA results demonstrated that the soluble human HCV core anti-idiotypic scFv to HCV core monoclonal antibody had a specific combination character. The molecular weight of expressed HCV core anti-idiotypic scFv was 28kD as shown by SDS-PAGE. Conclusion HCV core anti-Id scFv has been successfully expressed in E.coli.