针对猪瘟病毒E2蛋白的嵌合猪源化单克隆抗体的表达及抗病毒活性鉴定

Expression and antiviral activity of a chimeric porcinized monoclonal antibody (cHQ06) against E2 protein of classical swine fever virus

摘要:

猪瘟 (Classical swine fever，CSF) 是严重危害养猪业的一种烈性传染病，常造成巨大的经济损失，是世界动物卫生组织要求必须申报的动物疫病之一。猪瘟的病原是猪瘟病毒 (Classical swine fever virus，CSFV)，CSFV的结构蛋白由衣壳蛋白 (C) 和囊膜糖蛋白 (Erns、E1、E2) 构成。E2蛋白是CSFV主要的保护性抗原，可以诱导机体产生中和抗体，从而抵抗CSFV的感染。此前，本团队制备了一株针对CSFV E2蛋白的鼠源单克隆抗体HQ06。文中将HQ06抗体重链和轻链可变区基因与猪源恒定区基因嵌合后克隆至真核表达载体，利用中国仓鼠卵巢 (CHO) 细胞制备一株针对CSFV E2蛋白的嵌合猪源化单克隆抗体cHQ06。应用ELISA、Western blotting试验证实了cHQ06与CSFV E2蛋白具有良好的反应性；中和试验结果表明cHQ06可以中和CSFV。综上所述，本研究应用CHO细胞稳定表达了具有良好反应性和中和活性的针对CSFV E2蛋白的嵌合猪源化单克隆抗体cHQ06，为研究CSFV E2蛋白结构、功能以及开发新型的CSFV诊断和治疗制剂奠定基础。

Abstract:

Classical swine fever (CSF), one of OIE-listed diseases, is a highly contagious and economically important disease of pigs. Classical swine fever virus (CSFV) is the causative agent of CSF. The capsid (C) protein and the glycoproteins Erns, E1 and E2, are structural components of the virus. E2 is the most immunogenic protein of the CSFV glycoproteins, inducing neutralizing antibodies that provide protection against lethal CSFV challenge. In a previous study, we developed a murine MAb HQ06 against the E2 protein of CSFV. In this study, the variable region genes from HQ06 and constant regions gene of swine antibody are fused and cloned into the eukaryotic expression vectors to establish a cell line which can stably express a chimeric porcinized MAb (cHQ06) against E2 in CHO cell. The purified cHQ06 antibody protein was determined to be successfully generated, which exhibited high reactivity between cHQ06 and the E2 protein of CSFV by enzyme-linked immunosorbent assay (ELISA) and Western blotting. More importantly, we investigated the neutralizing activity of cHQ06 against CSFV. In conclusion, this study generated cHQ06 for efficient and stable production which can be used against to develop novel diagnostic assays, investigate the structure and function of the E2 protein and generate novel preparations of diagnosis and treatment.