猪瘟病毒E2蛋白4重复抗原表位的构建及抗原活性研究

利用PCR方法获得4次重复的猪瘟病毒E2蛋白中和性抗原表位基因，将其克隆到pGEM-5ZF( )载体，测序正确后亚克隆到pGEX-3X载体构建得到重组质粒pGEX-3X-4P。重组质粒在大肠杆菌中诱导表达了含4重复抗原表位的融合蛋白。该蛋白经纯化后，利用间接ELISA检测其与血清的反应性，结果表明，纯化的融合蛋白与兔抗CSFV E2血清有很强的反应性，与兔抗BVDV E2血清不反应，说明该重复抗原表位在鉴别诊断CSFV与猪的BVDV感染方面具有潜在的应用价值。

Expression and antigenicity of a 4-repeated epitope peptide of CSFV E2 protein

The peptide TAVSPTTLR is an antigenic epitope mapped recently on the E2 glycoprotein of classical swine fever virus. Based on its genetic sequence a gene fragment encoding repeatedly this epitope in quadruple form wasconstructed by using PCR and cloned into pGEM 5ZF followed by subcloning into expression vector pGEX 3X, resulting in the construction of pGEX 3X 4P. After transformation of E.coli JM109 with pGEX 3X 4P a 4 repeated epitope peptide of CSFV E2 was expressed in fusion with GST. This fused protein, refered to as GST 4P, was prepared by passing the culture product of transformed JM109 through Microspin GST Purification Module, then characterized for its reactivity respectively with some antisera in ELISA. The results showed that this quadruple epitope peptide could react well with rabbit anti CSFV E2 serum and pig anti CSFV serum, but not with rabbit anti BVDV E2 antiserum. This result indicated that this epitope is CSFV specific and the quadruple epitope constructed in the study was likely to be able to differentiate the infection of CSFV from BVDV in antibody ELISA.