猪圆环病毒2型Cap蛋白单克隆抗体的制备

本研究利用已构建的基因工程重组菌表达猪圆环病毒2型(porcine circovirus type 2,PCV2)ORF2编码的Cap蛋白,纯化后作为免疫原,免疫8周龄BALB/c小鼠,取其脾细胞与SP2/0骨髓瘤细胞融合。经间接免疫荧光试验(IFA)筛选及有限稀释法进行3次亚克隆后,本试验最终获得5株稳定分泌抗PCV2 Cap蛋白单克隆抗体的杂交瘤细胞,分别命名为3D12、4D5、4B9、4C9和4G10。其中4D5为IgG2b亚型,其余4株单克隆抗体均为IgG1亚型,轻链类型均为κ。Western blotting鉴定结果表明获得的5株单克隆抗体均不能特异性的识别47 ku重组PCV2 Cap蛋白;对病毒感染细胞进行IFA试验,结果显示5株单克隆抗体均特异性的识别病毒抗原,表明5株单克隆抗体识别的抗原表位均为构象表位。中和试验结果表明,5株单克隆抗体均有中和活性。本试验结果为进一步探索ORF2基因的结构、功能及建立快速准确的诊断方法奠定了基础。

Preparation of Monoclonal Antibodies against Porcine Circovirus Type 2 Cap Protein

The structural protein Cap encoded by ORF2 of porcine circovirus type 2 (PCV2) was expressed in genetic engineering recombinant bacteria and used as the immunogen after purification.Five hybridoma cell lines against PCV2 Cap protein named as 3D12,4D5,4B9,4C9 and 4G10,respectively,were developed after fusion between SP2/0 myeloma cells and spleen cells of BALB/c mice immunized with purified recombinant PCV2 Cap protein.Except the heavy chain type of 4D5 was identified as IgG2b,others were identified as IgG1;The light chains were all kappa.In Western blotting assay,all the monoclonal antibodies (mAbs) couldn't specifically recognize the 47 ku recombinant PCV2 Cap protein,but showed strong specific fluorescence in PCV2 infected PK15 cells in IFA,which indicated that all the mAbs recognized comformational epitope.The neutralization test showed that all the mAbs had neutralization activity.These results laid the foundation for further study of the structure and function of PCV2 ORF2 gene,and establishment of the method for diagnosing PCV2 rapidly and exactly.