Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore, Singapore.
J Virol Methods. 2010 May;165(2):222-9. doi: 10.1016/j.jviromet.2010.01.026. Epub 2010 Feb 10.
Two genotypes of porcine circovirus (PCV) have been described, the non-pathogenic PCV1 and the pathogenic PCV2 in pigs. PCV-ORF1 encodes Rep and Rep' proteins which have identical N-terminal sequence (RepN) within each PCV strain, but RepN has only 88% similarity between PCV1 and PCV2. Purified RepN of PCV2 was used as an immunogen to produce monoclonal antibodies (mAbs). 11 mAbs were screened out and established, and they were divided into two groups according to Western blot and IFA results. One group, including 1C1, bound only PCV2-RepN, while the other, including 3D10, had cross reactivity with RepN of both PCV1 and PCV2. Epitope mapping indicated that 1C1 and 3D10 recognized the linear epitopes L(39)FDYFIVG(46) and K(99)EGNLLIE(106) in PCV2-RepN, respectively. Protein sequence alignment of RepN indicated L(39)FDYFIVG(46) is conserved in all PCV2 in NCBI database, whereas the PCV1 has amino acid substitutions V(41)C(42) in this region. mAb 3D10 could recognize all PCV because all natural mutations in its epitope did not affect its binding. The information about characteristics and epitope of monoclonal antibodies may be useful for the development of diagnostic methods for PCV2 and for analyzing the function of Rep and Rep' of PCV.
两种猪圆环病毒（PCV）基因型已被描述，即非致病性的 PCV1 和致病性的 PCV2。PCV-ORF1 编码 Rep 和 Rep'蛋白，它们在每个 PCV 株中的 N 端序列（RepN）相同，但 PCV1 和 PCV2 之间 RepN 的相似度只有 88%。PCV2 的纯化 RepN 被用作免疫原来产生单克隆抗体（mAbs）。筛选出并建立了 11 株 mAb，根据 Western blot 和 IFA 结果将它们分为两组。一组包括 1C1，仅与 PCV2-RepN 结合，而另一组包括 3D10，与 PCV1 和 PCV2 的 RepN 均有交叉反应性。表位作图表明，1C1 和 3D10 分别识别 PCV2-RepN 中的线性表位 L(39)FDYFIVG(46)和 K(99)EGNLLIE(106)。RepN 的蛋白序列比对表明，L(39)FDYFIVG(46)在 NCBI 数据库中所有 PCV2 中都是保守的，而 PCV1 在该区域有氨基酸取代 V(41)C(42)。mAb 3D10 可以识别所有 PCV，因为其表位中的所有自然突变都不会影响其结合。这些关于单克隆抗体特征和表位的信息可能有助于开发 PCV2 的诊断方法，并分析 PCV 的 Rep 和 Rep'的功能。
