The major envelope protein, GP5, of a European porcine reproductive and respiratory syndrome virus contains a neutralization epitope in its N-terminal ectodomain
The major envelope protein, GP5, of a European porcine reproductive and respiratory syndrome virus contains a neutralization epitope in its N-terminal ectodomain
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DOI：
10.1099/vir.0.18957-0
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发表时间：
2003-06-01
影响因子：
3.8
通讯作者：
van Rijn, PA
中科院分区：
文献类型：
--
作者：
Wissink, EHJ;van Wijk, HAR;van Rijn, PA
先前已经产生了一组针对欧洲型猪繁殖和呼吸综合征病毒（PRRSV）的GP（5）蛋白的中和单克隆抗体（mAb）（Weiland等人，1999年）。这一组与荷兰分离株Intervet-10（1-10）的噬斑纯化病毒（PPV）亚群反应，但不与欧洲原型PRRSV LV反应。为了定位PPV株GP（5）蛋白的中和表位，测定了PPV的ORF 5核苷酸序列。当将该核苷酸序列衍生的氨基酸序列与PRRSV LV的氨基酸序列进行比较时，发现了4个氨基酸差异。使用定点突变，我们表明PPV株GP（5）序列第24位的脯氨酸残基能够被中和mAb识别。Pepscan分析表明，由中和mAb识别的表位从残基29延伸至35。令人惊讶的是，mAb在Pepscan系统中的反应性与24位上脯氨酸的存在无关。此外，残基24位于预测的信号肽内，这意味着信号肽不被切割或由于Pro（24）的存在而被切割，使得表位保持完整。我们的研究结果证实了在PRRSV GP（5）蛋白的N-末端胞外域中存在中和表位，并暗示了GP（5）的胞外域在PRRSV感染中的作用。
A set of neutralizing monoclonal antibodies (mAbs) directed against the GP(5) protein of European type porcine reproductive and respiratory syndrome virus (PRRSV) has been produced previously (Weiland et al., 1999). This set reacted with a plaque-purified virus (PPV) subpopulation of Dutch isolate Intervet-10 (1-10), but not with the European prototype PRRSV LV. In order to map the neutralization epitope in the GP(5) protein of the PPV strain, the ORF5 nucleotide sequence of PPV was determined. When the amino acid sequence derived from this nucleotide sequence was compared with that of PRRSV LV, four amino acid differences were found. Using site-directed mutagenesis, we showed that a proline residue at position 24 of the GP(5) sequence of the PPV strain enabled recognition by the neutralizing mAbs. Pepscan analysis demonstrated that the epitope recognized by the neutralizing mAbs stretched from residues 29 to 35. Surprisingly, the reactivity of the mAbs in the Pepscan system was independent of the presence of a proline in position 24. Moreover, residue 24 is located within the predicted signal peptide, implying that either the signal peptide is not cleaved or is cleaved due to the presence of Pro(24) such that the epitope remains intact. Our results demonstrate the presence of a neutralization epitope in the N-terminal ectodomain of the GP(5) protein of PRRSV and imply a role for the ectodomain of GP(5) in the infection of PRRSV.