Identification of novel epitopes targeting non-structural protein 2 of PRRSV using monoclonal antibodies
Identification of novel epitopes targeting non-structural protein 2 of PRRSV using monoclonal antibodies
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使用单克隆抗体鉴定针对 PRRSV 非结构蛋白 2 的新表位
DOI：
10.1007/s00253-019-09665-7
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发表时间：
2019-03-01
影响因子：
5
通讯作者：
Weng, Changjiang
中科院分区：
文献类型：
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作者：
Bi, Caihong;Shao, Zengyu;Weng, Changjiang
猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus，PRRSV）是一种严重危害养猪业的病毒。其非结构蛋白2（Nsp2）具有半胱氨酸蛋白酶结构域（PL2），对病毒复制至关重要，并作为宿主先天免疫调节的触发因素。在本研究中，产生了三种针对Nsp 2的单克隆抗体（mAb），命名为4A12、4G8和8H11。随后，利用具有部分重叠的重组肽序列来确定使用这些mAb的表位。我们发现了三个新的最小线性Nsp 2 B细胞表位，188 ELSDDSNRPV 197，42 HLKRYSPPAE 51和54 CGWHCISA61，它们分别由抗体4A12，4G8和8H11鉴定。结构分析表明，42HLKRYSPPAE 51和188ELSDDSNRPV 197分别位于Nsp 2的高变区1和高变区2。有趣的是，54CGWHCISA61位于PL2区域，该区域在所有动脉炎病毒中高度保守，特别是在预期的保守催化位点Cys54处。重要的是，54CGWHCISA61位于预期的Nsp2三维结构的内部区域，这表明该表位是隐蔽的。这些发现不仅为疫苗设计提供了有价值的见解，并为所鉴定的表位提供了诊断潜力，而且还揭示了在重要表位的选择压力下针对变异的保护机制。
Porcine reproductive and respiratory syndrome virus (PRRSV) is leading to huge losses in the swine industry worldwide. Its nonstructural protein 2 (Nsp2), with a cysteine protease domain (PL2), is crucial for virus replication and as a trigger to host innate immune regulation. In this study, three monoclonal antibodies (mAbs) to Nsp2, designated 4A12, 4G8, and 8H11, were generated. Subsequently, a sequence of recombinant peptides with partial overlap was utilized to determine the epitopes using these mAbs. We found three novel minimal linear Nsp2 B cell epitopes,188ELSDDSNRPV197,42HLKRYSPPAE51, and54CGWHCISA61, which were identified by the antibodies 4A12, 4G8, and 8H11, respectively. Structure analysis indicates that42HLKRYSPPAE51and188ELSDDSNRPV197are located separately in hypervariable region 1 and hypervariable region 2 of Nsp2. Interestingly,54CGWHCISA61is located in the PL2 region, which is highly conserved in all arteriviruses, particularly at the expected conserved catalytic site at Cys54. Importantly,54CGWHCISA61is located in the inner region of the expected 3D structure of Nsp2, which reveals that the epitope is cryptic. These findings not only provide valuable insight for vaccine design and hold diagnostic potential for the identified epitopes, but also reveal a protective mechanism against variation under selective pressure in an important epitope.