Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, PR China.
Virus Res. 2012 Aug;167(2):337-42. doi: 10.1016/j.virusres.2012.05.019. Epub 2012 May 30.
The complete VP1 protein of enterovirus 71 (EV71) and a series of truncations were expressed in Escherichia coli and their antigenic characteristics were studied. Immunoblot analysis showed the major immunoreactive region of the VP1 protein was located in the N-terminal portion at position of amino acid (aa) 1-100. The complete VP1 possessed strong cross-reactivity with antisera against coxsackievirus A16 (CA16) and echovirus 6 (Echo6), while the truncated fragment at position 1-100 aa only had weak cross-reactivity. Moreover, an EV71-specific linear epitope at position 94-105 aa was identified using two EV71-specific mAbs (2B9 and 5B7) with indirect ELISA, but could not be recognized by antibodies against EV71 virus particles. The complete and all of truncated VP1 proteins except His-VP1(202-297) and GST-VP1(202-248) failed to elicit a significant neutralizing antibody response in mice. His-VP1(202-297) and GST-VP1(202-248) containing neutralizing epitope(s) could be recognized only by anti-EV71 mouse sera but not rabbit or human sera. These findings may contribute to a further understanding of antigenic characteristics of the capsid protein VP1 and may be helpful to the development of diagnostic reagents and vaccines.
肠道病毒 71 型（EV71）的完整 VP1 蛋白和一系列截短体在大肠杆菌中表达，并研究了它们的抗原特性。免疫印迹分析显示，VP1 蛋白的主要免疫反应区位于 N 端的氨基酸（aa）1-100 位置。完整的 VP1 与抗柯萨奇病毒 A16（CA16）和埃可病毒 6（Echo6）的血清具有强烈的交叉反应性，而位于 1-100 aa 位置的截短片段仅有微弱的交叉反应性。此外，使用两种 EV71 特异性单克隆抗体（2B9 和 5B7）通过间接 ELISA 鉴定了位于位置 94-105 aa 的 EV71 特异性线性表位，但不能被针对 EV71 病毒颗粒的抗体识别。完整的 VP1 蛋白和所有截短的 VP1 蛋白（除了 His-VP1（202-297）和 GST-VP1（202-248））都不能在小鼠中引发显著的中和抗体反应。含有中和表位的 His-VP1（202-297）和 GST-VP1（202-248）只能被抗 EV71 小鼠血清识别，而不能被兔或人血清识别。这些发现可能有助于进一步了解衣壳蛋白 VP1 的抗原特性，并有助于开发诊断试剂和疫苗。
