National Institutes for Food and Drug Control, Beijing, China.
Virol J. 2012 Jan 20;9:26. doi: 10.1186/1743-422X-9-26.
To characterize the human humoral immune response against enterovirus 71 (EV71) infection and map human epitopes on the viral capsid proteins.
A series of 256 peptides spanning the capsid proteins (VP1, VP2, VP3) of BJ08 strain (genomic C4) were synthesized. An indirect enzyme-linked immunosorbent assay (ELISA) was carried out to detect anti-EV71 IgM and IgG in sera of infected children in acute or recovery phase. The partially overlapped peptides contained 12 amino acids and were coated in the plate as antigen (0.1 μg/μl). Sera from rabbits immunized with inactivated BJ08 virus were also used to screen the peptide panel.
A total of 10 human anti-EV71 IgM epitopes (vp1-14 in VP1; vp2-6, 21, 40 and 50 in VP2 and vp3-10, 12, 15, 24 and 75 in VP3) were identified in acute phase sera. In contrast, only one anti-EV71 IgG epitope in VP1 (vp1-15) was identified in sera of recovery stage. Four rabbit anti-EV71 IgG epitopes (vp1-14, 31, 54 and 71) were identified and mapped to VP1.
These data suggested that human IgM epitopes were mainly mapped to VP2 and VP3 with multi-epitope responses occurred at acute infection, while the only IgG epitope located on protein VP1 was activated in recovery phase sera. The dynamic changes of humoral immune response at different stages of infection may have public health significance in evaluation of EV71 vaccine immunogenicity and the clinical application of diagnostic reagents.
为了描述人体对肠道病毒 71 型（EV71）感染的体液免疫反应，并绘制病毒衣壳蛋白上的人表位图谱。
合成了一系列跨越 BJ08 株（基因组 C4）衣壳蛋白（VP1、VP2、VP3）的 256 个肽段。通过间接酶联免疫吸附试验（ELISA）检测急性期和恢复期感染儿童血清中的抗 EV71 IgM 和 IgG。部分重叠的肽段包含 12 个氨基酸，作为抗原（0.1 μg/μl）包被在平板上。用灭活的 BJ08 病毒免疫的兔血清也用于筛选肽段面板。
在急性期血清中鉴定出 10 个人抗 EV71 IgM 表位（VP1 中的 vp1-14；VP2 中的 vp2-6、21、40 和 50 以及 VP3 中的 vp3-10、12、15、24 和 75）。相比之下，恢复期血清中仅鉴定出一个抗 EV71 IgG 表位（VP1 中的 vp1-15）。鉴定出 4 个兔抗 EV71 IgG 表位（vp1-14、31、54 和 71），并定位到 VP1。
这些数据表明，人 IgM 表位主要定位于 VP2 和 VP3，急性感染时发生多表位反应，而恢复期血清中仅激活一个位于蛋白 VP1 上的 IgG 表位。感染不同阶段体液免疫反应的动态变化，在评估 EV71 疫苗免疫原性和临床应用诊断试剂方面，可能具有公共卫生意义。
