Monoclonal Antibody-Based Antigenic Mapping of Norovirus GII.4-2002
Monoclonal Antibody-Based Antigenic Mapping of Norovirus GII.4-2002
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DOI：
10.1128/jvi.06200-11
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发表时间：
2012-01-01
影响因子：
5.4
通讯作者：
Donaldson, Eric F.
中科院分区：
文献类型：
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作者：
Lindesmith, Lisa C.;Debbink, Kari;Donaldson, Eric F.
诺如病毒是人类流行性肠胃炎的主要原因，GII.4毒株造成的疾病负担约占总疾病负担的80%。使用血清和小鼠单克隆抗体（mab）进行的替代中和试验表明，抗原变异在面对群体免疫时保持了GII.4的持久性，因为新的大流行毒株的出现伴随着新进化的中和表位。为了潜在地识别可能在大流行毒株之间中和和进化的特异性阻断表位，用GII.4-2002病毒样颗粒（VLPs）对小鼠进行了过度免疫，并通过生化和免疫学分析对产生的单克隆抗体进行了表征。除了一个单克隆抗体外，所有单克隆抗体都识别出了1987年至2009年流行的GII.4 VLPs。一个单抗弱识别GII.4-1987和-1997，而与2002 VLPs强相互作用。该抗体具有高选择性，仅能有效阻断gii .4-2002配体结合。利用生物信息学分析，我们预测了由氨基酸407、412和413组成的GII.4表面表位的进化，并随后构建了突变体VLPs来测试表位对单抗结合和阻断潜力的影响。用1987年或2006年菌株中发现的表位替换2002年的表位，降低或减弱了gii .4-2002特异性阻断单抗对酶免疫测定的识别。这些数据确定了一个可能与保护性免疫相关的新的、不断发展的阻断表位，进一步支持了GII.4诺如病毒进化导致抗原变异的假设，使病毒能够逃脱保护性群体免疫，从而产生新的流行毒株。
Noroviruses are the primary cause of epidemic gastroenteritis in humans, and GII.4 strains cause similar to 80% of the overall disease burden. Surrogate neutralization assays using sera and mouse monoclonal antibodies (MAbs) suggest that antigenic variation maintains GII.4 persistence in the face of herd immunity, as the emergence of new pandemic strains is accompanied by newly evolved neutralization epitopes. To potentially identify specific blockade epitopes that are likely neutralizing and evolving between pandemic strains, mice were hyperimmunized with GII.4-2002 virus-like particles (VLPs) and the resulting MAbs were characterized by biochemical and immunologic assays. All of the MAbs but one recognized GII.4 VLPs representing strains circulating from 1987 to 2009. One MAb weakly recognized GII.4-1987 and -1997 while strongly interacting with 2002 VLPs. This antibody was highly selective and effective at blocking only GII.4-2002-ligand binding. Using bioinformatic analyses, we predicted an evolving GII.4 surface epitope composed of amino acids 407, 412, and 413 and subsequently built mutant VLPs to test the impact of the epitope on MAb binding and blockade potential. Replacement of the 2002 epitope with the epitopes found in 1987 or 2006 strains either reduced or ablated enzyme immunoassay recognition by the GII.4-2002-specific blockade MAb. These data identify a novel, evolving blockade epitope that may be associated with protective immunity, providing further support for the hypotheses that GII.4 norovirus evolution results in antigenic variation that allows the virus to escape from protective herd immunity, resulting in new epidemic strains.