ABSTRACT

The recent outbreaks of Zika virus (ZIKV) in flavivirus-endemic regions highlight the need for sensitive and specific serological tests. Previously we and others reported key fusion loop (FL) residues and/or BC loop (BCL) residues on dengue virus (DENV) envelope protein recognized by flavivirus cross-reactive human monoclonal antibodies and polyclonal sera. To improve ZIKV serodiagnosis, we employed wild type (WT) and FL or FL/BCL mutant virus-like particles (VLP) of ZIKV, DENV1 and West Nile virus (WNV) in enzyme linked immunosorbent assays (ELISA), and tested convalescent-phase serum or plasma samples from reverse-transcription PCR-confirmed cases with different ZIKV, DENV and WNV infections. For IgG ELISA, ZIKV WT-VLP had a sensitivity of 100% and specificity of 52.9%, which was improved to 83.3% by FL/BCL mutant VLP and 92.2% by the ratio of relative optical density of mutant to WT VLP. Similarly, DENV1 and WNV WT-VLP had a sensitivity/specificity of 100%/70.0% and 100%/56.3%, respectively; the specificity was improved to 93.3% and 83.0% by FL mutant VLP. For IgM ELISA, ZIKV, DENV1 and WNV WT-VLP had a specificity of 96.4%, 92.3% and 91.4%, respectively, for primary infection; the specificity was improved to 93.7–99.3% by FL or FL/BCL mutant VLP. An algorithm based on a combination of mutant and WT-VLP IgG ELISA is proposed to discriminate primary ZIKV, DENV and WNV infections as well as secondary DENV and ZIKV infection with previous DENV infections; this could be a powerful tool to better understand the seroprevalence and pathogenesis of ZIKV in regions where multiple flaviviruses co-circulate.

摘要

黄病毒流行地区最近爆发的寨卡病毒（ZIKV）突显了对敏感和特定血清学检测的需求。以前，我们和其他人报道了黄病毒交叉反应的人类单克隆抗体和多克隆血清识别的登革热病毒（DENV）包膜蛋白上的关键融合环（FL）残基和/或BC环（BCL）残基。为了改善ZIKV血清学诊断，我们在酶联免疫吸附测定（ELISA）中使用了ZIKV，DENV1和西尼罗河病毒（WNV）的野生型（WT）和FL或FL / BCL突变病毒样颗粒（VLP），并进行了恢复期的逆转录PCR确诊的不同ZIKV，DENV和WNV感染病例的三阶段血清或血浆样品。对于IgG ELISA，ZIKV WT-VLP的敏感性为100％，特异性为52.9％，通过FL / BCL突变体VLP和92提高到83.3％。突变体与WT VLP的相对光密度之比为2％。同样，DENV1和WNV WT-VLP的敏感性/特异性分别为100％/ 70.0％和100％/ 56.3％；FL突变VLP将特异性提高到93.3％和83.0％。对于IgM ELISA，ZIKV，DENV1和WNV WT-VLP对原发感染的特异性分别为96.4％，92.3％和91.4％。FL或FL / BCL突变体VLP将特异性提高到93.7–99.3％。提出了一种结合突变和WT-VLP IgG ELISA的算法来区分原发性ZIKV，DENV和WNV感染以及继发性DENV和ZIKV感染与先前的DENV感染。这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。DENV1和WNV WT-VLP的敏感性/特异性分别为100％/ 70.0％和100％/ 56.3％；FL突变VLP将特异性提高到93.3％和83.0％。对于IgM ELISA，ZIKV，DENV1和WNV WT-VLP对原发感染的特异性分别为96.4％，92.3％和91.4％。FL或FL / BCL突变体VLP将特异性提高到93.7–99.3％。提出了一种结合突变和WT-VLP IgG ELISA的算法来区分原发性ZIKV，DENV和WNV感染以及继发性DENV和ZIKV感染与先前的DENV感染。这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。DENV1和WNV WT-VLP的敏感性/特异性分别为100％/ 70.0％和100％/ 56.3％；FL突变VLP将特异性提高到93.3％和83.0％。对于IgM ELISA，ZIKV，DENV1和WNV WT-VLP对原发感染的特异性分别为96.4％，92.3％和91.4％。FL或FL / BCL突变体VLP将特异性提高到93.7–99.3％。提出了一种结合突变和WT-VLP IgG ELISA的算法来区分原发性ZIKV，DENV和WNV感染以及继发性DENV和ZIKV感染与先前的DENV感染。这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。对于IgM ELISA，ZIKV，DENV1和WNV WT-VLP对原发感染的特异性分别为96.4％，92.3％和91.4％。FL或FL / BCL突变体VLP将特异性提高到93.7–99.3％。提出了一种结合突变和WT-VLP IgG ELISA的算法来区分原发性ZIKV，DENV和WNV感染以及继发性DENV和ZIKV感染与先前的DENV感染。这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。对于IgM ELISA，ZIKV，DENV1和WNV WT-VLP对原发感染的特异性分别为96.4％，92.3％和91.4％。FL或FL / BCL突变体VLP将特异性提高到93.7–99.3％。提出了一种结合突变和WT-VLP IgG ELISA的算法来区分原发性ZIKV，DENV和WNV感染以及继发性DENV和ZIKV感染与先前的DENV感染。这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。DENV和WNV感染以及继发DENV和ZIKV继发DENV感染；这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。DENV和WNV感染以及继发DENV和ZIKV继发DENV感染；这可能是一个强大的工具，可以更好地了解多种黄病毒共同传播区域中ZIKV的血清阳性率和发病机理。