Center for Global Health, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, United States of America.
Department of Medicine, Loyola University Medical Center, Chicago, United States of America.
PLoS One. 2018 Nov 16;13(11):e0205743. doi: 10.1371/journal.pone.0205743. eCollection 2018.
Zika virus (ZIKV) is an emerging pathogen with no approved therapeutics and only limited diagnostics available. To address this gap, six mouse single-chain antibodies (scFvs) to ZIKV envelope (E) protein were isolated rapidly and efficiently from a ribosome-displayed antibody library constructed from the spleens of five immunized mice.
METHODOLOGY/RESULTS: In this report, we have generated a panel of mouse scFvs to ZIKV E protein using ribosome display. The six scFvs demonstrated no cross-reactivity with DENV2 NGC envelope protein, suggesting specificity for ZIKV E protein. These scFvs showed differences in their affinity: two (scFv45-3, scFv63-1) of them were dominant after four rounds of panning, and showed higher affinity (an apparent Kd values from 19 to 27 nM) than the other four (scFv5-1, scFv7-2, scFv38-1, and scFv51-2). All six scFvs showed ZIKV-neutralizing activity in the plaque reduction neutralization test (PRNT) assay and their neutralizing activity was positively correlated with their affinities.
CONCLUSIONS/SIGNIFICANCE: The scFvs (45-3 and 63-1) with highest affinity may have dual utility as diagnostics capable of recognizing ZIKV E subtypes and may be further developed to treat ZIKV infection. Our approach has the added advantage of generating Fc receptor-deficient antibodies, minimizing concern of antibody-dependent enhancement (ADE) of infection.
寨卡病毒（ZIKV）是一种新兴病原体，目前尚无批准的治疗方法，仅有有限的诊断方法。为了解决这一差距，我们从五只免疫小鼠的脾脏中构建的核糖体展示抗体文库中快速有效地分离出了六种针对 ZIKV 包膜（E）蛋白的小鼠单链抗体（scFvs）。
方法/结果：在本报告中，我们使用核糖体展示技术生成了一组针对 ZIKV E 蛋白的小鼠 scFvs。这六种 scFvs 与 DENV2 NGC 包膜蛋白没有交叉反应性，表明它们对 ZIKV E 蛋白具有特异性。这些 scFvs 在亲和力上存在差异：其中两种（scFv45-3 和 scFv63-1）在四轮筛选后占据主导地位，显示出更高的亲和力（表观 Kd 值为 19 至 27 nM），而其他四种（scFv5-1、scFv7-2、scFv38-1 和 scFv51-2）则较低。所有六种 scFvs 在蚀斑减少中和试验（PRNT）中均显示出中和 ZIKV 的活性，其中和活性与其亲和力呈正相关。
结论/意义：亲和力最高的 scFvs（45-3 和 63-1）可能具有双重用途，既可用作能够识别 ZIKV E 亚型的诊断工具，也可进一步开发用于治疗 ZIKV 感染。我们的方法具有生成 Fc 受体缺陷型抗体的额外优势，最大限度地减少了抗体依赖性增强（ADE）感染的担忧。
