Abstract:
Human coronavirus (hCoV) OC43 is endemic to global populations and usually causes asymptomatic or mild upper respiratory tract illness. Here, we demonstrate the neutralization efficacy of isolated nanobodies from alpacas immunized with the S1B and S1C domain of the hCoV-OC43 spike glycoprotein. A total of 40 nanobodies bound to recombinant OC43 protein with affinities ranging from 1 to 149 nM. Two nanobodies WNb 293 and WNb 294 neutralized virus at 0.21 and 1.79 nM, respectively. Intranasal and intraperitoneal delivery of WNb 293 fused to an Fc domain significantly reduced nasal viral load in a mouse model of hCoV-OC43 infection. Using X-ray crystallography, we observed that WNb 293 bound to an epitope on the OC43 S1B domain, distal from the sialoglycan-binding site involved in host cell entry. This result suggests that neutralization mechanism of this nanobody does not involve disruption of glycan binding. Our work provides characterization of nanobodies against hCoV-OC43 that blocks virus entry and reduces viral loads in vivo and may contribute to future nanobody-based therapies for hCoV-OC43 infections.
OBJECTIVE: The pandemic potential presented by coronaviruses has been demonstrated by the ongoing COVID-19 pandemic and previous epidemics caused by severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus. Outside of these major pathogenic coronaviruses, there are four endemic coronaviruses that infect humans: hCoV-OC43, hCoV-229E, hCoV-HKU1, and hCoV-NL63. We identified a collection of nanobodies against human coronavirus OC43 (hCoV-OC43) and found that two high-affinity nanobodies potently neutralized hCoV-OC43 at low nanomolar concentrations. Prophylactic administration of one neutralizing nanobody reduced viral loads in mice infected with hCoV-OC43, showing the potential for nanobody-based therapies for hCoV-OC43 infections.
摘要:
人类冠状病毒(hCoV)OC43是全球人群特有的,通常会导致无症状或轻度上呼吸道疾病。这里,我们证明了用hCoV-OC43刺突糖蛋白的S1B和S1C结构域免疫的羊驼分离的纳米抗体的中和功效。总共40个纳米抗体以1至149nM的亲和力与重组OC43蛋白结合。两个纳米抗体WNb293和WNb294在0.21和1.79nM中和病毒,分别。与Fc结构域融合的WNb293的鼻内和腹膜内递送在hCoV-OC43感染的小鼠模型中显著降低了鼻病毒载量。用X射线晶体学,我们观察到WNb293与OC43S1B结构域上的表位结合,远离与宿主细胞进入有关的唾液酸聚糖结合位点。该结果表明该纳米抗体的中和机制不涉及聚糖结合的破坏。我们的工作提供了针对hCoV-OC43的纳米抗体的表征,可阻止病毒进入并减少体内病毒载量,并可能有助于未来基于纳米抗体的hCoV-OC43感染疗法。
目的:持续的COVID-19大流行和先前由严重急性呼吸综合征冠状病毒和中东呼吸综合征冠状病毒引起的流行已经证明了冠状病毒带来的大流行潜力。除了这些主要的致病性冠状病毒,有四种地方性冠状病毒感染人类:hCoV-OC43,hCoV-229E,hCoV-HKU1和hCoV-NL63。我们确定了一组针对人类冠状病毒OC43(hCoV-OC43)的纳米抗体,并发现两个高亲和力纳米抗体在低纳摩尔浓度下有效地中和了hCoV-OC43。预防性施用一种中和纳米抗体降低了感染hCoV-OC43的小鼠中的病毒载量,显示了基于纳米抗体的治疗hCoV-OC43感染的潜力。