Fenobody: A Ferritin-Displayed Nanobody with High Apparent Affinity and Half-Life Extension
Fenobody: A Ferritin-Displayed Nanobody with High Apparent Affinity and Half-Life Extension
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Fenobody：具有高表观亲和力和半衰期延长的铁蛋白展示纳米抗体
DOI：
10.1021/acs.analchem.7b05217
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发表时间：
2018-05-01
影响因子：
7.4
通讯作者：
Yan, Xiyun
中科院分区：
文献类型：
--
作者：
Fan, Kelong;Jiang, Bing;Yan, Xiyun
纳米体由骆驼重链抗体的单域可变片段组成。纳米体生产工艺简单、成本低，在生物医学领域具有潜在的应用前景。偶尔，感兴趣的纳米体克隆对其靶抗原表现出较低的亲和力，这与它们较短的半衰期一起限制了生物分析或治疗应用。在这里，我们开发了一个新的平台，我们命名为fenobody，在这个平台上，一个针对H5N1病毒开发的纳米体以24mer的形式显示在铁蛋白表面。我们用纳米体取代铁蛋白的第五螺旋，构建了一个无纳米体。TEM分析表明，纳米小体以6 × 4束的形式出现在铁蛋白表面，这些簇状纳米小体在空间结构上具有灵活的抗原结合能力。将小体与目前使用的常规纳米体进行比较发现，抗h5n1小体的抗原结合表观亲和力显著提高（约360倍）。关键是，它们在小鼠模型中的半衰期延长比抗h5n1纳米体长10倍。此外，我们发现我们的小体在大肠杆菌中高度表达，并且是可溶性和热稳定的纳米笼，可以自组装为24个聚合物。总之，我们的研究结果表明，非体在增强纳米体的亲和力和延长纳米体半衰期方面比目前可用的系统具有独特的优势。我们的无体系统为各种大规模生物技术过程提供了一个合适的平台，并将极大地促进纳米体技术在这些领域的应用。
Nanobodies consist of a single domain variable fragment of a camelid heavy-chain antibody. Nanobodies have potential applications in biomedical fields because of their simple production procedures and low cost. Occasionally, nanobody clones of interest exhibit low affinities for their target antigens, which, together with their short half-life limit bioanalytical or therapeutic applications. Here, we developed a novel platform we named fenobody, in which a nanobody developed against H5N1 virus is displayed on the surface of ferritin in the form of a 24mer. We constructed a fenobody by substituting the fifth helix of ferritin with the nanobody. TEM analysis showed that nanobodies were displayed on the surface of ferritin in the form of 6 x 4 bundles, and that these clustered nanobodies are flexible for antigen binding in spatial structure. Comparing fenobodies with conventional nanobodies currently used revealed that the antigen binding apparent affinity of anti-H5N1 fenobody was dramatically increased (similar to 360-fold). Crucially, their half-life extension in a murine model was 10-fold longer than anti-H5N1 nanobody. In addition, we found that our fenobodies are highly expressed in Escherichia coli, and are both soluble and thermo-stable nanocages that self-assemble as 24-polymers. In conclusion, our results demonstrate that fenobodies have unique advantages over currently available systems for apparent affinity enhancement and half-life extension of nanobodies. Our fenobody system presents a suitable platform for various large-scale biotechnological processes and should greatly facilitate the application of nanobody technology in these areas.