Zhang Baoshan, Chao Cara W, Tsybovsky Yaroslav, Abiona Olubukola M, Hutchinson Geoffrey B, Moliva Juan I, Olia Adam S, Pegu Amarendra, Phung Emily, Stewart-Jones Guillaume, Verardi Raffaello, Wang Lingshu, Wang Shuishu, Werner Anne, Yang Eun Sung, Yap Christina, Zhou Tongqing, Mascola John R, Sullivan Nancy J, Graham Barney S, Corbett Kizzmekia S, Kwong Peter D
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
bioRxiv. 2020 Aug 22:2020.06.11.147496. doi: 10.1101/2020.06.11.147496.
Antigens displayed on self-assembling nanoparticles can stimulate strong immune responses and have been playing an increasingly prominent role in structure-based vaccines. However, the development of such immunogens is often complicated by inefficiencies in their production. To alleviate this issue, we developed a plug-and-play platform using the spontaneous isopeptide-bond formation of the SpyTag:SpyCatcher system to display trimeric antigens on self-assembling nanoparticles, including the 60-subunit lumazine synthase (LuS) and the 24-subunit ferritin. LuS and ferritin coupled to SpyTag expressed well in a mammalian expression system when an linked glycan was added to the nanoparticle surface. The respiratory syncytial virus fusion (F) glycoprotein trimer - stabilized in the prefusion conformation and fused with SpyCatcher - could be efficiently conjugated to LuS-SpyTag or ferritin-SpyTag, enabling multivalent display of F trimers with prefusion antigenicity. Similarly, F-glycoprotein trimers from human parainfluenza virus-type 3 and spike-glycoprotein trimers from SARS-CoV-2 could be displayed on LuS nanoparticles with decent yield and antigenicity. Notably, murine vaccination with the SARS-CoV-2 spike-LuS nanoparticles elicited ~25-fold higher neutralizing responses, weight-per-weight relative to spike alone. The versatile platform described here thus allows for multivalent plug-and-play presentation on self-assembling nanoparticles of trimeric viral antigens, with SARS-CoV-2 spike-LuS nanoparticles inducing particularly potent neutralizing responses.
自组装纳米颗粒上展示的抗原可刺激强烈的免疫反应，在基于结构的疫苗中发挥着越来越重要的作用。然而，此类免疫原的开发往往因生产效率低下而变得复杂。为缓解这一问题，我们开发了一种即插即用平台，利用SpyTag:SpyCatcher系统的自发异肽键形成，在自组装纳米颗粒上展示三聚体抗原，包括60亚基的鲁马嗪合酶（LuS）和24亚基的铁蛋白。当在纳米颗粒表面添加连接聚糖时，与SpyTag偶联的LuS和铁蛋白在哺乳动物表达系统中表达良好。呼吸道合胞病毒融合（F）糖蛋白三聚体——稳定在预融合构象并与SpyCatcher融合——可以有效地与LuS-SpyTag或铁蛋白-SpyTag偶联，从而实现具有预融合抗原性的F三聚体的多价展示。同样，来自人副流感病毒3型的F糖蛋白三聚体和来自SARS-CoV-2的刺突糖蛋白三聚体可以以相当高的产量和抗原性展示在LuS纳米颗粒上。值得注意的是，用SARS-CoV-2刺突-LuS纳米颗粒对小鼠进行疫苗接种引发的中和反应比单独使用刺突蛋白高约25倍（按重量计算）。因此，这里描述的通用平台允许在自组装纳米颗粒上对三聚体病毒抗原进行多价即插即用展示，其中SARS-CoV-2刺突-LuS纳米颗粒诱导特别有效的中和反应。
