Understanding spillover potential of European and African bat sarbecoviruses

了解欧洲和非洲蝙蝠沙病毒的溢出潜力

• 批准号: 10602805
• 负责人: Samantha Kathleen Zepeda
• 金额: $ 4.3万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10602805
• 关键词: 2019-nCoV; ACE2; Africa; African; Amino Acids; Animals; Antibodies; Antibody Therapy; Asia; Binding; Biological Assay; COVID-19 outbreak; Cell membrane; Cells; Chiroptera; Clinical; Clinical Treatment; Coronavirus; Coronavirus spike protein; Cryoelectron Microscopy; Development; Disease; Domestic Animals; Effectiveness; Europe; European; Foundations; Future; Genetic Drift; Genetic Recombination; Geographic Locations; Glycoproteins; Head Start Program; Human; Human Cell Line; Infection; Interferometry; Kenya; Knowledge; Location; Membrane Glycoproteins; Monoclonal Antibodies; Mutation; Nature; Neutralization Tests; Proteins; Publications; Reaction Time; Receptor Cell; Resistance; Russia; SARS coronavirus; Sarbecovirus; Southeastern Asia; Structure; System; Testing; Time; Transfection; Trees; Tropism; Vaccination; Vaccine Design; Vaccinee; Vaccines; Validation; Variant; Vesicular stomatitis Indiana virus; Viral; Virus; Virus Diseases; Zoonoses; biophysical analysis; clinical development; insight; member; mutation screening; pandemic preparedness; polyclonal antibody; prevent; receptor; receptor binding; response; tool; tool development; vaccine development; vaccine-induced antibodies; zoonotic coronavirus

Abstract The outbreak of SARS-CoV-2 in late 2019 has resulted in the loss of over 6 million lives worldwide. Since then, there has been an intense focus on the development of vaccines and clinical treatments to increase the survivability of the disease caused by this virus. However, in nature other diverse sarbecoviruses circulate which may present future spillover potential and for which these treatments may be ineffective. Clade 3 sarbecoviruses originate in Africa and Europe, outside of the regions considered to be sarbecovirus hotspots in Southeast Asia. The geographical location and the absence of native human ACE2 utilization from the earliest viruses discovered in this clade resulted in this clade being discounted. However, we have recently shown that one member of this clade, BtKY72 from Kenya, has the capacity to gain human ACE2 binding within one amino acid mutation and cellular entry within two mutations. Furthermore, we demonstrated for the first time that another member of this clade, Khosta-2 from Russia, can natively bind human ACE2 as a wildtype sequence. Together, our recent observations indicate the need to develop tools to study and inhibit potential human infection by this overlooked clade of viruses. Clade 3 may be the origin of a future sarbecovirus spillover, but current tools might have limited protective capacity due to the genetic divergence between Clade 3 and the prior human sarbecoviruses in the spike protein, the viral surface glycoprotein responsible for receptor binding and fusion of the viral envelope and the host cell membrane. I hypothesize that all members of this clade can gain human ACE2 utilization within a couple of mutations in the receptor binding domain of the spike glycoprotein but that current vaccines and antibody treatments will have reduced efficacy against clade 3 sarbecoviruses. In Aim 1 of this proposal, I will uncover receptor usage of all current members of clade 3 in Rhinolophus bat species with ranges in Africa, Europe, and Asia identify mutations that enable human ACE2 binding and cellular entry of these viruses making use of safe non-replicating pseudovirus systems. In Aim 2, I will establish what clinical tools in terms of vaccines and monoclonal antibody treatments would be effective at preventing cellular entry of clade 3 sarbecoviruses. Understanding current native receptor usage combined with a sequence assessment of sarbecoviruses that may be able to coinfect a specific species of Rhinolophus will give insight into the evolutionary possibilities available to these viruses. In addition, identification of mutations that enable human ACE2 binding and cellular entry in human cell lines will provide context on how close these viruses are to achieving this first step necessary for human spillover. Finally, the assessment of current tools for their effectiveness against clade 3 sarbecoviruses and the structural characterization of clade 3 spike ectodomains, will give us a head start should these viruses cross the species barrier in the future.

抽象的 2019年底，SARS-COV-2爆发导致全球丧生超过600万。自那以后， 人们非常关注疫苗和临床治疗的开发，以增加 该病毒引起的疾病的生存能力。但是，在本质上，其他各种SARBECOVIRASE循环 可能会呈现未来的溢出潜力，并且这些治疗方法可能无效。进化枝3 Sarbecoviruses起源于非洲和欧洲，在被认为是SARBECOVIRUS热点地区之外 东南亚。最早的地理位置和缺乏本地人类ACE2利用 在此进化枝中发现的病毒导致该进化枝被打折。但是，我们最近表明 该进化枝的一个成员，来自肯尼亚的BTKY72，具有获得人类ACE2结合的能力 两个突变内的氨基酸突变和细胞进入。此外，我们首次演示 该进化枝的另一个成员Khosta-2来自俄罗斯，可以将人类ACE2本地绑定为野外型 顺序。我们最近的观察结果共同表明需要开发研究和抑制潜力的工具 这种被忽视的病毒进化枝的人类感染。进化枝3可能是未来SARBECOVIRUS的起源 溢出物，但是由于进化枝之间的遗传差异，当前工具的保护能力可能有限 3和峰值蛋白中的先前的人Sarbecovires，病毒表面糖蛋白负责 病毒包膜和宿主细胞膜的受体结合和融合。我假设所有成员 该进化枝可以在受体结合结构域中的几个突变中获得人ACE2的利用 尖峰糖蛋白，但目前的疫苗和抗体治疗将降低针对 进化枝3 SARBECOVIRASE。在本提案的目标1中，我将发现所有当前成员的受体使用 3在非洲，欧洲和亚洲具有范围的Rhinolophus蝙蝠物种中，发现可以使人类的突变 这些病毒的ACE2结合和细胞进入，利用安全的非复制假病毒系统。在 AIM 2，我将在疫苗和单克隆抗体治疗方面确定哪些临床工具是 有效防止进化枝的细胞进入3个SARBECOVIRASE。了解当前的本地受体使用情况 结合对SARBECOVIRASE的序列评估，可能能够共同感染特定物种 Rhinolophus将深入了解这些病毒可用的进化可能性。此外， 鉴定可以使人ACE2结合和人类细胞系中细胞进入的突变将提供 关于这些病毒有多近的背景，要实现人类溢出所必需的第一步。最后， 评估当前工具的效力，以防止进化枝3 SARBECOVIRASS和结构性 进化枝3的表征，如果这些病毒越过物种 未来的障碍。