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

基本信息

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
项目类别：
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

项目摘要

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 年底爆发的 SARS-CoV-2 已导致全球超过 600 万人丧生。自那以后，人们高度关注疫苗和临床治疗的开发，以增加由这种病毒引起的疾病的生存能力。然而，在自然界中，还有其他不同的 sarbeco 病毒在传播这可能会带来未来的溢出潜力，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。地理位置和人类最早利用 ACE2 的情况并不存在在该进化枝中发现的病毒导致该进化枝被低估。然而，我们最近表明该分支的一个成员，来自肯尼亚的 BtKY72，有能力在一内获得人类 ACE2 结合氨基酸突变和两种突变内的细胞进入。此外，我们还首次展示了该分支的另一个成员，来自俄罗斯的 Khosta-2，可以作为野生型天然结合人类 ACE2 顺序。总之，我们最近的观察表明需要开发工具来研究和抑制潜在的人类被这一被忽视的病毒分支感染。进化枝 3 可能是未来 sarbecovirus 的起源溢出，但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 和之前的人类 sarbecovirus 中的刺突蛋白，病毒表面糖蛋白负责受体结合以及病毒包膜和宿主细胞膜的融合。我假设所有成员该进化枝的受体结合域中的几个突变可以获得人类 ACE2 的利用刺突糖蛋白，但目前的疫苗和抗体治疗将降低针对刺突糖蛋白的功效 sarbecoviruses 3 分支。在本提案的目标 1 中，我将揭示进化枝所有当前成员的受体使用情况 3 在分布于非洲、欧洲和亚洲的菊头蝠物种中发现了使人类能够生存的突变这些病毒利用安全的非复制假病毒系统进行 ACE2 结合和细胞进入。在目标 2，我将建立疫苗和单克隆抗体治疗方面的临床工具有效防止 clade 3 sarbecoviruses 进入细胞。了解当前天然受体的使用情况结合对可能能够共同感染特定物种的 sarbecovirus 进行序列评估菊头蝠将深入了解这些病毒的进化可能性。此外，鉴定使人类 ACE2 结合并进入人类细胞系的突变将提供这些病毒距离实现人类蔓延所需的第一步还有多远。最后，评估当前工具对 clade 3 sarbecoviruses 的有效性和结构进化枝 3 刺突胞外域的表征，将为我们在这些病毒跨物种时提供一个良好的开端未来的障碍。