Redefining the zoonotic potential of chronic wasting disease

重新定义慢性消耗性疾病的人畜共患潜力

基本信息

批准号：
10610969
负责人：
Sabine Gilch
金额：
$ 27万
依托单位：
UNIVERSITY OF CALGARY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10610969
关键词：
Address American Animals Asia Astrocytosis Biochemical Biological Bovine Spongiform Encephalopathy Brain Cattle Cell Culture Techniques Characteristics Chronic Wasting Disease Clinical Consumption Data Deer Deposition Disease Disease Outbreaks Dissociation Eating Endopeptidase K Europe Euthanasia Exhibits Exposure to Farm Feces Goals Health Human In Vitro Incubated Infection Link Macaca Macaca fascicularis Microtus Modeling Molecular Mus Neurodegenerative Disorders North America Oral Pathologic Pathway interactions Peptide Hydrolases Persons Phenotype PrP PrPSc Proteins Prion Diseases Prions Process Property Protein Fragment Protein Isoforms Public Health Reindeer Research Resistance Risk Rodent Route Saliva Testing Time Tissues Toxic effect Transgenic Mice Urine Zoonoses brain cell cervid disease transmission driving force epidemiologic data experimental study human model humanized mouse in vivo innovation insight mouse model nonhuman primate overexpression prion seeds reconstitution response single-cell RNA sequencing transmission process

项目摘要

The rapid expansion of chronic wasting disease (CWD), a prion disease of free-ranging and farmed deer, elk and moose, is a major and ongoing threat in North America. Approximately 1 in 36 Americans hunt deer and elk and eat venison, and it is estimated that 7,000 – 15,000 CWD-infected cervids are consumed annually. This fuels growing concerns about the human health risks imposed by CWD. There are no documented cases of CWD transmission to humans, even though with the long incubation periods of all prion diseases and the unknown presentation of CWD in humans definite conclusions are not possible. The zoonotic potential of prion diseases has been exemplified by bovine spongiform encephalopathy (BSE, mad cow disease) which resulted in a new form of human prion disease (vCJD). BSE was transmissible to Cynomolgus macaques and transgenic mice expressing the human prion protein. Initial results of CWD transmission studies to the same non-human primate and mouse models of human prion disease were not successful, corroborating the conclusion that the zoonotic potential of CWD is low, if not absent. Our groups were part of a consortium that inoculated Cynomolgus macaques via different routes with CWD. Some animals exhibited subtle clinical signs reminiscent of prion disease, and upon euthanasia, weak signs of vacuolation, PrPSc deposition and astrocytosis in the brain were found, while no proteinase K (PK) resistant prion protein (PrP) was detectable. We have now demonstrated for the first time that CWD from macaques can transmit clinical prion disease to transgenic mouse models of CWD and human prion disease, albeit in the absence of detectable PK-resistant PrP. Bona fide PrPSc was only detected upon 3rd passage from mouse to bank vole models. Altogether, this is the first evidence that CWD very likely has zoonotic potential. The goal of the current proposal is to redefine the zoonotic potential of CWD by characterizing the biological properties of CWD prions emerging upon experimental transmission into macaques, for obtaining important information on how CWD could manifest in humans. In Aim 1, we will study whether CWD from macaque (CWDmac) in bank voles represents a new prion strain, by comparing biochemical and biological properties to an array of known prion strains from different species. Aim 2 addresses the question whether CWDmac represents an intermediate prion strain, adaptable to cervids or humans upon passage, and possessing an expanded host range. We will address this by in vivo passage in cervidized or humanized mouse models. In vitro, we will utilize serial PMCA and a newly generated PrP0/0 cell culture model for infection, upon reconstitution with PrP from different species. In Aim 3, we will shed light on the observed dissociation between infectivity and the presence of bona fide PrPSc. We propose to identify atypical PrP fragments associated with CWDmac, and we will elucidate brain cell responses to CWDmac exposure by innovative single cell RNA sequencing. In summary, our studies will uncover the possible manifestation of CWD in humans, which is of critical importance for drawing definite conclusions about the zoonotic potential of CWD.

慢性消耗性疾病（CWD）的迅速蔓延，这是一种散养和养殖鹿、麋鹿的朊病毒病和驼鹿是北美的一个主要且持续的威胁，大约每 36 名美国人中就有 1 人狩猎鹿和麋鹿。并吃鹿肉，估计每年消耗 7,000 – 15,000 只感染 CWD 的鹿。加剧了人们对 CWD 造成的人类健康风险的日益担忧。目前还没有记录在案的病例。尽管所有朊病毒疾病的潜伏期都很长，但 CWD 会传播给人类慢性病在人类中的表现尚不清楚，不可能得出朊病毒的人畜共患病潜力的明确结论。以牛海绵状脑病（BSE，疯牛病）为例，该病导致一种新形式的人类朊病毒病（vCJD）可传播给猕猴和转基因动物。表达人类朊病毒蛋白的小鼠对相同非人类的 CWD 传播研究的初步结果。人类朊病毒病的灵长类动物和小鼠模型没有成功，证实了以下结论： CWD 的人畜共患可能性即使不是不存在，也很低。猕猴通过不同途径感染 CWD，一些动物表现出微妙的临床症状，让人想起朊病毒。疾病，安乐死后，大脑中出现微弱的空泡化、PrPSc 沉积和星形细胞增多迹象。发现，而我们现在已经证明没有检测到蛋白酶 K (PK) 抗性朊病毒蛋白 (PrP)。首次发现来自猕猴的 CWD 可将临床朊病毒病传播至 CWD 转基因小鼠模型和人类朊病毒病，尽管在没有可检测到的 PK 抗性 PrP 的情况下，只有真正的 PrPSc。总而言之，这是 CWD 非常明显的第一个证据。当前提案的目标是重新定义 CWD 的人畜共患潜力。通过表征实验传播中出现的 CWD 朊病毒的生物学特性在目标 1 中，我们研究了猕猴，以获得有关 CWD 如何在人类身上表现的重要信息。将研究银行田鼠中猕猴（CWDmac）的 CWD 是否代表一种新的朊病毒株，通过比较目标 2 针对一系列已知不同物种的朊病毒株的生化和生物学特性。 CWDmac 是否代表一种中间朊病毒株，可适应鹿科动物或人类的问题传代，并拥有扩大的宿主范围，我们将通过在体内传代来解决这个问题。在体外，我们将利用系列 PMCA 和新生成的 PrP0/0 细胞培养模型。对于感染，在用来自不同物种的 PrP 重建后，我们将阐明观察到的情况。感染性与真正的 PrPSc 之间的分离我们建议识别非典型 PrP。与 CWDmac 相关的片段，我们将通过创新的方式阐明脑细胞对 CWDmac 暴露的反应总之，我们的研究将揭示 CWD 在人类中可能的表现，这对于得出有关 CWD 人畜共患潜力的明确结论至关重要。