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

• 批准号: 10414935
• 负责人: Sabine Gilch
• 金额: $ 27万
• 依托单位: UNIVERSITY OF CALGARY
• 依托单位国家: 美国
• 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/10414935
• 关键词: Address; American; Animals; Asia; Astrocytosis; Biochemical; Biological; Bovine Spongiform Encephalopathy; Brain; Cattle; Cell Culture Techniques; Characteristics; Chronic Wasting Disease; Clinical; Conflict (Psychology); Consumption; Data; Deer; Deposition; Disease; Disease Outbreaks; Dissociation; Eating; Endopeptidase K; Europe; Euthanasia; Exhibits; Exposure to; Farm; Feces; Goals; Health; Human; In Vitro; Infection; Light; 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; Vacuole; 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

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.

自由放养和养殖的鹿、麋鹿和驯鹿的慢性消耗性疾病（CWD）的迅速蔓延， 和驼鹿，是北美的主要和持续的威胁。大约每36个美国人中就有一个人猎鹿和麋鹿。 并食用鹿肉，据估计，每年有7，000 - 15，000只感染了疯牛病的鹿被食用。这 这加剧了人们对慢性消耗病带来的人类健康风险的担忧。没有记录在案的 尽管所有朊病毒疾病的潜伏期都很长， CWD在人类中的未知表现不可能得出明确的结论。朊病毒的人畜共患病潜力 牛海绵状脑病（BSE，疯牛病）是一种典型的疯牛病， 一种新型的人类朊病毒病（vCJD）。BSE可传播给食蟹猴， 表达人类朊病毒蛋白的小鼠。慢性消耗病向同一非人类传播研究的初步结果 灵长类动物和小鼠模型的人类朊病毒疾病是不成功的，证实了结论， CWD的人畜共患病潜力很低，如果不是不存在的话。我们的小组是一个财团的一部分， 猕猴通过不同的路线与慢性消耗病。一些动物表现出轻微的临床症状，让人联想到朊病毒 疾病，并且在安乐死时，脑中空泡化、PrPSc沉积和星形胶质细胞增多的微弱迹象被发现。 发现，而没有蛋白酶K（PK）抗性朊病毒蛋白（PrP）是可检测的。我们已经证明了 首次发现猕猴慢性消耗病可将临床朊病毒疾病传播给慢性消耗病转基因小鼠模型 和人朊病毒病，尽管在没有可检测的PK-抗性PrP的情况下。Bona fide PrPSc仅 在小鼠至库田鼠模型的第3次传代时检出。总之，这是第一个证据表明，慢性消耗病非常 很可能有传染性目前提案的目标是重新定义慢性消耗病的人畜共患病潜力 通过表征实验传播中出现的慢性消耗病朊病毒的生物学特性， 进入猕猴体内，以获取有关慢性消耗病如何在人类身上表现的重要信息。目标1： 将研究来自银行田鼠猕猴（CWDmac）的CWD是否代表一种新的朊病毒株，通过比较 生物化学和生物学特性与来自不同物种的一系列已知朊病毒菌株的关系。目标2地址 问题是CWDmac是否代表一种中间朊病毒株， #21453;，并具有广泛的传播范围。我们将通过在子宫颈化的或 人源化小鼠模型。在体外，我们将使用连续PMCA和新生成的PrP 0/0细胞培养模型 用于感染，在用来自不同物种的PrP重建后。在目标3中，我们将阐明所观察到的 感染性和真正的PrPSc的存在之间的分离。我们建议识别非典型PrP 与CWDmac相关的片段，我们将阐明脑细胞对CWDmac暴露的反应， 单细胞RNA测序。总之，我们的研究将揭示慢性消耗病在人类中的可能表现， 这对于得出关于CWD的人畜共患病潜力的明确结论至关重要。