Redefining the zoonotic potential of chronic wasting disease

慢性衰弱病(CWD)的迅速蔓延，这是一种自由放牧和饲养的麋鹿的普恩病毒病 在北美，驼鹿是一个主要的、持续的威胁。大约每36个美国人中就有一个猎鹿和麋鹿 和吃鹿肉，据估计，每年消费7000-15000个感染CWD的鹿肉。这 这加剧了人们对CWD带来的人类健康风险的日益担忧。目前还没有记录在案的病例 慢性萎缩性脑病传播给人类，即使所有的普恩病毒疾病潜伏期很长， CWD在人类中的未知表现是不可能得出明确结论的。普恩病毒的人畜共患病潜力 疾病的例子是牛海绵状脑病(疯牛病)，它导致 在一种新形式的人类Pron病(VCJD)中。疯牛病可通过食蟹猴和转基因猴传播 表达人类病毒蛋白的小鼠。CWD在同一非人类中传播研究的初步结果 灵长类动物和小鼠的人类Pron病模型并不成功，证实了这样的结论 CWD的人畜共患病潜力很低，如果不是没有的话。我们的团队是接种食蟹猴疫苗的财团的一部分 CWD通过不同途径传播的猕猴。一些动物表现出细微的临床症状，让人想起普里恩 在安乐死后，大脑中出现空泡化、PrPSc沉积和星形细胞增多的微弱迹象 未检测到抗蛋白酶K(PK)蛋白(PrP)。我们现在已经演示了 猕猴慢性萎缩性脑病首次在转基因小鼠模型中传播临床病毒病 和人类PrP病，尽管没有检测到对PK耐药的PrP。真正的PrPSc只是 在第三次从老鼠模型传到银行田鼠模型时检测到。总之，这是CWD非常重要的第一个证据 很可能具有人畜共患病的潜力。当前提案的目标是重新定义慢性WD的人畜共患病潜力。 通过对实验传输中出现的CWD蛋白的生物学特性进行表征 进入猕猴，以获得关于慢性萎缩性脑病如何在人类身上表现的重要信息。在目标1中，我们 将通过比较来研究银行田鼠中猕猴的CWD(CWDmac)是否代表了一种新的Prion品系 对一系列来自不同物种的已知普恩病毒菌株的生化和生物学特性进行了研究。AIM 2的地址 CWDmac是否代表了一种适应于鹿或人类的中间病毒株的问题 通过，并且拥有更大的寄主范围。我们将通过在体内通过宫颈切开或 人性化的老鼠模型。在体外，我们将利用连续的PMCA和新产生的PrP0/0细胞培养模型 对于感染，在与来自不同物种的PrP重组后。在目标3中，我们将阐明观察到的 传染性和真正的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，我们将通过创新的方式阐明脑细胞对CWDmac暴露的反应 单细胞RNA测序。综上所述，我们的研究将揭示CWD在人类中的可能表现， 这对于对CWD的人畜共患病潜力得出明确的结论至关重要。

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.