Species Susceptibility Assay for Chronic Wasting Disease

描述（由申请人提供）：与狂犬病一样，慢性消耗性疾病（CWD）是一种致命的野生动物宿主传染病。防治慢性消耗病和其他野生动物朊病毒疾病的战略需要结合积极的监测和野生动物控制措施。查明易受慢性消耗病影响的物种特别重要，因为虽然野生传播方式仍不清楚，但无法预测目前流行病的可能影响。 在受朊病毒疾病影响的人类和动物的大脑中，称为PrPc的细胞糖蛋白转化为称为PrPsc的蛋白酶抗性致病同种型。在我们的实验室中，我们专注于开发一种新的方法，可以方便地用于各种朊病毒疾病的敏感性测试。该方法在含有PrPc的正常脑组织存在下，以生物化学方式放大朊病毒感染的组织匀浆中的PrPsc水平。我们已经成功地扩增PrPsc>10倍，在脑细胞膜制备生物化学没有洗涤剂或苛刻的物理破坏的细胞成分。 与体内PrPc转化为PrPsc的特征一致，我们的PrPsc扩增方法是朊病毒特异性的，并且取决于时间、pH和温度。值得注意的是，体外PrPsc扩增的程度与特定动物物种对体内朊病毒感染的易感性相关。此外，我们已经成功地从来自两种动物物种的四种不同朊病毒株扩增PrPsc。 我们现在建议测试的假设，即非鹿科物种可能是易感的慢性消耗病感染或亚临床携带。在与达特茅斯希区柯克医疗中心，新罕布什尔州渔业和游戏管理局，和新罕布什尔州国家兽医诊断实验室的合作伙伴关系，我们建议使用体外PrPsc扩增来衡量一系列潜在的宿主物种的潜在易感性慢性消耗病以及瘙痒症。待测试的物种包括人类、牛、猪、绵羊、山羊、鸡、狗、猫、郊狼、狐狸、浣熊、野猫、野兔和鹿鼠。这项工作的结果将有效地识别可能易受慢性消耗病和羊瘙痒病影响的物种，并有助于促进公共卫生监测和北美朊病毒疾病的控制工作。

DESCRIPTION (provided by applicant): Like rabies, chronic wasting disease (CWD) is a fatal infectious disease with a wildlife reservoir. Strategies to combat CWD and other wildlife prion diseases will require a combination of active surveillance and wildlife control measures. The identification of species susceptible to CWD is of particular importance because, while the mode of transmission in the wild remains unknown, it is not possible to predict the likely impact of the current epidemic. In the brains of humans and animals affected by prion diseases, a cellular glycoprotein termed PrPc converts into n protease-resistant pathogenic isoform called PrPsc. In our laboratory, we have focused on developing a novel method that can be conveniently used for susceptibility testing in a variety of prion diseases. This method amplifies PrPsc levels in prion-infected tissue homogenates biochemically in the presence of normal brain tissue containing PrPc. We have successfully amplified PrPsc>10-fold in brain membrane preparations biochemically without detergents or harsh physical disruption of cellular constituents. Consistent with the characteristics of PrPc conversion to PrPsc in vivo, our method of PrPsc amplification is prion-specific, and depends upon time, pH, and temperature. Significantly, the degree of PrPsc amplification in vitro correlates with the susceptibility of a specific animal species to prion infection in vivo. Furthermore, we have successfully amplified PrPsc from four different prion strains derived from two animal species. We now propose to test the hypothesis that non-cervid species might be susceptible to CWD infection or subclinical carriage. In partnership with the Dartmouth Hitchcock Medical Center, New Hampshire Fish and Game Authority, and New Hampshire State Veterinary Diagnostic Laboratory, we propose to use in vitro PrPsc amplification to measure the potential susceptibility of a range of potential host species to CWD as well as scrapie. Species to be tested include humans, cows, pigs, sheep, goats, chickens, dogs, cats, coyotes, foxes, raccoons, fisher cats, hares, and deer mice. The results of this work will efficiently identify species potentially susceptible to CWD and scrapie and help facilitate public health surveillance and control efforts for North American prion diseases.