TRANSGENETIC STUDIES OF PRION DISEASE IN CERVIDS

描述（由申请人提供）：我们广泛的长期目标是解决物种屏障和菌株特异性控制慢性消耗性疾病（CWD）发病和传播的机制，CWD是鹿和麋鹿的一种传染病，属于由朊病毒引起的动物和人类致命的、可传播的神经退行性疾病。我们的主要目标是使用成熟的转基因（Tg）方法来研究朊病毒蛋白（PrP）的主要结构元素和朊病毒菌株特性对CWD传播障碍的影响，解决CWD的起源和CWD菌株的流行，并确定病毒在动物之间传播的机制。提出了三个具体目的：(1)利用表达cervid (Cer) PrP [Tg(CerPrP)]的Tg小鼠模拟鹿和麋鹿的疾病，研究在没有常规致病性PrP积累的情况下，cervid (Cer) PrP在cervid （Cer）鼠间的传播机制和CWD的亚临床复制；(2)利用Tg方法评估CWD菌株变异和CerPrP多态性对CWD发病机制的影响，探讨CWD菌株在其他物种中的致病潜力；(3)利用新型嵌合小鼠/CerPrP构建物和Tg方法与体外PrP扩增的创新结合，探索物种依赖性CWD传播屏障的分子基础。解决CWD的传播机制将导致更好地控制cervid种群中的CWD，并允许更准确地评估暴露于CWD对人类和牲畜构成的风险。拟议的研究还将进一步加深我们对朊病毒繁殖，物种屏障和朊病毒菌株的一般分子事件的理解，这将最终导致人类和动物朊病毒疾病的合理治疗和诊断方法，并将在临床和亚临床朊病毒疾病的背景下提供有关感染因子分子性质的重要信息。

DESCRIPTION (provided by applicant): Our broad long-term objective is to address the mechanisms by which species barriers and strain specificities control the pathogenesis and transmission of chronic wasting disease (CWD), a contagious disease of deer and elk belonging to a group of fatal, transmissible neurodegenerative disorders of animals and humans caused by prions. Our major objectives are to use proven transgenic (Tg) approaches to study the means by which primary structure elements of the prion protein (PrP) and prion strain properties influence CWD transmission barriers, to address the origins of CWD and the prevalence of CWD strains, and to determine the mechanism of prion transmission among cervids. Three Specific Aims are proposed: (1) To use Tg mice expressing cervid (Cer) PrP [Tg(CerPrP)] that simulate disease in deer and elk to study the mechanisms of CWD transmission among cervids and sub-clinical CWD replication in the absence of accumulation of conventional forms of pathogenic PrP; (2) To use Tg approaches to assess the influence of CWD strain variation and CerPrP polymorphisms on CWD pathogenesis and to address the disease-causing potential of CWD strains in other species; and, (3) To probe the molecular basis of species-dependent CWD transmission barriers using novel chimeric murine/CerPrP constructs and an innovative combination of Tg approaches and in vitro PrP amplification. Addressing the mechanism of CWD transmission will lead to better CWD control in cervid populations and allow more accurate assessments of the risks posed to humans and livestock from exposure to CWD. The proposed studies will also further our understanding of the general molecular events underlying prion propagation, species barriers and prion strains that will ultimately result in rational therapeutic and diagnostic approaches for human and animal prion diseases and will provide important information about the molecular nature of the infectious agent in the contexts of clinical and sub-clinical prion disease.