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病（CWD）发病机制和传播的机制，CWD是鹿和麋鹿的一种传染性疾病，属于一组由朊病毒引起的动物和人类致命的传染性神经退行性疾病。我们的主要目标是使用成熟的转基因（Tg）的方法来研究朊病毒蛋白（PrP）的一级结构元件和朊病毒株的特性影响慢性消耗病传播障碍的手段，以解决慢性消耗病的起源和慢性消耗病株的流行，并确定朊病毒在鹿科动物之间传播的机制。本研究提出了三个具体的目的：（1）利用表达Cervid（Cer）PrP的Tg小鼠模拟鹿和麋鹿的疾病，研究CWD在鹿科动物间的传播机制和在缺乏常规形式的致病性PrP积累的情况下的亚临床CWD复制机制;（2）应用Tg方法研究慢性消耗病（CWD）家系变异和CerPrP基因多态性对CWD发病的影响，探讨CWD的发病机制。CWD菌株在其他物种中引起的可能性;和（3）使用新型嵌合小鼠/CerPrP构建体和Tg方法与体外PrP扩增的创新组合来探测物种依赖性CWD传播屏障的分子基础。解决CWD传播机制将导致更好地控制鹿科动物种群中的CWD，并允许更准确地评估暴露于CWD对人类和牲畜造成的风险。拟议中的研究也将进一步我们了解的一般分子事件的基础朊病毒的传播，物种障碍和朊病毒株，最终导致人类和动物朊病毒疾病的合理的治疗和诊断方法，并将提供重要的信息感染剂的分子性质的背景下，临床和亚临床朊病毒疾病。

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.