Infectious prion generation by mouse transgenesis

描述(申请人提供)：虽然已有广泛的研究集中在病毒病的病因上，但全长重组病毒蛋白(PrP)的感染性尚未被证明，也没有遗传性海绵状脑病(TSE)的动物模型。基于对麋鹿PrP结构的核磁共振研究，我们建立了一个与野生型PrP存在2个氨基酸差异的转基因小鼠模型，导致了小鼠PrP结构的改变。这只转基因小鼠有一个非常明确的刚性环，将β折叠与阿尔法螺旋连接起来。令人惊讶的是，转基因小鼠发生了一种自发的神经系统疾病，100%外显，特征是空泡改变、胶质增生、小胶质细胞激活和大脑中的PrP斑块，类似于患有慢性消瘦疾病(CWD)的鹿和变异型克雅氏病(VCJD)或Gerstmann-Straussler-Scheinker综合征(GSS)。我们的短期目标是确定新培育的有斑块的小鼠是否已经发展成一种传染性的普恩病毒疾病。如果具有感染性，这只转基因小鼠将是第一个从全长Pron蛋白遗传产生感染性TSE的模型，而且特别耐人寻味，因为确切的结构变化已经被表征。此外，我们将阐明这种已知的结构变化是否改变了物种屏障。我们提出的研究目标背后的假设是，“刚性环”(RL)PrP是一种错误折叠的蛋白质，会导致感染性淀粉样斑块和神经变性，类似于人类家族性TSE。这些研究的目的是：(1)确定RL PrP是否具有传染性，以及这两个突变如何改变物种屏障；(2)确定由刚性环引起的神经退行性疾病的特征，并了解神经退行性疾病的基础。这项使用所描述的RL小鼠的研究将是第一次通过转基因来模拟PrP的已知结构特征来研究TSE的易感性和发病机制。通过阐明RL结构在TSE易感性和致病机制中的作用，我们希望对PrP转化、PrP转化和种属屏障在PrP疾病中诱导的神经变性和斑块形成有基本的认识。

DESCRIPTION (provided by applicant): Although extensive research has focused on the etiologic agent in prion disease, infectivity of full length recombinant prion protein (PrP) has not yet been shown, and there is no genetic animal model of a transmissible spongiform encephalopathy (TSE). Based on structural PrP NMR studies of the elk PrP (K. Wuthrich laboratory), we have developed a transgenic mouse model with 2 amino acid differences from wild type PrP leading to a structural alteration in mouse PrP. The transgenic mouse has an extremely well- defined, rigid loop which connects a beta sheet with an alpha helix. Surprisingly, the transgenic mice develop a spontaneous neurologic disease with 100% penetrance characterized by vacuolar change, gliosis, microglial activation, and PrP plaques in the brain, similar to deer with chronic wasting disease (CWD) and patients with variant Creutzfeldt-Jakob disease (vCJD) or Gerstmann-Straussler-Scheinker syndrome (GSS). Our short term goal is to determine whether the newly developed mice with plaques have developed a transmissible prion disease. If infectious, this transgenic mouse would be the first model of an infectious genetically generated TSE from a full length prion protein, and would be particularly intriguing because the exact structural change has already been characterized. In addition, we will elucidate whether this known structural change has altered the species barrier. The hypothesis underlying our proposed research aims is that the "rigid loop" (RL) PrP is a misfolded protein which leads to infectious amyloid plaques and neurodegeneration, similar to a human familial TSE. The goals of the proposed studies are to: (1) determine whether the RL PrP is infectious and how the two mutations alter the species barrier and (2) characterize the neurodegenerative disease caused by the rigid loop and to understand the basis of the neurodegeneration. The studies using the described RL mouse would be the first time a known structural feature of PrP is modeled by transgenesis to study TSE susceptibility and pathogenesis. By elucidating the impact of the RL structure in TSE susceptibility and pathogenesis, we hope to gain basic insights into prion induced neurodegeneration and plaque formation, PrP conversion, and species barriers in prion disease.