TSE/Prion Cell Biology

TSE是一组影响多种哺乳动物的神经退行性疾病，包括绵羊和山羊（羊瘙痒病）、鹿属（cervid spp.）（慢性消耗性疾病）和人类（克雅氏病）。我们的研究集中在朊病毒蛋白（PrP），因为这种蛋白在控制TSE发病机制的许多方面，如疾病易感性和种间传播中起着关键作用。TSE疾病的中心事件涉及正常宿主细胞朊病毒蛋白（PrPC或PrP-sen）转化为部分蛋白酶抗性、聚集的疾病相关同种型（PrPSc或PrP-res）。TSE引起的病理学改变通常与PrP-res沉积有关，但神经退行性变的机制尚不清楚。感染因子的性质，称为朊病毒，仍然不确定，但被认为主要由错误折叠的PrP组成，可能与另一种宿主辅助分子复合。PrP-sen是糖基磷脂酰肌醇（GPI）锚定的糖蛋白，并且体内产生的大多数PrP-res含有该GPI锚。膜协会的正常和疾病相关的PrP亚型可能会影响朊病毒疾病和PrP-sen功能的许多特点。我们的工作重点是阐明摄取，复制和传播的朊病毒的机制，除了确定哺乳动物朊病毒的生化组成和调查的因素，有助于赋予这些朊病毒的感染性表型，所有蛋白质错误折叠疾病的独特功能。 在过去的一年中，我们：1）继续我们对小鼠适应性羊瘙痒症感染的新细胞培养模型的表征; 2）表征PrP-res膜结合对这种新细胞培养模型感染的影响; 3）尝试在新的PrP转基因小鼠模型中测定的重组PrP制剂中产生朊病毒感染性; 4）通过共聚焦显微镜继续表征PrP-res如何在神经元细胞中内化和运输; 5）开发了特异性标记PrP-sen分子的新方法，以可视化它们在未感染细胞中和在羊瘙痒病感染过程中的运输;和6）建立细胞培养模型以通过共聚焦显微镜观察其他修饰的朊病毒和淀粉样蛋白的运输。

TSEs are a group of neurodegenerative diseases affecting a wide variety of mammals including sheep and goats (scrapie), cervid spp. (chronic wasting disease), and humans (Creutzfeldt-Jakob disease). Our studies are focused on the prion protein (PrP) due to the critical role of this protein in controlling many aspects of TSE pathogenesis such as susceptibility to disease and interspecies transmission. A central event in TSE disease involves the conversion of the normal host cellular prion protein (PrPC or PrP-sen) to a partially protease-resistant, aggregated, disease-associated isoform (PrPSc or PrP-res). TSE-induced pathology is usually associated with PrP-res deposition, but the mechanism of neurodegeneration is not understood. The nature of the infectious agent, called a prion, remains uncertain but is thought to be composed primarily of misfolded PrP, perhaps in complex with another host accessory molecule(s). PrP-sen is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein, and the majority of PrP-res produced in vivo contains this GPI anchor. Membrane association of both normal and disease-associated PrP isoforms may influence many features of prion disease and PrP-sen function. Our work is focused on elucidating mechanisms of uptake, replication, and spread of prions, in addition to determining the biochemical composition of mammalian prions and investigating factors that contribute to imparting the infectious phenotype to these prions, a unique feature among all protein misfolding diseases. Over the past year we have: 1) continued our characterization of a new cell culture model for infection with mouse-adapted scrapie; 2) characterized the effect of PrP-res membrane association on infection of this new cell culture model; 3) attempted to generate prion infectivity in preparations of recombinant PrP assayed in new PrP transgenic mouse models; 4) continued to characterize how PrP-res is internalized and trafficked in neuronal cells by confocal microscopy; 5) developed new methods to specifically tag PrP-sen molecules to visualize their trafficking in uninfected cells and during the course of scrapie infection; and 6) established cell culture models to visualize the trafficking of other modified prion and amyloid proteins by confocal microscopy.