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。 在过去的一年里，我们：1）继续我们的表征如何PrP-res是内在的，并通过共聚焦显微镜神经元细胞中的运输，扩大我们的研究，以原代神经元培养系统; 2）验证和优化新的方法，以特异性标记PrP-sen分子，以可视化他们在未感染的细胞和瘙痒病感染过程中的运输; 3）创建了用于蛋白质标记的新化合物，其允许通过多种检测方法进行分析;以及4）进一步表征了我们的新型细胞培养模型，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 how PrP-res is internalized and trafficked in neuronal cells by confocal microscopy, expanding our studies to primary neuronal culture systems; 2) validated and optimized new methods to specifically tag PrP-sen molecules to visualize their trafficking in uninfected cells and during the course of scrapie infection; 3) created new compounds for protein labeling that allow analysis by a variety of detection methods; and 4) further characterized our novel cell culture models to visualize the trafficking of other modified prion and amyloid proteins by confocal microscopy.