TSE Prion Cell Biology

传染性海绵状脑病（Transmissible spongiform encephalopathies，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）转化为部分蛋白酶抗性、聚集的疾病相关同种型（PrPSc）。 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。 PrPC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PrPSc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PrPC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。 在2009年，我们：1）通过活细胞成像继续我们对PrPSc如何在神经元细胞中内化和运输的表征; 2）开发了特异性标记PrPC分子的新方法，以可视化它们在未感染细胞和瘙痒病感染过程中的运输; 3）应用这些新方法揭示了抗TSE化合物的不同作用机制以及PrPSc和PrPC的转运途径; 4）创造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;和5）开发了表达各种PrPC突变蛋白的新细胞培养模型。 通过这些努力，2009年出版了两份出版物。

Transmissible spongiform encephalopathies (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) to a partially protease-resistant, aggregated, disease-associated isoform (PrPSc). 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). PrPC is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein, and the majority of PrPSc 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 PrPC 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. In 2009, we have: 1) continued our characterization of how PrPSc is internalized and trafficked in neuronal cells by live cell imaging; 2) developed new methods to specifically tag PrPC molecules to visualize their trafficking in uninfected cells and during the course of scrapie infection; 3) applied these new methods to reveal new insights into the differential mechanisms of action of anti-TSE compounds and trafficking pathways of PrPSc and PrPC; 4) created new compounds for protein labeling that allow analysis by a variety of detection methods; and 5) developed new cell culture models expressing various PrPC mutant proteins. These efforts led to two publications in 2009.