TSE Prion Cell Biology

TSE是一组神经退行性疾病，影响多种哺乳动物，包括绵羊和山羊(瘙痒病)、鹿种。(慢性消耗性疾病)和人类(克雅氏病)。我们的研究主要集中在Prion蛋白(PrP)上，因为该蛋白在控制TSE发病的许多方面起着关键作用，如疾病易感性和物种间传播。TSE病的一个中心事件涉及将正常宿主细胞内的Prion蛋白(PrPC)转换为部分抗蛋白酶的、聚集的、疾病相关的亚型(PrPSc)。TSE诱导的病理通常与PrP-res沉积有关，但其神经退行性变的机制尚不清楚。这种被称为PrP的感染性病原体的性质尚不清楚，但人们认为它主要由错误折叠的PrP组成，可能与另一种宿主辅助分子(S)形成了复合体。PrPC是一种糖基磷脂酰肌醇(GPI)锚定的糖蛋白，体内产生的PrPSc大多含有这个GPI锚定。正常PrP亚型和疾病相关PrP亚型的膜结合可能影响PrPC疾病的许多特征和PrPC功能。我们的工作集中在阐明Prion的摄取、复制和传播机制，以及确定哺乳动物Prion的生化组成和调查导致这些Prion具有感染性表型的因素，这是所有蛋白质错误折叠疾病的一个独特特征。 在过去的一年里，我们通过活体细胞成像继续我们对PrPSc如何内化和运输到神经细胞的表征，将我们的研究扩展到原代神经元培养系统；2)验证和优化了专门标记PrPC分子的新方法，以可视化其在未感染细胞和瘙痒病感染过程中的运输；3)应用这些新方法来揭示抗TSE化合物的作用机制和PrPSc和PrPC的运输途径；4)创建新的蛋白质标记化合物，使各种检测方法能够进行分析；5)开发出表达各种PrPC突变蛋白的新的细胞培养模型；以及6)进一步表征了我们的新细胞培养模型，以通过活细胞成像来可视化其他修饰的Pron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) 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 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 PrPSc is internalized and trafficked in neuronal cells by live cell imaging, expanding our studies to primary neuronal culture systems; 2) validated and optimized 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 mechanism of action of an anti-TSE compound and trafficking pathways of PrPSc and PrPC; 4) created new compounds for protein labeling that allow analysis by a variety of detection methods; 5) developed new cell culture models expressing various PrPC mutant proteins; and 6) further characterized our novel cell culture models to visualize the trafficking of other modified prion and amyloid proteins by live cell imaging.