Characterization of de novo generation of infectious prions

传染性朊病毒从头产生的表征

• 批准号: 7647869
• 负责人: Joaquin Castilla
• 金额: $ 3.26万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2009-05-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7647869
• 关键词: Address; Affect; Affinity; Age; Animal Model; Animals; Antibodies; Biochemical; Biologic Characteristic; Biological; Biological Assay; Bovine Spongiform Encephalopathy; Brain; Case Study; Cations; Cattle; Cells; Characteristics; Chronic Wasting Disease; Collection; Communicable Diseases; Comparative Study; Conscious; Country; Creutzfeldt-Jakob Syndrome; Data; Deer; Dependence; Detergents; Disease; Environment; Environmental Exposure; Epidemiologic Studies; Epidemiology; Europe; European; Event; Experimental Models; Face; Frequencies; Generations; Genes; Genetic; Genetic Polymorphism; Goals; Goat; Hamsters; Hand; Human; Immune; In Vitro; Incubated; Individual; Infectious Agent; Inherited; Investigation; Japan; Kinetics; Laboratories; Lesion; Life; Measures; Methodology; Methods; Microtus; Modeling; Modification; Molecular; Monoclonal Antibodies; Mouse Strains; Mus; Mutate; Mutation; Names; Nature; Neurodegenerative Disorders; New Zealand; Oryctolagus cuniculus; Pattern; Peromyscus; Phase; Play; PrP; PrPSc Proteins; Prion Diseases; Prions; Process; Proteins; Reaction; Research Design; Resistance; Rodent; Rodent Model; Role; Ruminants; Sampling; Scheme; Scrapie; Seeds; Sheep; Somatic Mutation; Sonication; Source; Specificity; Staging; Steel; Techniques; Technology; Temperature; Testing; Time; Transgenic Animals; Transgenic Mice; Transgenic Model; Transgenic Organisms; Tube; Wild Animals; Wild Type Mouse; Work; Yeasts; base; cervid; deoxyhemoglobin; design; in vivo; magnetic beads; molecular phenotype; novel; overexpression; particle; pathogen; protein misfolding cyclic amplification; prototype; public health relevance; recombinant PrP

DESCRIPTION (provided by applicant): Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative disorders affecting both humans and animals. There is no available treatment or therapy for these fatal diseases. TSEs can have diverse origins, including hereditary, sporadic (putatively spontaneous), and infectious. The occurrence of spontaneous cases of prion diseases in humans (sporadic CJD) and in other species, i.e. Bovine spongiform encephalopathy (BSE) in US cattle and Nor98 (atypical scrapie) in New Zealand sheep, provide evidence that this infrequent spontaneous phenomenon may occur naturally. There are no reported cases of spontaneously- occurring (de novo) prion disease in experimental wild-type rodent models. The infectious agent associated with TSEs, the prion, appears to be composed uniquely of a protein which is a conformationally-modified version (PrPSc) of a natural prion protein (PrPC). The disease is transmitted by the conversion of host PrPC into PrPSc induced by small quantities of PrPSc contained in the infectious agent. We have recently described a novel technique, Protein Misfolding Cyclic Amplification (PMCA), which mimics this process in vitro, but with greatly accelerated kinetics, enabling PrPSc amplification in the test tube. This technique has been used to efficiently amplify a variety of prion strains from mice, hamsters, bank voles, deer, cattle, sheep, and humans. In addition, the in vitro generated prions possess key prion features, i.e., they are infectious in vivo and maintain their prion strain specificity. However, it has not been previously possible to generate infectivity de novo, starting with healthy material. In other words, the spontaneous generation of prions has been hypothesized to be restricted to an infrequent in vivo phenomenon in only a few species. To mimic spontaneous generation of infectivity in vitro is one of the most important challenges that the prion field currently faces. In preliminary studies, we have generated infectious prions from ten different rodent species (including wild animals) starting with non-infectious brains. The major goal of this project is the de novo generation and characterization of a diversity of infectious prion strains using several in vitro and in vivo approaches as well as revealing the intrinsic mechanisms involved by distinguishing amplification of minimal preexisting seed PrPSc from "in vitro spontaneous" generation. Finally, we will extend this study to other species to mimic what may already be happening in nature. PUBLIC HEALTH RELEVANCE: Prion diseases are a group of fatal and infectious neurodegenerative disorders affecting humans and animals for which no therapy is available. The nature of the infectious agent is at the center of passionate controversy. The mechanism by prion agent propagates the disease in vivo is being subject to intense investigation. The most common origin of the disease is an unfamiliar spontaneous phenomenon. Unfortunately, there are no reported cases of spontaneously-occurring (de novo) prion diseases in experimental models making the study of this intriguing occurrence more difficult. In this proposal, we show strong evidence using rodent models where this phenomenon can be mimicked in vitro. This find opens enormous possibilities for understanding the prion diseases and for designing new therapies inconceivable until now.

描述（由申请方提供）：传染性海绵状脑病（TSE）是一组影响人类和动物的神经退行性疾病。这些致命疾病没有可用的治疗或疗法。TSE可以有不同的起源，包括遗传性、散发性（脓疱性自发）和传染性。人类（散发性CJD）和其他物种中朊病毒病的自发病例，即美国牛的牛海绵状脑病（BSE）和新西兰绵羊的Nor98（非典型瘙痒病）的发生，提供了这种罕见的自发现象可能自然发生的证据。在实验性野生型啮齿动物模型中没有自发发生（从头）朊病毒病的报告病例。与TSE相关的感染因子朊病毒似乎由天然朊病毒蛋白（PrPC）的构象修饰形式（PrPSc）的蛋白质独特组成。该疾病通过感染原中含有的少量PrPSc诱导宿主PrPC转化为PrPSc而传播。我们最近描述了一种新的技术，蛋白质错误折叠循环扩增（PMCA），它在体外模拟这一过程，但大大加速动力学，使PrPSc扩增在试管中。该技术已被用于有效地扩增来自小鼠、仓鼠、田鼠、鹿、牛、羊和人类的各种朊病毒株。此外，体外产生的朊病毒具有关键的朊病毒特征，即，它们在体内具有感染性并保持其朊病毒株特异性。然而，以前不可能从健康材料开始重新产生感染性。换句话说，朊病毒的自发产生被假设为仅限于少数物种中罕见的体内现象。在体外模拟感染性的自发产生是朊病毒领域目前面临的最重要的挑战之一。在初步研究中，我们已经从10种不同的啮齿动物（包括野生动物）的非感染性大脑中产生了感染性朊病毒。该项目的主要目标是从头生成和表征的感染性朊病毒株的多样性，使用几种体外和体内的方法，以及揭示所涉及的内在机制，通过区分扩增最小的预先存在的种子PrPSc从“体外自发”的一代。最后，我们将把这项研究扩展到其他物种，以模仿自然界中可能已经发生的事情。公共卫生关系：朊病毒病是一组影响人类和动物的致命和传染性神经退行性疾病，目前尚无治疗方法。传染源的性质是激烈争论的中心。朊病毒在体内传播疾病的机制正在受到深入的研究。这种疾病最常见的起源是一种不熟悉的自发现象。不幸的是，在实验模型中没有报道自发发生（从头）朊病毒疾病的病例，这使得对这种有趣的事件的研究更加困难。在这个提议中，我们使用啮齿动物模型显示了强有力的证据，在这些模型中，这种现象可以在体外模拟。这一发现为理解朊病毒疾病和设计迄今为止无法想象的新疗法提供了巨大的可能性。