Replication mechanism of human prions

人类朊病毒的复制机制

• 批准号: 8312479
• 负责人: WITOLD K SUREWICZ
• 金额: $ 54万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8312479
• 关键词: Antibodies; Biologic Characteristic; Biological Assay; Brain; Classification; Code; Complement; Complex; Coupled; Creutzfeldt-Jakob Syndrome; Data; Deuterium; Development; Disease; Endopeptidase K; Evolution; Foundations; Goals; Human; Hydrogen; Immunoassay; In Vitro; Laboratory Study; Lead; Mass Spectrum Analysis; Measurement; Measures; Mesocricetus auratus; Methods; Molecular; Molecular Conformation; Mus; Nerve Degeneration; Nervous system structure; Neurodegenerative Disorders; Parents; Pathogenesis; Patients; Peptide Hydrolases; PrP sequence; PrPC Proteins; PrPSc Proteins; Prion Diseases; Prions; Procedures; Process; Property; Protein Precursors; Protocols documentation; Reaction; Recombinants; Resistance; Resolution; Rodent; Seeds; Serial Passage; Site; Somatic Mutation; Spectroscopy, Fourier Transform Infrared; Spin Labels; Structural Models; Structure; Structure-Activity Relationship; Therapeutic; Therapeutic Intervention; Western Blotting; age related; base; conformer; design; disease phenotype; human PrP; insight; novel; novel therapeutics; pathogen; prion-based; protein misfolding; protein misfolding cyclic amplification; research study; trait

DESCRIPTION (provided by applicant): Prions, unprecedented among infectious pathogens, are composed of misfolded proteins. Mammalian prions tend to accumulate at high levels in the nervous system, causing fatal neurodegeneration. The most common form of human prion disorders is sporadic Creutzfeldt-Jakob disease (sCJD). The origin, spectrum, and structure of sCJD prions are unknown. The extraordinary phenotypic variability of the disease suggests the existence of many different conformers of pathogenic prion protein (PrPSc) coding for distinct CJD prion strains. Moreover, the co-existence of different proteolytic fragments of PrPSc in approximately 40% of sCJD brains has raised the intriguing possibility that conformationally distinct sCJD prions coexist in the same host. This, in turn, raises fundamental questions about the origin of sCJD prions, their evolution and hypothetical interference. The focus of this application is to decipher the conformation of PrPSc in sCJD patients and to elucidate the mechanism underlying the replication of human prions. Novel conformational methods in tandem with protein misfolding cyclic amplification (PMCA) and conformation-dependent immunoassay (CDI) will be used to identify the conformations and critical domains in human PrPSc that code for different strains of sCJD prions. The analysis of hydrogen/deuterium exchange in brain-derived PrPSc and PrPSc-like conformers amplified in vitro by PMCA, together with site-directed spin labeling strategy, should allow us to elucidate the strain- dependent conformational mechanism in the replication of natural sCJD prions. Furthermore, measurements of replication rates of sCJD prions with tandem CDI and PMCA combined with structural data should determine the specific conformational features of brain PrPSc that modulate replication rates and thus the progression rate of the disease. The ultimate goal of these studies is to advance our understanding of the molecular mechanisms governing the replication of human prion strains and the impact of PrPSc conformation upon the sCJD phenotype and transmissibility of the disease. This insight is critical for efforts to develop therapeutic strategies targeting sCJD PrPSc or its replication.

描述（由申请人提供）：朊病毒是传染性病原体中前所未有的，由错误折叠的蛋白质组成。哺乳动物的朊病毒倾向于在神经系统中大量积聚，导致致命的神经变性。人类朊病毒疾病最常见的形式是散发克雅氏病（sCJD）。sCJD朊病毒的起源、谱和结构尚不清楚。该疾病的异常表型变异性表明存在许多不同的致病性朊病毒蛋白（PrPSc）构象，编码不同的CJD朊病毒株。此外，在大约40%的sCJD大脑中存在不同的PrPSc蛋白水解片段，这提出了一种有趣的可能性，即构象不同的sCJD朊病毒在同一宿主中共存。这反过来又提出了关于sCJD朊病毒的起源、进化和假设干扰的基本问题。本应用的重点是破译sCJD患者PrPSc的构象，并阐明人类朊病毒复制的机制。新的构象方法将与蛋白质错误折叠循环扩增（PMCA）和构象依赖免疫测定（CDI）相结合，用于鉴定人类PrPSc中编码不同sCJD朊病毒菌株的构象和关键结构域。通过PMCA体外扩增的脑源PrPSc和PrPSc样构象的氢/氘交换分析，以及位点定向自旋标记策略，将使我们能够阐明天然sCJD朊病毒复制过程中菌株依赖的构象机制。此外，用串联CDI和PMCA结合结构数据测量sCJD朊病毒的复制率，应该确定大脑PrPSc调节复制率的特定构象特征，从而确定疾病的进展速度。这些研究的最终目的是促进我们对控制人类朊病毒株复制的分子机制的理解，以及PrPSc构象对sCJD表型和疾病传播性的影响。这一发现对于开发针对sCJD PrPSc或其复制的治疗策略至关重要。