Identifying the Role of PrPSc Distribution & Other Proteins in Prion Pathogenesis

项目描述（由申请人提供）：本项目的目的是增加我们对朊病毒传播的认识，这将有助于我们了解朊病毒的病理，并找到治疗这些疾病的方法。朊病毒疾病包括一系列影响人类和一些重要商业动物的遗传性、自发性和传染性神经病变。目前，还没有已知的治疗或治愈朊病毒疾病的方法，部分原因是朊病毒的病理机制和朊病毒繁殖所需的过程尚未得到很好的了解。通过确定朊病毒传播所必需的辅助因子，我们对朊病毒发病机制的理解将大大增强。许多证据（包括转基因小鼠的研究、细胞培养感染试验、酵母朊病毒繁殖中的类似因素和体外转化试验）表明，除了朊病毒蛋白的初级序列和表达水平外，还有其他因素影响朊病毒的繁殖。然而，尽管经过多年的研究，我们对哺乳动物这一过程的了解仍然有限。在某种程度上，这种缺乏进展可能是由于候选药物的选择基于个体的低通量研究。在目标一中，我们将利用RNA干扰的力量，在高通量细胞培养试验中识别调节朊病毒繁殖的潜在因素，并确认我们在敲除小鼠中最有希望的成功。成功鉴定哺乳动物朊病毒繁殖因子不仅可以提供新的药物靶点，而且可以让我们解释为什么有些细胞系在朊病毒蛋白表达水平高的情况下对朊病毒感染具有抗性。在目标二中，我们将在感染了几种朊病毒菌株的细胞系上使用RNAi来确定哪些潜在的朊病毒繁殖因子对于朊病毒繁殖总是必需的，哪些因子仅对特定菌株是必需的。在目标三中，我们将验证a

DESCRIPTION (provided by applicant): The goal of this project is to increase our understanding of prion propagation, which will help us to understand prion pathology and find treatments for these diseases. Prion diseases encompass a range of genetic, spontaneous, and transmitted neuropathologies that affect humans and a number of commercially important animals. At present, there is no known treatment or cure for prion diseases, in part because the mechanisms underlying prion pathology and the processes required for prion propagation are not well understood. Our understanding of prion pathogenesis would be greatly enhanced by identifying the auxiliary factors that are necessary for prion propagation. Numerous lines of evidence (including work in transgenic mice, cell culture infection assays, analogous factors in yeast prion propagation, and in vitro conversion assays) suggest that additional factors besides the primary sequence and expression level of the prion protein influence prion propagation. However, despite years of study, our understanding of this process in mammals is still limited. In part, this lack of progress may be due to the selection of candidates based on individual, low throughput studies. In aim one, we will harness the power of RNA interference to identify potential factors that modulate prion propagation in high throughput cell culture assays, and confirm our most promising hits in knockout mice. Successfully identifying mammalian prion propagation factors would not only provide new drug targets, but may allow us to explain why some cell lines are recalcitrant to prion infection despite high levels of prion protein expression In aim two we will use RNAi on a panel of cell lines infected with several prion strains to identif which of these potential prion propagation factors are always necessary for prion propagation and which of these factors are only necessary for specific strains. In aim three we will validate a subset of these potential prion propagation factors using existing mouse knockout lines. Increasing evidence that other neurodegenerative diseases are caused by a prion-like mechanism raises the possibility that these results could have a broad impact on human health.