Detection of Prions

Prion蛋白的病理异构体(PrPres)可以作为Prion疾病的标志物，但需要更多的实用测试来进行临床前诊断和对许多Prion感染的敏感检测。在此之前，我们已经证明震颤诱导转换(QuIC)试验可以检测到感染瘙痒病的仓鼠脑组织中亚毫微克级PrPres的水平，并将脑脊液(CSF)样本与正常和感染瘙痒病的仓鼠区分开来。在2009财年，我们使QuIC反应适用于具有医学和农业意义的普恩病毒疾病：人类变异型克雅氏病(VCJD)和羊瘙痒病。人和绵羊脑匀浆标本在1-2天内可被区分为PrPres阳性和阴性，灵敏度为10-100毫微克PrPres。更重要的是，在短短32小时内，我们就能够将脑脊液样本与感染和未感染的羊区分开来。这是首次在瘙痒病阳性来源的脑脊液中检测到PrPres。这种新方法能够相对快速和灵敏地检测人CJD和绵羊瘙痒病PrPres，并可能促进实用的临床前诊断试验的发展。

The pathological isoform of the prion protein (PrPres) can serve as a marker for prion diseases, but more practical tests are needed for preclinical diagnosis and sensitive detection of many prion infections. Previously we showed that the quaking-induced conversion (QuIC) assay can detect sub-femtogram levels of PrPres in scrapie-infected hamster brain tissue and distinguish cerebral spinal fluid (CSF) samples from normal and scrapie-infected hamsters. During FY2009, we adapted the QuIC reaction to prion diseases of medical and agricultural interest: human variant Creutzfeldt-Jakob disease (vCJD) and sheep scrapie. Prion-positive and negative brain homogenate samples from humans and sheep were discriminated within 1-2 days with a sensitivity of 10-100 femtograms PrPres. More importantly, in as little as 32h we were able to distinguish CSF samples from scrapie-infected and uninfected sheep. This is the first time that PrPres is detected in scrapie positive derived CSF. This new method enables the relatively rapid and sensitive detection of human CJD and sheep scrapie PrPres and may facilitate the development of practical preclinical diagnostic tests.