De Novo Generation of a Unique Cervid Prion Strain Using Protein Misfolding Cyclic Amplification.
De Novo Generation of a Unique Cervid Prion Strain Using Protein Misfolding Cyclic Amplification.
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使用蛋白质错误折叠循环扩增从头生成独特的鹿朊病毒菌株。
DOI：
10.1128/msphere.00372-16
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发表时间：
2017
期刊：
影响因子：
4.8
通讯作者：
Zabel,MarkD
中科院分区：
文献类型：
--
作者：
Meyerett-Reid,Crystal;Wyckoff,AChristy;Spraker,Terry;Pulford,Bruce;Bender,Heather;Zabel,MarkD
大量证据支持这一假设，即朊病毒是错误折叠的，感染性的，不溶性的，蛋白酶抗性蛋白（PrPRES）缺乏指导核酸，导致传染性海绵状脑病（TSE）。蛋白质错误折叠循环扩增（PMCA）提供了额外的证据，证明PrPRes作为模板，可以将未感染的正常脑匀浆（NBH）中存在的正常细胞朊蛋白（PrPC）转化为感染性错误折叠PrPRESisisisoform。人类PrPC已被证明自发转化为错误折叠的病理状态，引起散发性克雅氏病（sCJD）。一些研究人员报告了通过体外试验（包括PMCA）自发产生的朊病毒。在这里，我们使用我们的标准PMCA方案和来自表达鹿朊病毒的转基因小鼠（TgCerPrP小鼠）的NBH，在我们的实验室中测试鹿朊病毒的新生率。我们在第4、5和7轮分别以1.6%、5.0%和6.7%的低累积率产生了de novoprions。朊病毒接种到正常未感染的TgCerPrP小鼠后引起传染性慢性消耗性疾病（CWD），并显示出独特的生化特性相比，其他鹿朊病毒株。我们的结论是，PMCA的鹿科PrPC从正常的脑匀浆自发产生一个新的鹿科朊病毒株。这些数据支持鹿科动物发生散发性慢性消耗病的可能性。重要提示：慢性消耗病是唯一已知的影响自由放养野生动物的TSE，特别是麋鹿、鹿、驼鹿、驯鹿和驯鹿等鹿科动物。慢性消耗病在北美、韩国和最近的北方欧洲的自由放养和圈养畜群中已成为地方病。朊病毒研究界继续争论慢性消耗病的起源。在科罗拉多和怀俄明州出现的慢性消耗病的原始疫源地与绵羊TSE瘙痒病一致，表明瘙痒病朊病毒可能适应了鹿科动物，从而导致慢性消耗病。然而，新出现的证据支持的想法，即鹿PrPC可能更容易错误折叠的病理亚型。在这里，我们测试的假设，即鹿PrPC可以自发地错误折叠到novoprions。慢性消耗病是否可以作为散发性TSE自发出现或代表一种新的TSE引起的猫适应性瘙痒症朊病毒深刻影响监测和缓解策略。播客：关于这篇文章的播客。
Substantial evidence supports the hypothesis that prions are misfolded, infectious, insoluble, and protease-resistant proteins (PrPRES) devoid of instructional nucleic acid that cause transmissible spongiform encephalopathies (TSEs). Protein misfolding cyclic amplification (PMCA) has provided additional evidence that PrPRes acts as a template that can convert the normal cellular prion protein (PrPC) present in uninfected normal brain homogenate (NBH) into the infectious misfolded PrPRESisoform. Human PrPChas been shown to spontaneously convert to a misfolded pathological state causing sporadic Creutzfeldt-Jakob disease (sCJD). Several investigators have reported spontaneous generation of prions byin vitroassays, including PMCA. Here we tested the rate ofde novogeneration of cervid prions in our laboratory using our standard PMCA protocol and NBH from transgenic mice expressing cervid PrPC(TgCerPrP mice). We generatedde novoprions in rounds 4, 5, and 7 at low cumulative rates of 1.6, 5.0, and 6.7%, respectively. The prions caused infectious chronic wasting disease (CWD) upon inoculation into normal uninfected TgCerPrP mice and displayed unique biochemical characteristics compared to other cervid prion strains. We conclude that PMCA of cervid PrPCfrom normal brain homogenate spontaneously generated a new cervid prion strain. These data support the potential for cervids to develop sporadic CWD.IMPORTANCECWD is the only known TSE that affects free-ranging wildlife, specifically cervids such as elk, deer, moose, caribou, and reindeer. CWD has become endemic in both free-ranging and captive herds in North America, South Korea, and, most recently, northern Europe. The prion research community continues to debate the origins of CWD. Original foci of CWD emergence in Colorado and Wyoming coincident with the sheep TSE scrapie suggest that scrapie prions may have adapted to cervids to cause CWD. However, emerging evidence supports the idea that cervid PrPCmay be more prone to misfolding to the pathological isoform. Here we test the hypothesis that cervid PrPCcan spontaneously misfold to createde novoprions. Whether CWD can arise spontaneously as a sporadic TSE or represents a new TSE caused by cervid-adapted scrapie prions profoundly impacts surveillance and mitigation strategies.Podcast: A podcast concerning this article is available.