Xie Zhiliang, O'Rourke Katherine I, Dong Zhiqian, Jenny Allen L, Langenberg Julie A, Belay Ermias D, Schonberger Lawrence B, Petersen Robert B, Zou Wenquan, Kong Qingzhong, Gambetti Pierluigi, Chen Shu G
Institute of Pathology and National Prion Disease Pathology Surveillance Center, Case Western Reserve University, Cleveland, Ohio 44106, USA.
J Biol Chem. 2006 Feb 17;281(7):4199-206. doi: 10.1074/jbc.M509052200. Epub 2005 Dec 7.
Chronic wasting disease (CWD), a transmissible prion disease that affects elk and deer, poses new challenges to animal and human health. Although the transmission of CWD to humans has not been proven, it remains a possibility. If this were to occur, it is important to know whether the "acquired" human prion disease would show a phenotype including the scrapie prion protein (PrP(Sc)) features that differ from those associated with human sporadic prion disease. In this study, we have compared the pathological profiles and PrP(Sc) characteristics in brains of CWD-affected elk and deer with those in subjects with sporadic Creutzfeldt-Jakob disease (CJD), as well as CJD-affected subjects who might have been exposed to CWD, using histopathology, immunohistochemistry, immunoblotting, conformation stability assay, and N-terminal protein sequencing. Spongiform changes and intense PrP(Sc) staining were present in several brain regions of CWD-affected animals. Immunoblotting revealed three proteinase K (PK)-resistant bands in CWD, representing different glycoforms of PrP(Sc). The unglycosylated PK-resistant PrP(Sc) of CWD migrated at 21 kDa with an electrophoretic mobility similar to that of type 1 human PrP(Sc) present in sporadic CJD affecting subjects homozygous for methionine at codon 129 (sCJDMM1). N-terminal sequencing showed that the PK cleavage site of PrP(Sc) in CWD occurred at residues 82 and 78, similar to that of PrP(Sc) in sCJDMM1. Conformation stability assay also showed no significant difference between elk CWD PrP(Sc) and the PrP(Sc) species associated with sCJDMM1. However, there was a major difference in glycoform ratio of PrP(Sc) between CWD and sCJDMM1 affecting both subjects potentially exposed to CWD and non-exposed subjects. Moreover, PrP(Sc) of CWD exhibited a distinct constellation of glycoforms distinguishable from that of sCJDMM1 in two-dimensional immunoblots. These findings underline the importance of detailed PrP(Sc) characterization in trying to detect novel forms of acquired prion disease.
慢性消耗病（CWD）是一种影响麋鹿和鹿的可传播朊病毒病，给动物和人类健康带来了新挑战。尽管CWD向人类的传播尚未得到证实，但仍有可能发生。如果这种情况发生，了解“获得性”人类朊病毒病是否会表现出一种包括与人类散发性朊病毒病相关特征不同的瘙痒病朊病毒蛋白（PrP(Sc)）特征的表型就很重要。在本研究中，我们使用组织病理学、免疫组织化学、免疫印迹、构象稳定性分析和N端蛋白测序，比较了受CWD影响的麋鹿和鹿大脑中的病理特征和PrP(Sc)特性，以及散发性克雅氏病（CJD）患者和可能接触过CWD的CJD患者大脑中的病理特征和PrP(Sc)特性。在受CWD影响的动物的几个脑区出现了海绵状变化和强烈的PrP(Sc)染色。免疫印迹显示CWD中有三条蛋白酶K（PK）抗性条带，代表PrP(Sc)的不同糖型。CWD未糖基化的PK抗性PrP(Sc)在21 kDa处迁移，其电泳迁移率与散发性CJD中影响密码子129处甲硫氨酸纯合子的患者（sCJDMM1）中存在的1型人类PrP(Sc)相似。N端测序表明，CWD中PrP(Sc)的PK切割位点位于第82和78位残基，与sCJDMM1中PrP(Sc)的切割位点相似。构象稳定性分析还表明，麋鹿CWD PrP(Sc)与sCJDMM1相关的PrP(Sc)物种之间没有显著差异。然而，在可能接触过CWD的患者和未接触过CWD的患者中，CWD和sCJDMM1的PrP(Sc)糖型比例存在重大差异。此外，在二维免疫印迹中，CWD的PrP(Sc)表现出与sCJDMM1不同的独特糖型组合。这些发现强调了在试图检测新型获得性朊病毒病时详细表征PrP(Sc)的重要性。
