CWD: A Model of Prion Transmission via Saliva and Urine

描述（由申请人提供）：与人类变异型克雅氏病（vCJD）一样，感染宫颈慢性消耗性疾病（CWD）的动物体内感染性朊病毒的水平通常超出常规检测方法的检测范围。此外，朊病毒疾病的发病机制和传播机制尚不明确。开发对CWD敏感的死前检测方法和了解传播对于最终控制人和动物的朊病毒疾病至关重要。我们建议研究提供者的CWD作为vCJD/prion传播的模型。CWD PrPres已被证明存在于各种排泄物中并可传播，包括受感染鹿的唾液、血液、尿液和粪便，尽管其他生物样本也可能作为鹿之间的传播途径。此外，这些排泄物中PrPres的可检测水平和确切来源尚未得到证实。我们提出了探索朊病毒疾病的发病机制和传播的三个目标：(1)在第一个目标中，我们将使用敏感扩增试验sPMCA评估外周组织对CWD朊病毒早期积累的影响。这些发现将与使用更传统的测定方法（如免疫组织化学）获得的结果进行比较。(2)在目标2中，我们将通过使用生物测定法和PMCA在多个时间点从受感染的宫颈采集样本，试图确定唾液和尿液中朊病毒脱落的动力学。研究结果将与外周组织的早期检测结果（Aim 1）以及当前死前检测的敏感性和特异性进行比较。(3)在Aim 3中，我们将使用免疫细胞和组织化学、生物测定和PMCA研究生物样品中感染性朊病毒的组织和细胞起源。这些研究结果将有助于了解CWD、BSE和vCJD的发病机制和传播潜力。

DESCRIPTION (provided by applicant): The levels of infectious prions in animals infected with chronic wasting disease (CWD) in cervids, as with variant Creutzfeldt-Jakob-disease (vCJD) in human, are often beyond the limits of detection using conventional assays. In addition, the mechanisms of pathogenesis and transmission of prion diseases are not clearly defined. Development of sensitive antemortem assays for CWD and an understanding of transmission are critical for the eventual control of prion diseases of both man and animals. We propose to study CWD of cervids as a model for vCJD/prion transmission. CWD PrPres has been shown to be present and transmissible in various excreta, including saliva, blood, urine and feces of infected deer, though other biological samples may also serve as routes of transmission between cervids. In addition, detectable levels and the exact source of PrPres in these excreta have yet to be demonstrated. We propose three aims which explore the pathogenesis and transmission of prion diseases: (1) in Aim 1, we will evaluate peripheral tissues for early accumulation of CWD prions using a sensitive amplification assay, sPMCA. These findings will be compared with those achieved using more traditional assays such as immunohistochemistry. (2) In Aim 2, we will seek to determine the kinetics of prion shedding in saliva and urine through samples collected at multiple time points from infected cervids using bioassay and PMCA. Findings will be compared to results of early detection in peripheral tissues (Aim 1) as well as the sensitivity and specificity of current antemortem assays. (3) In Aim 3, we will investigate the tissue and cellular origins infectious prions in biological samples using immunocyto- and histochemistry, bioassay, and PMCA. The results of these studies will contribute greatly to the understanding of pathogenesis and transmission potential of CWD, BSE, and vCJD.