Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
Minnesota Center for Prion Research and Outreach (MNPRO), University of Minnesota, St. Paul, MN, 55108, USA.
Sci Rep. 2022 Jul 18;12(1):12246. doi: 10.1038/s41598-022-16323-y.
Diagnostic tools for the detection of protein-misfolding diseases (i.e., proteopathies) are limited. Gold nanoparticles (AuNPs) facilitate sensitive diagnostic techniques via visual color change for the identification of a variety of targets. In parallel, recently developed quaking-induced conversion (QuIC) assays leverage protein-amplification and fluorescent signaling for the accurate detection of misfolded proteins. Here, we combine AuNP and QuIC technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with chronic wasting disease (CWD), a prion disease of cervids. Our newly developed assay, MN-QuIC, enables both naked-eye and light-absorbance measurements for detection of misfolded prions. MN-QuIC leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. In addition to laboratory-based tests, we deployed to a rural field-station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not-detected deer at the field site in 24 h, thus documenting the portability of the assay. White-tailed deer tissues used to validate MN-QuIC included medial retropharyngeal lymph nodes, parotid lymph nodes, and palatine tonsils. Importantly, all of the white-tailed deer (n = 63) were independently tested using ELISA, IHC, and/or RT-QuIC technologies and results secured with MN-QuIC were 95.7% and 100% consistent with these tests for positive and non-detected animals, respectively. We hypothesize that electrostatic forces help govern the AuNP/prion interactions and conclude that MN-QuIC has great potential for sensitive, field-deployable diagnostics for CWD, with future potential diagnostic applications for a variety of proteopathies.
用于检测蛋白质错误折叠疾病(即蛋白质构象病)的诊断工具十分有限。金纳米粒子(AuNPs)通过视觉颜色变化促进了灵敏的诊断技术,从而可以识别各种靶标。与此同时,最近开发的震颤诱导转换(QuIC)检测法利用蛋白质扩增和荧光信号来准确检测错误折叠的蛋白质。在这里,我们将 AuNP 和 QuIC 技术结合起来,用于可视化检测从感染慢性消耗病(CWD)的野生白尾鹿组织中扩增的错误折叠朊病毒。我们新开发的 MN-QuIC 检测法可以进行裸眼和吸光度测量,用于检测错误折叠的朊病毒。MN-QuIC 利用了经济实惠且便于携带的基本实验室设备,从而可以在各种环境下实时进行朊病毒诊断。除了实验室检测外,我们还将该检测方法部署到明尼苏达州东南部的一个农村野外站,并在现场进行了 CWD 检测。我们成功地证明了 MN-QuIC 在非传统实验室环境中是有效的,在现场进行了盲法分析,并在 24 小时内正确识别了野外站的所有 CWD 阳性和 CWD 未检出鹿,从而证明了该检测方法的便携性。用于验证 MN-QuIC 的白尾鹿组织包括咽后正中淋巴结、腮腺淋巴结和腭扁桃体。重要的是,所有白尾鹿(n = 63)都使用 ELISA、IHC 和/或 RT-QuIC 技术进行了独立测试,MN-QuIC 的测试结果与这些测试方法的阳性和未检出动物的结果分别有 95.7%和 100%的一致性。我们假设静电引力有助于控制 AuNP/朊病毒相互作用,并得出结论,MN-QuIC 具有用于 CWD 敏感、现场部署诊断的巨大潜力,未来可能还有各种蛋白质构象病的诊断应用。