Agricultural, Life and Environmental Sciences Faculty, University of Alberta, Edmonton, AB, Canada.
Faculty of Science, University of Alberta, Edmonton, AB, Canada.
PLoS Pathog. 2018 Nov 29;14(11):e1007414. doi: 10.1371/journal.ppat.1007414. eCollection 2018 Nov.
Chronic wasting disease (CWD), an environmentally transmissible, fatal prion disease is endemic in North America, present in South Korea and has recently been confirmed in northern Europe. The expanding geographic range of this contagious disease of free-ranging deer, moose, elk and reindeer has resulted in increasing levels of prion infectivity in the environment. Soils are involved in CWD horizontal transmission, acting as an environmental reservoir, and soil mineral and organic compounds have the ability to bind prions. Upper horizons of soils are usually enriched with soil organic matter (SOM), however, the role of SOM in prion conservation and mobility remains unclear. In this study, we show that incubation of PrPCWD with humic acids (HA), a major SOM compound, affects both the molecular weight and recovery of PrPCWD. Detection of PrPCWD is reduced as HA concentration increases. Native HA extracted from pristine soils also reduces or entirely eliminates PrPCWD signal. Incubation of CWD prions with HA significantly increased incubation periods in tgElk mice demonstrating that HA can reduce CWD infectivity.
慢性消耗病（CWD）是一种环境传播的致命朊病毒病，在北美洲流行，在韩国也有发现，最近在北欧也得到了证实。这种传染性疾病在自由放养的鹿、驼鹿、麋鹿和驯鹿中的地理范围不断扩大，导致环境中的朊病毒感染水平不断上升。土壤参与了 CWD 的水平传播，充当了环境储库，土壤中的矿物质和有机化合物具有结合朊病毒的能力。土壤的上层通常富含土壤有机质（SOM），然而，SOM 在朊病毒的保存和迁移中的作用仍不清楚。在这项研究中，我们表明，用腐殖酸（HA）——一种主要的 SOM 化合物——孵育 PrPCWD 会影响 PrPCWD 的分子量和回收率。随着 HA 浓度的增加，PrPCWD 的检测量减少。从原始土壤中提取的天然 HA 也降低或完全消除了 PrPCWD 的信号。用 HA 孵育 CWD 朊病毒显著延长了 tgElk 小鼠的潜伏期，表明 HA 可以降低 CWD 的感染性。
