Department of Civil Engineering, University of Nebraska-Lincoln, Peter Kiewit Institute, Omaha, Nebraska, United States of America.
PLoS One. 2012;7(8):e44051. doi: 10.1371/journal.pone.0044051. Epub 2012 Aug 24.
Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrP(c) from complete digestion, while both unbound and soil-bound infectious PrP(Sc) proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment.
在食源性朊病毒进入并感染下消化道之前，摄入的朊病毒会在鹿科和牛科动物的瘤胃中进行厌氧消化。此前，尚未对土壤结合型朊病毒对瘤胃消化的易感性进行评估。在这项研究中，我们将传染性脑组织匀浆中的朊病毒以及与一系列土壤和土壤矿物质结合的朊病毒进行体外瘤胃消化，并通过 Western blot 检测 PrP 水平的变化。与粘土的结合似乎可以保护非感染性仓鼠 PrP(c) 免受完全消化，而未结合和土壤结合的传染性 PrP(Sc) 则对瘤胃消化具有很强的抗性。此外，在对未结合的仓鼠 HY TME 朊病毒和与粉质粘壤土结合的 HY TME 朊病毒进行主动瘤胃消化后，并未观察到颅内潜伏期的变化。这些结果表明，无论是未结合的还是土壤结合的朊病毒，都可以在不降低感染性的情况下轻易地在瘤胃消化中存活，这进一步支持了朊病毒在环境中通过土壤传播慢性消瘦病（CWD）和瘙痒病的可能性。
