Properzi Francesca, Badhan Anjna, Klier Steffi, Schmidt Christian, Klöhn Peter C, Wadsworth Jonathan D F, Clarke Anthony R, Jackson Graham S, Collinge John
a MRC Prion Unit, Department of Neurodegenerative Disease , UCL Institute of Neurology , London , UK.
Prion. 2016 May 3;10(3):251-61. doi: 10.1080/19336896.2016.1181250.
The mouse-adapted scrapie prion strain RML is one of the most widely used in prion research. The introduction of a cell culture-based assay of RML prions, the scrapie cell assay (SCA) allows more rapid and precise prion titration. A semi-automated version of this assay (ASCA) was applied to explore a range of conditions that might influence the infectivity and properties of RML prions. These include resistance to freeze-thaw procedures; stability to endogenous proteases in brain homogenate despite prolonged exposure to varying temperatures; distribution of infective material between pellet and supernatant after centrifugation, the effect of reducing agents and the influence of detergent additives on the efficiency of infection. Apparent infectivity is increased significantly by interaction with cationic detergents. Importantly, we have also elucidated the relationship between the duration of exposure of cells to RML prions and the transmission of infection. We established that the infection process following contact of cells with RML prions is rapid and followed an exponential time course, implying a single rate-limiting process.
小鼠适应株瘙痒病朊病毒株RML是朊病毒研究中使用最广泛的毒株之一。基于细胞培养的RML朊病毒检测方法——瘙痒病细胞检测法（SCA）的引入，使得朊病毒滴定更加快速和精确。该检测方法的半自动版本（ASCA）被用于探索一系列可能影响RML朊病毒感染性和特性的条件。这些条件包括对冻融程序的抗性；尽管长时间暴露于不同温度下，但对脑匀浆中内源性蛋白酶的稳定性；离心后感染性物质在沉淀和上清液之间的分布、还原剂的作用以及去污剂添加剂对感染效率的影响。与阳离子去污剂相互作用可显著提高表观感染性。重要的是，我们还阐明了细胞暴露于RML朊病毒的持续时间与感染传播之间的关系。我们确定，细胞与RML朊病毒接触后的感染过程迅速，且呈指数时间进程，这意味着存在单一的限速过程。
