Mouse-adapted scrapie infection of SN56 cells: Greater efficiency with microsome-associated versus purified PrP-res
Mouse-adapted scrapie infection of SN56 cells: Greater efficiency with microsome-associated versus purified PrP-res
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DOI：
10.1128/jvi.80.5.2106-2117.2006
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发表时间：
2006-03-01
影响因子：
5.4
通讯作者：
Caughey, B
中科院分区：
文献类型：
--
作者：
Baron, GS;Magalhaes, AC;Caughey, B
传染性海绵状脑病病原体或朊病毒感染细胞的过程尚不清楚。我们采用了一种新的可分化细胞系（SN56），该细胞系易受三种小鼠适应的瘙痒病菌株的感染，以深入了解细胞感染过程。通过比较用瘙痒病脑微粒体或纯化的去污剂提取的 PrP-res 处理的细胞中持续产生的 PrP-res，检查了与微粒体膜相关的疾病相关 PrP (PrP-res) 对感染效率的影响。当对输入的 PrP-res 量进行标准化时，与纯化的 PrP-res 相比，痒病脑微粒体诱导显着增强的持久性 PrP-res 形成。受感染的 SN56 细胞向培养上清液中释放低水平的 PrP-res，这也有效地引发了受体细胞的感染。有趣的是，用荧光标记标记的微粒体被 SN56 细胞内化成小囊泡，随后在神经炎过程中发现。当与培养孔结合以减少感染过程中的内化时，痒病微粒体诱导的长期 PrP-res 产生少于悬浮微粒体。受感染的 SN56 细胞的长期分化伴随着 PrP-res 形成的减少。我们的观察提供的证据表明，PrP-res 与膜和/或其他微粒体成分的结合有助于细胞感染。
The process by which transmissible spongiform encephalopathy agents, or prions, infect cells is unknown. We employed a new differentiable cell line (SN56) susceptible to infection with three mouse-adapted scrapie strains to gain insight into the cellular infection process. The effect of disease-associated PrP (PrP-res) association with microsomal membranes on infection efficiency was examined by comparing sustained PrP-res production in cells treated with either scrapie brain microsomes or purified, detergent-extracted PrP-res. When normalized for quantity of input PrP-res, scrapie brain microsomes induced dramatically enhanced persistent PrP-res formation compared to purified PrP-res. Infected SN56 cells released low levels of PrP-res into the culture supernatant, which also efficiently initiated infection in recipient cells. Interestingly, microsomes labeled with a fluorescent marker were internalized by SN56 cells in small vesicles, which were subsequently found in neuritic processes. When bound to culture wells to reduce internalization during the infection process, scrapie microsomes induced less long-term PrP-res production than suspended microsomes. Long-term differentiation of infected SN56 cells was accompanied by a decrease in PrP-res formation. Our observations provide evidence that infection of cells is aided by the association of PrP-res with membranes and/or other microsomal constituents.