Neary K, Caughey B, Ernst D, Race R E, Chesebro B
Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana 59840.
J Virol. 1991 Feb;65(2):1031-4. doi: 10.1128/JVI.65.2.1031-1034.1991.
The scrapie agent has been propagated in vitro in mouse neuroblastoma cells. To further characterize the tissue culture-derived scrapie agent, we studied the effects of protease and nuclease digestion on the agent derived from these cells. The scrapie agent in these cells was found to be resistant to protease digestions for short times but was inactivated by prolonged digestion at high protease concentrations. In contrast, digestion with a variety of nucleases did not alter the agent titer. These results demonstrate that the agent requires an essential protein or proteins for infectivity. If the agent also contains a nucleic acid genome, it must be more nuclease resistant than the majority of cellular DNA and RNA. These properties of the tissue culture-derived scrapie agent were identical to those of brain-derived scrapie agent and thus cannot be attributed to secondary effects of tissue pathology, since the infected cell cultures show no cytopathic effects as a result of infection.
瘙痒病病原体已在小鼠神经母细胞瘤细胞中进行体外增殖。为了进一步表征源自组织培养的瘙痒病病原体，我们研究了蛋白酶和核酸酶消化对源自这些细胞的病原体的影响。发现这些细胞中的瘙痒病病原体在短时间内对蛋白酶消化具有抗性，但在高蛋白酶浓度下长时间消化会使其失活。相比之下，用多种核酸酶消化不会改变病原体滴度。这些结果表明，病原体的感染性需要一种或多种必需蛋白质。如果病原体还含有核酸基因组，那么它一定比大多数细胞DNA和RNA更耐核酸酶。源自组织培养的瘙痒病病原体的这些特性与源自脑的瘙痒病病原体的特性相同，因此不能归因于组织病理学的继发效应，因为受感染的细胞培养物未因感染而表现出细胞病变效应。
