羊瘙痒病小鼠适应株139A可突破种属屏障颅内感染金黄地鼠  

Mouse-adapted Scrapie Strain 139A Can Overcome Species Barrier to Induce Spongiform Encephalopathy in Golden Hamster

作　　者：张宝云[1] 侯星生[1] 高晨[1] 高建梅[1] 周晓勃[1] 洪涛[1] 董小平[1] 

机构地区：[1]中国疾病预防控制中心病毒病预防控制所,北京100052

出　　处：《病毒学报》2002年第4期337-341,共5页Chinese Journal of Virology

基　　金：国家自然科学基金委海外杰出青年项目(39928018);国家自然科学基金委项目(30070038);国家自然科学基金委重点项目(30130070);国家863计划项目(2001AA215391)

摘　　要：羊瘙痒病感染因子可以根据疾病发生的潜伏期、临床病程、神经病理学特征以及PrPSc分子特征等分为不同的毒株,目前已经证实有20余种。在可传播性海绵状脑病的发病过程中存在着明显的种属屏障作用。将小鼠适应株139A颅内接种至金黄地鼠,以观测感染因子对种属屏障的突破及感染特征。在接种385～405天后,感染动物出现明显症状,与以往报道的金黄地鼠适应株263K不同,139A毒株发病动物出现严重的瘙痒,而无明显的共济失调。感染动物自出现明显症状到死亡的时间明显长于263K毒株感染金黄地鼠。进一步脑组织电镜和Westernblot检测证实,存在有羊瘙痒病相关纤维和PrP-res。这证明小鼠适应株139A可突破种属屏障感染金黄地鼠。经系统比较,139A和263K毒株在潜伏期、主要临床症状和临床病程显示出明显的差异,而PrP-res的泳动位置和糖基化比率差异不大,仅139A毒株的单糖基化分子位置似乎略高于263K。动态观测处于潜伏期的接种动物脑组织羊瘙痒病相关纤维和PrP-res,发现PrPSc的出现明显早于临床症状。Infectious agents of scrapie can be classified into different strains based on the incubation periods,clinical course,distinct neuropathological changes and molecular properties of PrPScMore than twenty isolates of scrapie have been identified up to dateDuring the pathogenesis of transmissible spongiform encephalopathy(TSE),a species barrier is usually observed when infected with heterogenetic agentsA mouseadapted scrapie agent 139A was intracerebrally inoculated to hamsters and the infectious pathogenesis was studied385 to 405 days after inoculation,clinical signs were observed in the infected animalsDiffering from homogenic infection in hamster with a hamsteradapted scrapie 263K,all 139Ainfected animals possessed severe itch,but without ataxia which is the main symptom of 263Kinfected animalsThe clinical course from occurrence of symptoms to death of 139Ainfected hamsters was longer than that of 263Kinfected onesElectronic microscopy and PrP specific Western blot assay revealed the scrapieassociated fibrils(SAF)and proteaseresistant PrP(PrPres) in the brain tissues of the infected animals,indicating that 139A could overcome species barrier and induce spongiform encephalopathy in hamsterComparing two strains of scrapie 139A and 263K,the significant differences were identified in the incubation times,the main clinical signs and clinical coursesThe electrophoresis patterns and glycosylation percentages of PrPres of two strains were similar,only with a little difference in mobility of monoglycosal PrPres moleculesDynamic monitoring of SAF and PrPres in the brain tissues of 139Ainfected hamsters during the incubation period showed that the appearances of SAF and PrPres were much earlier than that of clinical sig

关 键 词：羊瘙痒病小鼠适应株139A 种属屏障 颅内感染 金黄地鼠 羊瘙痒病相关纤维 PrP^Sc 感染动物实验 

分 类 号：S852.659.7[农业科学—基础兽医学]