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朊病毒(PrPSc)是由动物体内正常朊蛋白PrPc构象改变形成的,PrPSc与PrPC在氨基酸序列上完全一致,PrPC中α-螺旋丰富而PrPSc富含β-折叠。目前,科学家还未研究清楚PrP的生理机能。人们普遍认为:人和动物感染朊病毒病时除PrP外还存在一些重要的辅助因子影响着PrPC变构、PrPSc传播、PrPSc引起神经细胞凋亡等病变过程,因此,研究朊蛋白的各种辅助因子将有助于阐明这方面的问题,这些辅助因子包括各种金属离子,如Ca2+、Cu2+、Fe2+、Mn2+。作者概述金属离子对朊蛋白结构和功能的影响,以及它们在朊病毒病的发病过程中可能起的作用。 相似文献
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梅花鹿朊蛋白核心片段的基因克隆与高效表达 总被引：1，自引：1，他引：0
本试验根据梅花鹿朊蛋白基因序列设计引物,利用PCR的方法从梅花鹿基因组DNA中扩增朊病毒蛋白酶抵抗区域PrPres,将该片段分别与表达载体pET-Trx和pET-His连接,构建重组表达载体pET-Trx-PrPres和pET-His-PrPres。分别将两个重组表达载体转入E.coli BL21(DE3) plys宿主菌中,37 ℃诱导4 h,经SDS-PAGE分析,Trx-PrPres和His-PrPres表达量分别为38.2%和30.1%。 相似文献
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本研究旨在检测绵羊组织中朊病毒受体37kDa/67kDa LRP/LR mRNA水平并探讨其与朊病毒组织嗜性的关系.选用背景相似的6只内蒙绵羊,提取组织RNA.反转录RT-PCR构建cDNA模板;利用本研究前期构建的标准质粒及标准曲线,对组织中该受体mRNA水平进行Real-time(实时)荧光定量PCR检测.结果表明,大脑皮质中的受体表达水平最高(P<0.05),其次为心脏和脑干,中等表达的器官依次为海马、小脑、脾脏、丘脑、肠系膜淋巴结、肝脏和肾脏,表达量最低为肺脏(P<0.05).结果提示,朊病毒受体--37kDa/67kDa LRP/LR在绵羊各组织中的表达量高低与朊病毒的复制程度有一定的相关性,受体LRP/LR表达量较高的区域朊病毒复制水平相对较高.结果提示朊病毒入侵机体后,组织器官PrPsc聚集程度可能与受体37kDa/67kDa LRP/LR表达水平相关. 相似文献
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传染性海绵状脑病及其分子生物学诊断 总被引：1，自引：0，他引：1
传染性海绵状脑病是一种区别于普通流行病的人兽共患病 ,其病原体是一种具有传染性的、未知功能的糖蛋白 ,命名为蛋白质感染颗粒 ,即朊病毒。它是一个超出经典病毒学和生物学的全新概念。朊病毒是有机体的正常细胞蛋白质错误折叠的产物 ,其扩增机制和致病机制不同于一般病毒。传染性海绵状脑病潜伏期长 ,传染性强且无法治愈 ,机体免疫系统对朊病毒不识别。目前 ,传染性海绵状脑病的诊断已达到分子水平 ,国际上主要利用抗 Pr P抗体、脑脊液中蛋白质的改变以及实时 PCR和质谱分析法等手段来进行临床诊断和病原体的检测。 相似文献
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试验旨在明确T淋巴细胞在中国恒河猴各组织中的表型与分布,为疾病模型研究提供基础数据。取外周血、腹股沟淋巴结、肠系膜淋巴结及肠道组织,从中分离出淋巴细胞。使用流式细胞术检测分析各种表型的淋巴细胞在组织间的分布。结果表明,淋巴结中CD4+ /CD8+ T细胞比值高于外周血,肠道固有层中最低,三者差异显著。记忆性T细胞在外周血和肠道固有层T细胞中比重较大,而淋巴结中主要为幼稚T细胞。CD4+ T细胞中中心记忆T细胞Tcm为主要亚群,而CD8+ T细胞主要为效应记忆细胞Tem。外周血与肠道固有层中增殖T细胞比例相当,而淋巴结中T细胞增殖水平相对较低。各组织中CXCR4受体表达量普遍高于CCR5受体,其中肠道固有层CCR5受体表达水平最高。值得注意的是,有一小群表型CD3+ CD4+ CD8low的细胞仅在肠道固有层中存在,经分析其功能活性应高于肠道CD4单阳性T细胞。因此,测定了健康中国恒河猴各表型T淋巴细胞在多种淋巴组织中的基础数值,为相关模型研究奠定基础。 相似文献
6.
朊病毒研究进展 总被引：2，自引：0，他引：2
朊病毒是一种不含核酸的蛋白浸染子,主要引起人和动物的中枢神经疾病。目前,由其引起的朊病毒病在世界多国已有发生,危害严重,经济损失巨大,并对人类的健康构成很大威胁。该病毒蛋白是一种膜糖蛋白,至少有两种基本形式,即PrPc与PrPsc,PrPsc对紫外线及消毒剂有很强的抵抗力;朊蛋白基因是单拷贝基因,高度保守,但在物种间可能存在易感性相关基因。病毒的复制呈指数增长过程,需朊病毒结合因子参与。病毒的致病性在于正常的朊病毒蛋白PrPc转变为PrPsc,PrPsc是发病的直接原因。另外,对其检测和防治目前也有了新的方法及措施。文章就朊病毒概念、蛋白、基因、复制、致病机理及检测与防治作了综述。 相似文献
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本研究采用聚丙烯酰胺凝胶电泳技术对193头广西西林水牛和196头广西富钟水牛的血清运铁蛋白、白蛋白和淀粉酶的基因型、基因型频率及遗传变异系数进行分析,探讨这两个品种的遗传背景。结果表明,西林水牛和富钟水牛运铁蛋白(Tf)受TfA和TfD两个等位基因控制,基因频率TfD＞TfA,以TfD为优势基因,DD为优势基因型;西林水牛和富钟水牛的白蛋白(Alb)受AlbA和AlbX两个等位基因控制,基因频率为AlbX＞AlbA,以AlbX为优势基因,西林水牛以XX为优势基因型,而富钟水牛以AX为优势基因型;富钟水牛血清淀粉酶(Amy)存在AA、AB、BB、BC、AC、CC 6种基因型,受AmyA、AmyB、AmyC 3个等位基因控制,在AmyⅠ、AmyⅡ中都是以AmyA为优势基因,分别以AB和BC为优势基因型。本研究结果发现,3种血清蛋白在西林水牛和富钟水牛中不存在性别差异(P＞0.05),提示广西这两个优良地方水牛品种的遗传稳定性较好。 相似文献
11.
Transmissible spongiform encephalopathies (TSEs) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. TSEs are comprised of fatal neurodegenerative disorders affecting both human and animals. Prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) Creutzfeldt–Jacob disease in humans, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. TSEs are characterized by the formation and accumulation of transmissible (infectious) disease-associated protease-resistant prion protein (PrPSc), mainly in tissues of the central nervous system. The exact molecular processes behind the conversion of PrPC into PrPSc are not clearly understood. Correlations between prion protein polymorphisms and disease have been found, however in what way these polymorphisms influence the conversion processes remains an enigma; is stabilization or destabilization of the prion protein the basis for a higher conversion propensity? Apart from the disease-associated polymorphisms of the prion protein, the molecular processes underlying conversion are not understood. There are some notions as to which regions of the prion protein are involved in refolding of PrPC into PrPSc and where the most drastic structural changes take place. Direct interactions between PrPC molecules and/or PrPSc are likely at the basis of conversion, however which specific amino acid domains are involved and to what extent these domains contribute to conversion resistance/sensitivity of the prion protein or the species barrier is still unknown. 相似文献
12.
Thorsten Kuczius Martin H. Groschup 《Comparative immunology, microbiology and infectious diseases》2013
A feature of transmissible spongiform encephalopathies is the accumulation of infectious prion proteins (PrPSc), which are formed by the conversion of physiological prion proteins (PrPC). As PrPC, which is modified posttranslationally with various types of glycoproteins, serves as the substrates for PrPSc conversion, various PrPC subtypes may play a role in the formation of PrPSc and species-specific transmission; the cattle disease BSE is transmissible naturally to humans, but the sheep disease scrapie is not. To reveal new mechanisms modulating prion conversion, we analyzed the PrPC profiles by determining the differential PrPC protein solubilities in the anionic and nonionic detergents N-lauroylsarcosine, N-octyl-β-d-glucopyranoside, CHAPS and deoxycholic acid. We compared the resulting solubility profiles of human PrPC with the solubility profiles of PrPC from sheep and cattle. The PrPC subtypes were differentially soluble. However, non-glycosylated PrPC from cattle and human was found explicitly in the insoluble fraction, while non-glycosylated ovine PrPC was detected in the soluble fraction. These findings indicate the existence of low-solubility PrPC phenotypes in cattle and humans. 相似文献
13.
L-type bovine spongiform encephalopathy (L-BSE) is an atypical form of BSE that is transmissible to cattle and several lines of prion protein (PrP) transgenic mice, but not to wild-type mice. In this study, we examined the transmissibility of sheep-passaged L-BSE prions to wild-type mice. Disease-associated prion protein (PrPSc) was detected in the brain and/or lymphoid tissues during the lifespan of mice that were asymptomatic subclinical carriers, indicating that wild-type mice were susceptible to sheep-passaged L-BSE. The morphological characteristics of the PrPSc of sheep-passaged L-BSE included florid plaques that were distributed mainly in the cerebral cortex and hippocampus of subsequent passaged mice. The PrPSc glycoform profiles of wild-type mice infected with sheep-passaged L-BSE were similar to those of the original isolate. The data indicate that sheep-passaged L-BSE has an altered host range and acquired transmissibility to wild-type mice. 相似文献
14.
Yong-Chul Jeon Jin-Kyu Choi Eun-Kyung Choi Richard I. Carp Yong-Sun Kim 《Journal of veterinary science (Suw?n-si, Korea)》2013,14(1):21-26
Chronic wasting disease (CWD) is classified as a transmissible spongiform encephalopathy or prion disease that affects cervids. CWD has been reported in 15 US states, two Canadian provinces, and in imported elk on several farms in Korea. This study was conducted to examine the molecular biological and pathogenic characteristics of a CWD-associated prion isolated in Korea. The epidemiological origin of this pathogen was also determined. Homozygous TgElk mice were infected with a CWD-affected elk brain pool prepared from the brain of an imported Canadian elk. We measured the incubation time of the pathogen, neuropathological changes by immunohistochemical staining, the pattern(s) of scrapie prion protein (PrPSc) deposition, and PrPSc protein profiles by Western blotting. We found that TgElk mice infected with brain homogenate from the elk suffering from CWD showed incubation times, vacuolar degeneration, and PrPSc accumulation similar to those previously reported in the literature. Our results suggest that homozygous TgElk mice efficiently transmit CWD with short incubation times and that this animal can serve a valuable research model and reliable in vivo diagnostic tool. 相似文献
15.
Christina M. Carlson Jay R. Schneider Joel A. Pedersen Dennis M. Heisey Christopher J. Johnson 《Canadian journal of veterinary research》2015,79(1):68-73
Meadow voles (Microtus pennsylvanicus) are permissive to chronic wasting disease (CWD) infection, but their susceptibility to other transmissible spongiform encephalopathies (TSEs) is poorly characterized. In this initial study, we intracerebrally challenged 6 meadow voles with 2 isolates of sheep scrapie. Three meadow voles acquired a TSE after the scrapie challenge and an extended incubation period. The glycoform profile of proteinase K-resistant prion protein (PrPres) in scrapie-sick voles remained similar to the sheep inocula, but differed from that of voles clinically affected by CWD. Vacuolization patterns and disease-associated prion protein (PrPSc) deposition were generally similar in all scrapie-affected voles, except in the hippocampus, where PrPSc staining varied markedly among the animals. Our results demonstrate that meadow voles can acquire a TSE after intracerebral scrapie challenge and that this species could therefore prove useful for characterizing scrapie isolates. 相似文献
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M. Mazza B. Iulini G. Vaccari P.L. Acutis F. Martucci E. Esposito S. Peletto S. Barocci B. Chiappini C. Corona I. Barbieri M. Caramelli U. Agrimi C. Casalone R. Nonno 《Research in veterinary science》2010,88(3):478-485
Nor98 is an atypical scrapie strain characterized by a molecular pattern and brain distribution of the pathological prion protein (PrPSc) different from classical scrapie. In Italy, 69 atypical cases have been identified so far and all were characterized as Nor98 strain. In this paper we report an unusual case in a sheep which showed immunohistochemical and molecular features of PrPSc different from the other atypical cases. The sheep was from an outbreak where the index and the other four cases were affected by classical scrapie. Histopathological, immunohistochemical and Western blot analyses on the brain of the unusual case revealed the simultaneous presence of pathological features characteristic of Nor98 and classical scrapie. Interestingly, the prevalent disease phenotype in the brainstem was classical scrapie-like, while in the cerebral cortex and cerebellum the Nor98 phenotype was dominant. The sub-mandibular lymph node was positive and showed a PrPSc molecular pattern referable to classical scrapie. The PrP genotype was AL141RQ/AF141RQ. Taken together, the occurrence of classical scrapie in the outbreak, the PrP genotype, the involvement of different cellular targets in the brain and the pathological and molecular PrPSc features observed suggest that this unusual case may result from the co-existence of Nor98 and classical scrapie. 相似文献
17.
Rohana P. Dassanayake Thomas C. Truscott Dongyue Zhuang David A. Schneider Sally A. Madsen-Bouterse Alan J. Young James B. Stanton William C. Davis Katherine I. O'Rourke 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(2):179-186
Scrapie is diagnosed antemortem in sheep by detecting misfolded isoforms of prion protein (PrPSc) in lymphoid follicles of the rectal mucosa and nictitating membranes. Assay sensitivity is limited if (a) the biopsy is collected early during disease development, (b) an insufficient number of follicles is collected, or (c) peripheral accumulation of PrPSc is reduced or delayed. A blood test would be convenient for mass live animal scrapie testing. Currently approved techniques, however, have their own detection limits. Novel detection methods may soon offer a non-animal-based, rapid platform with detection sensitivities that rival the prion bioassay. In anticipation, we sought to determine if diseased animals could be routinely identified with a bioassay using B lymphocytes isolated from blood sample volumes commonly collected for diagnostic purposes in small ruminants. Scrapie transmission was detected in five of six recipient lambs intravenously transfused with B lymphocytes isolated from 5~10 mL of blood from a naturally scrapie-infected sheep. Additionally, scrapie transmission was observed in 18 ovinized transgenic Tg338 mice intracerebrally inoculated with B lymphocytes isolated from 5~10 mL of blood from two naturally scrapie-infected sheep. Based on our findings, we anticipate that these blood sample volumes should be of diagnostic value. 相似文献
18.
Ben C Maddison John Spiropoulos Christopher M Vickery Richard Lockey Jonathan P Owen Keith Bishop Claire A Baker Kevin C Gough 《Veterinary research》2015,46(1)
Ovine scrapie can be transmitted via environmental reservoirs. A pool of ovine scrapie isolates were incubated on soil for one day or thirteen months and eluted prion was used to challenge tg338 mice transgenic for ovine PrP. After one-day incubation on soil, two PrPSc phenotypes were present: G338 or Apl338ii. Thirteen months later some divergent PrPSc phenotypes were seen: a mixture of Apl338ii with either G338 or P338, and a completely novel PrPSc deposition, designated Cag338. The data show that prolonged ageing of scrapie prions within an environmental matrix may result in changes in the dominant PrPSc biological/biochemical properties. 相似文献
19.
Kevin C Gough Claire A Baker Hugh A Simmons Steve A Hawkins Ben C Maddison 《Veterinary research》2015,46(1)
Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrPSc can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises. 相似文献