van Keulen L J, Schreuder B E, Meloen R H, Poelen-van den Berg M, Mooij-Harkes G, Vromans M E, Langeveld J P
Department of Pathobiology, Central Veterinary Institute, Lelystad, The Netherlands.
Vet Pathol. 1995 May;32(3):299-308. doi: 10.1177/030098589503200312.
A converted form of the normal cellular prion protein (PrP) accumulates in the brains of sheep with scrapie. We describe an immunohistochemical method for identifying scrapie-associated PrP (PrPSc) in periodate-lysine-paraformaldehyde-fixed brain tissue, which provides adequate preservation of tissue morphology. After pretreatment of tissue sections with formic acid and hydrated autoclaving, we located PrPSc in the brains of 50 sheep with natural scrapie by use of antipeptide antisera raised against ovine PrP. No PrP was seen in 20 sheep without histopathologic signs of scrapie. PrPSc that did not stain for amyloid was present in the cytoplasm and at the cell membrane of both neurons and astrocytes. Large amounts of PrPSc were seen at the cell membrane of neurons in the medulla oblongata and pons, whereas PrPSc accumulated at the cell membrane of astrocytes of the glial limitans in all brain regions. PrPSc that stained for amyloid was located in the walls of blood vessels and perivascularly in the brains of 32 (64%) of 50 sheep, mainly in the thalamus and never in the pons or medulla oblongata. No apparent topographic relationship existed between PrPSc that stained for amyloid and PrPSc accumulation associated with neurons or astrocytes. In all scrapie-affected sheep, PrPSc was present in brain regions with vacuolation, but it could also be detected in regions with minimal or no vacuolation. We conclude that the immunohistochemical detection of PrP can be an important confirmative test in scrapie diagnosis.
正常细胞朊蛋白（PrP）的一种转化形式在患有羊瘙痒病的绵羊大脑中蓄积。我们描述了一种免疫组织化学方法，用于在高碘酸盐-赖氨酸-多聚甲醛固定的脑组织中鉴定与瘙痒病相关的PrP（PrPSc），该方法能充分保存组织形态。在用甲酸预处理组织切片并进行高压湿热处理后，我们使用针对绵羊PrP产生的抗肽抗血清，在50只患有自然瘙痒病的绵羊大脑中定位了PrPSc。在20只没有瘙痒病组织病理学迹象的绵羊中未发现PrP。未染成淀粉样的PrPSc存在于神经元和星形胶质细胞的细胞质及细胞膜中。在延髓和脑桥的神经元细胞膜上可见大量PrPSc，而在所有脑区的胶质界膜星形胶质细胞的细胞膜上PrPSc都有蓄积。染成淀粉样的PrPSc位于50只绵羊中32只（64%）的血管壁和血管周围，主要在丘脑，而在脑桥或延髓中从未发现。染成淀粉样的PrPSc与与神经元或星形胶质细胞相关的PrPSc蓄积之间不存在明显的地形关系。在所有受瘙痒病影响的绵羊中，PrPSc存在于有空泡形成的脑区，但在空泡形成最少或没有空泡形成的区域也能检测到。我们得出结论，PrP的免疫组织化学检测在瘙痒病诊断中可以是一项重要的确诊试验。
