Dassanayake Rohana P, Truscott Thomas C, Zhuang Dongyue, Schneider David A, Madsen-Bouterse Sally A, Young Alan J, Stanton James B, Davis William C, O'Rourke Katherine I
Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6630,
J Vet Sci. 2015;16(2):179-86. doi: 10.4142/jvs.2015.16.2.179. Epub 2014 Dec 24.
Scrapie is diagnosed antemortem in sheep by detecting misfolded isoforms of prion protein (PrP(Sc)) 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 PrP(Sc) 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 510 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 510 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.
通过检测直肠黏膜和瞬膜淋巴滤泡中朊病毒蛋白（PrP(Sc)）的错误折叠异构体，可在生前诊断绵羊的羊瘙痒病。如果（a）在疾病发展早期采集活检样本，（b）采集的滤泡数量不足，或（c）PrP(Sc)的外周积累减少或延迟，则检测灵敏度会受到限制。血液检测对于大规模活体动物羊瘙痒病检测会很方便。然而，目前批准的技术有其自身的检测限。新型检测方法可能很快会提供一个基于非动物的快速平台，其检测灵敏度可与朊病毒生物测定法相媲美。预期之下，我们试图确定是否可以使用从小反刍动物诊断常用采血量的血样中分离的B淋巴细胞，通过生物测定法常规鉴定患病动物。在静脉内输注从一只自然感染羊瘙痒病的绵羊510 mL血液中分离的B淋巴细胞的6只受体羔羊中，有5只检测到羊瘙痒病传播。此外，在用从两只自然感染羊瘙痒病的绵羊510 mL血液中分离的B淋巴细胞脑内接种的18只羊化转基因Tg338小鼠中，观察到了羊瘙痒病传播。基于我们的发现，我们预计这些采血量应具有诊断价值。
