title: Classical natural ovine scrapie prions detected in practical volumes of blood by lamb and transgenic mouse bioassays.
abstract: 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 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.
authors.affiliation: Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6630, USA.rohana1@vetmed.wsu.edu.
authors.forename: Rohana P
authors.initials: RP
authors.lastname: Dassanayake
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Truscott
authors.forename: Dongyue
authors.initials: D
authors.lastname: Zhuang
authors.forename: David A
authors.initials: DA
authors.lastname: Schneider
authors.forename: Sally A
authors.initials: SA
authors.lastname: Madsen-Bouterse
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Young
authors.forename: James B
authors.initials: JB
authors.lastname: Stanton
authors.forename: William C
authors.initials: WC
authors.lastname: Davis
authors.forename: Katherine I
authors.initials: KI
authors.lastname: O'Rourke
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000473:pathology*; D001681:Biological Assay / Q000662:veterinary*; D051379:Mice; D008822:Mice, Transgenic; D011328:Prions / Q000097:blood*; D012608:Scrapie / Q000097:blood / Q000175:diagnosis* / Q000635:transmission; D012756:Sheep
chemical_list: D011328:Prions
keywords: B lymphocytes; Tg338 mice; blood; prions; scrapie