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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #401215
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies

Location: Virus and Prion Research

Title: The chronic wasting disease agent from white-tailed deer fails to adapt to sheep upon second passage

Author
item FRESE, ALEXIS - Oak Ridge Institute For Science And Education (ORISE)
item Cassmann, Eric
item WEST GREENLEE, HEATHER - Iowa State University
item Greenlee, Justin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2023
Publication Date: 5/30/2023
Citation: Frese, A.J., Cassmann, E.D., West Greenlee, H.M., Greenlee, J.J. 2023. The chronic wasting disease agent from white-tailed deer fails to adapt to sheep upon second passage (abstract). Meeting Abstract. 4th International Chronic Wasting Disease Symposium, May 30-June 3, 2023, Denver, Colorado.

Interpretive Summary:

Technical Abstract: Interspecies transmission of chronic wasting disease (CWD) is highly variable and dependent upon multiple factors. This study used sheep and transgenic mice to investigate the susceptibility of sheep to the CWD agent from white-tailed deer and to characterize subsequent passages of the resulting disease. Suffolk sheep (n=15) with PRNP genotypes VRQ/ARQ, ARQ/ARQ, or ARQ/ARR were inoculated intracranially with CWD prions from white-tailed deer. Western blots and ELISA’s were performed on brain and lymphoid tissues to analyze PrPSc accumulation. PrPSc was detected in 4/15 sheep in the brainstem at the level of the obex, with an average incubation period of 41 months. In affected sheep, distribution of PrPSc was limited to the central nervous system, suggesting that environmental shedding of CWD prions from sheep would be negligible. Brain material from one positive sheep (ARQ/ARQ) was used to inoculate mice expressing the mouse (C57BL/6; 20 ul of 10% homogenate) or sheep VRQ (Tg338; 20 ul of 1% homogenate) PRNP. Inoculum from the CWD-positive sheep did not cause disease or result in detectable PrPSc in ovinized mice after incubation of 800 days. However, upon passage to C57BL/6, 4/20 mice were positive with an average incubation period of 684 days. Upon second passage to C57BL/6 mice, the attack rate increased to 14/15 with a mean incubation period of 380 days. Overall, this data suggests that the CWD agent from white-tailed deer is unlikely to present a major risk to sheep, but further assessments should be conducted in mice expressing the ARQ ovine prion protein.