Scrapie is a spongiform encephalopathy of sheep and goats which can be transmitted experimentally to several other animal species. Most importantly Bovine Spongiform Encephalopathy (BSE) is believed to have been acquired from sheep with scrapie. Similar diseases are recognized in humans. No etiologic agent has been identified. However, the proteinase K resistant form (PrP-res) of an endogenous protein designated prion protein (PrP) purifies with infectivity and is important to disease pathogenesis. We developed a sensitive assay for PrP-res and utilized it to diagnose scrapie in sheep. Diagnosis based on PrP-res detection was much more accurate and less subjective than the currently used method of diagnosis based on the microscopic evaluation of brain. We also showed that PrP-res analysis of spleen or lymph node was nearly as accurate as analysis of brain. We have determined that PrP-res accumulates prior to clinical disease in sheep lymph node and placenta. Thus ante-mortem diagnosis of sheep scrapie is possible. PrP-res analysis is being used to test tissues from cattle in order to determine if spongiform encephalopathy currently exists in U.S. cattle and whether an epidemic similar to BSE in Great Britain is possible in the U.S.A. So far no positive cases have been identified. PrP-res analysis should also be relevant for diagnosis of the human disease counterparts. The influence of PrP gene sequences on interspecies transmission of spongiform encephalopathies, the relative importance of neurons and astrocytes on disease pathogenesis, and the importance of peripheral lymphoid tissue on disease are also being studied. All of these investigations utilize transgenic mice which express hamster PrP (HPrP) protein. Expression of HPrP has been restricted in the mice to either neurons or astrocytes thus allowing us to study the impact of each cell type on species tropism and scrapie pathogenesis. In addition, other mice have been acquired which express no PrP at all and are being used to study the importance of PrP on disease. Information obtained from these studies should suggest cell types or tissues which might be the target of eventual therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Intramural Research (Z01)
Project #
1Z01AI000265-15
Application #
2566732
Study Section
Special Emphasis Panel (LPVD)
Project Start
Project End
Budget Start
Budget End
Support Year
15
Fiscal Year
1996
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Race, Brent L; Meade-White, Kimberly D; Ward, Anne et al. (2007) Levels of abnormal prion protein in deer and elk with chronic wasting disease. Emerg Infect Dis 13:824-30
Meade-White, Kimberly; Race, Brent; Trifilo, Matthew et al. (2007) Resistance to chronic wasting disease in transgenic mice expressing a naturally occurring allelic variant of deer prion protein. J Virol 81:4533-9
Raymond, Gregory J; Raymond, Lynne D; Meade-White, Kimberly D et al. (2007) Transmission and adaptation of chronic wasting disease to hamsters and transgenic mice: evidence for strains. J Virol 81:4305-14
Kocisko, David A; Caughey, Byron; Morrey, John D et al. (2006) Enhanced antiscrapie effect using combination drug treatment. Antimicrob Agents Chemother 50:3447-9
Kocisko, David A; Vaillant, Andrew; Lee, Kil Sun et al. (2006) Potent antiscrapie activities of degenerate phosphorothioate oligonucleotides. Antimicrob Agents Chemother 50:1034-44
Kocisko, David A; Caughey, Winslow S; Race, Richard E et al. (2006) A porphyrin increases survival time of mice after intracerebral prion infection. Antimicrob Agents Chemother 50:759-61
Criado, Jose R; Sanchez-Alavez, Manuel; Conti, Bruno et al. (2005) Mice devoid of prion protein have cognitive deficits that are rescued by reconstitution of PrP in neurons. Neurobiol Dis 19:255-65
Chesebro, Bruce; Trifilo, Matthew; Race, Richard et al. (2005) Anchorless prion protein results in infectious amyloid disease without clinical scrapie. Science 308:1435-9
Silveira, Jay R; Raymond, Gregory J; Hughson, Andrew G et al. (2005) The most infectious prion protein particles. Nature 437:257-61
Kocisko, David A; Morrey, John D; Race, Richard E et al. (2004) Evaluation of new cell culture inhibitors of protease-resistant prion protein against scrapie infection in mice. J Gen Virol 85:2479-83

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