CPB 697 RESEARCH SEMINAR
Juergen A. Richt, DVM,
PhD
Veterinary Medical Officer
Lead Scientist, Prion Diseases Laboratory
National Animal Disease Center, USDA
2300 Dayton Ave
Ames, IA
“Animal Prion Diseases in the
VPTH
112
Transmissible spongiform
encephalopathy (TSE) agents or prions induce
fatal neurodegenerative diseases in humans and in other mammals.
They are transmissible among their species of origin, but they can
also cross some species barriers and induce infection with or
without disease in other species. Human TSEs include
Creutzfeldt–Jakob
disease (CJD), Gerstmann–Sträussler–Scheinker syndrome, Kuru,
and fatal familial insomnia. In animals,
4 distinct TSE diseases are recognized: scrapie
in sheep and goats, transmissible mink encephalopathy (TME) in mink,
chronic wasting disease (CWD) in cervids,
and bovine spongiform encephalopathy (BSE) in cattle. BSE is
transmissible via BSE-contaminated feed to cats (feline spongiform
encephalopathy, FSE) and exotic ungulates (exotic ungulate
encephalopathy, EUE). Prion diseases are caused by propagation of misfolded forms of the normal cellular prion
protein PrP(C), such as PrP(BSE) in BSE in cattle and
PrP(CJD) in CJD in humans. Disruption of PrP(C) expression in mice, a species that does not
naturally contract prion diseases, results in no
apparent developmental abnormalities. We generated and characterized PrP(C)-deficient cattle produced by a sequential
gene-targeting system. At over 20 months of age, the cattle are clinically,
physiologically, histopathologically, immunologically and reproductively normal. PrP(C)-deficient cattle may be a useful model for prion research and could provide industrial bovine products
free of prion proteins.