ABSTRACT

TR A N S M I S S I B L E spongiform encephalopathies are neurodegenerative dis-eases, which include Scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, Creutzfeldt-Jakob disease (CJD), fatal familial insomnia (FFI), Gerstmann-Straussler-Scheinker syndrome (GSS) and Kuru in humans. Today these diseases have raised great concern, especially in Europe, since 46 cases of a new variant form of CJD (nvCJD) have appeared in the United Kingdom as well as one case in France (status September 1999). nvCJD differs from "classical" CJD in many aspects, among them the fact that patients are very young (the mean age is 29 years in nvCJD versus about 60 years in sporadic CJD) and exhibit in thin sections of the brain typical amyloid plaques dubbed "florid plaques" because of their daisy-like appearance. People worldwide are worried about the risks of BSE transmission to humans and new findings suggest that BSE is in fact transmissible to humans: (1) macaques inoculated with prions originating from BSE-infected cattle developed the same florid plaques as nvCJD patients: (2) experiments employing transgenic animals carrying the Prn-p gene coding for human PrP developed the disease after inoculation with BSE prions and nvCJD showed the same glycosylation pattern as BSE in FVB mice: (3) wild-type mice inoculated with prions from humans suffering from nvCJD developed the disease after the same period of time as animals inoculated with BSE prions and showed the same lesion profiles: and (4) human PrP can be converted by bovine PrPB S E into the proteinase K-resistant state.