Similar Signature of the Prion Protein in Natural Sheep Scrapie and Bovine Spongiform Encephalopathy-Linked Diseases

It has been suggested that specific molecular features could characterize the protease-resistant prion protein (PrP res) detected in animal species as well as in humans infected by the infectious agent strain that causes bovine spongiform encephalopathy (BSE). Studies of glycoform patterns in such diseases in French cattle and cheetahs, as well as in mice infected by isolates from both species, revealed this characteristic molecular signature. Similar studies of 42 French isolates of natural scrapie, from 21 different flocks in different regions of France, however, showed levels of the three glycoforms comparable to those found in BSE-linked diseases. Moreover, the apparent molecular size of the unglycosylated form was also indistinguishable among all different sheep isolates, as well as isolates from BSE in cattle. Overall results suggest that scrapie cases with features similar to those of BSE could be found more frequently in sheep than previously described.