Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice

摘要

Classical bovine spongiform encephalopathy (BSE) is the only zoonotic prion disease described to date. Although the zoonotic potential of atypical BSE prions have been partially studied, an extensive analysis is still needed. We conducted a systematic study by inoculating atypical BSE isolates from different countries in Europe into transgenic mice overexpressing human prion protein (PrP): TgMet 129 , TgMet/Val 129 , and TgVal 129 . L-type BSE showed a higher zoonotic potential in TgMet 129 mice than classical BSE, whereas Val 129 -PrP variant was a strong molecular protector against L-type BSE prions, even in heterozygosis. H-type BSE could not be transmitted to any of the mice. We also adapted 1 H- and 1 L-type BSE isolate to sheep-PrP transgenic mice and inoculated them into human-PrP transgenic mice. Atypical BSE prions showed a modification in their zoonotic ability after adaptation to sheep-PrP producing agents able to infect TgMet 129 and TgVal 129 , bearing features that make them indistinguishable of sporadic Creutzfeldt-Jakob disease prions.