Figure 3.

Schematic presentation of the mechanism, illustrating genesis of PrP^Sc triggered by rPrP fibrils. In a first step, rPrP fibrils seeded atypical PrP^res, a transmissible form of PrP that replicates silently without causing clinical disease. Replication of atypical PrP^res occasionally produces PrP^Sc in seeding events that appears to be rare and stochastic as described for a deformed templating mechanism. PrP^Sc replicates faster than atypical PrP^res and eventually replaces it during serial passages. The two forms atypical PrP^res and PrP^Sc can be distinguished after PK treatment via staining Western blot analyses with discriminating antibodies. Atypical PrP^res, alternative self-replicating state of prion protein; PrP^Sc, prion protein scrapie isoform; rPrP, recombinant prion protein. From [185].