National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2011

15. Sc237 hamster PrPSc and Sc237-derived mouse PrPSc generated by interspecies in vitro amplification exhibit distinct pathological and biochemical properties in tga20 transgenic mice


  Prions are the infectious agents responsible for transmissible spongiform encephalopathy. They are composed primarily of a pathogenic form (PrPSc) of the host-encoded prion protein (PrPC). Recent studies have revealed that protein misfolding cyclic amplification (PMCA), a highly sensitive method for PrPSc detection, can overcome the species barrier in several xenogeneic combinations of PrPSc seed and PrPC substrate. Although these findings provide valuable insight into the origin and diversity of prions, the differences between PrPSc generated by interspecies PMCA and by in vivo cross-species transmission have not been described. This study investigated the histopathological and biochemical properties of PrPSc in the brains of tga20 transgenic mice inoculated with Sc237 hamster scrapie prion and PrPSc from mice inoculated with Sc237-derived mouse PrPSc, which had been generated by interspecies PMCA using Sc237 as the seed and normal mouse brain homogenate as the substrate. Tga20 mice overexpressing mouse PrPC were susceptible to Sc237 after primary transmission. PrPSc in the brains of mice inoculated with Sc237-derived mouse PrPSc and in the brains of mice inoculated with Sc237 differed in their lesion profiles and accumulation patterns, Western blot profiles, and denaturant resistance. In addition, these PrPSc exhibited distinctive virulence profiles on secondary passage. These results suggest that different in vivo and in vitro environments result in propagation of PrPSc with different biological properties.
(Prion Disease Research Center)


Yoshioka M. et al (2011) Microbiol. Immunol. 55(5):331-340