Dynamic Analyses of PrP and PrPsc in Brain Tissues of Golden Hamsters Infected With Scraple Strain 263K Revealed Various PrP Forms

Key words: 
• Transmissible spongiform encephalopathies (TSEs) /
• Prion /
• Scrapie /
• Glycosylation /
• Scrapie-associated fibril (SAF)

Abstract: Objective To expatiate dynamic changes in hamsters infected with scrapie strain 263K, to observe the presence and aggravation of various forms of PrP and PrPSc during incubation period, and to probe primarily the relationship between the onset of clinic manifestations and the presence of different PrPSc forms. Methods Hamster-adapted scrapie strain 263K was intracerebrally inoculated into hamsters. Different forms of PrP and PrPSc were monitored dynamically by Western blot and immuno-histochemical assays. The presence of scrapie-associated fibril (SAF) was assayedby electron microscopy analysis (EM) and immuno-golden EM. Results PrPSc was initiallydetected in the brain tissues of the animals in 20 days post-inoculation by immunohistochemistry and 40 days with Western blot. Quantitative evaluations revealed that the amounts of PrP and PrPSc inbrain tissues increased along with the incubation. Several high and low molecular masses of PrP wereseen in the brains of the long-life span infected animals. Deglycosylation assays identified that the truncated PrP in the infected brains showed similar glycosylation patterns as the full-length PrP. The presence of short fragments was seemed to relate with the onset of clinical conditions. Conclusion These results indicate that infectious agents exist and accumulate in central nerve system prior to the onset of the illness. Various molecular patterns of PrPSc may indwell in brain tissues during the infection.