NR AXWH
AU Shikiya,R.A.; Bartz,J.C.
TI In Vitro Amplification of Prion Strains
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Natural and Experimental Strains P02.09
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Background: Prion diseases affect both humans and animals. Prions are thought to be comprised solely of the abnormal isoform of the prion protein, PrPsc which is posttranslationally derived from the normal isoform, PrPc. A crucial event in the transmission TSE's is the interaction of PrPsc with PrPc, which results in a structural change in the normal PrPc protein, increasing its ß-sheet content and converting it to PrPsc. Distinct prion strains have been identified that are operationally defined by differences in neuropathology when inoculated in experimental animals. Experimental evidence suggests that prion strain diversity is encoded by distinct conformations of PrPsc. As an example, the hyper (HY) and drowsy (DY) strains of hamster-adapted transmissible mink encephalopathy (TME) have different clinical signs, incubation periods, neuropathology and the biochemical and structural properties of PrPsc.
Objective: Investigate if in vitro amplification of the HY and DY TME prion strains maintains the unique strain properties. To accomplish this we used the protein misfolding cyclic amplification (PMCA) technique.
Methods: The PMCA technique is designed to mimic, at an accelerated rate, some of the fundamental steps involved in PrPsc conversion in vivo. In brief, a small amount of PrPsc is incubated with excess PrPc to increase PrPsc abundance. The newly formed PrPsc is sonicated to fragment it into smaller units, which will catalyze the formation of new PrPsc. This incubation and sonication cycle is repeated several times. We used HY or DY infected hamster brain as the PrPsc source and uninfected hamster brain as the PrPc source.
Results: After several rounds of sonication and incubation cycles we were able to amplify both of the HY and DY TME strains. Based on biochemical studies, the amplified strains is not different from those obtained from previous in vivo studies.
Conclusions: These results show that different prion strains can be amplified in vitro, suggesting that the PMCA technique can mimic the conditions needed for strainspecific in vivo conversion of PrPc into PrPsc.
AD R. Shikiya, J. Bartz, Creighton University, Medical Microbiology and Immunology, USA
SP englisch
PO Schottland