NR AXRH
AU Lewis,V.; Lawson,V.A.; Masters,C.L.; Hill,A.F.; Collins,S.J.
TI Investigating the Subcellular Location of the Infectious "Prion" and its Relationship to PrPres in a Cell Culture Model of Prion Disease
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Oral Abstracts FC3.2
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Vortrag
AB
Background: The precise pathogenic and transmission mechanisms in prion diseases are not yet understood. It remains possible that PrPres, a protease resistant misfolded conformer of the normal cellular prion protein PrPc, although serving as a highly reliable marker of disease on pathological examination and associated biochemical assays, may be a relatively inert end point of the pathogenic process. Molecules closely associated with PrPres, including other PrP species (PrP*), perhaps produced during the conversion of PrPc to PrPres, may significantly contribute to disease. Such hypotheses are supported by the occurrence of disease transmission and clinical illness despite the presence of very little PrPres. Further, co-factors and the precise subcellular environment of PrPres or PrP* may be critical factors in determining efficiency of pathogenesis and transmissibility.
Aims: To identify the subcellular location of the most infectious "prions", and using a novel method clarify the relationship between transmissibility and PrPres .
Methods: Nycodenz gradients were used to perform density gradient fractionation of lysates of prion infected cells. The location of PrPres and subcellular organelles within the fractions were determined by western blot or dot blot analysis. Fractions were used to infect recipient cells. Various factors influencing efficiency of transmission were evaluated using a cell blot method and quantitation of PrPres produced by recipient cells.
Results: The most infectious fractions were not always "raft" associated, and did not correlate with those containing the highest levels of PrPres. Further, other co-factors not associated or bound to the infectious "prion", have a relatively minor influence on infection efficiency.
Conclusions: Our results provide evidence to support the contention that although PrPres may constitute an important component of the infectious unit, other closely related PrP species (PrP*), and/or co-factors associated with the infectious entity, are also likely to be determinants of transmission efficiency.
AD V. Lewis, V.A. Lawson, Steven J. Collins, University of Melbourne, Department of Pathology, Australia; C.L. Masters, Mental Health Research Institute of Victoria, Australia; Andrew F. Hill, Bio21 Molecular Science & Biotechnology Institute, Department of Biochemistry & Molecular Biology, Australia
SP englisch
PO Schottland