NR AXSX
AU Morales,R.; Castilla,J.; Saa,P.; Soto,C.
TI In Vitro Prion Propagation of Prion Strains
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Oral Abstracts FC2.2
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Vortrag
AB Prions are unconventional infectious agents responsible for transmissible spongiform encephalopathies. It has been extensively described that the misfolded form of prion protein (termed PrPsc) represents the major, or probably the only component of the infectious agent. It is well established that the prion infectious agent, like conventional micro-organisms, exhibit strain variation. Prion strains can be differentiated by their particular in vivo and in vitro characteristics, including clinical signs, differences in incubation period, pattern of brain lesions and biochemical properties of PrPsc. Understanding how a single protein can provide the diversity to sustain the strain phenomenon has been a challenge for the prion hypothesis. We have described that PrPsc can be propagated indefinitely in vitro to generate infectious material using the protein misfolding cyclic amplification (PMCA) technology. Here we demonstrate that prion strains characteristics can be replicated in vitro by PMCA. Our results show in vitro amplification of various established mouse strains including RML, ME7, 301C, 139A, and 79A. PrPsc associated to all these strains was in vitro propagated using the same PrPc substrate and the newly generated misfolded protein exhibit the typical properties of the parental strain. Moreover, wild type mice inoculated intracerebrally with in vitro generated PrPsc from each strain developed clinical signs, brain lesion pattern and biochemical characteristics identical to the animals inoculated with brain infectious material. Interestingly, incubation times and thus the specific infectivity (infectivity per unit of PrPsc) was the same for in vitro and in vivo generated infectious material in each strain. In vitro replication of prion strains has been expanded to sincs7 and sincp7 polymorphic mice models as well as crossing species barriers (interspecies propagation). Our results suggest that the strain characteristics of prions can be maintained by in vitro replication of PrPsc and therefore, that strain phenomenon is enciphered exclusively on the prion structure.
AD R. Morales, J. Castilla, P. Saá, C. Soto, University of Texas Medical Branch, Neurology, USA
SP englisch
PO Schottland