NR AOXX
AU Piening,N.; Bertsch,U.; Windl,O.; Bieschke,J.G.; Sarafoff,N.; Agrimi,U.; Kretzschmar,H.A.
TI The bank vole, a wild rodent species suitable as a model to investigate the molecular basis of the species barrier
QU International Conference - Prion diseases: from basic research to intervention concepts - TSE-Forum, 08.10.-10.10.2003, Gasteig, München - Poster session - BR-70
PT Konferenz-Poster
AB
Scrapie and BSE are transmissible spongiform encephalopathies (TSE) characterized by the accumulation of an abnormal protease-resistant isoform of the prion protein (PrPsc) in the brain, which is thought to be the infectious agent. The conversion of the normal, protease-sensitive form of the prion protein (PrPc) to PrPsc is a central event in these diseases and can be modelled in different cell-free conversion systems.
TSEs often require a long incubation time when the infectious agent is transferred to another species, a phenomenon known as the "species barrier". The fact that such a species barrier is also encountered in cell-free conversion reactions, leads to the assumption that the amino acid sequence of the prion protein has an important role for the conversion process.
Transmission studies with bank voles (Clethrionomys glareolus), a wild rodent species, have revealed that compared to mouse these rodents are highly susceptible to natural scrapie but show apparent resistance to BSE infection. Sequence comparison has identified four amino acid residues that are likely to be responsible for the differential susceptibility of the bank vole to scrapie and BSE.
We will explore the species barrier of transmission to bank vole using cell-free conversion assays as described by Kocisko et al. (1994) and the protein misfolding cyclic amplification (PMCA) by Saborio, Permanne and Soto (2001).
For the Kocisko assay the sequence of the bank vole PrP gene was cloned into suitable expression vectors, allowing expression in mammalian cells. This cellular vole PrPc and mutagenised versions of it will now be incubated with PrPsc prepared from infected voles, sheep and cattle. Using the PMCA assay, we have shown that PrPc from bank vole can be converted to its protease-resistant form by PrPsc from itself and by PrPsc from other species. We have therefore two systems in hand to explore on the molecular level the differential susceptibility of bank voles to scrapie and BSE.
AD N. Piening, U. Bertsch, J. Bieschke, N. Sarafoff, H.A. Kretzschmar, Institut für Neuropathology, Ludwig-Maximilians Universität, Munich, Germany; O. Windl, TSE Molecular Biology Department, VLA-Weybridge, Surrey, UK; U. Agrimi, Instituto Superiore di Sanità, Rome, Italy
SP englisch
PO Deutschland