NR AWFV
AU Gonzalez,L.; Martin,S.; Dagleish,M.P.; Siso,S.; Steele,P.; Jeffrey,M.J.
TI Phenotypes of PRPcwd accumulation in cervids: the sheep experience
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre, Workshop of the Neuroprion Cervid Group - Chronic Wasting Disease (CWD): Current knowledge and European perspective 2006, 3.10.2006
PT Konferenz-Vortrag
AB Chronic wasting disease (CWD) is a naturally occurring prion disease of cervids in North America. It was first recognized almost 40 years ago but its origin and relationship to other transmissible spongiform encephalopathies is unclear. Despite the fact that it affects several species of free ranging and farmed deer and elk, little is known about strain variability of the aetiological agent. For several years we have been using two immunohistochemical (IHC) approaches to study and characterize the phenotype of disease-associated PrP (PrPd) accumulation in sheep TSEs. One of them, the so-called epitope mapping, is based on the use of a panel of antibodies against different amino-acid sequences of PrP. This method has allowed us to distinguish between experimental sheep BSE, natural scrapie and a experimental source of sheep scrapie (CH1641). The other approach, called PrPd profiling, is based on the identification and scoring of different morphological and cell associated types of PrPd that accumulate in the brain of clinically affected animals. The IHC phenotypes defined in this way appear to correlate mainly with the source of infection or prion strain and, in some cases, also with the PrP genotype, while other factors such as the route of infection, breed and dose do not have any effect. We believe that these approaches may be useful for the definition of IHC phenotypes in CWD and further assessment of the factors that can influence such phenotypes. We have performed some preliminary examinations on a few CWD cases in American and Canadian elk which indicate the presence of several types of intra- and extra-cellular PrPd deposition in those brains. It would appear that the American cases can be differentiated from the Canadian ones on the basis of the relative proportion of those types, i.e., on their PrPd profiles. Moreover, those profiles are very different from that of a single UK red deer that developed clinical disease after intra-cerebral challenge with BSE. This animal showed a different epitope mapping pattern compared to all of the CWD cases examined. Although these are very preliminary observations they would point towards a lack of relationship between BSE and CWD and also perhaps towards the existence of more than one strain of CWD agent.
AD Lorenzo González (l.gonzalez@vla.defra.gsi.gov.uk), Stuart Martin, Sílvia Sisó (s.siso@vla.defra.gsi.gov.uk), Martin J. Jeffrey (m.jeffrey@vla.maff.gov.uk), VLA Lasswade Veterinary Laboratory, Pentlands Science Park, Bush Loan, Penicuik, Edinburgh EH26 OPZ, Scotland, UK; M.P. Dagleish, P. Steele, Moredun Institute, Pentlands Science Park, Bush Loan, Midlothian EH26 0PZ, UK; L. Terry, R. Horton, G. Dexter: VLA-Weybridge, Addlestone, Surrey KT15 3NB, UK
SP englisch
PO Italien