Abnormal prion protein in genetically resistant sheep from a
scrapie-infected flock
J.-Y. Madec1, S. Simon2, S. Lezmi1, A. Bencsik1, J. Grassi2 and T. Baron1
1 AFSSA Lyon, 31 avenue Tony Garnier, 69364 Lyon cedex 07, France
2 CEA, Service de Pharmacologie et d'Immunologie, CEA/Saclay, France
Correspondence
J.-Y. Madec
jy.madec@lyon.afssa.fr
The central molecular event in transmissible spongiform
encephalopathies, such as scrapie in sheep, is the accumulation in
tissues of an abnormal isoform of the cellular prion protein. A previous
investigation of 26 sheep showed that the accumulation of PrPres in
brain correlated more with the prnp genotype than with the severity of
the clinical disease. Here, the ability of a sandwich ELISA to detect
PrPres distribution in the brain was demonstrated. Immunohistochemistry
also strongly supported the hypothesis that the dorsal motor nucleus of
the vagus nerve is the possible entry site in the brain for the scrapie
agent. Remarkably, three asymptomatic (or possibly asymptomatic for
scrapie) sheep carrying an allele known to be associated with clinical
scrapie resistance (ARR), which were negative for the detection of
PrPres by Western blotting and immunohistochemistry, were positive for
the presence of PrPres by ELISA, raising the possibility of carriers
resistant to the disease and possibly contributing to the persistence of
scrapie in certain flocks.
http://vir.sgmjournals.org/cgi/content/abstract/85/11/3483?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1097700246431_1433&stored_search=&FIRSTINDEX=0&volume=85&issue=11&search_url=http%3A%2F%2Fvir.sgmjournals.org%2Fcgi%2Fsearchtss