Molecular discrimination of atypical bovine spongiform encephalopathy strains from a geographical region spanning a wide area in Europe.
Transmissible spongiform encephalopathy strains can be differentiated by their behavior in bioassays and by molecular analyses of the disease-associated prion protein (PrP) in a posttranslationally transformed conformation (PrPSc). Until recently, isolates from cases of bovine spongiform encephalopathy (BSE) appeared to be very homogeneous. However, a limited number of atypical BSE isolates have recently been identified upon analyses of the disease-associated proteinase K (PK) resistance-associated moiety of PrPSc (PrPres), suggesting the existence of at least two additional BSE PrPres variants. These are defined here as the H type and the L type, according to the higher and lower positions of the nonglycosylated PrPres band in Western blots, respectively, compared to the position of the band in classical BSE (C-type) isolates. These molecular PrPres variants, which originated from six different European countries, were investigated together. In addition to the migration properties and glycosylation profiles (glycoprofiles), the H- and L-type isolates exhibited enhanced PK sensitivities at pH 8 compared to those of the C-type isolates. Moreover, H-type BSE isolates exhibited differences in the binding of antibodies specific for N- and more C-terminal PrP regions and principally contained two aglycosylated PrPres moieties which can both be glycosylated and which is thus indicative of the existence of two PrPres populations or intermediate cleavage sites. These properties appear to be consistent within each BSE type and independent of the geographical origin, suggesting the existence of different BSE strains in cattle. The choice of three antibodies and the application of two pHs during the digestion of brain homogenates provide practical and diverse tools for the discriminative detection of these three molecular BSE types and might assist with the recognition of other variants.
Jacobs
Jorg G
JG
Central Institute for Animal Disease Control (CIDC-Lelystad), 8203 AA 2004, Lelystad. The Netherlands.
Langeveld
Jan P M
JP
Biacabe
Anne-Gaëlle
AG
Acutis
Pier-Luigi
PL
Polak
Miroslaw P
MP
Gavier-Widen
Dolores
D
Buschmann
Anne
A
Caramelli
Maria
M
Casalone
Cristina
C
Mazza
Maria
M
Groschup
Martin
M
Erkens
Jo H F
JH
Davidse
Aart
A
van Zijderveld
Fred G
FG
Baron
Thierry
T
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015153:Blotting, Western; D001933:Brain Stem / Q000378:metabolism*; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000453:epidemiology* / Q000378:metabolism*; D019286:Endopeptidase K / Q000378:metabolism / Q000494:pharmacology; D005060:Europe / Q000453:epidemiology; D014644:Genetic Variation; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D018620:PrPSc Proteins / Q000145:classification* / Q000235:genetics* / Q000378:metabolism; D011328:Prions / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018620:PrPSc Proteins; D011328:Prions; D019286:Endopeptidase K