title: TSE strain differentiation in mice by immunohistochemical PrP(Sc) profiles and triplex Western blot.
abstract: TSE strains are routinely identified by their incubation period and vacuolation profile in the brain after intracerebral inoculation and serial passaging in inbred mouse lines. There are some major drawbacks to this method that are related to the variation in vacuolation that exists in the brains of mice infected with the same TSE strain and to variation between observers and laboratories in scoring vacuolation and determining the final incubation period.
  
  
  OBJECTIVE
  We investigated the potential of PrP(Sc) immunohistochemistry and triplex Western blotting as possible alternative methods to differentiate between TSE strains.
  
  
  METHODS
  TSE reference strains ME7, 87A/87V, 22A/22C, 79A/79V and 301C/301V were intracerebrally inoculated in RIII or VM inbred mice that differ in their PrP genotype. Immunohistochemical PrP(Sc) profiles were drawn up by scanning light microscopy both on coronal and sagittal sections.
  
  
  RESULTS
  On the basis of the localization of PrP(Sc) in the cerebral cortex, hippocampus, and cerebellar cortex and the overall type of PrP(Sc) staining, all TSE strains could be well differentiated from each other through their typical strain dependent characteristics. In addition, Western blot showed that the combination of glycosylation profile and 12B2 epitope content of PrP(Sc) allowed to distinguish between all reference strains except for ME7 and 22A in VM mice.
  
  
  CONCLUSIONS
  TSE strains in mice can be identified on the basis of their PrP(Sc) profile alone. The potential to identify TSE strains in ruminants with these PrP(Sc) profiles after a single primary passage in mice will be the topic of future studies.
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Lucien J M
authors.initials: LJ
authors.lastname: van Keulen
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Jan P M
authors.initials: JP
authors.lastname: Langeveld
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Corry H
authors.initials: CH
authors.lastname: Dolstra
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Jorg
authors.initials: J
authors.lastname: Jacobs
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Alex
authors.initials: A
authors.lastname: Bossers
authors.affiliation: Department of Bacteriology and TSEs, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Fred G
authors.initials: FG
authors.lastname: van Zijderveld
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018620:PrPSc Proteins / Q000276:immunology / Q000378:metabolism*; D017096:Prion Diseases / Q000276:immunology / Q000473:pathology*; D012608:Scrapie / Q000276:immunology / Q000473:pathology*
chemical_list: D018620:PrPSc Proteins
keywords: PrP-res; TSE strains; immunohistochemistry; prion diseases; scrapie PrP; triplex Western blot