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Scrapie is a mammalian transmissible spongiform encephalopathy or prion disease that predominantly affects sheep and goats. Scrapie has been shown to overcome the species barrier via experimental infection of other rodents. To confirm the re-transmissibility of the mouse-adapted ME7 scrapie strain to ovine prion protein (PrP) transgenic mice, mice of an ovinized transgenic mouse line carrying the Suffolk sheep PrP gene that contained the A136 R154 Q171/ARQ allele were intracerebrally inoculated with brain homogenates obtained from terminally ill ME7-infected C57BL/6J mice. Herein, we report that the mouse-adapted ME7 scrapie strain was successfully re-transmitted to the transgenic mice expressing ovine PrP. In addition, we observed changes in the incubation period, glycoform profile, and pattern of scrapie PrP (PrPSc) deposition in the affected brains. PrPSc deposition in the hippocampal region of the brain of 2nd-passaged ovine PrP transgenic mice was accompanied by plaque formation. These results reveal that the mouse-adapted ME7 scrapie strain has the capacity to act as a template for the conversion of ovine normal monomeric precursors into a pathogenic form in ovine PrP transgenic mice. The change in glycoform pattern and the deposition of plaques in the hippocampal region of the brain of the 2nd-passaged PrP transgenic mice are most likely cellular PrP species dependent rather than being ME7 scrapie strain encoded. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is classified as a transmissible spongiform encephalopathy or prion disease that affects cervids. CWD has been reported in 15 US states, two Canadian provinces, and in imported elk on several farms in Korea. This study was conducted to examine the molecular biological and pathogenic characteristics of a CWD-associated prion isolated in Korea. The epidemiological origin of this pathogen was also determined. Homozygous TgElk mice were infected with a CWD-affected elk brain pool prepared from the brain of an imported Canadian elk. We measured the incubation time of the pathogen, neuropathological changes by immunohistochemical staining, the pattern(s) of scrapie prion protein (PrPSc) deposition, and PrPSc protein profiles by Western blotting. We found that TgElk mice infected with brain homogenate from the elk suffering from CWD showed incubation times, vacuolar degeneration, and PrPSc accumulation similar to those previously reported in the literature. Our results suggest that homozygous TgElk mice efficiently transmit CWD with short incubation times and that this animal can serve a valuable research model and reliable in vivo diagnostic tool. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies (mAbs) specific for the abnormal prion protein isoform (PrPres) are indispensable for diagnosing chronic wasting disease (CWD). In this study, eight mAbs were developed by immunizing PrP knockout mice with recombinant elk PrP and an immunogenic PrP peptide. The reactivity of the mAbs to recombinant PrP and the PrP peptide was measured, and their isotypes were subsequently determined. Among them, four mAbs (B85-05, B85-08, B85-12, and B77-75) were shown by Western blotting to recognize proteinase K-treated brain homogenate derived from an elk suffering from CWD. [ABSTRACT FROM AUTHOR]

Polymorphisms of the prion protein gene (PRNP) have been detected in several cervid species. In order to confirm the genetic variations, this study examined the DNA sequences of the PRNP obtained from 33 captive sika deer (Cervus nippon laiouanus) in Korea. A total of three single-nucleotide polymorphisms (SNPs) at codons 100, 136 and 226 in the PRNP of the sika deer were identified. The polymorphic site located at codon 100 has not been reported. The SNPs detected at codons 100 and 226 induced amino acid substitutions. The SNP at codon 136 was a silent mutation that does not induce any amino acid change. The genotype and allele frequencies were determined for each of the SNPs. [ABSTRACT FROM AUTHOR]