Use of bovine recombinant prion protein and real-time quaking-induced conversion to detect cattle transmissible mink encephalopathy prions and discriminate classical and atypical L- and H-Type bovine spongiform encephalopathy

PLoS One. 2017 Feb 22;12(2):e0172391. doi: 10.1371/journal.pone.0172391. eCollection 2017.

Abstract

Prions are amyloid-forming proteins that cause transmissible spongiform encephalopathies through a process involving conversion from the normal cellular prion protein to the pathogenic misfolded conformation (PrPSc). This conversion has been used for in vitro assays including serial protein misfolding amplification and real-time quaking induced conversion (RT-QuIC). RT-QuIC can be used for the detection of prions in a variety of biological tissues from humans and animals. Extensive work has been done to demonstrate that RT-QuIC is a rapid, specific, and highly sensitive prion detection assay. RT-QuIC uses recombinant prion protein to detect minute amounts of PrPSc. RT-QuIC has been successfully used to detect PrPSc from different prion diseases with a variety of substrates including hamster, human, sheep, bank vole, bovine and chimeric forms of prion protein. However, recombinant bovine prion protein has not been used to detect transmissible mink encephalopathy (TME) or to differentiate types of bovine spongiform encephalopathy (BSE) in samples from cattle. We evaluated whether PrPSc from TME and BSE infected cattle can be detected with RT-QuIC using recombinant bovine prion proteins, and optimized the reaction conditions to specifically detect cattle TME and to discriminate between classical and atypical BSE by conversion efficiency. We also found that substrate composed of the disease associated E211K mutant protein can be effective for the detection of TME in cattle and that wild type prion protein appears to be a practical substrate to discriminate between the different types of BSEs.

MeSH terms

  • Animals
  • Brain / metabolism*
  • Cattle
  • Diagnosis, Differential
  • Encephalopathy, Bovine Spongiform / diagnosis*
  • Mink
  • Prion Proteins / isolation & purification*
  • Prion Proteins / metabolism

Substances

  • Prion Proteins

Grants and funding

This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agriculture Research Service. The funder of the work did not influence study design, data collection and analysis, decision to publish, and preparation of the manuscript.