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Updated: Jun 15, 2026
Procedures for Identifying Infectious Prions After Passage Through the Digestive System of an Avian Species
Published on: November 6, 2013
Disease-associated prion protein in the dental tissue of mice infected with scrapie
H Okada1, M Sakurai, T Yokoyama
1Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan. okadahi@affrc.go.jp
Abstract:
Transmissible spongiform encephalopathies (TSEs) induce fatal neurodegenerative diseases in man and animals. The present study demonstrates immunohistochemically the presence of disease-associated prion protein (PrP(Sc)) in the epithelial cell rests of Malassez (ERM) of mice experimentally infected with ME7 scrapie by the intracerebral route. Mouse bioassay of scrapie-infected dental tissue revealed prolonged incubation periods, suggesting that there are relatively low amounts of infectious agent in dental tissue compared with the brain. These findings indicate that PrP(Sc) may spread from the brain to the ERM along the cranial nerves via the trigeminal ganglion that innervates the dental tissues. Dental tissue might therefore be a potential source of PrP(Sc) for horizontal transmission of TSEs.
Insights
Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases. This study found disease-associated prion protein (PrP(Sc)) in mouse dental tissues, suggesting a potential route for horizontal disease transmission.
Area of Science:
- Neuroscience
- Pathology
- Veterinary Medicine
Background:
- Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases affecting humans and animals.
- Prion diseases are characterized by the accumulation of abnormal prion protein (PrP(Sc)).
Purpose of the Study:
- To investigate the presence and potential role of disease-associated prion protein (PrP(Sc)) in dental tissues during scrapie infection.
- To explore the pathway of PrP(Sc) spread from the brain to dental tissues.
Main Methods:
- Immunohistochemistry was used to detect PrP(Sc) in the epithelial cell rests of Malassez (ERM) in mice infected with ME7 scrapie.
- Mouse bioassay was performed on scrapie-infected dental tissue to determine infectivity.
Main Results:
- Disease-associated prion protein (PrP(Sc)) was detected immunohistochemically in the ERM of experimentally infected mice.
- Mouse bioassays of dental tissue showed prolonged incubation periods compared to brain tissue.
- These findings suggest PrP(Sc) can spread from the brain to ERM via cranial nerves.
Conclusions:
- The epithelial cell rests of Malassez in dental tissues harbor PrP(Sc) following scrapie infection.
- Dental tissue may serve as a potential reservoir for the horizontal transmission of TSEs.
- PrP(Sc) likely spreads from the brain to dental tissues along neural pathways.
