Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2005
Publication Date: 10/18/2005
Citation: Bessen, R.A., Dejoia, C., Dlakic, W., Sorg, R., O’Connell, K., Tucker, T., Kunkle, R.A., Hamir, A.N., Richt, J.A. 2005. Prion infection of mucosal tissue [abstract]. TSE Forum, Prion 2005: Between Fundamentals and Society's Needs. p. 31. Interpretive Summary:
Technical Abstract: To investigate the site(s) of agent shedding in prion disease we determined the distribution of the prion agent in tongue mucosal tissue from sheep, elk, and rodents with experimental prion disease. We examined the tongue as a peripheral target of prion infection since it is a densely innervated tissue located at the oral mucosa. PrP**Sc was present in tongues from elk infected with the chronic wasting disease agent and sheep infected with the scrapie agent. In hamsters intracerebrally inoculated with the prion agent, PrP**Sc was found in nerve fibers and skeletal muscle cells as well as in taste buds of the tongue. In fungiform papillae in the tongue, laser scanning confocal microscopy demonstrated that the distribution of PrP**Sc was consistent with deposition in axons, taste cells, and the synapse between axon terminals and these neuroepithelial cells. These findings suggest that the prion agent can spread from the brain stem to sensory cells at the tongue mucosa via cranial nerves. Direct inoculation of the prion agent into the chorda tympani nerve (i.e., where the Vth and VIIth cranial nerves join together) resulted in initial prion agent deposition in the nucleus of the solitary tract in the brain stem and, in the tongue, in taste buds of the fungiform papillae. This finding indicates that one route of prion agent invasion of the tongue mucosa from the brain stem is via the VIIth (facial) nerve. PrP**Sc deposition was also present in the stratified squamous epithelium of the tongue, but only in fungiform papillae surrounding PrP**Sc-positive taste buds. Laser scanning confocal microscopy studies defining the relationship of PrP**Sc deposition in axons and epithelial cells in the stratified squamous epithelium will be discussed.