PrP Sc in Salivary Glands of Scrapie-Affected Sheep

Abstract

The salivary glands of scrapie-affected sheep and healthy controls were investigated for the presence of the pathological prion protein (PrP ^Sc ). PrP ^Sc was detected in major (parotid and mandibular) and minor (buccal, labial, and palatine) salivary glands of naturally and experimentally infected sheep. Using Western blotting, the PrP ^Sc concentration in glands was estimated to be 0.02 to 0.005% of that in brain. Immunohistochemistry revealed intracellular depositions of PrP ^Sc in ductal and acinar epithelia and occasional labeling in the lumina of salivary ducts. The presence of PrP ^Sc in salivary glands highlights the possible role of saliva in the horizontal transmission of scrapie.