NR AXTQ
AU Nonno,R.; Vascellari,M.; Mutinelli,F.; Bigolaro,M.; Di Bari,M.A.; Melchiotti,E.; Marcon,S.; D'Agostino,C.; Vaccari,G.; Conte,M.; De Grossi,L.; Rosone,F.; Pifferi,A.R.; Agrimi,U.
TI PrPsc in Salivary Glands of Scrapie-affected Sheep
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Epidemiology, Risk Assessment and Transmission P04.72
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Epidemiological and experimental studies suggest that the spread of scrapie among sheep mainly occurs by horizontal transmission, either by direct transmission or by prion being shed into the environment. In this context, the shedding of scrapie agent from infected body compartments has to be postulated. To date, prion infectivity has not been described in saliva, nasal secretions, respiratory aerosols, urine, or feces in naturally occurring scrapie infection. Salivary glands have not been extensively investigated for the presence of infectivity or pathological prion protein (PrPsc). In this work, the salivary glands of scrapie-affected sheep and healthy controls were analysed for the presence of PrPsc.
PrPsc was detected in the parotid, mandibular, buccal, palatine and labial glands of sheep with natural scrapie, as well as in the parotid and buccal glands of experimentally challenged sheep. Collectively, 16 out of 18 (89%) scrapie-affected sheep showed PrPsc in at least one salivary gland.
In both mucous and serous glands, immunohistochemistry revealed intracellular deposition of PrPsc in ductal and acinar epithelium and occasional labelling into the lumen of salivary ducts draining saliva into the oral cavity. PET-blot analysis showed that these positive deposits were proteinase K-resistant. By Western blot, the typical three-band pattern of PrPsc was detected in all types of salivary glands investigated. Protease resistant PrPsc from salivary glands and brain displayed similar molecular weight upon deglycosylation. By plotting Western blot signals of glands against scrapie-infected brain we determined that the PrPsc concentration in salivary glands ranged between 0.02 and 0.005% that of brain.
Taken together, these findings show that a significant proportion of sheep with scrapie accumulates low levels of PrPsc in salivary glands. The presence of PrPsc at this level highlights the possible role of saliva in the horizontal transmission of scrapie. Further studies on the kinetics of PrPsc accumulation in salivary gland during the pre-clinical phase of scrapie infection are underway, and the results will be presented.
AD R. Nonno, M.A. Di Bari, S. Marcon, C. D'Agostino, G. Vaccari, M. Conte, U. Agrimi, Istituto Superiore di Sanità, Italy; M. Vascellari, F. Mutinelli, M. Bigolaro, E. Melchiotti, Istituto Zooprofilattico Sperimentale delle Venezie, Italy; L. De Grossi, F. Rosone, A.R. Pifferi, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Italy
SP englisch
PO Schottland