NR ARDQ
AU Meske,V.; Albert,F.; Ohm,T.G.
TI Entry of PrPsc in small gut of mouse
QU TSE-Forum, 4. Kongress - Nationale TSE-Forschungsplattform, Düsseldorf 28.10.-29.10.2004, Poster PATH-04
PT Konferenz-Poster
AB
In scrapie, a transmissible subacute spongiform encephalopathy of sheep, the alimentary tract is considered to be a major route of entry of infection. The involvement of the gut-associated lymphoid tissues in early steps of the pathogenesis has been shown in rodents and the accumulation of the agent in peripheral lymphoid tissues appears to facilitate neuroinvasion. Follicular dendritic cells have been considered as the cells of the lymphoid system that sustain replication of the agent in transmissible spongiform encephalopathies. Also the presence of mature B-lymphocytes has been shown to influence the course of infection in mice. However, precise identity of the digestive system tissues and cells which are primary involved in the uptake of infectious agent is still under investigation.
Aim of our study is to investigate the uptake of Prionsc protein (PrPsc) in small gut after a short incubation time. In order to determine the areas of highest PrPsc-protein concentration associated with tissue after an incubation with infected material, we placed complete intact small guts from mice in a circulating buffer system. The mucosa-side was rinsed for at least 2.5 h with buffer containing PrPsc-infected brain extracts (hamster) or non-infected brain homogenates as control. Whereas the muscle-side was placed within a glas-chamber containing solely buffer. After incubation, the tissue was thoroughly washed, fixed and dissected in 2 cm parts. The tubes were opened, spread, washed again and finally embedded in paraffin with the mucosa oriented downwards. The tissue-blocks were cut parallel to the surface starting from the muscle-side towards the mucosa-side. The sections were transferred on nitrocellulose membrane and PET-blots using 3F4-antibodies recognising hamster prion-protein were performed. Detection was based on alkaline phosphatase NBT/BCIP colorimetric system. Blots were optically evaluated using a binocular and the numbers of signals per segment were counted. We found that signals were exclusively located within the mucosa. The detected PrPsc was not evenly distributed along the small gut. An accumulation of signals was detected in the area of the prospective ileum. In an ongoing experiment we try to determine the cellular location of the scrapie protein by means of high-sensitive immunhistochemistry using the parts of the small gut which exhibited the strongest signals in PET-blot.
AD Meske, V., Albert F. and Ohm T.G., Centrum für Anantomie, Charité, Abteilung Klinische Zell- und Neurobiologie, Philippstr. 11, 10115 Berlin
SP englisch
PO Deutschland
OR Tagungsband