NR ATQE
AU Di Guardo,G.; Malatesta,D.; Mara,M.; Petrucci,L.; Lalatta,G.; Chiocchetti,R.; Clavenzani,P.; Bortolami,R.; Agrimi,U.; D'Agostino,C.; Vaccari,G.; Ligios,C.; De Grossi,L.; Rosone,F.; Marruchella,G.
TI Pathogenetic studies on the enteric nervous system of Sarda breed sheep with different PrP genotypes following oral experimental scrapie infection*
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Pathogenesis PATH-41
PT Konferenz-Poster
AB
The enteric nervous system (ENS) represents, along with Peyer's patches, a body district that is known to play a key role in the early pathogenesis of sheep scrapie. Despite this, no information is available on the cell types residing within ENS plexuses which are involved in the course of infection, nor on the morpho-functional changes, if any, affecting such cellular elements in comparison with those taking place inside central nervous system neurons.
The present study was carried out on the myenteric plexuses (MPs) and submucosal plexuses (SMPs) from the ileum of 22 Sarda breed sheep carrying different PrP genotypes and experimentally infected per os with scrapie at 6 months of age, which were euthanized at definite time intervals throughout two consecutive years.
Ileal segments were collected from each animal and submitted to an appropriate PrPsc immunohistochemistry (IHC) protocol, which was carried out using the F99 monoclonal antibody (MoAb). From additional ileal segments, 6-8 cm long, "wholemount" preparations were obtained, in order to investigate human neuronal protein (Hu), nitric oxide synthase (nNOS), calbindin (CALB) and glial fibrillary acidic protein (GFAP) immunoreactivity (IR) by means of suitable fluorescent Abs.
Six out of the 22 sheep under study, all of the ARQ/ARQ genotype, showed IHC evidence of PrPsc in their ENS, particularly at the MP level. A dramatic reduction of CALB-IR was found in the MPs and SMPs from the above 6 animals, with exclusive immunolabelling of neuronal nuclei in several cases. The same sheep also showed focal areas of decreased GFAP-IR, with two of them and another ARR/ARR subject exhibiting an impressive reduction of nNOS-IR in their MPs.
The above findings suggest that CALB-IR neurons and enteroglial cells residing within ENS plexuses are involved in the pathogenesis of scrapie infection in sheep.
*Granting Institutions: Italian MIUR (PRIN 2004), Universities of Teramo and Bologna, Italian Ministry of Health.
AD G.Di Guardo, D.Malatesta, M.Marà, L.Petrucci, R.Bortolami, U.Agrimi, C.D'Agostino, G.Vaccari, Università degli Studi di Teramo, Facoltà di Medicina Veterinaria, Dipartimento di Scienze Biomediche Comparate, Italy; G.Lalatta, R.Chiocchetti, P.Clavenzani, F.Rosone, Università degli Studi di Bologna, Facoltà di Medicina Veterinaria, Dipartimento di Morfofisiologia Veterinaria e Produzioni Animali, Italy; C.Ligios, Istituto Zooprofilattico Sperimentale della Sardegna, Italy; L.De Grossi, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Italy; G.Marruchella, Università degli Studi di Teramo, Facoltà di Medicina Veterinaria, Dipartimento di Scienze Biomediche Comparate, Italy
SP englisch
PO Deutschland