NR AXNZ
AU Harders,F.L.; Smits,M.A.; van Keulen,L.J.M.; van Zijderveld,F.G.; Bossers,A.
TI Identification of Early Natural Scrapie-Specific Gene Expression Changes in Tonsil and Peyer's Patches of Sheep Using a Sheep cDNA Microarray
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Pathology and Pathogenesis P03.43
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
All currently used routine diagnostics for TSEs are thus far solely based on the detection of pathogically folded accumulated prion protein (PrP). The process of TSE agent-uptake, which most likely takes place in the gut via the ileal Peyer's patches, is still poorly understood, as is the host response to the TSE agent itself. This research focuses on the identification of new biomarkers (other than PrP) that might be useful to extend current TSE diagnostics and/or allowing us to better understand the TSE micro-pathogenesis. We studied the host response by determining the geneexpression-
profiles in the very early phase of a natural scrapie infection in sheep using own generated sheep cDNA arrays. We have used a self-generated sheep cDNA microarray containing about 7.4k unique features in triplicate. These features were derived from a large normalised EST library of tonsil and Peyer's patches of sheep (non-infected and infected of different PrP genotypes). The unique features were determined by sequencing, clustering and assembling over 13.000 sequenced ESTs into 1.850 contigs and 2.594 singletons. To probe the sheep arrays we collected and mRNA preserved many different tissues that include tonsil, Peyer's patches of ileum and jejunum, brain regions, blood, muscle regions and RLNs. These materials were collected at different time points (0, 3, 8 and 32 weeks) of sheep having different PrP genotypes after natural exposure to scrapie or from scrapie-free sheep. Tissues used for array hybridisation were also checked by IHC for scrapie to be able to link the found gene expression differences to the kinetics of PrPsc deposition. Approximately 200 genes in total for the ileal Peyers-patch from VRQ/VRQ animals at the time points 0, 3, and 8 weeks of age were significantly regulated (182 up- and 18 down-regulated). About 46 of these genes shared non-specific regulation (33 up- and 13 down) with the 0 weeks time point. One of the 154 remaining genes was specific regulated in the 3 weeks time point, 14 genes shared regulation in the 3 and 8 weeks time point (all up-
regulated), and 139 genes were significantly regulated (134 up- and 5 down-regulated) in the 8 weeks time point. A selection of these genes are being confirmed by RT-PCR methods on a large selection of other tissues as well. The current status of the gene expression profiling will be presented in relation to PrP genotype, length of incubation, tissue, and PrPsc accumulation.
AD F.L. Harders, L.J.M. van Keulen, F.G. van Zijderveld, A. Bossers, CIDC-Lelystad, Netherlands; M.A. Smits, ASG-Lelystad, Netherlands
SP englisch
PO Schottland