NR AWNH
AU Schätzl,H.M.; Gilch,S.; Nunziante,M.; Vorberg,I.
TI Between propagation and clearance: prions in cultured cells
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Oral sessions ORAL-37
PT Konferenz-Vortrag
AB The biogenesis and pathogenesis of prions is ideally studied in cell culture. Unfortunately, the de novo prion infection of cultured cells is still an unpredictable and often unsuccessful event. We tried to establish and validate novel cell culture systems which are robust and reproducible, allowing the study of prion propagation as well as the analysis of cellular susceptibility factors. In addition, we are using these systems for devising experimental therapeutic approaches against prion infections. We have recently established a novel cell culture system based on neuronal PrP0/0 cells which becomes susceptible to prion infection upon reintroduction of a PrPc of choice, without having endogenous wild-type PrPc in the background. Stable, fast and robust expression of exogenous PrP is accomplished by retroviral transduction. By using epitope tagging de novo infection can easily be monitored, already after a few passages. The system is susceptible to selected prion strains and is at the same time a donor system by significantly releasing prions in the supernatant. A second line of studies addresses putative anti-prion strategies, e.g. by eliminating PrPc as substrate for prion conversion or by increasing the cellular clearance capacity for prions. In line of the first, we have established various peptide-based aptamers, embedded in a TrxA folding scaffold, by screening a combinatorial library for PrP interactors. Both the addition of recombinant proteins from outside as well as endogenous expression within cells indicates a potential for reduction of PrPsc propagation. In addition, we have further studied the impact of cholesterol biosynthesis pathways on prion replication. Interestingly, when searching for cellular susceptibility factors for infection by microarray assays, a significant proportion of differentially expressed genes was implicated in regulation of cholesterol. Taken together, this gives solid evidence that the cellular cholesterol homeostasis has an impact on prion propagation. Interestingly and vice versa, also prion infection has a profound influence on cholesterol pathways and it seems that there is an adaptation of cultured cells to productive prion infection.
AD Institute of Virology, Technical University of Munich, Munich, Germany. E-mail: schaetzl@lrz.tum.de
SP englisch
PO Italien