This proposal aims primarily at developing improved or new cell culture systems in which infectious agents (or prions) causing Transmissible Spongiform Encephalopathies in human or animals can be propagated. Although the propagation of rodent-adapted TSE agents has been achieved in a few cell lines, there is an obvious need for more reliable, manipulatable and more informative in-vitro systems which would be able to support the replication of TSE agents infecting rodent as well as other species. Three major objectives of the project are: i) to derive primary and established cell culture systems and to evaluate them for their ability to propagate or to be infected by a TSE agent ; ii) to express natural or engineered mutants forms of the host-encoded PrP protein as a means of elucidating its role in the cell susceptibility and of increasing permissiveness to the infectious agent ; iii) to investigate the molecular events leading to the conversion of the normal protein into its pathological isoform (PrPsc), a key feature in the TSE infection process. Three groups with both common and specific expertises have decided to interface in order to achieve the above objectives. Their collaboration will allow the implementation of a set of complementary approaches focused mainly on the ovine and the murine species. The proposed cell systems will mostly involve cells derived from the central nervous system, including neurons, but also peripheral cells, such as resident dentritic cells. Cell clones overexpressing normal, mutated or hybrid PrP-encoding genes from different animal species will be isolated. The cultures will be infected with TSE agents through incubation with infectious materials, mainly from natural ovine scrapie and mouse-adapted strains, or co-cultivation with already infected cells. The generation of abnormal PrP isoforms, as assessed by biochemical means or imaging at the single cell level, will be taken as an indicator of successful infection or propagation. Inoculation to mice will be performed to formally prove the replication of the infectious agent in the cultures.
Funding SchemeCSC - Cost-sharing contracts
SE1 9RT London