<p>Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases that include Creutzfeldt-Jakob disease, bovine spongiform encephalopathy and sheep scrapie. TSE disease pathology and mechanisms within the central nervous system (CNS) of an infected host largely remains unclear. At the cellular level, the uptake of protease resistant prion protein (PrP-res), which strongly correlates with infectivity and is a valid marker for TSE infection, is one of the earliest events that must occur during TSE infection. Given the difficulty of clearly distinguishing input PrP-res from either PrP-res or protease-sensitive PrP (PrP-sen) made by the cell, the uptake of PrP-res from an infectious inoculum into the host cell remains a poorly understood process. Through the development of a novel assay to exclusively detect input PrP-res we hypothesized that the acute infection of cells by PrP-res is mediated through general processes such as endocytosis, whereas internalization, retention, and propagation of PrP-res are dictated by specific characteristics of both the host cell and PrP-res. Using PrP-res tagged with a unique epitope to the mouse monoclonal antibody 3F4, we developed a detection system to specifically follow the acute cellular uptake of PrP-res. Mouse neural and fibroblast cells were exposed to three different mouse scrapie strains and PrP-res from the inoculum monitored. For all strains, PrP-res uptake was rapid and independent of both cellular prion protein expression and cell type. However, only 30%-40% of the cells were able to internalize PrP-res and PrP-res aggregate size influenced PrP-res uptake. Furthermore, infectious brain homogenate PrP-res was taken up more efficiently then PrP-res in either microsome or partially purified preparations. Our results suggest that PrP-res aggregate size, the PrP-res microenvironment, and/or host cell-specific factors can all influence whether or not a cell takes up PrP-res following exposure to TSE infectivity.</p>
| Identifer | oai:union.ndltd.org:MONTANA/oai:etd.lib.umt.edu:etd-09092008-155126 |
| Date | 01 October 2008 |
| Creators | Greil, Christopher Scott |
| Contributors | Richard Bridges, Keith Parker, David Poulsen, Leonard Evans, Suzette A Priola |
| Publisher | The University of Montana |
| Source Sets | University of Montana Missoula |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.umt.edu/theses/available/etd-09092008-155126/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Montana or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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