Novel Strategies for the Detection of Infectious Prion Proteins

Bovine Spongiform Encephalopathy (BSE) and other transmissible prion diseases represent an important agricultural issue and pose unique diagnostic challenges. Unlike conventional microbes, prions do not require agent-specific nucleic acid in order to multiply. Propagation occurs in infected animals when normal prion protein (PrPc) becomes 'misfolded' into an infectious form (PrPsc) in a template-driven process. No PrPsc specific probes have been developed and conventional methods rely on differences in the sensitivity of PrPc from PrPsc to chemical reagents for detection. BSE has had a devastating impact on foreign agricultural economies and despite a U.S. agricultural ban on ruminant protein imports from these countries, BSE remains a bio-security threat. New methods for the sensitive detection of PrPsc in animals, their by-products and the environment are essential for preventing the transmission of disease. We will develop strategies for the extraction and enrichment of PrPsc for use in the development of novel diagnostic reagents and platforms. These models will be used for the assessment of low-level PrPsc in pre-clinical animals and the environment. Methods will focus on isolation of PrPsc in detergent resistant membranes, utilization of sensitive transgenic mice as models of infectivity, cell based bioassay, and production of monoclonal antibodies. The generation and establishment of new reagents and detection platforms will provide the necessary diagnostic tools to achieve early detection of low-level PrPsc in contaminated biological and environmental samples. Documents SCA with UCSF. Formerly 5325-32000-007-02S (4/08).