Polymenidou
Fakultäten » Medizinische Fakultät » Neuropathologie, Institut für » Prof. Dr. Adriano Aguzzi » Polymenidou
Completed research project
| Title / Titel | Development of a non-invasive blood-based prion diagnostic method: Investigation of PrPC and PrPSc plasma levels after peripheral administration of novel anti-PrP antibodies | ||
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| Abstract (PDF, 14 KB) | |||
| Summary / Zusammenfassung | Prion diseases or transmissible spongiform encephalopathies (TSEs) are invariably fatal neurodegenerative disorders of infectious, sporadic or genetic origin, affecting humans and a wide variety of animals. Diagnosis of prion diseases is in most cases impossible at any preclinical stage and the disease is usually recognized only after onset of severe clinical symptoms. All currently EU-approved methods of diagnostic assay for the presence of TSE rest on the detection of PrPSc which represents the only disease-specific molecule identified to date [1]. I have created and exhaustively characterized a collection of novel monoclonal anti-PrP antibodies (named POM1-POM19) with various specificities and intriguing features. I plan to utilize these tools to develop a highly sensitive blood-based prion diagnostic method by (a) developing a sandwich ELISA protocol for detecting PrPC and PrPSc in plasma with combinations of non-competing antibodies and (b) peripheral administration of the novel antibodies in healthy and prion diseased mice. The latter approach has been recently reported to induce an impressive increase of up to 1000-fold in the level of plasma Abeta in Alzheimer’s disease animal models [2, 3]. It was hypothesized that peripheral antibodies against Abeta can act as a ‘sink’ to sequester Abeta after efflux from the CNS. I plan to investigate this phenomenon in the context of prion disease by testing the effect of peripheral administration of novel monoclonal anti-PrP antibodies in PrPC and PrPSc plasma levels of healthy and scrapie sick mice. Our research proposal consists of three main projects. 1. I plan to develop a highly sensitive ELISA protocol for detecting PrPC and PrPSc in plasma. Detection of PrPC and/or PrPSc in plasma of healthy or affected individuals is to date problematic due to low amounts and insufficient detection limits of the currently used diagnostic methods. Our novel monoclonal antibodies (POM1-POM19) show sensitivity approximately 1-log higher than the 6H4 monoclonal antibody (Figure 1), currently the most widely used antibody in prion diagnosis. I have established that our antibodies have specificities that span the whole sequence of the mature prion protein and I have determined suitable POM mAb pairs with non-competing epitopes. I will now utilize this data for establishing a highly sensitive sandwich ELISA for PrPC and PrPSc detection. I will use wild type (WT), PrP-deficient (Prnpo/o, Zurich I) and PrP-overexpressing (Tg20) mice to determine the best antibody pair and the detection limits of our developed method. 2. I will use the established protocol to monitor PrPC and PrPSc plasma levels during prion infection. I will perform a time course analysis of plasma PrPC and PrPSc following prion inoculation in WT and Tg20 mice to identify any detectable changes during preclinical and clinical stages. 3. I will investigate the effect of peripheral administration of novel anti-PrP antibodies in PrPC and PrPSc plasma levels and determine any possible correlation with prion disease stage. I will repeat the above mentioned time course including previous administration of antibodies with various epitopes. I have established that all our antibodies bind on PrPC from blood and that some of those also bind to the disease associated isoform PrPSc. Peripheral administration of monoclonal antibodies against Abeta induced an impressive increase in the level of plasma Abeta in treated mice. It was proposed that peripheral antibodies against Abeta can act as a ‘sink’ to sequester Abeta after efflux from the CNS. I seek to determine whether a similar phenomenon can occur in prion disease with a panel of novel and highly sensitive anti-PrP antibodies with diverse epitope specificities. In the case that I find an antibody that induces a rapid increase in plasma PrPC and/or PrPSc, this can form the basis of a blood test to identify prion-disease-type changes in living mice and maybe also preclinical CJD patients. |
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| Keywords / Suchbegriffe | prion disease, monoclonal antibodies | ||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Forschungskredit der Universität Zürich |
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| Duration of Project / Projektdauer | Nov 2005 to Oct 2006 |