Prions cause rapidly progressive neurodegenerative diseases clinically characterized by cognitive impairment, cerebellar ataxia, and death within approximately seven months in the case of sporadic Creutzfeldt-Jakob disease. Prion disorders occur following the auto-catalytic conversion and aggregation of the cellular prion protein. The structural determinants of the prion protein (PrP) that govern prion conversion and enable pathogenic prions to spread into and through the CNS, targeting distinct cell populations, are unknown. A major goal of this proposal is to understand the mechanisms that underlie prion conversion and cell-specific targeting. In this project, we have previously pursued a broad range of approaches, from in vitro conversion assays to newly generated transgenic mice, to determine the role of a PrP segment having exceptionally high sequence variability among mammals, the ?2-?2 loop (residues 165-175). We discovered that the ?2-?2 loop is a key segment of cellular PrP that impacts cross-species prion transmission, impedes transmission of deer and elk prions to humans, and alters the pathogenic prion conformation in a sequence-dependent manner. We also found that amino acid substitutions in the loop led to de novo prion disease in mice. Finally, we determined that elements of the PrP primary sequence, and not secondary structure, control prion conversion. In this renewal, we aim to identify the key contributors to prion aggregate assembly. We build on our observation that structural features of PrP together with host glycosaminoglycans drive efficient prion conversion. First, we will identify the highly amyloidogenic interacting segments that trigger prion conversion and will test rationally-designed inhibitors to block aggregation. Second, we will define how post-translational modifications (PTM) of PrP modify the prion plaque morphology and pathogenesis using mouse models expressing PTM variants of PrP that were newly generated using CRISPR-Cas systems. Third, we will identify the sulfated glycosaminoglycans bound to prion aggregates by liquid chromatography-mass spectrometry, and will determine the impact of length, abundance, and pattern of heparan sulfate chains on prion cell tropism and disease progression in mouse models. We expect that these studies will define the PrP determinants and endogenous host factors that trigger prion conversion, revealing new therapeutic targets to block prion assembly and spread.

Public Health Relevance

Prion diseases are caused by aggregation of the cellular prion protein into a toxic form that induces a rapidly progressive and ultimately fatal neurological disease. Prion aggregates spread throughout the central nervous system, targeting specific cell types depending on the prion protein conformation. We propose to investigate the mechanisms underlying the formation of prion aggregates and replication by select cellular subsets in the brain in order to identify new therapeutic targets to treat prion disease.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
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Special Emphasis Panel (ZRG1)
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Wong, May
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University of California, San Diego
Schools of Medicine
La Jolla
United States
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Aguilar-Calvo, Patricia; Bett, Cyrus; Sevillano, Alejandro M et al. (2018) Generation of novel neuroinvasive prions following intravenous challenge. Brain Pathol 28:999-1011
Orrù, Christina D; Soldau, Katrin; Cordano, Christian et al. (2018) Prion Seeds Distribute throughout the Eyes of Sporadic Creutzfeldt-Jakob Disease Patients. MBio 9:
Sikorska, Beata; Gajos, Agata; Bogucki, Andrzej et al. (2017) Electron microscopic and confocal laser microscopy analysis of amyloid plaques in chronic wasting disease transmitted to transgenic mice. Prion 11:431-439
Kurt, Timothy D; Aguilar-Calvo, Patricia; Jiang, Lin et al. (2017) Asparagine and glutamine ladders promote cross-species prion conversion. J Biol Chem 292:19076-19086
Aguilar-Calvo, Patricia; Xiao, Xiangzhu; Bett, Cyrus et al. (2017) Post-translational modifications in PrP expand the conformational diversity of prions in vivo. Sci Rep 7:43295
Bett, Cyrus; Lawrence, Jessica; Kurt, Timothy D et al. (2017) Enhanced neuroinvasion by smaller, soluble prions. Acta Neuropathol Commun 5:32
Klionsky, Daniel J (see original citation for additional authors) (2016) Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). Autophagy 12:1-222
Keene, C Dirk; Darvas, Martin; Kraemer, Brian et al. (2016) Neuropathological assessment and validation of mouse models for Alzheimer's disease: applying NIA-AA guidelines. Pathobiol Aging Age Relat Dis 6:32397
Kurt, Timothy D; Sigurdson, Christina J (2016) Cross-species transmission of CWD prions. Prion 10:83-91
Annamalai, Karthikeyan; Gührs, Karl-Heinz; Koehler, Rolf et al. (2016) Polymorphism of Amyloid Fibrils In Vivo. Angew Chem Int Ed Engl 55:4822-5

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