Advances Toward Prion Therapeutics Using Genome-Wide Discovery

Author

Kathryn Schneider Beauchemin, Dartmouth CollegeFollow

Author ORCID Identifier

https://orcid.org/0000-0003-2748-4423

Date of Award

2025

Document Type

Thesis (Ph.D.)

Department or Program

Biochemistry and Cell Biology

First Advisor

Surachai Supattapone

Abstract

Prion diseases are rapidly progressing, invariably fatal neurodegenerative diseases that affect humans and animals. At the core of all prion diseases is a single protein, the mammalian prion protein (PrP). The conformational change of PrP from its cellular conformation (PrP^C), into a misfolded conformation (PrP^Sc) is central to prion pathogenesis.

There are currently no effective therapies for any type of prion disease. The search for anti-prion therapeutics has faced numerous challenges, including prion strain specificity, drug resistance, delivery to the brain, limited efficacy against human disease despite favorable outcomes in rodent models, and efficacy that is highly dependent on the timing of administration. Despite these challenges, substantial advancements have been achieved. Specifically, therapies that reduce PrP^C levels have demonstrated significant potential and successfully circumvent many of these obstacles. PrP^C is required at the cell surface for initial prion infection, to sustain infection, and for prion-induced neurotoxicity. Therefore, therapies that reduce the amount of PrP^C at the cell surface could be clinically relevant.

I performed genome-wide CRISPR-Cas9 knockout screens to identify regulators of cell surface PrP^C in the prion-susceptible neuronal-like cell line, CAD5. These screens identified core genes involved in cell surface PrP^C expression, revealed differences based on cellular differentiation state, and suggested potential therapeutic targets for prion disease. These genome-wide discovery efforts identified the oligosaccharyltransferase complex (OST), an enzyme complex essential for N-linked glycosylation, as a novel therapeutic target for prion disease. Inhibition of OST effectively treats rodent and human prions in culture, illustrating how genetic discovery can enhance our understanding of complex disease.

Creative strategies may be necessary to treat prion diseases. Therefore, we tested alternating treatment regimens with existing anti-prion therapeutics to avoid the emergence of drug-resistant prions. Additionally, I developed a method to perform FACS-based screening for genetic modifiers of prion infection in cultured cells. This will enable future genetic discovery experiments in prion-infected cells. The studies detailed herein aim to contribute to the progression of therapeutic development for prion diseases.

Recommended Citation

Beauchemin, Kathryn Schneider, "Advances Toward Prion Therapeutics Using Genome-Wide Discovery" (2025). Dartmouth College Ph.D Dissertations. 361.
https://digitalcommons.dartmouth.edu/dissertations/361