(56h) Engineering Modular, Portable RNA-Based Control Systems for Cellular Reprogramming

Reprogramming of commonly accessible cells into rare, difficult-to-isolate cell types such as neurons massively advances our ability to model neurodegenerative diseases in vitro. When fully developed, reprogramming will revolutionize how we repair and replace damaged tissue. While reprogrammed neurons hold great potential for regenerative medicine and in vitro disease modeling, low reprogramming rates limit the practical use of these cells. To address the issue of limited reprogramming and define mechanisms that facilitate reprogramming, we have recently developed a chemical-genetic cocktail that increases the reprogramming rate of fibroblasts to neurons and other neural cell types by 100-fold. Additionally, induction of highly efficient reprogramming results in induced neurons with greater functional maturity. However, there remain several challenges to realizing the potential of reprogrammed cells for drug screening, disease modeling, and regenerative medicine. Diverse challenges exist to developing reprogramming methods that are both highly-efficient and translationally-feasible. To achieve the greatest potential for therapeutic application, reprogramming tools should be compatible with integration-free methods including adeno-associated viruses (AAVs) and RNA-based viruses. However, an enormous fraction of synthetic regulatory elements and genetic controllers rely on DNA-protein interactions precluding use in RNA-based viruses and constraining even DNA-based designs. For broadest adoption across delivery platforms, control systems for cellular reprogramming need to be compact and portable. To tackle these challenges, I will present our work towards developing RNA-based regulatory devices and control systems that autonomously guide cells from a donor identity to new neural identity.