Join us to hear from Matthew Shoulders of MIT!

Abstract: A key limitation of protein engineering via current state-of-the-art directed evolution workflows performed in test tubes, Escherichia coli, or yeast is that these approaches often yield products that fail to function when introduced into relevant settings, such as valuable bacterial species, plants, and especially mammalian cells. Instead, functions evolved in other or simpler systems are often derailed in these environments by off-target interactions, poor stability, inappropriate modification/localization, or many other serious problems. This frontier challenge could theoretically be addressed by always leveraging the relevant cell system itself as the design, engineering, and quality control factory for biomolecule discovery and optimization. With these challenges in mind, we developed the first rapid and efficient system for continuous directed evolution directly in living mammalian cells. In our approach, essentially a mammalian phage-assisted continuous evolution (mPACE) platform, the ability of a highly error-prone adenovirus to propagate is coupled to the activity of a biomolecule of interest within the human cell itself. The system is designed for safety, speed, and ease-of-use. Critically, mutagenesis, selection, and amplification all occur concurrently in this platform, maximizing the benefits of natural selection and the throughput of experiments. I will discuss progress in the application of mammalian cell-based continuous directed evolution to the engineering of desired biomolecule functions in human cells. I will also discuss the development of advanced targeted mutagenesis techniques based on our MutaT7 platform, which can enable continuous directed evolution in many diverse cell and in vivo settings.