Engineered synthetic translational control for next generation mRNA gene therapies

Abstract

Synthetic mRNA is an emerging therapeutic modality for gene and cell therapy. Unlike their synthetic DNA counterparts, synthetic mRNA has an increased safety profile due to its transient gene expression and ability to express outside of the nucleus. Furthermore, it can be more easily delivered to cells via entry only into the cytoplasm. While synthetic biology as a field has existed for over two decades, the main area of research and development has focused on DNA interfaces, building on the mechanisms of transcription factors with small molecule interfaces to create multi-input/multi-output genetic circuitry. Until recently, the field had not developed sufficient synthetic circuit control devices at the translational level due to 1) lack of perceived need and 2) deficiency of available natural systems for adaptation. In this thesis, I present the construction of a diverse synthetic biology toolbox for RNA-only synthetic biology. The creation of new synthetic biology frameworks can be broken down into three modules: Build, Control, and Apply. In the Build phase, I demonstrate how the current toolbox of mRNA binding and recognition proteins can be utilized to form diverse and orthogonal gene regulatory networks. In Control, I construct regulatory networks capable of responding to exogenous signals and utilize advanced circuit design to motivate dynamic control for novel behaviors. When I transition to Apply, I illustrate that these next-generation circuits can be layered into biologically active modalities that are therapeutically relevant. Taken as a whole, the work presented here represents a merging of the fields of synthetic biology and mRNA therapeutics, and serves as a foundational proof-of-principle for future efforts to expand synthetic biology across novel modalities.