Engineering genetic sensors and circuits to construct programmable cells

The last decade has witnessed the tremendous power of synthetic biology in constructing simplified, synthetic genetic systems that can help understand complex biological processes. However, its full potential for practical applications has yet to be exploited. One of its promising applications is to build programmable cells which can integrate various environmental inputs and implement synthetic control over cellular processes. Here, we harness a toolbox of genetic parts (e.g., inducible promoters and regulatory proteins and RNAs) from a variety of organisms to build genetic devices and programs. To this end, such genetic parts have been mined from bacteria and assembled into genetic devices, which have been characterized using reporter proteins as outputs. Our programmable cells contain (i) environmental sensors, including oxygen, temperature, pH, and/or light sensors, which enable the engineered cells to distinguish different environmental conditions; and (ii) multi-input logic circuits with genetic memory modules, which direct the cells to generate outputs only when userdefined conditions are met. We will present progress on the creation of such engineered bacterial cells which can be used for real-world applications, mainly focusing on infectious disease prevention.