Synthetic digital computation in human cells

DNA recombinase, such as Cre, is one of the most powerful and widely used tools for regulating gene expression in mammalian systems. Currently, most works utilize only one recombinase, thus displaying limited spatiotemporal control. Here, through the use of orthogonal recombinases, we have developed a suite of synthetic genetic circuits with advanced computation capabilities in human cells. All 16 possible 2-input/1-output logic gates have been generated. In addition, multi-input/multi-output logic gates, such as half-adder, half-subtractor, and full-adder, have also been created. To demonstrate the multiplexing capability of DNA recombinases, we have constructed up to 8-input AND gates. Through the unique properties of DNA recombinase, we are able to significantly reduce the complexity of all the circuits and engineer the output generating components (non recombinase expressing portion), into a single transcription unit. These circuits pave the foundation for engineering advance computation in mammalian cells with direct applications in generating more accurate animal models and improving cell-based therapy.