Multi-layered computational gene networks by engineered tristate logics

So far, biocomputation strictly follows traditional design principles of digital electronics, which could reach their limits when assembling gene circuits of higher complexity. Here, by creating genetic variants of tristate buffers instead of using conventional logic gates as basic signal processing units, we introduce a tristate-based logic synthesis (TriLoS) framework for resource-efficient design of multi-layered gene networks capable of performing complex Boolean calculus within single-cell populations. This sets the stage for simple, modular, and low-interference mapping of various arithmetic logics of interest and an effectively enlarged engineering space within single cells. We not only construct computational gene networks running full adder and full subtractor operations at a cellular level but also describe a treatment paradigm building on programmable cell-based therapeutics, allowing for adjustable and disease-specific drug secretion logics in vivo. This work could foster the evolution of modern biocomputers to progress toward unexplored applications in precision medicine. [Display omitted] •Tristate buffers comprise upstream switches that directly control downstream switches•This is suitable for construction of multi-layered gene networks in mammalian cells•This allows flexible mapping of various logic algorithms of interest in living cells•Layered tristate buffers can match various logically minimized therapeutic algorithms By using engineered tristate buffers as basic signal processing units in mammalian cells, various arithmetic logics of interest can be flexibly and systematically mapped to construct complex computational gene networks for diverse applications in biocomputation and cell-based therapies.