Search bioRxiv⌕ Search

Biology subjects

Makri-Pistikou, A.-M.

Publications and source records attributed to Makri-Pistikou, A.-M..

2 recordsLinked to original sources

DIALECT: DNA-Programmable Synthetic Cells Communicate with Mammalian Cells through Synthetic Receptors

Synthetic cells can regulate mammalian signalling through the controlled release of diffusible protein ligands, but coupling programmable synthetic-cell senders to orthogonal, engineered mammalian receptors remains challenging. Here we present DIALECT (DNA-Instructed Assembly of Ligands for Engineered Cellular Transduction), a platform in which proteinosome-based synthetic cells translate sequence-defined DNA inputs into coiled-coil signalling ligand outputs for engineered mammalian receptors. DNA-ligand conjugates are localized within semipermeable proteinosomes through DNA hybridization and released by toehold-mediated DNA strand displacement (TMSD). The released ligands diffuse to neighbouring mammalian cells and activate cognate CC-GEMS receptors, inducing JAK/STAT3 signalling and reporter activation, with a higher response in cognate than non-cognate receiver cells under activation conditions. We further implement distributed Boolean AND logic using two independently programmed proteinosome populations that respond to distinct DNA inputs and release complementary ligand components. Simultaneous addition of both inputs produces substantially higher reporter activity than the respective single-input conditions, consistent with extracellular assembly of an active receptor agonist. DIALECT thus establishes a modular interface linking DNA-based molecular computation in synthetic cells to orthogonal signalling pathways in mammalian cells, providing a foundation for hybrid artificial-biological communication networks.

synthetic biology↗

Engineered microRNA feedback circuits enable tunable and autonomous control of synthetic receptor activity

Synthetic receptors are powerful tools for cellular engineering, yet their utility is often constrained by constitutive activity and the absence of natural feedback mechanisms that maintain cellular homeostasis. To address this, we engineered an autonomous regulatory circuit for synthetic Notch (synNotch) receptor activation using an orthogonal microRNA (miRNA)-mediated negative feedback mechanism in mammalian cells. Specifically, synNotch activation induces the expression of a synthetic miRNA that targets complementary sites engineered into the synNotch transcript, resulting in a self-limiting feedback loop. We demonstrate that synNotch repression positively correlates with the number of miRNA target sites integrated into the receptor transcript, enabling tunable control of receptor expression. Furthermore, flow cytometry and live-cell imaging analyses revealed effective suppression of synNotch expression following activation. Downstream target gene expression peaked at approximately 48 hours post-activation before gradually declining as the feedback circuit engaged. This approach achieves autonomous synthetic receptor regulation--eliminating the need for external intervention--and enables tunable response dynamics through rational circuit design. Our miRNA feedback strategy provides a generalizable platform for engineering self-regulating synthetic receptor systems with improved control and predictability for cellular engineering applications.

synthetic biology↗