Modular Extracellular Sensors for Cell-based Biosensors

NU 2011-109B

Inventors

Joshua Leonard*

Rachel Dudek

Nichole Daringer

Short Description

Engineered receptors designed to control gene expression

Background

Engineering mammalian cell-based devices that monitor and therapeutically modulate human physiology is a promising and emerging frontier in clinical synthetic biology. However, realizing this vision required new technologies enabling engineered circuitry to sense and respond to physiologically relevant cues. Currently, no existing technology enables an engineered cell to sense exclusively extracellular ligands, including proteins and pathogens, without relying upon native cellular receptors or signal transduction pathways that may be subject to crosstalk with native cellular components.

Abstract

Northwestern researchers have developed a platform technology of living cell-based biosensors named Modular Extracellular Sensor Architecture (MESA). They designed and engineered modular receptors as a means to control intracellular gene expression. In this technology, they created MESA receptors to form heterodimeric structures upon extracellular ligand binding. The proximity of the intracellular regions allows a protease chain of one structure to cleave and release a transcription factor in the other, which then induces gene expression in the nucleus. The researchers have iteratively improved MESA receptor designs for improved performance characteristics and achieved simultaneous reduction in background and enhancement of the signal-to-noise ratio. This sensing modality is novel in that it does not require the use of any native protein-protein interactions for signal transduction, i.e. it can be fully orthogonal, and thus is not susceptible to native regulatory mechanisms. They demonstrated ligand-inducible activation of MESA signaling, optimization of receptor performance using design-based approaches, and generation of MESA biosensors that produce outputs in the form of either transcriptional regulation or transcription-independent reconstitution of enzymatic activity. This systematic, quantitative platform characterization provides a framework for engineering MESA to recognize novel ligands and for integrating these sensors into diverse mammalian synthetic biology applications.

Status of Technology

• Constructed MESA-based biosensor prototypes
• Demonstrated proof of concept of prototype in vitro

Applications

• Diagnostic purposes, such as detecting and quantifying analytes
• In vivo animal model use
• Cell engineering-based therapeutics

Advantages

• Enhanced signal to noise ratio
• Not susceptible to native regulatory mechanisms

Publication

Daringer N, Dudek R, Schwarz K and Leonard J (2014) Modular Extracellular Sensor Architecture for Engineering Mammalian Cell-based Devices. ACS Synthetic Biology, 3: 892-902.

IP Status

Issued US Patent No. 9,732,392