Rewiring human cellular input–output using modular extracellular sensors

Developers

Kelly A. Schwarz, Nichole M. Daringer, Taylor B. Dolberg, Joshua N. Leonard.

Description of the technology

Engineered cell-based therapies comprise a promising emerging strategy for treating diverse diseases. Realizing this promise requires new tools for engineering cells to sense and respond to soluble extracellular factors, which provide information about both physiological state and the local environment. Engineered cell receptors or receptor-signal transduction systems, which are able to sense ligands unrecognizable by native receptors or systems, serve as examples of these tools.

This technology proposes an engineering strategy, leveraging a self-contained receptor-signal transduction system termed modular extracellular sensor architecture (MESA) by using biosensors. Each MESA receptor comprises two transmembrane chains-the target chain (TC) and the protease chain (PC). In this system, ligand-binding-induced dimerization of receptor extracellular domains promotes intracellular trans-cleavage of the target chain by the protease chain, which releases a sequestered engineered transcription factor into the cytoplasm. While previous work demonstrated the feasibility of the MESA mechanism, ligand recognition was limited to detection of model small-molecule analytes.

The authors of the technology have investigated whether we could leverage the MESA design to generate a general platform for rewiring cellular functions in response to physiologically relevant cues. They have developed MESA receptors that enable cells to sense vascular endothelial growth factor (VEGF) and, in response, secrete interleukin 2 (IL-2). By implementing these receptors in human T cells, we created a customized function not observed in nature-an immune cell that responds to a normally immunosuppressive cue (VEGF) by producing an immunostimulatory factor (IL-2). Because this platform utilizes modular, engineerable domains for ligand binding (antibodies) and output (programmable transcription factors based upon Cas9), this approach may be readily extended to novel inputs and outputs.

Practical application

The technology has a high potential for future use in bioengineering.
Being included to engineer cells that respond to a target extracellular cue via the expression of either transgenes or endogenous genes, MESA platform could facilitate the rapid implementation and evaluation of diverse therapeutic strategies.

Additionally, the MESA platform could provide unique capabilities for fundamental research in multicellular networks and whole organisms, e.g., to monitor, in a spatially and temporally resolved fashion, the presence of VEGF in a living animal. Besides, MESA platform could complement genetic tools such as knockouts and knockins to enable the testing of novel hypotheses pertaining to multicellular network function.

Thus, MESA is a promising novel technology for the mammalian synthetic biology. This generalizable approach for rewiring cellular functions could enable both translational applications and fundamental biological research.

Laboratories

• Department of Chemical and Biological Engineering, Northwestern University, Evanston (USA)
• Center for Synthetic Biology, Northwestern University, Evanston (USA)
• Chemistry of Life Processes Institute, Northwestern University, Evanston (USA)
• Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston (USA)

Links

Publications

• Schwarz, K.A. et al. «Rewiring human cellular input-output using modular extracellular sensors." 13 Nature Chemical Biology (2017): 202–209.
• Schwarz, K.A. & Leonard, J.N. «Engineering cell-based therapies to interface robustly with host physiology." 105 Adv. Drug Deliv. Rev. (2016): 55–65.
• Daringer, N.M., et al. «Modular extracellular sensor architecture for engineering mammalian cell-based devices." 3 ACS Synth. Biol. (2014): 892–902.