Synthetic Gene Circuits Enable Systems-Level Biosensor Trigger Discovery at the Host-Microbe Interface

Area of Science:

• Synthetic biology
• Microbial engineering
• Gut microbiome research

Background:

• Engineering synthetic circuits in intestinal bacteria offers a novel approach for disease diagnosis, treatment, and prevention.
• The limited availability of known biosensors restricts the development of disease-responsive engineered bacteria.
• Expanding the repertoire of bacterial biosensors is crucial for enhancing their sensing and response capabilities within the host environment.

Purpose of the Study:

• To identify novel bacterial biosensor triggers responsive to signals in the healthy and diseased mammalian gut.
• To develop a platform for rapid, systems-level screening of biosensor triggers.
• To enable the construction of diagnostic and therapeutic circuits using engineered bacteria.

Main Methods:

• Utilized a genetic memory circuit in Escherichia coli for screening.
• Developed a pipeline for rapid library construction and screening using next-generation sequencing and computational analysis.
• Tested libraries of promoter-ribosome binding site (RBS) combinations, incorporating RBS variation to optimize sensitivity.

Main Results:

• Successfully identified and validated novel biosensor triggers that selectively activate the synthetic memory circuit in the gut.
• Discovered biosensor triggers with enhanced responses in an inflamed gut model through comparative screening.
• Demonstrated the reliability of systems-level screening for identifying responsive biosensor triggers from pooled libraries.

Conclusions:

• Systems-level screening is a powerful method for discovering novel gut-specific biosensor triggers.
• The developed platform facilitates disease-specific screening, advancing the understanding and clinical management of intestinal diseases.
• This work expands the toolkit for engineered probiotics, paving the way for more complex synthetic biology applications in the gut.