A whole-cell platform for discovering synthetic cell adhesion molecules in bacteria

Area of Science:

• Synthetic biology
• Microbiology
• Protein engineering

Background:

• Programmable bacterial cell-cell adhesion is crucial for various applications.
• Existing methods for identifying cell adhesion molecules (CAMs) targeting bacterial membrane proteins are limited.
• A generalizable strategy is needed to discover CAMs that recognize native bacterial membrane proteins.

Purpose of the Study:

• To develop a whole-cell screening platform for discovering CAMs targeting bacterial membrane proteins.
• To engineer programmable bacterial cell-cell adhesion using a synthetic nanobody library.
• To demonstrate the platform's efficacy in identifying functional CAMs.

Main Methods:

• Utilized a synthetic bacteria-displayed nanobody library.
• Employed the bacterial type IV secretion system for a positive feedback enrichment mechanism.
• Screened for nanobodies targeting specific bacterial outer membrane proteins (TraN, OmpA, OmpC).

Main Results:

• Successfully identified functional CAMs targeting three distinct bacterial outer membrane proteins.
• Demonstrated the efficacy of the whole-cell screening platform in CAM discovery.
• Established a method for selective enrichment of bacteria displaying target-specific nanobodies.

Conclusions:

• The developed whole-cell screening platform is effective for discovering bacterial cell-adhesion molecules.
• This approach enables the engineering of programmable bacterial cell-cell adhesion.
• The findings support applications such as directing antibacterial activity towards specific target bacteria in mixed populations.