Functional characterization and optimization of protein expression in Treponema denticola shuttle plasmids

Area of Science:

• Microbiology
• Genetics
• Oral Health

Background:

• Oral spirochetes, like *Treponema denticola*, are key pathogens in periodontal disease, disrupting tissue homeostasis.
• Genetic analysis of these bacteria is challenging due to limitations in existing molecular tools.
• *T. denticola* serves as a model organism for studying spirochete biology and host interactions.

Purpose of the Study:

• To improve the utility of the *E. coli-T. denticola* shuttle plasmid system for rigorous genetic analysis.
• To characterize promoter activity and develop an inducible expression system for *T. denticola*.
• To enable optimized gene expression for genetic complementation and functional studies in oral spirochetes.

Main Methods:

• Expanded characterization of an *E. coli-T. denticola* shuttle plasmid.
• Evaluation of diverse promoter activities for gene expression.
• Development and testing of the first inducible expression system in *T. denticola*.

Main Results:

• Demonstrated enhanced transformation efficiency using a modified shuttle plasmid.
• Characterized relative activities of various promoters for precise gene expression control.
• Successfully established an inducible system for controlled expression of plasmid-encoded genes in *Treponema*.

Conclusions:

• Customization of shuttle plasmids is crucial for successful genetic manipulation in oral spirochetes.
• The optimized shuttle plasmid and inducible system significantly expand research capabilities for *Treponema*.
• This work facilitates future studies on spirochete physiology, behavior, and pathogenesis.