A versatile genomic transgenesis platform with enhanced λ integrase for human Expi293F cells

Area of Science:

• Biotechnology
• Molecular Biology
• Cell Biology

Background:

• Reliable cell-based platforms are crucial for biopharmaceutical development.
• Existing methods can suffer from transgene instability and expression variability.

Purpose of the Study:

• To develop a novel, stable transgenesis platform for human Expi293F cells.
• To enable reliable long-term testing and production of biologics.
• To demonstrate the platform's utility for monoclonal antibody expression.

Main Methods:

• Utilized enhanced λ integrase for site-specific DNA recombination.
• Established a characterized single genomic locus as an artificial landing pad.
• Inserted multi-transgene constructs for anti-PD-1 monoclonal antibody expression.

Main Results:

• Achieved stable transgene insertion without selection pressure.
• Observed no transgene instability or expression variation.
• Demonstrated that transcription unit orientation impacts antibody expression levels.
• Showcased successful encapsulation of engineered cells in mini-bioreactors for continuous antibody secretion.

Conclusions:

• The developed platform provides a stable and reliable method for transgene integration.
• This technology facilitates long-term biotherapeutic testing and production.
• The platform offers modularity for future genome engineering applications and improved cell-based therapies.