Engineered NLS-PBase system boosts stability and productivity in recombinant cell lines.

Area of Science:

• Biotechnology
• Cell Biology
• Molecular Biology

Background:

• Chinese hamster ovary (CHO) cells are crucial for therapeutic protein production.
• Genomic heterogeneity causes clonal variability and unstable expression in CHO cells.
• Robust cell line development is needed to isolate stable, high-expressing clones.

Purpose of the Study:

• To enhance recombinant cell line performance through improved genomic stability and productivity.
• To evaluate the efficacy of an optimized PiggyBac system for cell line development.
• To investigate the impact of a nuclear localization signal (NLS) on transgene stability and expression.

Main Methods:

• Utilized the PiggyBac system for transgene integration in CHO cells.
• Employed GFP reporter analysis to assess clone yield and expression levels.
• Modified the PiggyBac transposase with a nuclear localization signal (NLS).
• Analyzed transgene integration sites and their effect on expression stability.

Main Results:

• The PiggyBac system significantly increased the yield of stable and high-expression clones.
• NLS-modified transposase demonstrated superior stability in recombinant cell lines and polyclonal pools.
• Transgene integration into specific genomic loci promoted enhanced and stable expression.
• Recombinant mAb expression increased by 97% in pools, with improved productivity in cell lines.
• Over 50% of minipools derived from optimized system showed robust growth.

Conclusions:

• The NLS-optimized PiggyBac system effectively improves transgene stability and expression in CHO cells.
• This strategy streamlines the cell line screening process for therapeutic protein production.
• Enhanced genomic stability and productivity contribute to more efficient biomanufacturing.