CHO Cell Line Selection through Multi-Criteria Analysis Reveals Critical Impact of Gas Overlay

Area of Science:

• Biotechnology
• Bioprocess Engineering
• Cell Line Development

Background:

• Developing high-titer Chinese Hamster Ovary (CHO) cell lines is crucial for monoclonal antibody (MAb) production.
• Clone selection significantly impacts bioreactor performance and overall process efficiency.

Purpose of the Study:

• To introduce and validate a multivariate data analysis (MVDA) approach for selecting optimal CHO cell clones.
• To integrate diverse parameters including productivity, growth, metabolic activity, and expression stability into clone selection.
• To evaluate the scalability and performance of selected clones under varying CO2 conditions.

Main Methods:

• Application of MVDA to in-house data from 24 CHO clones producing omalizumab.
• Selection of eight stable, high-performing clones for further evaluation.
• Bioreactor cultures (0.75-1 L) with and without air overlay to modulate dissolved CO2 levels.
• Analysis of productivity, cell growth, viability, and product accumulation.

Main Results:

• MVDA identified lead clones differently than conventional screening when stability and metabolic data were included.
• Cultures without air overlay (high CO2) showed significantly improved performance: 1.69-fold higher titer, 1.43-fold greater specific productivity, and higher peak cell density.
• Selected clones demonstrated sustained product accumulation over 17-21 days and consistent performance across different CO2 conditions.

Conclusions:

• MVDA offers a comprehensive strategy for CHO cell line selection, improving upstream bioprocess development.
• High CO2 conditions, often considered detrimental, can unexpectedly enhance MAb production in specific CHO clones.
• The identified lead clone demonstrates robustness and scalability, suitable for early-stage bioprocess development.