Mitochondrial membrane potential identifies cells with high recombinant protein productivity

Area of Science:

• Biotechnology
• Cell Biology
• Bioprocessing

Background:

• Cell line development for biotherapeutics is time-consuming and resource-intensive.
• High-throughput screening for productivity markers is crucial for efficient cell line development.
• Single-cell cloning via fluorescence-activated cell sorting (FACS) is a standard method.

Purpose of the Study:

• To develop a novel strategy for enhancing the selection efficiency of high-yielding clonal cell lines.
• To identify higher productivity cells at the FACS stage using a marker predictive of metabolic activity.
• To reduce the time and resources required for cell line development.

Main Methods:

• Utilized a dual-emission dye (Mito-ID) to stain live cells and measure mitochondrial membrane potential (Ψm).
• Correlated Ψm fluorescence intensity with known fed-batch titers of producer cell lines.
• Employed FACS to sort cells based on optimal Ψm staining intensity to enrich for higher producers.

Main Results:

• Mitochondrial membrane potential (Ψm) intensity, measured by Mito-ID, correlates with recombinant protein production titers.
• FACS-based cell sorting using Ψm effectively enriches for higher-producing clones from transfectant pools.
• The method was successfully applied to various antibody formats, yielding phenotypically stable clones.

Conclusions:

• A novel, viable cell staining method measuring mitochondrial membrane potential (Ψm) can identify higher productivity cells during FACS.
• This strategy integrates enrichment with cloning, significantly improving efficiency in cell line development.
• The method offers a time- and resource-saving approach for identifying high-yield cell lines for biotherapeutic production.