Metabolic Flux Analysis Reveals Cell Line-Specific Rewiring in CHO Cells Following TCA Cycle Intermediate Feeding for...

Area of Science:

• Biotechnology
• Cell Biology
• Metabolic Engineering

Background:

• Chinese hamster ovary (CHO) cells are critical for producing therapeutic proteins.
• Traditional pH control using CO2 sparging can limit metabolic optimization.
• Tricarboxylic acid (TCA) cycle intermediates offer a potential alternative for pH control and metabolic modulation.

Purpose of the Study:

• To investigate the impact of feeding acidic TCA cycle intermediates (malic, succinic, α-ketoglutaric acid) on CHO cell culture performance and metabolism.
• To evaluate the use of these intermediates as pH control agents replacing CO2 sparging.
• To understand cell line-specific metabolic responses to intermediate feeding.

Main Methods:

• Utilized two industrial IgG-producing CHO cell lines.
• Employed Carbon-13 metabolic flux analysis (13C-MFA) to track metabolic pathways.
• Monitored cell culture performance parameters and metabolic profiles.

Main Results:

• Intermediate feeding significantly rewired central carbon and nitrogen metabolism, with distinct cell line responses.
• Enhanced TCA cycle fluxes, reduced glucose consumption, and decreased lactate accumulation were observed.
• α-ketoglutaric acid feeding induced divergent nitrogen assimilation patterns (glutamine vs. glutamate).
• Metabolic shifts correlated with altered redox balance and increased cell-specific IgG productivity.

Conclusions:

• Feeding TCA cycle intermediates is a viable strategy for pH control and metabolic optimization in CHO cell cultures.
• Metabolic responses are compound- and cell line-specific, requiring tailored approaches.
• This method holds promise for enhancing biopharmaceutical production processes.