The Less the Better: How Suppressed Base Addition Boosts Production of Monoclonal Antibodies With Chinese Hamster Ovary Cells

Biopharmaceutical production processes strive for the optimization of economic efficiency. Among others, the maximization of volumetric productivity is a key criterion. Typical parameters such as partial pressure of CO(2) (pCO(2)) and pH are known to influence the performance although reasons are not yet fully elucidated. In this study the effects of pCO(2) and pH shifts on the phenotypic performance were linked to metabolic and energetic changes. Short peak performance of q(mAb) (23 pg/cell/day) was achieved by early pCO(2) shifts up to 200 mbar but followed by declining intracellular ATP levels to 2.5 fmol/cell and 80% increase of q(Lac). On the contrary, steadily rising q(mAb) could be installed by slight pH down-shifts ensuring constant cell specific ATP production (q(ATP)) of 27 pmol/cell/day and high intracellular ATP levels of about 4 fmol/cell. As a result, maximum productivity was achieved combining highest q(mAb) (20 pg/cell/day) with maximum cell density and no lactate formation. Our results indicate that the energy availability in form of intracellular ATP is crucial for maintaining antibody synthesis and reacts sensitive to pCO(2) and pH-process parameters typically responsible for inhomogeneities after scaling up.