Metabolic phenotyping of CHO cells varying in cellular biomass accumulation and maintenance during fed-batch culture

Abstract CHO cell lines capable of high‐level recombinant protein product biosynthesis during fed‐batch culture are still generally obtained by intensive empirical screening of transfected cells rather than knowledge‐guided cellular engineering. In this study, we investigate how CHO cell lines create and maintain cellular biosynthetic capacity during fed‐batch culture to achieve the optimal combination of rapid exponential proliferation and extended maintenance of high cell biomass concentration. We perform a comparative meta‐analysis of mitochondrial and glycolytic functions of 22 discrete parental CHO cell lineages varying in fed‐batch culture performance to test the hypotheses that (i) “biomass‐intensive” CHO cells exhibit conserved differences in metabolic programming and (ii) it is possible to isolate parental CHO cell lines with a biomass‐intensive phenotype to support fed‐batch bioproduction processes. We show that for most parental CHO cell lines, rapid proliferation and high late‐stage culture performance are mutually exclusive objectives. However, quantitative dissection of mitochondrial and glycolytic functions revealed that a small proportion of clones utilize a conserved metabolic program that significantly enhances cellular glycolytic and mitochondrial oxidative capacity at the onset of late‐stage culture. We reveal the central importance of dynamic metabolic re‐programming to activate oxidative mitochondrial function as a necessary mechanism to support CHO cell biosynthetic performance during culture.