Quantifying the Impact of Bcl-2Δ Overexpression Upon Central Metabolism Through 13C Metabolic Flux Analysis

Monoclonal antibodies are among the most expensive class of drugs to produce in biopharma today.  While the primary goal is to maximize the overall rate of antibody production, most industrial cell lines instead generate an excess of lactate.  Lactate production often corresponds with limited mitochondrial capacity.  Interestingly enough, apoptotic pathways are often associated with a shift in typical mitochondrial function.  We have determined in prior work with Chinese Hamster Ovary (CHO) cells that by altering the apoptotic pathways through the overexpression of Bcl-2Δ, metabolic pathways are altered as well.  Not only can the onset of programmed cell death be delayed by overexpression of Bcl-2Δ, but the activation of wasteful catabolic pathways, specifically lactate production, can be minimized during exponential phase.  During stationary phase, cells overexpressing Bcl-2Δ have an increased capacity to consume lactate that was formerly produced, allowing overall viable cell density (VCD) to decline at a decreased rate, despite limited glucose availability.  We will present how this corresponds with increased TCA activity and to what level overall metabolic reprogramming is taking place to lead to these exhibited phenotypes.  These two unique phases will be independently discussed based upon a complete stoichiometric analysis and C13 metabolic flux analysis.