(133c) The Metabolic Effects of An Anti-Apoptotic Protein Bcl-2Δ Overexpressing CHO Cell Line

Incorporating apoptotic resistance into production cell
lines holds remarkable potential for several industrial applications, especially
that of monoclonal antibody (mAb) production.  However, the associated impacts on cellular
metabolism are only beginning to be understood, especially in regards to how
anti-apoptotic proteins regulate lactate production and mitochondrial
metabolism.  We are therefore
investigating the global metabolic reprogramming that takes place in Chinese
Hamster Ovary (CHO) cells that have been engineered to overexpress the
anti-apoptotic Bcl-2Δ protein.  Our
previous work has shown that limiting glutamine availability can have profound
impacts on growth and lactate accumulation in CHO cell cultures. Specifically,
when initial glutamine concentration was halved, the outgoing lactate flux was
reduced by more than 50% while growth rate was increased by roughly 30%. When
overexpressing Bcl-2Δ, outgoing lactate flux and incoming glucose flux were
reduced by roughly 40%, and the IVCD over the life of the culture was increased
by over 30%. We are currently applying ¹³C metabolic flux analysis
(MFA) to investigate how Bcl-2D
interacts with glucose and glutamine availability to control metabolic fluxes
in CHO cell cultures.  Our goal is to
generate comprehensive flux maps that depict the flow of carbon through central
metabolism under conditions of varying glucose and glutamine availability to
demonstrate the impact of Bcl-2Δ overexpression.  We will present our current view of how
nutrient availability and anti-apoptotic proteins interact to control lactate
production and central metabolic fluxes in CHO cells.