Effect of BCL-2 Expression on Hybridoma Cell Growth During Stressful Conditions

Abstract

Two transfected hybridoma cell lines TB/C3-bcl2, (overexpressing the Bcl-2 protein) and TB/C3-pEF (control cell line), were compared to assess the potential of Bcl-2 in preventing apoptosis. The conditions examined were batch cultures, growth in diluted media, and long-term fermentations in a high cell density fixed-bed reactor.

The membrane intact index (percentage of cells with intact membranes determined by trypan blue staining) of the TB/C3-bcl2 cell line decreased much slower than that of the control cell line during the dying phase of the batch cultures. No significant difference in the consumption (glucose, glutamine) and production rates (lactate, ammonia, antibodies) was notable in the exponential phase of the experiments.

When comparing the cell lines in diluted media the advantage of the Bcl-2 overexpressing cell line was again a higher membrane intact index at increasing dilution steps.

Comparing both cell lines in a fixed-bed reactor at various dilution rates revealed a significant difference in antibody production. TB/C3-bcl2 produced twice as many antibodies as the control cell line for all steady-states. But no difference in the consumption (glucose, glutamine) and production (lactate, ammonia) rates was observable.