Monoclonal Antibody Productivity of Hybridoma Cells Under Active Hypothermic Growth Condition

Abstract

In our previous study, the enhanced specific monoclonal antibody (mAb) productivity of hybridoma cells grown under mild hypothermic condition (32 °C) was proportional to the population of S-phase cells, and inversely proportional to the population of G1-phase cells. However, the volumetric mAb production at 32 °C was lower compared to 37 °C due to its lower maximum viable cell density. This finding implies that control proliferation at G1 phase is not the priority factor in determining the productivity of mAb under hypothermic condition. Hence, in the present study, the effect of active hypothermic growth on the monoclonal antibody productivity of hybridoma C₂E₇ was investigated. The growth of hybridoma under hypothermic condition (32 °C) was stimulated through the supplementation of high serum concentration (up to 30%) into the culture medium. The results showed that the specific and volumetric mAb productivity of hybridoma cultured at 32 °C and supplemented with 30% FBS (active hypothermic growth) was 1.34 and 1.38-folds higher than the control culture (37 °C and supplemented with 10% FBS). Real time PCR quantification of mAb (IgM) expression level showed that the enhanced specific hypothermic productivity was found related to the elevated IgM mRNA level during lag and early exponential hypothermic growth. Hence, higher viable cells density during the lag and early exponential phase of hypothermic growth is critical for improved total hypothermic productivity of mAb by hybridoma cells.