Stimulation of monoclonal antibody production of hybridoma cells by butyrate: evaluation of a feeding strategy and characterization of cell behaviour.

Experiments, earlier performed in our laboratory, showedthe stimulating effect of butyric acid on monoclonalantibody production by hybridoma cells. Itssimulaneous inhibitory effect on cell growth canhowever compensate for this, so that no increase ofmonoclonal antibody titer might be obtained. We showin this article an experiment with addition of butyricacid in the middle of the growth phase of a batchculture, as a strategy to take real profit of such anaddition by a significant increase of final monoclonalantibody concentration. Indeed, in this way asignificant cell density could be obtained before theaddition of butyric acid, while the remaining culturetime was still sufficiently long for its action,resulting in a two fold increase of final monoclonalantibody titer. The experiment was carried out in a 2 L bioreactor, showing the real practical interest ofsuch an addition for the large scale production ofproteins. Furthermore, analysis of the produced IgG bySDS-PAGE and Western blot did not reveal structuralchanges after stimulation by butyric acid. An originalpoint of our study is the characterization of the cellbehaviour, by flow cytometry and other relatedtechniques, leading to a better insight in the effectof the butyric acid addition on cell growth andmonoclonal antibody production. Although there existsa lot of knowledge about the effects of butyrate oncells in the field of molecular biology, our article isat our knowledge one of the first to show some of itseffects on cell behaviour in bioreactor culture,carried out under perfectly defined and controlledconditions, and with the aim to stimulate monoclonalantibody production.