Co-culture of the 55-6 B cell hybridoma with the EL-4 thymoma cell. Effect on cell growth and monoclonal antibody production

Abstract

The cell growth and monoclonal antibody production of the 55-6 hybridoma cell co-cultured with the murine thymoma cell line EL-4 at different initial 55-6:EL-4 ratios were investigated. Both populations were seeded in co-culture without previous stimulation and therefore with low constitutive CD40 and CD40 ligand (CD154) expression levels, and in the absence of exogenous co-stimuli. Viable cell density and growth rate data seem to suggest a competition for nutrients, which is detrimental for both cells in terms of biomass production and also of growth rate for 55-6. Final concentrations of antibody and specific antibody production rates were affected by the initial 55-6:EL-4 ratio. The 4:1 ratio yielded the highest IgG2a concentration, whereas the highest specific antibody production rate was obtained at the 2:1 ratio. Changes mainly in CD154 and also in CD40 expression in cocultures could suggest cross-talk between both populations. In conclusion, different types of interactions are probably present in this co-culture system: competition for nutrients, cognate interaction and/or autocrine or paracrine interactions that influence the proliferation of both cells and the hybridoma antibody secretion. We are hereby presenting a pre-scale-up process that could speed up the optimization of largescale monoclonal antibodies production in bioreactors by emulating the in vivo cell-cell interaction between B and T cells without previous stimulation or the addition of co-stimulatory molecules.

ASC Spheroid Geometry and Culture Oxygenation Differentially Impact Induction of Preangiogenic Behaviors in Endothelial Cells

“…This could suggest that the low levels of VEGF secretion were not sufficient to counteract nutrient competition exerted by the ASCs. Competition for nutrients in cocultures has been reported in other cell systems, with the potential to reduce expected cell behaviors (18,30). While 10k, 2% oxygen samples did achieve a higher final level of VEGF, this concentration represents cumulative secretion over 24 h and was not instantaneously available, as in VEGF control samples.…”