SCALE-UP OF THE ADENOVIRUS EXPRESSION SYSTEM FOR THE PRODUCTION OF RECOMBINANT PROTEIN IN HUMAN 293S CELLS

Human 2938 cells, a cell line adapted to suspension culture, were grow n to 5x10(6) cells/ml in batch with calcium-free DMEM. These cells, in fected with new constructions of adenovirus vectors, yielded as much a s 10 to 20% recombinant protein with respect to the total cellular pro tein content. Until recently, high specific productivity of recombinan t protein was limited to low cell density infected cultures of no more than 5 x 10(5) cells/ml. In this paper, we show with a model protein, Protein Tyrosine Phosphatase 1C, how high product yield can be mainta ined at high cell densities of 2x10(6) cells/mi by a medium replacemen t strategy. This allows the production of as much as 90 mg/L of active recombinant protein per culture volume. Analysis of key limiting/inhi biting medium components showed that glucose addition along with pH co ntrol can yield the same productivity as a medium replacement strategy at high cell density in calcium-free DMEM. Finally, the above results were reproduced in 3L bioreactor suspension culture thereby establish ing the scalability of this expression system. The process we develope d is used routinely with the same success for the production of variou s recombinant proteins and viruses.