Effect of iron sources on the glycosylation macroheterogeneity of human recombinant IFN-γ produced by CHO cells during batch processes

Abstract

In the biopharmaceutical industry, the control of glycosylation to satisfy the quality consistency of recombinant proteins produced during a process has become an important issue. Indeed, the glycosylation pattern of recombinant proteins could be influenced by different factors including the cell line used, environmental factors such as oxygenation, temperature, shear stresses, extracellular pH... and the availability of nutrients. As previously reported [1,2], the BDM medium is able to support a better CHO cell growth and a higher IFN-g production compared to RPMI medium supplemented with serum. In addition, when BDM medium is used, CHO cells are capable to maintain a high percentage of doubly-glycosylated glycoforms of recombinant IFN-g produced during the whole process. Conversely, monoglycosylated and non-glycosylated IFN-g forms increased during batch cultures performed with RPMI serum medium. Iron is an important nutrient and is reported to support essential functions in cells. In this study, the impact of different iron sources on the CHO cell growth, as well as on the production and the glycosylation of a human recombinant IFN-g were investigated.