Effect of surfactant pluronic F-68 on CHO cell growth, metabolism, production, and glycosylation of human recombinant IFN-γ in mild operating conditions

The control of glycosylation to satisfy regulatory requirements and quality consistency of recombinant proteins produced by different processes has become an important issue. With two N‐glycosylation sites, γ‐interferon (IFN‐γ) can be seen as a prototype of a recombinant therapeutic glycoprotein for this purpose. The effect of the nonionic surfactant Pluronic F‐68 (PF‐68) on cell growth and death was investigated, as well as production and glycosylation of recombinant IFN‐γ produced by a CHO cell line that was maintained in a rich protein‐free medium in the absence or presence of low agitation. Under these conditions, a dose‐dependent effect of PF‐68 (0–0.1%) was shown not only to significantly enhance growth but also to reduce cell lysis. Interestingly, supplementing the culture medium with PF‐68 led to increased IFN‐γ production as a result of both higher cell densities and a higher specific production rate of IFN‐γ. If cells were grown with agitation, lack of PF‐68 in the culture medium decreased the fraction of the fully glycosylated IFN‐γ glycoform (2N) from 80% to 65–70% during the initial period. This effect appeared to be due to a lag phase in cell growth observed during this period. Finally, a global kinetic study of CHO cell metabolism indicated higher efficiency in the utilization of the two major carbon substrates when cultures were supplemented with PF‐68. Therefore, these results highlight the importance of understanding how media surfactant can affect cell growth as well as cell death and the product quality of a recombinant glycoprotein expressed in CHO cell cultures. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011