Chemostat Culture Studies on CHO Cells Producing Interferon-γ

Abstract

The physiology of a recombinant Chinese hamster ovary cell line in glucose-limited chemostat culture has been studied over a range of dilution rates (D=0.008-0.020h-1). There was a deviation of the specific growth rate (µ) from D at low dilution rates due to an increased specific death rate. Extrapolation of these data suggested a minimum specific growth rate of 0.011h-1 (µmax=0 0.025h-1). The specific rate of glucose uptake increased linearly with µ and KS was calculated to be 59.6µM. There was also a linear increase in the rate of lactate production with a higher yield of lactate from glucose at high growth rates. The specific rate of IFN-γ production increased with µ in a manner indicative of a growth related product. Despite changes in the IFN-γ production rate and cell physiology, the pattern of IFN-γ glycosylation was similar at all except the lowest growth rates where there was a decrease in the proportion of fully glycosylated IFN-γ.