Effects of phosphatidic acid on recombinant protein production by Chinese hamster ovary cells in serum-free culture

When recombinant Chinese hamster ovary (CHO) cells (ATCC CRL-8200) producing human interferon-gamma (hIFN-gamma) were incubated with exogenously supplied phosphatidic acid (PA) from egg yolk lecithin in a serum-free medium, PA induced increases in both the density of viable cells and concentration of hIFN-gamma secreted into the medium. Dispersion of PA with a non-ionic surfactant, Tween 80, further enhanced both cell growth and hIFN-gamma production. Replacement of the culture medium containing PA by fresh medium without PA in the course of a static culture did not influence cell growth indicating that PA is required to be continuously present in a serum-free medium to stimulate cell growth. Using a fresh medium containing PA for replacement resulted in significant enhancement of both cell density and hIFN-gamma yield. These results suggest that PA is a promising constituent of low-protein serum-free media for the effective production of recombinant proteins. (C) 2002 Elsevier Science B.V All rights reserved.