High Yield Culture of Human Fibroblasts on Microcarriers: A First Step in Production of Fibroblast-Derived Interferon (Human Beta Interferon)

Production of large quantities of diploid human fibroblasts in small culture volumes can be achieved using microcarrier culture techniques. Modification of the microcarrier culture procedure to include a virtually static attachment period and a reduced culture volume during the first 6 hr of culture was shown to double the attachment efficiency of the cells, improve the culture growth rate and increase final cell yields. Using the modified culture procedure yields greater than 2 x 10(6) cells/ml could be regularly obtained when 7--8 viable cells/microcarrier were used to inoculate a culture containing 3 mg of Cytodex 1 microcarriers/ml. A protocol for the mass production of human beta interferon from microcarrier cultures is described. After priming the culture with beta interferon the superinduction step involves use of a poly (I) . poly(C)/DEAE-Dextran complex. Modifications to the microcarrier culture procedure and to the interferon production sequence enable the production of 3 x 10(8) IU of interferon from a 5 liter microcarrier culture of human fibroblasts. This quantity of interferon corresponds to a yield of approximately 30 IU/10(3) cells or 2 x 10(4) IU/mg of microcarrier.