Inhibition by Interferon of Thymidine Uptake in Chemostat Cultures of L1210 Cells

Mouse interferon preparations inhibited the incorporation of [3H]-thymidine into acid-insoluble material of mouse leukemia L1210 cells cultivated under steady-state conditions in a chemostat. Interferon exerted only a transitory and less pronounced effect on [3H]-deoxyadenosine incorporation and had no effect on the content of total DNA per cell. Study of [3H]-thymidine uptake at 1 degree into acid-soluble cellular material showed that interferon reduced the uptake of this labeled nucleoside whereas the uptake of [3H]-deoxyadenosine and [3H]-deoxy-D-glucose was not inhibited. The effect of interferon on [3H]-thymidine uptake occurred prior to the inhibitory action on cell multiplication. It is suggested that the inhibitory of [3H]-thymdine uptake reflected specific changes in the cell membrane of interferon-treated cells which may be relevant to the understanding of the antiviral and other biological effects of interferon.