Effects of interferon on cell and virus growth in transformed human cell lines

The anticellular and antiviral effects of human leukocyte interferons were studied in vitro in the transformed human embryonic cell lines. RSa and RSb. The growth of these cells was inhibited and they began to deteriorate about 48 h after treatment with 500 units/ml of interferon. When interferon was washed out within 48 h, their growth recovered gradually. The effects of interferon on cell growth depended on the amount of interferon added per cell. A subline, named IFr, was isolated which grows in the presence of 2000 units/ml of interferon, whereas growth of vesicular stomatitis virus in these cells is suppressed by 10 units/ml of interferon, just as in the parent cells. The anticellular and antiviral effects of interferon on IFr cells are discussed in relation to cell surface receptors.