Antiproliferative effect of interferon on a Burkitt's lymphoma cell line

The effect of interferon (IF) on the growth of a Burkitt's lymphoma cell line was analysed. The degree of depression of cell doublings was the same if the cells were in a steady state mode of exponential growth or in a resting state (G0) when IF was added. As IF had a lag time of 24 h before decreased growth could be observed, cells in G0 did not seem to be more sensitive when growth was estimated by cell counts expressed as cell doublings. IF inhibited cells to proceed into the cell cycle and the possibility that IF may increase the escape into a G0 loop is discussed.