DIFFERENTIAL-EFFECTS OF PURE HUMAN ALPHA AND GAMMA INTERFERONS ON FIBROBLAST CELL-GROWTH AND THE CELL-CYCLE

Pure human .alpha. and recombinant .gamma. interferons had differential effects on 2 strains of fetal lung fibroblasts [HEL 23 and HEL 27] in vitro. .alpha. Interferon had little effect on long-term cell growth, whereas .gamma. interferons, both glycosylated and non-glycosylated, were cytotoxic. When synchronized cells were studied, .alpha. interferon prolonged both G1 and S + G2 phases of the cell cycle, whereas .gamma. interferon only affected the G1 phase.