Antiviral and cell-growth inhibitory activities of highly purified L-cell interferon. An analysis of quantitative disproportions.

Purified mouse L-cell interferon induced with Newcastle disease virus was subjected to polyacrylamide gel electrophoresis. A profile characterized by two components was obtained. The faster peak represented about 90-99 per cent of antiviral activity. Both components exerted a cell-growth inhibitory effect on L cells. A study of the quantitative relations between antiviral and cell-growth inhibitory activites of the two peaks revealed a discrepancy between these two activities in the fast peak. An analysis of this phenomenon suggests that the binding capacity of the fast moving molecular species of interferon is lower in young cells than in aged cells, i.e. those incubated for 3 days. Such differences were not observed when the slow molecular species was examined. It was concluded that both inherent properties of molecular components of interferon and the age (and species) of cells used in tests influence the outcome of interferon action on the cell.