Interferon synthesis in human diploid cells pretreated with insulin.

Interferon production by Newcastle disease virus in human diploid (WI-38) cells was greatly reduced in the absence of serum. Pretreatment of the serum-free cells with insulin in excess of 1.2 IU/ml for 2 h before induction considerably increased the amount of interferon produced. No enhancement of interferon production was seen when the cells were exposed to insulin 2 h after induction or later. The insulin's effect persisted for at least 6 h after its removal, but not for 24 h. A possible mechanism of insulin action is discussed.