Effect of interferon on Vero cells persistently infected with SSPE virus and lytically infected with measles virus.

The effect of lymphoblastoid interferon (IFN) on viral polypeptides synthesized in a Vero cell culture persistently infected with subacute sclerosing panencephalitis virus (SSPE-Vero) was compared to that of Vero cells infected with exogenous measles virus. After IFN treatment there was no significant decrease in the synthesis of SSPE viral proteins, but inhibition of synthesis of measles polypeptides was readily seen. In Vero and SSPE-Vero cells IFN was able to inhibit replication of Sindbis virus although the effect in Vero cells was significantly more sensitive. In both cell lines IFN was able to stimulate 2'--5' oligoadenylate synthetase (E enzyme) but not the protein kinase system. The SSPE-Vero cells showed a lower basal level of E enzyme activity than the Vero cells.