Simultaneous Viral and Non-Viral Interferon Production in Human Cell Cultures 1

Summary

Homogeneous monolayers of human fibroblasts were infected with Newcastle disease virus (NDV) and 1 hr later treated with the synthetic RNA polycytidylate: polyinosinate (poly C:I). The induction of interferon by poly C:I and NDV could be distinguished on the basis of differences in (1) the kinetics of interferon production, and (2) the sensitivity to inhibitors of RNA and protein synthesis. The results indicated that both poly C:I and NDV were fully able to induce the production of interferon in these dually stimulated monolayers. The release of interferon induced by poly C:I appeared to be terminated shortly before the appearance of viral interferon in the extracellular medium. Our findings suggest that termination of the nonviral interferon response did not involve direct inactivation of interferon. It appears that a inhibitor substance blocked the continued formation of nonviral interferon, without significantly affecting the induction of viral interferon.