Kinetics of antiviral state in cells activated by interferons in vitro.

It was found that development of antiviral state in cells activated by IFN alpha and beta were quite rapid. After 6-7 h treatment IFN alpha and IFN beta protected cells completely and their effects lasted for another 9-12 h after removing them from the cultures. Then the effect declined, but some protective action remained after 48 h of incubation. IFN-gamma was different from IFN alpha or beta. It activated cells much more slowly, and could not protect cells completely before 24 h of treatment. When we compared three concentrations of IFN-alpha, the cells could not be protected completely by 5 IU/ml, and kinetics were similar with 250 and 25 IU/ml. When we added anti-IFN-alpha serum before IFN treatment, the development of the antiviral state was inhibited. The results suggested that one should adopt different ways when titrating and using different forms of IFN, and it might not be needed to use maximal tolerated doses and daily administrations, and to keep the high level of IFN for a long time. We think that these results might be useful for the clinicians considering the optimal schedule for IFN treatment.