Inhibition of interferon secretion in human fibroblast by vinblastine.

Vinblastine treatment of superinduced human fibroblast (FS-4) cultures strongly inhibited interferon (IFN) secretion and resulted in intracellular accumulation of IFN activity. The cell-associated IFN migrated slower than secreted IFN in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating a larger size. The results suggest the presence of a possible precursor form of mature HuIFN-beta with biological activity.