Inhibition of RNA and protein synthesis in interferon-treated HeLa cells infected with vesicular stomatitis virus.

Synthesis of vesicular stomatitis virus RNA and protein is almost completely inhibited in HeLa cells treated with relatively high doses of human fibroblast interferon. With lower concentrations of interferon virus replication is inhibited, but near normal amounts of virus RNA are found in cells infected at a m.o.i. of 10. All the virus RNA species are found in these cells with the exception of genomic size RNA. In contrast, synthesis of all the virus proteins is equally inhibited in proportion to the interferon concentration used to treat the cells. This inhibition is due to a decline in the rate of protein synthesis, which occurs in interferon-treated cells sooner after infection than in untreated cells. The decreased rate of protein synthesis is accompanied by a change in the polysome pattern of infected cells, characterized by polysome run-off and increase in 80S ribosomes. At the same time, a larger proportion of the virus poly(A)-containing RNA is not associated with polysomes in interferon-treated cells than in control cells. The non-polysomal virus RNA has a sedimentation rate identical with that of polysomal virus RNA. Possible causes for the decline in the rate of protein synthesis observed in interferon-treated cells are discussed.