Induction of Interferon by Nonreplicating Single-Stranded RNA Virus 1

Summary

A study was undertaken to help determine whether the input virions of a nonreplicating single-stranded RNA virus could stimulate interferon production. Rat embryo cells were treated with inhibitors of protein synthesis during infection with chikungunya virus. After 4.5 hr incubation, RNA synthesis was inhibited with actinomycin D and 1 hr later the inhibition of protein synthesis was reversed by washing. There after, the culture fluids were tested for production of interferon. Since not even partial replication of chikungunya virus or its components was demonstrable under the conditions of inhibition of protein synthesis, the finding of full yields of interferon indicated that a component of the input virion stimulated production of the interferon. The results of control experiments make it unlikely that contaminating double-stranded RNA was the stimulus for interferon production. Since viral and other nucleic acids are the most general inducers of interferon, and since the input chikungunya virion contains single-stranded RNA, it seems probable that at least certain single-stranded viral RNAs can stimulate interferon production.

The authors acknowledge the helpful suggestions and criticisms made by Dr. H. B. Levy.