Thymol Suppression of Protein Synthesis in Influenza Virus-Infected and Uninfected Chick Embryo Fibroblast Cells 1

Abstract

Summary

Thymol in a concentration ot 0.66 m M (100 μg/ml) during a 15-min exposure suppressed incorporation of leucine into protein in chick embryo fibroblast cells uninfected and infected with influenza A/ PR/8/34 by 73 and 80% respectively. Lesser concentrations of thymol showed progressively less effect. Formation of high molecular weight protein, probably cellular in origin, was less suppressed than that of lower molecular weight proteins in both infected and uninfected cell preparations.

Periodic sampling during simultaneous pulsing with [³H]leucine and exposure to 0.33 mM thymol, showed that leucine penetrated thymol-treated, infected, and uninfected cells, to about the same extent as cells not exposed to thymol, indicating an intra-cellular site of effect of suppression of leucine incorporation rather than a membrane effect.

Influenza virus-infected cells incorporated into protein only 57% of the amount of leucine incorporated by uninfected CEF.

Mr. Philip M. Cordell gave valuable assistance in this study. We thank Dr. David Ailing, National Institute of Allergy and Infectious Diseases, NIH, Be-thesda, Maryland, for assistance with statistical evaluations.