Abstract
In human fibroblast cells treated with interferon, cytomegalovirus- specified immediate early RNA was found associated with the polyribosomes at concentrations and size classes similar to the virus RNA found in non-treated cells, Interferon treatment inhibited the translation of the immediate early virus mRNA; the relative rate of virus-specified immediate early protein and antigen synthesis decreased with increasing concentrations of interferon. In addition, the relative amount of virus-specified RNA associated with the polyribosomes at early times after infection was significantly reduced by treatment of the cells with interferon. Inhibition of infectious virus production in interferon-treated cells was primarily due to inhibition of immediate early virus protein synthesis and secondarily to suppression of early virus RNA synthesis. The role of the virus-specified immediate early proteins in regulating subsequent virus gene expression is discussed.