Species-specific posttranscriptional regulation of interferon synthesis

Abstract

Human fibroblast and Syrian hamster embryo cells were induced to synthesize interferon (IF) with rIn . rCn and rIn . rCn + DEAE-dextran, respectively. Following induction, these cells synthesized IF for only a short time before entering into a repressed state and shutting off the synthesis of IF. Homologous and heterologous whole cell translational systems were developed to investigate the molecular basis for the shut-off of IF synthesis. These systems allowedd for the introduction of exogenous hamster and human IF-mRNAs into intact normal and repressed hamster and human cells via an improved CaCl2 precipitation technique. Human IF-mRNA was translated in normal human and hamster cells and in repressed hamster cells but not in repressed human cells. In contrast, the hamster IF-mRNA was translated in normal human, normal hamster, and repressed human cells but not in repressed hamster cells. These results indicate that a species-specific mechanism inhibiting translation of IF-mRNA is directly responsible for the shut-off of IF synthesis in human fibroblasts and Syrian hamster embryo cells.

Structural requirements of (2′–5′) oligoadenylate for protein synthesis inhibition in human fibroblasts

“…Cell Growth. The growth and propagation of human cell strain HF926 has been described previously (23). For this study 2.5 x 104 cells per well were plated into 96-well cluster plates (Costar) at least 24 hours prior to use.…”