Using two-dimensional electrophoresis on total and nuclear extracts of human fibroblasts, we compared
polypeptide patterns of cells treated with
interferon-beta (IFN-beta), IFN-gamma, or with dsRNA in the presence of anti-IFN
antibodies. The analysis of whole-
cell extracts revealed that, after a 6-h treatment, the three agents induce the synthesis of a common set of
proteins in addition to others that are specifically induced either by IFNs or by dsRNA. After a 15-h treatment, this common set of
proteins was only induced by IFNs. Furthermore, at this time, IFNs also regulated
proteins whose synthesis was specifically induced or repressed by
poly(I).
poly(C) in the 6-h treated cells. These results indicate that
poly(I).
poly(C) regulates
protein expression more rapidly and more transiently than IFNs. The analysis of nuclear extracts showed similar differential kinetics of
protein expression. However, a greater number of
polypeptides was found to have their synthesis specifically induced by dsRNA. Moreover,
poly(I).
poly(C) was found to be mitogenic in these cells and did not induce a significant resistance to
vesicular stomatitis virus (VSV). This study provides evidence for an overlap in the expression of
proteins by dsRNA and IFNs, although these compounds do not share the same
biological activities.