Cell Growth & Differentiation, Vol 3, Issue 2 93-100, Copyright © 1992 by American Association of Cancer Research
Increased levels of interferon regulatory element-binding activities in nuclei of high interferon-producing If-1h mice
L Daigneault and D Skup
Institut du cancer de Montreal, Quebec, Canada.
The transient induction of type I interferon (IFN) genes following a viral
infection involves transcriptional derepression and activation, mediated by
positive and negative factors which bind to upstream cis-acting elements.
We have transfected the human IFN-beta gene into primary splenocytes from
mice regulated by the If-1 locus and have shown that the exogenous gene is
regulated by this locus in a manner similar to that of endogenous IFN
genes. Using nuclear extracts from splenocytes of C57BL/6 (If-1h) and
BALB/c (If-1l) mice in gel retardation assays, we found that levels of
DNA-binding activities for the interferon regulatory element and its
subelements were constitutive in nuclear extracts of spleen cells. Levels
of DNA binding to the interferon regulatory element were higher in extracts
from the nuclei of If-1h mice and thus correlate with the higher levels of
human IFN-beta mRNA detected in these transfected cells and the
transcription of the endogenous IFN genes. Higher levels of
DNA-binding/transcription factors found in nuclei from spleen cells of
If-1h mice may be involved in the expression of the If-1 phenotype.