Only the HLA class I gene minimal promoter elements are required for
transactivation by human cytomegalovirus immediate early genes
LJ Burns, JF Waring, JJ Reuter, MF Stinski and GD Ginder
Department of Medicine, University of Minnesota, Minneapolis.
The immediate early (IE) genes of human cytomegalovirus (HCMV) are
expressed in lymphocytes and are known to transactivate both viral and
cellular promoters. The mechanism by which IE gene products of HCMV
transactivate expression of the HLA A2 gene promoter in Jurkat cells, a
T-lymphocyte cell line, was investigated. Transient expression assays were
performed using plasmids containing the HLA A2 promoter-regulatory region
linked to the bacterial chloramphenicol acetyltransferase (CAT) gene and a
plasmid expressing the CMV IE genes. The upregulation of the HLA A2
promoter by HCVM IE gene products was shown not to be secondary to either
interferon-gamma or -alpha. Previously described MHC class I regulatory or
enhancer elements such as the interferon-stimulated response element
(ISRE), NF-kappa B and H2TF1 binding sequences, and the interferon
consensus sequence (ICS) were not required for transactivation of the A2
promoter. Rather, the only known regulatory elements in the HLA A2 promoter
necessary for both basal expression and transactivation by HCVM IE gene
products are the CCAAT box and TATA box motifs. These results support a
model in which HCVM IE gene products act through the minimal HLA A2
promoter elements to increase gene expression.
Volume 81,
Issue 6,
pp. 1558-1566,
03/15/1993
Copyright © 1993 by The American Society of Hematology
