Immediate early gene 2 of human cytomegalovirus increases interleukin 2 receptor-alpha gene expression

Previously, we demonstrated that the cytomegalovirus (CMV) immediate early 2 (IE2) gene product upregulates interleukin-2 receptor-alpha (IL-2R alpha) gene expression. To further define this effect, we used a series of IL-2R alpha promoter truncations to identify that the primary site of CMV IE2 activity was in the region between -281 and -273 of the IL-2R alpha promoter, an area without known transcription factor activity. Deletion of known transcription factor enhancer elements resulted in a similar decrease in IE2-driven promoter activation. This unique sequence from the IL-2R alpha promoter was shown to drive a minimal promoter in the presence of IE2. These studies identify a new transcription factor binding site in the IL-2R alpha promoter, which may be specifically responsive to the CMV IE2 gene product. These studies also suggest that one mechanism whereby CMV infection may result in organ transplant rejection is through increased IL-2R alpha expression.