Activation of the human delta-globin gene promoter in primary adult erythroid cells

Restoration of the CCAAT box or insertion of an erythroid Kruppel-like factor (EKLF) binding site in the delta promoter activates its expression in several erythroid cell lines, We extended these studies using a novel primary human adult erythroid cell (hAEC) system to investigate these effects at the late erythroblast stage, Restoration of the CCAAT box: at -70 bp, or insertion of an EKLF binding site at -85 bp or -95 bp in the promoter significantly increased delta globin gene expression in hAEC. Our results demonstrate that the altered CCAAT box (CCAAC) and the lack of an EKLF binding site in delta-globin contribute to its low level of expression in the hAEC model as well.