A T Cell-specific Enhancer of the Human CD40 Ligand Gene

Abstract

We observed that the human CD40 ligand (CD40L) gene 5-flanking region conferred weak promoter activity in activated CD4 T cells, suggesting that additional regions are required for optimal CD40L gene transcription. We therefore examined a 3-flanking segment of the CD40L gene, which contained a putative NF-B/Rel ciselement, for its ability to enhance CD40L promoter function. This segment augmented CD40L promoter activity in an orientation-independent manner in CD4 T-lineage cells but not in human B cell or monocyte cell lines.