Induction of macrophage inflammatory protein-1 beta gene expression in human monocytes by lipopolysaccharide and IL-7

HuMIP-1 beta is a member of a gene family of inflammatory cytokines whose expression is induced by proinflammatory and mitogenic stimuli. The gene was rapidly induced in human peripheral blood monocytes by either LPS or IL-7. However, IL-7 was unable to induce HuMIP-1 beta mRNA in peripheral blood T cells. The induction of HuMIP-1 beta mRNA in monocytes by IL-7 or LPS was inhibited by IL-4. The 5'-regulatory region of the HuMIP-1 beta gene was cloned and sequenced. An analysis of this sequence revealed three consensus-binding sites for the nuclear factor PU.1 and three potential glucocorticoid response elements. However, the HuMIP-1 beta gene appears to be unresponsive to dexamethasone. Also present in the 5'-regulatory region was a LPS-responsive element located within 455 bp 5' to the start of transcription.