Cloning of the human gene for intercellular adhesion molecule 1 and analysis of its 5'-regulatory region. Induction by cytokines and phorbol ester.

摘要: Human intercellular adhesion molecule-1 (ICAM-1), a specific ligand for the lymphocyte function-associated Ag-1 (LFA-1), plays an important role in leukocyte-endothelial cell interactions. It is induced by proinflammatory cytokines such as IL-1, TNF-alpha, or IFN-gamma. However, little known concerning intracellular regulatory mechanisms which trigger ICAM-1 up-regulation. In order to study potential elements involved induction we have cloned human gene and 5 kb of its 5'-regulatory region. The sequence cDNA was found be distributed over seven exons separated six introns, whereby each five extracellular Ig-like domains encoded own exon. upstream harbors number motifs implicated regulation expression eukaryotic genes, including binding sites transcription factors SP-1, AP-1, NF-kB. Primer extension S1 nuclease analysis revealed two initiation 319 bp 41 translation start site. Consensus TATA boxes were at expected positions about 25 both sites. Reverse transcriptase polymerase chain reaction showed differential use A549 HS913T cells. Both RNA seem code same protein. For studies 1.3-kb EcoRI/SalI fragment 5'-flanking region used promote linked luciferase reporter transient-transfection assays Treatment cells with IL-1 TNF-alpha resulted two- fourfold increase activity. Furthermore, sixfold could achieved after treatment phorbol ester PMA. contrast, agents that cAMP levels did not induce Northern blot investigate kinetics mRNA synthesis upon These data suggest up-regulation occurs least partly transcriptional level. Deletion sequences responsible promotion inhibition transcription. particular, functionally distinct regions been characterized: short containing NF-kB site has shown function activator, followed immediately downstream acting silencer element. Therefore, seems modulated multiple cis-acting elements.