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Transcriptional control of the human MCP‐2 gene promoter by IFN‐γ and IL‐1β in connective tissue cells
Author(s) -
Coillie Els,
Aelst Ilse,
Fiten Pierre,
Billiau Alfons,
Damme Jo,
Opdenakker Ghislain
Publication year - 1999
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.66.3.502
Subject(s) - biology , microbiology and biotechnology , transfection , transcription (linguistics) , cell culture , gene expression , gene , promoter , mutant , genetics , linguistics , philosophy
Human monocyte chemotactic protein‐2 (MCP‐2) is a member of the CC chemokine family. It is produced by mononuclear leukocytes, diploid fibroblasts, and tumor cells after induction with IL‐1β or IFN‐γ. To understand the transcriptional regulation of the gene, we have analyzed the structure and function of the promoter region. The sequence of the 5′‐flanking region was determined and the transcription start site was found to be located at 68 nucleotides upstream of the ATG translation start codon. 5′‐Deletion mutants were generated and transfected into E 6 SM diploid fibroblasts and MG‐63 osteosarcoma cells. Expression was measured by luciferase assay in transfected unstimulated cells and after stimulation with IL‐1β, IFN‐γ, or a combination. The region between nucleotides ‐143 and ‐73 (relative to the transcription initiation site), containing putative cis ‐elements for GATA‐1, H‐APF1, AP‐1, and GAS, is important for basal transcription levels in both cell lines. Stimulation for 18 h with IL‐1β alone failed to affect expression of any of the constructs both in diploid fibroblasts and in osteosarcoma cells. In both cell lines IFN‐γ increased the activity of all mutants that possessed the region between ‐340 and ‐301. In MG‐63 cells, stimulation with the combination of IL‐1β and IFN‐γ caused an additional increase in expression of the constructs from ‐340 onward. Finally, the presence of transcription factors in nuclear extracts of MG‐63 cells and their specificity to bind to various oligonucleotide probes in this [‐340; ‐301] region were evidenced by electromobility shift assays. These results show that IFN‐γ, produced by lymphocytes and NK cells, induces the transcription of the MCP‐2 gene in fibroblasts and thereby can indirectly contribute to recruitment of various leukocyte cell types to inflammatory sites. J. Leukoc. Biol. 66: 502–511; 1999.