HLA-G gene transcriptional regulation in trophoblasts and blood cells: differential binding of nuclear factors to a regulatory element located 1.1 kb from exon 1.
The HLA-G antigen is specifically expressed on trophoblasts at the maternal-fetal interface, while expression of classical class I HLA-A, -B, -C products is repressed in this tissue. The transcriptional level of the HLA-G gene is high in trophoblast cells and in JEG-3 choriocarcinoma cells, is markedly reduced in blood cells, and is shown here to be undetectable in the YT2C2 NK cell line. In an attempt to understand molecular mechanisms controlling cell-specific transcriptional regulation of the HLA-G gene in these cells, we focused our study on protein interaction with a 244-bp region located over 1.1 kb from exon 1, which has been shown to direct HLA-G expression in transgenic mouse trophoblast. Three specific complexes were detected, two of which are found exclusively in cells showing HLA-G transcriptional activity. The YT2C2 nuclear extracts contain restricted DNA-binding activity of an additional factor which could correlate with repression of HLA-G transcription in these cells.
Moreau
P
P
Départment of Recherche Médicale, Hôpital St-louis, Paris, France.
Paul
P
P
Gourand
L
L
Prost
S
S
Dausset
J
J
Carosella
E
E
Kirszenbaum
M
M
D005091:Exons / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology*; D006680:HLA Antigens / Q000235:genetics* / Q000378:metabolism; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000378:metabolism; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics*; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D016133:Polymerase Chain Reaction; D012045:Regulatory Sequences, Nucleic Acid / Q000276:immunology*; D014158:Transcription, Genetic / Q000276:immunology*; D014327:Trophoblasts / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D009687:Nuclear Proteins