Transfected trophoblast-derived human cells can express a single HLA class I allelic product.
The human trophoblast-derived JAR cell line, that does not express polymorphic HLA class I antigens even after IFN induction, can be stably transfected by genomic clones encoding the entire HLA-A2, -A3 and -B7 alpha-chain genes. The transfected genes were expressed at the cell surface in association with endogenous beta 2-microglobulin (shown by FCM analysis) as a single allelic product without reexpression of any endogenous class I gene (shown by 1D.IEF analysis). Furthermore, TNF-alpha and IFN-gamma, alone and synergistically, increase cell surface expression of transfected MHC class I/endogenous beta 2m heterodimers without induction of endogenous class I alpha-chain genes. These data show that the MHC class I-negative JAR human cell line might be used for transfections with the aim of establishing human cells expressing just one defined MHC class I allele for functional and regulatory studies. These findings are discussed in relation to the methylated status solely of endogenous class I alpha-chain genes in JAR cells and suggest that transfected class I genes are not regulated in the same fashion and, in particular, that constitutive and TNF/IFN inducible trans-acting regulatory factors able to bind to cis-promoter/enhancer sequences of class I DNA are likely to be present.
Boucraut
J
J
Laboratoire d'Immunologie, Faculté de Médecine de la Timone, Marseille, France.
Hakem
R
R
Gauthier
A
A
Fauchet
R
R
Le Bouteiller
P
P
D000483:Alleles; D000951:Antigens, Neoplasm / Q000096:biosynthesis; D002822:Choriocarcinoma / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005805:Genes, MHC Class I; D006680:HLA Antigens / Q000096:biosynthesis*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008745:Methylation; D011247:Pregnancy; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000494:pharmacology; D013268:Stimulation, Chemical; D014157:Transcription Factors / Q000502:physiology; D014162:Transfection; D014327:Trophoblasts / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014594:Uterine Neoplasms / Q000473:pathology; D001613:beta 2-Microglobulin / Q000096:biosynthesis
D000951:Antigens, Neoplasm; D006680:HLA Antigens; D011994:Recombinant Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D001613:beta 2-Microglobulin; D007371:Interferon-gamma