HLA-G transcription studies during the different stages of normal and malignant hematopoiesis.
Specific expression of the non classical class I HLA-G gene on trophoblasts, the only fetal tissue in contact with maternal cells which lack MHC class I antigens, may indicate a role of this gene in fetal-maternal tolerance. We recently reported HLA-G transcription in peripheral blood leukocytes. In this work, we have investigated HLA-G transcription in hematopoietic stem cells, in different hematopoietic lineages and in malignant cells by using a RT-PCR technique. PCR amplification with primers specific to the exon 2 and the 3' untranslated region has enabled to detect HLA-G transcription in B and T cell populations. No transcription was found in CD34+ cells, in thymocytes, in polynuclear cells, in monocytes and in natural killer cells. Among the malignancies analyzed, HLA-G is transcribed in 2 of 13 cases of acute leukemia characterized by a monocytic contingent, in 3 of 6 CLL and in all the cases of B-NHL (n = 6). No HLA-G transcription was detected in myeloma (n = 2). The splicing type does not seem to be linked to a lymphocyte subpopulation nor to a malignant proliferation stage. These results suggest that HLA-G is a marker of mature lymphoid cells and may play an immunological function as a peptide presenting molecule. HLA-G transcription in some cases of malignancy might indicate a contribution to the tumoral progression by blocking natural killing reaction.
Amiot
L
L
Laboratoire d'Hématologie et de la biologie des cellules sanguines, Université de Rennes I, France.
Onno
M
M
Renard
I
I
Drénou
B
B
Guillaudeux
T
T
Le Bouteiller
P
P
Fauchet
R
R
D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation; D015973:Gene Expression Regulation, Leukemic; D015972:Gene Expression Regulation, Neoplastic; D006680:HLA Antigens / Q000096:biosynthesis / Q000235:genetics*; D059951:HLA-G Antigens; D019337:Hematologic Neoplasms / Q000235:genetics / Q000276:immunology*; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D016131:Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000276:immunology* / Q000378:metabolism; D009928:Organ Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D013945:Thymoma / Q000235:genetics / Q000276:immunology; D013953:Thymus Neoplasms / Q000235:genetics / Q000276:immunology; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I