HLA-G class I gene expression in normal and malignant hematopoietic cells.
The class Ib HLA-G gene encodes for a molecule which is selectively expressed in fetal placental cells. Fetomaternal tolerance could be partially explained by the interactions between HLA-G molecules and KIR receptors of decidual NK cells. To determine whether the presence of HLA-G antigens might constitute a factor of immune tolerance during the tumoral process, we compared the expression of the HLA-G gene in normal and malignant hematopoietic cells. Despite a HLA-G transcriptional activity in several lymphocytes and monocytes, no antigens are found at the cell surface or in the cytosol using the specific HLA-G mAb, 87G. This lack of expression does not appear modified in malignant hematopoietic cells. However, treatment of the monohistiocytic cell line U937 with different cytokines enabled the expression of HLA-G antigens to be induced. We suggest that the potential induction of HLA-G molecules in monocytic malignant cells following secretion of cytokines may constitute a factor of immune tolerance in patients.
Laboratoire Universitaire d'Hématologie et de la Biologie des Cellules Sanguines, Faculté de Médecine, Université de Rennes, I, France.
L
L
Amiot
M
M
Onno
B
B
Drénou
C
C
Monvoisin
R
R
Fauchet
D002461:Cell Line, Transformed / Q000187:drug effects; D016207:Cytokines / Q000494:pharmacology; D017931:DNA Primers / Q000737:chemistry; D005434:Flow Cytometry; D015870:Gene Expression; D005805:Genes, MHC Class I / Q000235:genetics*; D006680:HLA Antigens / Q000235:genetics* / Q000378:metabolism; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007938:Leukemia / Q000235:genetics* / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000378:metabolism
D016207:Cytokines; D017931:DNA Primers; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I