Resistance of HLA-G and HLA-A2 transfectants to lysis by decidual NK cells.
Trophoblast cells from normal first trimester pregnancies have been shown to express the nonclassical Class I molecule, HLA-G, which is nonpolymorphic and has a heavy chain of 40 kDa. These HLA-G-expressing trophoblast cells infiltrate into maternal decidua, which contains abundant uterine-specific CD56bright natural killer (NK) cells. We believe HLA-G may act as a protective molecule against decidual NK lysis and thus allow trophoblast survival in the maternal tissues. To test this hypothesis, we have constructed HLA-G and HLA-A2 transfectants using LCL 721.221 HLA-null cells. We observed that both of these antigens protected target cells from NK effectors isolated from decidua or peripheral blood, although the effect of HLA-G is not as marked as that of HLA-A2. Our results, therefore, show that in this experimental system expression of a nonclassical Class 1 HLA molecule is also correlated with NK resistance in the same way as a classical Class I HLA molecule.
Chumbley
G
G
Research Group in Human Reproductive Immunobiology, University of Cambridge, England.
King
A
A
Robertson
K
K
Holmes
N
N
Loke
Y W
YW
D015152:Blotting, Northern; D016923:Cell Death; D003602:Cytotoxicity, Immunologic; D003656:Decidua / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000276:immunology; D014162:Transfection; D014327:Trophoblasts / Q000276:immunology*
D006680:HLA Antigens; D015789:HLA-A2 Antigen; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I