HLA-G expression in trophoblast cells is independent of embryonic development.
HLA-G is a nonclassical major histocompatibility complex class I molecule that is selectively expressed on cytotrophoblasts at the feto-maternal interface where it may play a major role in maternal-fetal tolerance. In this study, we compared HLA-G expression in trophoblasts from normal and pathologic pregnancies by immunohistochemical analysis. First, we found a defective HLA-G expression in miscarriages associated with hypotrophic but normal eggs. Conversely, by studying molar pregnancies, we observed a high HLA-G expression in complete and partial hydatidiform moles. Finally, HLA-G expression could be visualized in extravillous trophoblasts that develop outside of their normal environment, as reported here in ectopic pregnancies. Taken together, these results suggest that HLA-G expression in extravillous trophoblasts is induced in an autonomous manner, independently of embryonic development, and may be an integral part of placental development allowing its tolerance from maternal immune system.
Rabreau
M
M
Institut d'Histo-Cyto-Pathologie, Le Bouscat, France. ihcp@wanadoo.fr
Rouas-Freiss
N
N
Landi
M
M
Le Danff
C
C
Carosella
E D
ED
D000022:Abortion, Spontaneous / Q000276:immunology; D005187:Fallopian Tubes / Q000473:pathology; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D006828:Hydatidiform Mole / Q000276:immunology; D007150:Immunohistochemistry; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D011271:Pregnancy, Ectopic / Q000276:immunology; D014327:Trophoblasts / Q000276:immunology*
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I