HLA-G, pre-eclampsia, immunity and vascular events.
Pre-eclampsia, one of the main complications in pregnancy, is characterised by shallow cytotrophoblast invasion of decidua as well as by vascular endothelial cell dysfunction, leading to a poor perfusion of placenta. A striking feature of pre-eclamptic pregnancies is that expression of HLA-G protein is reduced in term placentas compared with normal pregnancy. How such HLA-G deficient expression may be related to the pre-eclamptic pathology is unknown. Here, we review the major structural characteristics of HLA-G and some of its functions that have been recently characterised. Soluble HLA-G1 isoform down-regulates both CD8(+) and CD4(+) T cell reactivity. HLA-G also modulates innate immunity by binding to several NK and/or decidual receptors, inducing particular cytokine secretion. HLA-G was shown to be less susceptible to human cytomegalovirus-derived US protein down-modulation. Finally, soluble HLA-G1 down-regulates endothelial cell proliferation and migration. In view of these different HLA-G properties, we will briefly discuss how defective HLA-G function may contribute to the low trophoblast invasion and vascular abnormalities observed in pre-eclamptic placentas.
Le Bouteiller
Philippe
P
INSERM U563, Centre de Physiopathologie Toulouse-Purpan, Bât. A, Hôpital Purpan, Cedex 3, 31059 Toulouse, France. phil.lb@toulouse.inserm.fr
Pizzato
Nathalie
N
Barakonyi
Aliz
A
Solier
Corinne
C
D000818:Animals; D017209:Apoptosis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement; D003587:Cytomegalovirus / Q000502:physiology; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006680:HLA Antigens / Q000502:physiology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D010920:Placenta / Q000276:immunology* / Q000378:metabolism; D011225:Pre-Eclampsia / Q000276:immunology* / Q000378:metabolism; D011247:Pregnancy; D014327:Trophoblasts / Q000276:immunology / Q000502:physiology*
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I