Soluble HLA-G protein secreted by allo-specific CD4+ T cells suppresses the allo-proliferative response: a CD4+ T cell regulatory mechanism.
We recently reported that the nonclassical HLA class I molecule HLA-G was expressed in the endomyocardial biopsies and sera of 16% of heart transplant patients studied. The aim of the present report is to identify cells that may be responsible for HLA-G protein expression during the allogeneic reaction. Carrying out mixed lymphocyte cultures in which the responder cell population was depleted either in CD4(+) or CD8(+) T cells, we found that soluble HLA-G5 protein but not the membrane-bound HLA-G isoform was secreted by allo-specific CD4(+) T cells from the responder population, which suppressed the allogeneic proliferative T cell response. This inhibition may be reversed by adding the anti-HLA-G 87G antibody to a mixed lymphocyte culture. That may indicate a previously uncharacterized regulatory mechanism of CD4(+) T cell proliferative response.
Lila
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N
Service de Recherches en Hémato-Immunologie, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Départment de Recherche Médicale, Hôpital Saint-Louis, 1 Avenue Claude-Vellefaux, 75010 Paris, France.
Rouas-Freiss
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N
Dausset
J
J
Carpentier
A
A
Carosella
E D
ED
D017209:Apoptosis / Q000276:immunology; D015153:Blotting, Western / Q000379:methods; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002455:Cell Division; D005434:Flow Cytometry / Q000379:methods; D006680:HLA Antigens / Q000096:biosynthesis / Q000276:immunology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007519:Isoantigens / Q000096:biosynthesis / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D020033:Protein Isoforms / Q000096:biosynthesis / Q000276:immunology; D012995:Solubility; D013347:Subcellular Fractions
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D007519:Isoantigens; D020033:Protein Isoforms