HLA-G is found in lipid rafts and can act as a signaling molecule.
Hum Immunol
; 68(1): 1-11, 2007 Jan.
Article
em En
| MEDLINE
| ID: mdl-17207707
ABSTRACT
HLA-G protein is the functional homolog of Qa-2, the product of the mouse preimplantation embryo development (Ped) gene. Embryos expressing Qa-2 on the cell surface exhibit a faster rate of preimplantation cleavage and preferential survival in utero compared with Qa-2-negative embryos. Qa-2 is glycosylphosphatidylinositol (GPI) linked in the cell membrane. As a result, Qa-2 proteins cluster in cholesterol- and sphingolipid-rich lipid raft microdomains in the cell membrane and can signal via raft-associated intracellular signaling molecules. Using T cells as a model system, cross-linking of Qa-2 on the cell membrane has been shown to induce proliferation of resting cells. HLA-G, like Qa-2, lacks a cytoplasmic domain capable of transducing signals from the cell surface to the nucleus, but unlike Qa-2, HLA-G has a short six-amino acid cytoplasmic tail rather than a GPI anchor. To test whether HLA-G, like Qa-2, is located in lipid rafts and can act as a signaling molecule, we used an HLA-G transgenic mouse system. T cells were isolated and tested for HLA-G expression by immunofluorescence and for localization of HLA-G in lipid rafts by immunofluorescence and Western blotting. Next, the T cells were cross-linked with anti-HLA-G antibody to test for induction of proliferation. Our novel results show that HLA-G, like GPI-linked Qa-2, is present in lipid rafts in the cell membrane and can act as a signaling molecule to induce proliferation of resting T cells.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Antígenos de Histocompatibilidade Classe I
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Transdução de Sinais
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Microdomínios da Membrana
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Antígenos HLA
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article