Abstract
HIV has evolved several strategies to evade recognition by the host immune system including down-regulation of major histocompatibility complex (MHC) class I molecules. However, reduced expression of MHC class I molecules may stimulate natural killer (NK) cell lysis in cells of haematopoietic lineage. Here, we describe how HIV counteracts stimulation of NK cells by stabilizing surface expression of the non-classical MHC class I molecule, HLA-E. We demonstrate enhanced expression of HLA-E on lymphocytes from HIV-infected patients and show that in vitro infection of lymphocytes with HIV results in up-regulation of HLA-E expression and reduced susceptibility to NK cell cytotoxicity. Using HLA-E transfected K-562 cells, we identified the well-known HIV T-cell epitope p24 aa14-22a as a ligand for HLA-E that stabilizes surface expression of HLA-E, favouring inhibition of NK cell cytotoxicity. These results propose HIV-mediated up-regulation of HLA-E expression as an additional evasion strategy targeting the antiviral activities of NK cells, which may contribute to the capability of the virus in establishing chronic infection.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP Binding Cassette Transporter, Subfamily B, Member 2
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ATP Binding Cassette Transporter, Subfamily B, Member 3
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ATP-Binding Cassette Transporters / genetics
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ATP-Binding Cassette Transporters / metabolism
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Amino Acid Sequence
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Antigens, CD / metabolism
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Base Sequence
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CD4-Positive T-Lymphocytes / immunology
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Case-Control Studies
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Cytotoxicity, Immunologic
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DNA / genetics
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Epitopes / metabolism
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HIV Core Protein p24 / genetics
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HIV Core Protein p24 / metabolism
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HIV Infections / genetics*
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HIV Infections / immunology*
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HIV Infections / virology
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HIV-1 / immunology
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HIV-1 / pathogenicity
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HLA Antigens / genetics*
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HLA Antigens / metabolism*
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HLA-E Antigens
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Histocompatibility Antigens Class I / genetics*
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Histocompatibility Antigens Class I / metabolism*
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Humans
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In Vitro Techniques
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K562 Cells
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Killer Cells, Natural / immunology*
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Lectins, C-Type / metabolism
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Ligands
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Molecular Sequence Data
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NK Cell Lectin-Like Receptor Subfamily D
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Receptors, Immunologic / metabolism
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Receptors, Natural Killer Cell
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Transfection
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Up-Regulation
Substances
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ATP Binding Cassette Transporter, Subfamily B, Member 2
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ATP Binding Cassette Transporter, Subfamily B, Member 3
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ATP-Binding Cassette Transporters
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Antigens, CD
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Epitopes
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HIV Core Protein p24
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HLA Antigens
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Histocompatibility Antigens Class I
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Lectins, C-Type
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Ligands
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NK Cell Lectin-Like Receptor Subfamily D
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RNA, Messenger
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Receptors, Immunologic
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Receptors, Natural Killer Cell
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TAP1 protein, human
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TAP2 protein, human
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DNA