Abstract
HLA-DM is a major histocompatibility complex (MHC) class II-like molecule that facilitates antigen processing by catalyzing the exchange of invariant chain-derived peptides (CLIP) from class II molecules for antigenic peptides. HLA-DO is a second class II-like molecule that physically associates with HLA-DM in B cells. HLA-DO was shown to block HLA-DM function. Purified HLA-DM-DO complexes could not promote peptide exchange in vitro. Expression of HLA-DO in a class II+ and DM+, DO- human T cell line caused the accumulation of class II-CLIP complexes, indicating that HLA-DO blocked DM function in vivo and suggesting that HLA-DO is an important modulator of class II-restricted antigen processing.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Antigen Presentation*
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Antigens, Differentiation, B-Lymphocyte / metabolism
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B-Lymphocytes / immunology*
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HLA-D Antigens / metabolism*
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HLA-DR3 Antigen / metabolism
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Histocompatibility Antigens Class II / metabolism
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Humans
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Molecular Sequence Data
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Nuclear Proteins*
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T-Lymphocytes / immunology*
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Trans-Activators / genetics
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Transfection
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Tumor Cells, Cultured
Substances
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Antigens, Differentiation, B-Lymphocyte
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H-2O antigen
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H2-M antigens
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HLA-D Antigens
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HLA-DM antigens
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HLA-DO antigens
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HLA-DR3 Antigen
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Histocompatibility Antigens Class II
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MHC class II transactivator protein
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Nuclear Proteins
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Trans-Activators
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invariant chain