Abstract
Major histocompatibility complex class II (MHC II) molecules capture peptides within the endocytic pathway to generate T cell receptor (TCR) ligands. Immature dendritic cells (DCs) sequester intact antigens in lysosomes, processing and converting antigens into peptide-MHC II complexes upon induction of DC maturation. The complexes then accumulate in distinctive, nonlysosomal MHC II+ vesicles that appear to migrate to the cell surface. Although the vesicles exclude soluble lysosomal contents and antigen-processing machinery, many contain MHC I and B7 costimulatory molecules. After arrival at the cell surface, the MHC and costimulatory molecules remain clustered. Thus, transport of peptide-MHC II complexes by DCs not only accomplishes transfer from late endocytic compartments to the plasma membrane, but does so in a manner that selectively concentrates TCR ligands and costimulatory molecules for T cell contact.
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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Animals
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Antibodies, Monoclonal
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Antigen Presentation*
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Antigens, CD / immunology
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Antigens, CD / metabolism
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B-Lymphocytes / immunology
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B-Lymphocytes / metabolism
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B7-2 Antigen
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Biological Transport
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Bridged Bicyclo Compounds, Heterocyclic / pharmacology
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Cell Membrane / immunology
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Cell Membrane / metabolism
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Cells, Cultured
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Dendritic Cells / immunology*
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Dendritic Cells / metabolism*
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Endocytosis
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Endosomes / immunology
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Endosomes / metabolism
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Histocompatibility Antigens Class I / immunology
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Histocompatibility Antigens Class I / metabolism
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Histocompatibility Antigens Class II / immunology
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Histocompatibility Antigens Class II / metabolism*
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Kinetics
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Ligands
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Lipopolysaccharides / immunology
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Lysosomes / immunology
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Lysosomes / metabolism
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Membrane Glycoproteins / immunology
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Membrane Glycoproteins / metabolism
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Mice
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Mice, Inbred C3H
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Muramidase / immunology
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Muramidase / metabolism*
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Peptide Fragments / immunology
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Peptide Fragments / metabolism*
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Receptors, Antigen, T-Cell / metabolism
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Thiazoles / pharmacology
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Thiazolidines
Substances
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Antibodies, Monoclonal
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Antigens, CD
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B7-2 Antigen
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Bridged Bicyclo Compounds, Heterocyclic
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Cd86 protein, mouse
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Histocompatibility Antigens Class I
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Histocompatibility Antigens Class II
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I-Ak antigen
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I-E-antigen
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Ligands
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Lipopolysaccharides
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Membrane Glycoproteins
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Peptide Fragments
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Receptors, Antigen, T-Cell
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Thiazoles
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Thiazolidines
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hen egg lysozyme peptide (46-61)
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Muramidase
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latrunculin B