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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
8
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pubmed:dateCreated |
1993-11-9
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pubmed:abstractText |
Exogenous protein Ag are processed within endocytic compartments to produce peptides that bind to class II MHC (MHC-II) molecules for presentation to T cells. We have now identified a subcellular compartment in which immunogenic peptides bind to MHC-II as a subset of high density lysosomes. Immunoelectron microscopy of whole cells and dense Percoll gradient subcellular fractions showed early tubulovesicular lysosomes with high levels of MHC-II. Typical mature lysosomes contained less MHC-II. Pulse-chase biosynthetic labeling of macrophages followed by immunoprecipitation of MHC-II from dense lysosomal fractions showed that MHC-II molecules targeted efficiently to lysosomes after biosynthesis. Moreover, lysosomal MHC-II molecules were rapidly loaded with immunogenic peptide (as detected by T cells) soon after exposure of macrophages to Ag and before similar expression of peptide-MHC-II complexes on the plasma membrane; this loading was blocked at 18 degrees C. We propose that nascent MHC-II molecules target to early tubulovesicular lysosomes and bind immunogenic peptides therein; the resulting peptide-MHC-II complexes are then transported to the plasma membrane.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0022-1767
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
151
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3988-98
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8409381-Animals,
pubmed-meshheading:8409381-Antigen Presentation,
pubmed-meshheading:8409381-Biological Transport,
pubmed-meshheading:8409381-Cells, Cultured,
pubmed-meshheading:8409381-Histocompatibility Antigens Class II,
pubmed-meshheading:8409381-Lysosomes,
pubmed-meshheading:8409381-Macrophages, Peritoneal,
pubmed-meshheading:8409381-Mice,
pubmed-meshheading:8409381-Mice, Inbred CBA,
pubmed-meshheading:8409381-Microscopy, Immunoelectron,
pubmed-meshheading:8409381-Peptides,
pubmed-meshheading:8409381-T-Lymphocytes
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pubmed:year |
1993
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pubmed:articleTitle |
Immunogenic peptides bind to class II MHC molecules in an early lysosomal compartment.
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pubmed:affiliation |
Institute of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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