Abstract
Although dispensable, costimulation through CD28 facilitates activation of naïve T lymphocytes. CD28 engagement led to the redistribution and clustering of membrane and intracellular kinase-rich raft microdomains at the site of T cell receptor (TCR) engagements. Although not affecting TCR down-regulation, this process led to higher and more stable tyrosine phosphorylation of several substrates and higher consumption of Lck. These results may provide a general mechanism for amplifying receptor signaling by reorganization of membrane microdomains.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Antigen-Presenting Cells / immunology
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CD28 Antigens / immunology
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CD28 Antigens / metabolism*
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CD3 Complex / immunology
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Cell Membrane / metabolism
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G(M1) Ganglioside / metabolism
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Humans
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Lymphocyte Activation*
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Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / metabolism
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Membrane Lipids / metabolism*
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Phosphorylation
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Phosphotyrosine / metabolism
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Receptors, Antigen, T-Cell / immunology
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Receptors, Antigen, T-Cell / metabolism*
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Signal Transduction
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T-Lymphocytes / immunology*
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T-Lymphocytes / metabolism
Substances
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CD28 Antigens
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CD3 Complex
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Membrane Lipids
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Receptors, Antigen, T-Cell
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Phosphotyrosine
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G(M1) Ganglioside
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Lymphocyte Specific Protein Tyrosine Kinase p56(lck)