Abstract
T cell receptor (TCR) contact with self ligands keeps T cells alive and is shown here to cause naive CD8(+), but not CD4(+), T cells to be hypersensitive to certain gamma(c) cytokines, notably interleukin (IL)-2, IL-15, and IL-7. Hypersensitivity of CD8(+) T cells to IL-2 was dependent on a low-level TCR signal, associated with high expression of CD5 and GM1, a marker for lipid rafts, and was abolished by disruption of lipid rafts. By contrast, CD4(+) T cells expressed low amounts of GM1 and were unresponsive to IL-2. Physiologically, sensitivity to IL-7 and IL-15 maintains survival of resting CD8(+) T cells, whereas sensitivity to IL-2 may be irrelevant for normal homeostasis but crucial for the immune response. Thus, TCR contact with antigen upregulates GM1 and amplifies responsiveness of naive CD8(+) T cells to IL-2, thereby making the cells highly sensitive to exogenous IL-2 from CD4(+) T helper cells.
Copyright 2010 Elsevier Inc. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Autoantigens / immunology
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Autoantigens / metabolism
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CD8-Positive T-Lymphocytes / immunology
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CD8-Positive T-Lymphocytes / metabolism*
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CD8-Positive T-Lymphocytes / pathology
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Cell Survival / immunology
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Cells, Cultured
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Cytokines / immunology
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Cytokines / metabolism*
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Glycosphingolipids / biosynthesis*
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Glycosphingolipids / genetics
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Glycosphingolipids / immunology
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Histocompatibility Antigens / metabolism
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Homeostasis
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Interleukin Receptor Common gamma Subunit / metabolism
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Membrane Microdomains / metabolism*
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Mice
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Mice, Inbred C57BL
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Peptide Fragments / immunology
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Peptide Fragments / metabolism
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Protein Binding / immunology
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Receptors, Antigen, T-Cell / metabolism
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T-Lymphocyte Subsets / immunology
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T-Lymphocyte Subsets / metabolism*
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T-Lymphocyte Subsets / pathology
Substances
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Autoantigens
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Cytokines
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Glycosphingolipids
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Histocompatibility Antigens
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Interleukin Receptor Common gamma Subunit
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Peptide Fragments
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Receptors, Antigen, T-Cell