Abstract
The binding of NKG2D to its ligands strengthens the cross-talk between natural killer (NK) cells and dendritic cells, particularly at early stages, before the initiation of the adaptive immune response. We found that retinoic acid early transcript-1ε (RAE-1ε), one of the ligands of NKG2D, was persistently expressed on antigen-presenting cells in a transgenic mouse model (pCD86-RAE-1ε). By contrast, NKG2D expression on NK cells, NKG2D-dependent cytotoxicity and tumour rejection, and dextran sodium sulphate-induced colitis were all down-regulated in this mouse model. The down-regulation of NKG2D on NK cells was reversed by stimulation with poly (I:C). The ectopic expression of RAE-1ε on dendritic cells maintained NKG2D expression levels and stimulated the activity of NK cells ex vivo, but the higher frequency of CD4(+) NKG2D(+) T cells in transgenic mice led to the down-regulation of NKG2D on NK cells in vivo. Hence, high levels of RAE-1ε expression on antigen-presenting cells would be expected to induce the down-regulation of NK cell activation by a regulatory T-cell subset.
Keywords:
NKG2D; natural killer; regulation; retinoic acid early transcript-1; transgenic mouse.
© 2013 John Wiley & Sons Ltd.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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B7-2 Antigen / genetics*
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CD4-Positive T-Lymphocytes / drug effects
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CD4-Positive T-Lymphocytes / immunology
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CD4-Positive T-Lymphocytes / metabolism*
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Cells, Cultured
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Colitis / chemically induced
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Colitis / immunology
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Colitis / metabolism
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Colitis / prevention & control
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Dendritic Cells / immunology
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Dendritic Cells / metabolism
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Dextran Sulfate
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Disease Models, Animal
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Down-Regulation
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Killer Cells, Natural / drug effects
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Killer Cells, Natural / immunology
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Killer Cells, Natural / metabolism*
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Ligands
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Melanoma, Experimental / immunology
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Melanoma, Experimental / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mice
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Mice, Inbred C57BL
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Mice, Transgenic
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NK Cell Lectin-Like Receptor Subfamily K / genetics
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NK Cell Lectin-Like Receptor Subfamily K / metabolism*
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Poly I-C / pharmacology
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Promoter Regions, Genetic
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T-Lymphocytes, Regulatory / immunology
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T-Lymphocytes, Regulatory / metabolism
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Time Factors
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Transforming Growth Factor beta / metabolism
Substances
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B7-2 Antigen
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Cd86 protein, mouse
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Klrk1 protein, mouse
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Ligands
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Membrane Proteins
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NK Cell Lectin-Like Receptor Subfamily K
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Raet1e protein, mouse
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Transforming Growth Factor beta
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Dextran Sulfate
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Poly I-C