Abstract
Positive selection occurs in the thymic cortex, but critical maturation events occur later in the medulla. Here we defined the precise stage at which T cells acquired competence to proliferate and emigrate. Transcriptome analysis of late gene changes suggested roles for the transcription factor NF-κB and interferon signaling. Mice lacking the inhibitor of NF-κB (IκB) kinase (IKK) kinase TAK1 underwent normal positive selection but exhibited a specific block in functional maturation. NF-κB signaling provided protection from death mediated by the cytokine TNF and was required for proliferation and emigration. The interferon signature was independent of NF-κB; however, thymocytes deficient in the interferon-α (IFN-α) receptor IFN-αR showed reduced expression of the transcription factor STAT1 and phenotypic abnormality but were able to proliferate. Thus, both NF-κB and tonic interferon signals are involved in the final maturation of thymocytes into naive T cells.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Animals
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Cell Differentiation / genetics
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Cell Differentiation / immunology*
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Cell Movement / genetics
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Cell Movement / immunology
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Cell Proliferation / genetics
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Flow Cytometry
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MAP Kinase Kinase Kinases / genetics
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MAP Kinase Kinase Kinases / immunology
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MAP Kinase Kinase Kinases / metabolism
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Mice, Inbred C57BL
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Mice, Knockout
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Mice, Transgenic
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NF-kappa B / genetics
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NF-kappa B / immunology*
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NF-kappa B / metabolism
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Oligonucleotide Array Sequence Analysis
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Receptor, Interferon alpha-beta / immunology*
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Receptor, Interferon alpha-beta / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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STAT1 Transcription Factor / genetics
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STAT1 Transcription Factor / immunology
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STAT1 Transcription Factor / metabolism
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T-Lymphocytes / immunology*
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T-Lymphocytes / metabolism
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Thymocytes / immunology
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Thymocytes / metabolism
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Thymus Gland / cytology
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Thymus Gland / immunology*
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Thymus Gland / metabolism
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Transcriptome / genetics
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Transcriptome / immunology
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Tumor Necrosis Factor-alpha / genetics
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Tumor Necrosis Factor-alpha / immunology
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Tumor Necrosis Factor-alpha / metabolism
Substances
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NF-kappa B
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STAT1 Transcription Factor
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Stat1 protein, mouse
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Tumor Necrosis Factor-alpha
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Receptor, Interferon alpha-beta
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MAP Kinase Kinase Kinases
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MAP kinase kinase kinase 7