Abstract
Interleukin-1 receptor-associated kinase (IRAK)-4 is a serine-threonine kinase that plays an important role in innate and adaptive immune responses. While the requirement of IRAK-4 kinase activity has been studied in the context of IL-1R signaling, it is not clear whether IRAK-4 requires its kinase function for all of its roles in the immune system. IRAK-4 kinase-dead knock-in (IRAK-4KD/KD) mice were generated to further elucidate whether IRAK-4 kinase activity is required for IRAK-4 to induce cytokine production. IRAK-4KD/KD mice were impaired in their ability to produce cytokines in response to in vivo challenge with lipopolysaccharide (LPS), a potent TLR4 ligand. Cytokine production was also reduced in macrophages and dendritic cells from IRAK-4KD/KD mice in response to LPS and other TLR ligands. In addition, adaptive immune responses were impaired in IRAK-4KD/KD mice. Although in vitro T cell proliferation in response to TCR activation was unaffected in IRAK-4-deficient mice, in vivo T cell responses to lymphocytic choriomeningitits virus infection were significantly impaired in IRAK-4-knockout mice or mice expressing the kinase-dead mutant of IRAK-4. Collectively, these results indicate that IRAK-4 kinase activity is required for IRAK-4-dependent signaling in innate and adaptive immunity.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antigens, Viral / immunology
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CD4-Positive T-Lymphocytes / immunology
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CD4-Positive T-Lymphocytes / metabolism
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CD8-Positive T-Lymphocytes / immunology
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CD8-Positive T-Lymphocytes / metabolism
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Glycoproteins / immunology
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Immunity, Cellular / immunology*
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Immunity, Innate / immunology*
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Interferon-gamma / metabolism
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Interleukin-1 Receptor-Associated Kinases / genetics
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Interleukin-1 Receptor-Associated Kinases / metabolism*
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Interleukin-6 / blood
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Interleukin-6 / metabolism
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Lipopolysaccharides / pharmacology
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Lymphocyte Activation / immunology
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Lymphocytic Choriomeningitis / immunology
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Lymphocytic Choriomeningitis / virology
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Lymphocytic choriomeningitis virus / immunology
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Macrophages / cytology
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Macrophages / drug effects
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Macrophages / metabolism
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Mice
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Mice, Inbred C57BL
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Mice, Inbred Strains
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Mice, Knockout
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Mice, Transgenic
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Oligodeoxyribonucleotides / pharmacology
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Peptide Fragments / immunology
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Peptidoglycan / pharmacology
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Spleen / cytology
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Spleen / immunology
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Spleen / virology
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T-Lymphocytes, Cytotoxic / immunology
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Teichoic Acids / pharmacology
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Tumor Necrosis Factor-alpha / blood
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Tumor Necrosis Factor-alpha / metabolism
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Viral Proteins / immunology
Substances
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Antigens, Viral
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CPG-oligonucleotide
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Glycoproteins
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Interleukin-6
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Lipopolysaccharides
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Oligodeoxyribonucleotides
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Peptide Fragments
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Peptidoglycan
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Teichoic Acids
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Tumor Necrosis Factor-alpha
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Viral Proteins
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glycoprotein peptide 33-41, Lymphocytic choriomeningitis virus
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lipoteichoic acid
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Interferon-gamma
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Interleukin-1 Receptor-Associated Kinases
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Irak4 protein, mouse