Abstract
The imidazoquinoline compounds imiquimod and R-848 are low-molecular-weight immune response modifiers that can induce the synthesis of interferon-alpha and other cytokines in a variety of cell types. These compounds have potent anti-viral and anti-tumor properties; however, the mechanisms by which they exert their anti-viral activities remain unclear. Here we show that the imidazoquinolines activate immune cells via the Toll-like receptor 7 (TLR7)-MyD88-dependent signaling pathway. In response to the imidazoquinolines, neither MyD88- nor TLR7-deficient mice showed any inflammatory cytokine production by macrophages, proliferation of splenocytes or maturation of dendritic cells. Imidazoquinoline-induced signaling events were also abolished in both MyD88- and TLR7-deficient mice.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing
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Adjuvants, Immunologic
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Aminoquinolines / immunology*
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Animals
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Antigens, Differentiation / metabolism*
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Antiviral Agents / immunology*
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Bone Marrow Cells / immunology
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Dendritic Cells
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Drosophila Proteins*
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Imidazoles / immunology*
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Imiquimod
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Interferon Inducers / immunology
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Macrophages, Peritoneal / immunology
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Membrane Glycoproteins / metabolism*
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Mice
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Mice, Mutant Strains
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Myeloid Differentiation Factor 88
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Receptors, Cell Surface / metabolism*
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Receptors, Immunologic / metabolism*
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Spleen / cytology
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Spleen / immunology
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Toll-Like Receptor 7
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Toll-Like Receptors
Substances
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Adaptor Proteins, Signal Transducing
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Adjuvants, Immunologic
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Aminoquinolines
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Antigens, Differentiation
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Antiviral Agents
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Drosophila Proteins
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Imidazoles
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Interferon Inducers
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Membrane Glycoproteins
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Myd88 protein, mouse
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Myeloid Differentiation Factor 88
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Receptors, Cell Surface
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Receptors, Immunologic
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Toll-Like Receptor 7
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Toll-Like Receptors
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Imiquimod
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resiquimod