Abstract
Toll-like receptor (TLR) family acts as pattern recognition receptors for pathogen-specific molecular patterns. We previously showed that TLR2 recognizes Gram-positive bacterial components whereas TLR4 recognizes LPS, a component of Gram-negative bacteria. MyD88 is shown to be an adaptor molecule essential for TLR family signaling. To investigate the role of TLR family in host defense against Gram-positive bacteria, we infected TLR2- and MyD88-deficient mice with Staphylococcus aureus. Both TLR2- and MyD88-deficient mice were highly susceptible to S. aureus infection, with more enhanced susceptibility in MyD88-deficient mice. Peritoneal macrophages from MyD88-deficient mice did not produce any detectable levels of cytokines in response to S. aureus. In contrast, TLR2-deficient macrophages produced reduced, but significant, levels of the cytokines, and TLR4-deficient macrophages produced the same amounts as wild-type cells, indicating that S. aureus is recognized not only by TLR2, but also by other TLR family members except for TLR4.
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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Animals
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Antigens, Differentiation / genetics*
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Antigens, Differentiation / physiology
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Down-Regulation / genetics
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Down-Regulation / immunology
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Drosophila Proteins*
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Genetic Predisposition to Disease*
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Hot Temperature
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Immunity, Innate / genetics
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Interleukin-6 / biosynthesis
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Macrophages, Peritoneal / immunology
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Macrophages, Peritoneal / metabolism
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Membrane Glycoproteins / deficiency*
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Membrane Glycoproteins / genetics*
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Membrane Glycoproteins / physiology
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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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Myeloid Differentiation Factor 88
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Receptors, Cell Surface / deficiency*
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Receptors, Cell Surface / genetics*
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Receptors, Cell Surface / physiology
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Receptors, Immunologic*
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Staphylococcal Infections / genetics*
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Staphylococcal Infections / immunology*
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Staphylococcal Infections / mortality
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Staphylococcus aureus / immunology*
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Survival Analysis
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Toll-Like Receptor 2
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Toll-Like Receptor 4
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Toll-Like Receptors
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Tumor Necrosis Factor-alpha / biosynthesis
Substances
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Adaptor Proteins, Signal Transducing
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Antigens, Differentiation
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Drosophila Proteins
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Interleukin-6
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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 2
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Toll-Like Receptor 4
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Toll-Like Receptors
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Tumor Necrosis Factor-alpha