Abstract
Dendritic cells (DCs) and macrophages (MFs) are important multifunctional immune cells. Like other cell types, they express hundreds of different microRNAs (miRNAs) that are recently discovered post-transcriptional regulators of gene expression. Here we present updated miRNA expression profiles of monocytes, DCs and MFs. Compared with monocytes, ∼50 miRNAs were found to be differentially expressed in immature and mature DCs or MFs, with major expression changes occurring during the differentiation. Knockdown of DICER1, a protein needed for miRNA biosynthesis, led to lower DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) and enhanced CD14 protein levels, confirming the importance of miRNAs in DC differentiation in general. Inhibition of the two most highly up-regulated miRNAs, miR-511 and miR-99b, also resulted in reduced DC-SIGN level. Prediction of miRNA-511 targets revealed a number of genes with known immune functions, of which TLR4 and CD80 were validated using inhibition of miR-511 in DCs and luciferase assays in HEK293 cells. Interestingly, under the cell cycle arrest conditions, miR-511 seems to function as a positive regulator of TLR4. In conclusion, we have identified miR-511 as a novel potent modulator of human immune response. In addition, our data highlight that miRNA influence on gene expression is dependent on the cellular environment.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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B7-1 Antigen / genetics
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B7-1 Antigen / immunology
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B7-1 Antigen / metabolism
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Cell Adhesion Molecules / genetics
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Cell Adhesion Molecules / immunology
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Cell Adhesion Molecules / metabolism
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Cell Differentiation / physiology
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DEAD-box RNA Helicases / genetics
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DEAD-box RNA Helicases / immunology
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DEAD-box RNA Helicases / metabolism
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Dendritic Cells / cytology
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Dendritic Cells / immunology
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Dendritic Cells / metabolism*
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Gene Expression Profiling
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Gene Expression Regulation / physiology*
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Gene Knockdown Techniques
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HEK293 Cells
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Humans
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Lectins, C-Type / genetics
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Lectins, C-Type / immunology
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Lectins, C-Type / metabolism
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Lipopolysaccharide Receptors / genetics
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Lipopolysaccharide Receptors / immunology
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Lipopolysaccharide Receptors / metabolism
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Macrophages / cytology
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Macrophages / immunology
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Macrophages / metabolism*
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MicroRNAs / biosynthesis*
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MicroRNAs / genetics
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MicroRNAs / immunology
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MicroRNAs / metabolism
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Monocytes / cytology
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Monocytes / immunology
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Monocytes / metabolism*
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Receptors, Cell Surface / genetics
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Receptors, Cell Surface / immunology
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Receptors, Cell Surface / metabolism
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Ribonuclease III / genetics
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Ribonuclease III / immunology
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Ribonuclease III / metabolism
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Toll-Like Receptor 4 / biosynthesis*
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Toll-Like Receptor 4 / genetics
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Toll-Like Receptor 4 / immunology
Substances
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B7-1 Antigen
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Cell Adhesion Molecules
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DC-specific ICAM-3 grabbing nonintegrin
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Lectins, C-Type
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Lipopolysaccharide Receptors
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MicroRNAs
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Receptors, Cell Surface
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TLR4 protein, human
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Toll-Like Receptor 4
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DICER1 protein, human
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Ribonuclease III
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DEAD-box RNA Helicases