22 research outputs found

    Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists

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    <p>Abstract</p> <p>Background</p> <p>Plasmacytoid Dendritic Cells (pDC) comprise approximately 0.2 to 0.8% of the blood mononuclear cells and are the primary type 1 interferon (IFN), producing cells, secreting high levels of IFN in response to viral infections. Plasmacytoid dendritic cells express predominantly TLRs 7 & 9, making them responsive to ssRNA and CpG DNA. The objective of this study was to evaluate the molecular and cellular processes altered upon stimulation of pDC with synthetic TLR 7 and TLR 7/8 agonists. To this end, we evaluated changes in global gene expression upon stimulation of 99.9% pure human pDC with the TLR7 selective agonists 3M-852A, and the TLR7/8 agonist 3M-011.</p> <p>Results</p> <p>Global gene expression was evaluated using the Affymetrix U133A GeneChip<sup>® </sup>and selected genes were confirmed using real time TaqMan<sup>® </sup>RTPCR. The gene expression profiles of the two agonists were similar indicating that changes in gene expression were solely due to stimulation through TLR7. Type 1 interferons were among the highest induced genes and included IFNB and multiple IFNα subtypes, IFNα2, α5, α6, α8, α1/13, α10, α14, α16, α17, α21. A large number of chemokines and co-stimulatory molecules as well as the chemokine receptor CCR7 were increased in expression indicating maturation and change in the migratory ability of pDC. Induction of an antiviral state was shown by the expression of several IFN-inducible genes with known anti-viral activity. Further analysis of the data using the pathway analysis tool MetaCore gave insight into molecular and cellular processes impacted. The analysis revealed transcription networks that show increased expression of signaling components in TLR7 and TLR3 pathways, and the cytosolic anti-viral pathway regulated by RIG1 and MDA5, suggestive of optimization of an antiviral state targeted towards RNA viruses. The analysis also revealed increased expression of a network of genes important for protein ISGylation as well as an anti-apoptotic and pro-survival gene expression program.</p> <p>Conclusion</p> <p>Thus this study demonstrates that as early as 4 hr post stimulation, synthetic TLR7 agonists induce a complex transcription network responsible for activating pDC for innate anti-viral immune responses with optimized responses towards RNA viruses, increased co-stimulatory capacity, and increased survival.</p

    Immune-mediated changes in actinic keratosis following topical treatment with imiquimod 5% cream

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    BACKGROUND: The objective of this study was to identify the molecular processes responsible for the anti-lesional activity of imiquimod in subjects with actinic keratosis using global gene expression profiling. METHODS: A double-blind, placebo-controlled, randomized study was conducted to evaluate gene expression changes in actinic keratosis treated with imiquimod 5% cream. Male subjects (N = 17) with ≥ 5 actinic keratosis on the scalp applied placebo cream or imiquimod 3 times a week on nonconsecutive days for 4 weeks. To elucidate the molecular processes involved in actinic keratosis lesion regression by imiquimod, gene expression analysis using oligonucleotide arrays and real time reverse transcriptase polymerase chain reaction were performed on shave biopsies of lesions taken before and after treatment. RESULTS: Imiquimod modulated the expression of a large number of genes important in both the innate and adaptive immune response, including increased expression of interferon-inducible genes with known antiviral, anti-proliferative and immune modulatory activity, as well as various Toll-like receptors. In addition, imiquimod increased the expression of genes associated with activation of macrophages, dendritic cells, cytotoxic T cells, and natural killer cells, as well as activation of apoptotic pathways. CONCLUSION: Data suggest that topical application of imiquimod stimulates cells in the skin to secrete cytokines and chemokines that lead to inflammatory cell influx into the lesions and subsequent apoptotic and immune cell-mediated destruction of lesions

    Woubalem Birmachu

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    Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists-3

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    <p><b>Copyright information:</b></p><p>Taken from "Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists"</p><p>http://www.biomedcentral.com/1471-2172/8/26</p><p>BMC Immunology 2007;8():26-26.</p><p>Published online 12 Oct 2007</p><p>PMCID:PMC2175514.</p><p></p>and 3M-011 using the Affymetrix GeneChip U133A as described in Methods. D1 and D2, designate two different donors for pDC preparation in which the pDC purity was > 99%. Global gene expression was determined using the Affymetrix U133A GeneChip. Two-way hierarchical clustering was performed as described in the Methods section, using the Unweighted Pair-Group Method with Arithmetic mean (UPGMA) and the Euclidean similarity measure. The log2 fold change values were used for the analysis. Insert bar chart shows the expression change scale with red, green, and white signifying increased, decreased, and unchanged expression, respectively. Expression changes were evaluated with respect to vehicle stimulated pDC from the same donor. Expression changes for the 680 genes are documented in Additional File

    Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists-7

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    <p><b>Copyright information:</b></p><p>Taken from "Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists"</p><p>http://www.biomedcentral.com/1471-2172/8/26</p><p>BMC Immunology 2007;8():26-26.</p><p>Published online 12 Oct 2007</p><p>PMCID:PMC2175514.</p><p></p> 3M-852A and 3M-011. The network was generated from a list of genes with GO process classification of anti-apoptosis, using the shortest path algorithm. The network highlights the large number of anti-apoptotic genes that are increased in expression with a concomitant decrease in expression of key pro-apoptotic genes including several that are transscriptionally regulated by p53. Remaining network details are as described in Figure 6

    Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists-2

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    <p><b>Copyright information:</b></p><p>Taken from "Transcriptional networks in plasmacytoid dendritic cells stimulated with synthetic TLR 7 agonists"</p><p>http://www.biomedcentral.com/1471-2172/8/26</p><p>BMC Immunology 2007;8():26-26.</p><p>Published online 12 Oct 2007</p><p>PMCID:PMC2175514.</p><p></p>on using a Luminex 25-Plex assay. (A) Secreted TNFα, IL8, IFNα, MIP-1α, MIP-1β and IL6. (B) secreted IL1β, IL2R, IL12P70, Rantes, GM-CSF, MCP-1, and IP-10. Dotted bars, vehicle stimulated samples; hatched bars, 3M-852A-stimulated samples and solid bars, 3M-011-stimulated samples. The results are expressed as mean + SD, n = 2 donors
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