Project description:Irradiated granulocyte macrophage-colony stimulating factor (GM-CSF)-transduced autologous tumor cells induce substantial antitumor immunity through the maturation and migration of dendritic cells (DCs). However, little is known about the key molecules involved in GM-CSF-sensitized DCs (GM-DCs) in tumor draining lymph nodes (TDLNs). We initially confirmed that mice subcutaneously injected with poorly immunogenic syngeneic Lewis lung carcinoma (LLC) cells transduced with Sendai virus encoding GM-CSF (LLC/SeV/GM) significantly rejected the tumor growth. Using microarray expression profiling, we obtained a large number of gene expression data files from GM-DCs and control DCs in TDLNs, and subjected them to network-based cluster analysis and unexpectedly unraveled the expression levels of type I IFNs-related genes specifically expressed in plasmacytoid DCs (pDC) were robustly up-regulated in GM-DCs. In vivo depletion assay showed that pDC-depleted mice treated with subcutaneous LLC/SeV/GM cells abrogated the antitumor effects observed in control mice. Moreover combination use of imiquimod for TLR7 triggering on pDC with irradiated LLC/SeV/GM cells induced a significant therapeutic antitumor effect with marked induction of CD9+ pDC with antitumor phenotype, whereas other control mice groups had only minimal to-modest antitumor responses, implicating that this combined vaccine strategy using imiquimod could be promising for improvement of GM-CSF-induced antitumor immunity.
Project description:Irradiated granulocyte macrophage-colony stimulating factor (GM-CSF)-transduced autologous tumor cells induce substantial antitumor immunity through the maturation and migration of dendritic cells (DCs). However, little is known about the key molecules involved in GM-CSF-sensitized DCs (GM-DCs) in tumor draining lymph nodes (TDLNs). We initially confirmed that mice subcutaneously injected with poorly immunogenic syngeneic Lewis lung carcinoma (LLC) cells transduced with Sendai virus encoding GM-CSF (LLC/SeV/GM) significantly rejected the tumor growth. Using microarray expression profiling, we obtained a large number of gene expression data files from GM-DCs and control DCs in TDLNs, and subjected them to network-based cluster analysis and unexpectedly unraveled the expression levels of type I IFNs-related genes specifically expressed in plasmacytoid DCs (pDC) were robustly up-regulated in GM-DCs. In vivo depletion assay showed that pDC-depleted mice treated with subcutaneous LLC/SeV/GM cells abrogated the antitumor effects observed in control mice. Moreover combination use of imiquimod for TLR7 triggering on pDC with irradiated LLC/SeV/GM cells induced a significant therapeutic antitumor effect with marked induction of CD9+ pDC with antitumor phenotype, whereas other control mice groups had only minimal to-modest antitumor responses, implicating that this combined vaccine strategy using imiquimod could be promising for improvement of GM-CSF-induced antitumor immunity. Mouse GM-CSF induced gene expression in mature dendritic cells in tumor draining lymph nodes from C57/BL6N female mouse was measured at 2 days after s.c. tumor challenge with GM-CSF gene-transduced LLC cells (LLC/SeV/GM) or control cells (LLC, LLC/SeV/GFP).
Project description:Comparison of the RNA expression profiles of CD14+ monocytes from human peripheral blood with derived dendritic cells (DCs) and macrophages (MACs) obtained by exposure with GM-CSF/IL-4 and GM-CSF, respectively, and with mature DCs and MACs after lipopolysaccharide (LPS) exposure The expression profiles of RNA of human CD14+ monocytes were compared with derived immature dendritic cells (iDCs) and macrophages (iMACs) following GM-CSF/IL-4 and GM-CSF incubation, and then activation/maturation with lypopolysaccharyde (LPS) using the Affymetrix PrimeView Human Gene Expression array (Affymetrix, Santa Clara, CA). This platform allows the interrogation of >36,000 transcrits and variants per sample. The samples were hybridized in the array following the manufacturerâ??s instructions. Total RNA isolated by standard procedures from CD14+ cells (total monocytes, MOs) corresponding to three sets of samples of monocytes (MOs), derived immature DCs and MACs (iDCS and iMACS) and activated/mature DCs and MACs following incubation with LPS (mDCS and mMACs)
Project description:To assess the effect of carbon nanotubes substrated on dendritic cell (DCs) properties, DCs were generated from human monocytes of healthy donors as previously described (Aldinucci A et al, 2010). In particular, isolated monocytes were cultured for 6 days in medium supplemented with GM-CSF (1000U/ml) and IL-4 (1000U/ml), in presence or absence of multi-walled carbon nanotubes (MWCNT); then DCs were activated by 24 hours of incubation with LPS (1ug/ml). RNA extracted from floating and CNT adherent DCs were then used for transcriptional profilingthen used
Project description:Comparison of the DNA methylation profiles of CD14+ monocytes from human peripheral blood with derived dendritic cells (DCs) and macrophages (MACs) obtained by exposure with GM-CSF/IL-4 and GM-CSF, respectively, and with mature DCs and MACs after lipopolysaccharide (LPS) exposure The methylation profiles of bisulfite-modified DNA of human CD14+ monocytes were compared with derived immature dendritic cells (iDCs) and macrophages (iMACs) following GM-CSF/IL-4 and GM-CSF incubation, and then activation/maturation with lypopolysaccharyde (LPS) using the Infinium HumanMethylation450 BeadChips (Illumina, Inc., San Diego, CA,). This platform allows the interrogation of >485,000 methylation sites per sample at single-nucleotide resolution, and comprises an average of 17 CpG sites per gene in the 99% of RefSeq genes. 96% of CpG islands are covered, with additional coverage in CpG island shores and the regions flanking them. The samples were hybridized in the array following the manufacturerâs instructions. Total DNA isolated by standard procedures from CD14+ cells (total monocytes, MOs) corresponding to three sets of samples of monocytes (MOs), derived immature DCs and MACs (iDCS and iMACS) and activated/mature DCs and MACs following incubation with LPS (mDCS and mMACs)
Project description:Monocytes can differentiate into macrophages or dendritic cells. When treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) monocytes differentiate into macrophage-like cells. Here, we report that pharmacological blockade of the nuclear receptor PPARγ in monocytes turns GM-CSF into a potent inducer of dendritic cell (Mo-DC) differentiation. Remarkably, simultaneous blockade of PPARγ and mTORC1 in the presence of GM-CSF promoted the differentiation of Mo-DCs with a stronger phenotypic stability and immunogenic profile when compared with canonical Mo-DCs differentiated by treatment with GM-CSF and IL-4. Moreover, and in contrast with the observations made with GM-CSF and IL-4, blockade of PPARγ and mTORC1 was shown to be able to induce the differentiation of monocyte-derived macrophages (Mo-Macs) into Mo-DCs. Transcriptional profiling performed at either early time points, as well as at the end of the differentiation process, revealed marked differences in the gene expression signature between Mo-DCs induced by GM-CSF and IL-4 and Mo-DCs induced by GM-CSF in the presence of PPARγ and/or mTORC1 inhibitors, thus suggesting diverging differentiation pathways. Our observations might contribute, not only to a better understanding of the mechanisms involved in Mo-DCs differentiation but also to improving the efficacy of both, DC vaccines and therapies focusing on the modulation of myeloid cell functions.
Project description:Lipopolysaccharide (LPS) can either promote or prevent T helper-2 (Th2) cell-allergic responses. However, the underlying mechanism remains unknown. We show here that LPS activity switches from pro-pathogenic to protective depending on the production of GM-CSF by non-classical monocytes. In the absence of GM-CSF, LPS can favor pathogenic Th2 cell responses by supporting the trafficking of lung migratory dendritic cells (mDC2s) into the lung-draining lymph node. However, when non-classical monocytes produce GM-CSF, LPS and GM-CSF synergize to differentiate monocyte-derived DCs (moDCs) that instruct mDC2s for Th2 cell suppression. Importantly, only allergens with cysteine protease activity trigger GM-CSF production by non-classical monocytes. Hence, the therapeutic effect of LPS is restricted to allergens with this enzymatic activity. Treatment with GM-CSF, however, restores the protective effects of LPS. Thus, GM-CSF produced by non-classical monocytes acts as a rheostat that fine-tunes the pathogenic and therapeutic functions of LPS.
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive M-NM-1-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-M-NM-3-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response. Total 6 samples were examined. Splenic dendritic cells were treated with IL-21 and/or GM-CSF studying STAT3 and STAT5B binding in the genome
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive α-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-γ-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response.
Project description:Comparison of the RNA expression profiles of CD14+ monocytes from human peripheral blood with derived dendritic cells (DCs) and macrophages (MACs) obtained by exposure with GM-CSF/IL-4 and GM-CSF, respectively, and with mature DCs and MACs after lipopolysaccharide (LPS) exposure The expression profiles of RNA of human CD14+ monocytes were compared with derived immature dendritic cells (iDCs) and macrophages (iMACs) following GM-CSF/IL-4 and GM-CSF incubation, and then activation/maturation with lypopolysaccharyde (LPS) using the Affymetrix PrimeView Human Gene Expression array (Affymetrix, Santa Clara, CA). This platform allows the interrogation of >36,000 transcrits and variants per sample. The samples were hybridized in the array following the manufacturer’s instructions.