Interferon-gamma critically determines dendritic cell function
ABSTRACT: A growing body of evidence suggests that inflammatory cytokines have a dualistic role in immunity. In this study, we sought to determine the direct effects IFN-gamma on the differentiation and maturation of human peripheral blood monocyte-derived dendritic cells (moDC). Here, we report that following differentiation of human peripheral-blood monocytes into moDCs with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4, interferon-gamma (IFN-gamma) induces moDC maturation and up-regulates the co-stimulatory markers CD80, CD86, CD95, and MHC Class I, enabling moDCs to effectively generate antigen-specific CD4+ and CD8+ T cell responses for multiple viral and tumor antigens. Interestingly, early exposure of monocytes to high concentrations of IFN-gamma promotes monocyte differentiation into macrophages, despite the presence of GM-CSF and IL-4. However, under low concentrations of IFN-gamma, monocytes continue to differentiate into dendritic cells possessing a unique gene-expression profile, resulting in impairments in subsequent maturation by IFN-gamma and an inability to generate effective antigen-specific CD4+ and CD8+ T cell responses compared to standard moDCs. Monocytes differentiated in the presence of low levels of IFN-gamma downregulate IFN-gamma receptor expression, impairing their response to an inflammatory rechallenge. These findings demonstrate the ability of IFN-gamma to impart differential programs on human moDCs which shape the antigen-specific T cell responses they induce. Timing and intensity of exposure to IFN-gamma can thus determine whether moDCs are tolerogenic or immunostimulating. Human monocyte-derived dendritic cells from 4 healthy donors were differentiated with either GM-CSF and IL-4 (n=4) or GM-CSF, IL-4, and IFN-gamma (n=4). These samples were subsequently hybridized to arrays as 4 biological repeats for each of the two treatment conditions.
Project description:Expression profiles at different time points during dendritic cell differentiation (induced by specific culture conditions) including monocytes as well as expression profiles between monocytes and completely differentiated cells (macrophages at day7 and dendritic cells at day7, respectively) were compared. Monocyte-derived dendritic cells (DC) were obtained by culturing elutriated monocytes with 20U/ml IL-4, 280U/ml GM-CSF and 10% FCS; monocyte-derived macrophages (MAC) were obtained by culturing elutriated monocytes with 2% AB serum. Three to seven biological replicates that are derived from independent healthy donors were included. One-color based gene expression. 2 datasets: dendritic cell kinetic study and comparison of monocyte, macrophage, and dendritic cells
Project description:GM-CSF positve CD4 cells are found at sites of inflammation. The purpose of this study was to understand their transcriptional profile relative to known Th1 and Th17 subsets. Overall design: Human CD4 T cells were isolated by magnetic negative selection and activated with PMA and ionomycin. A cytokine capture assay was used to isolate CD45RA-positive, cytokine negative, IFN-gamma-single-positive, IL-17A-single-positive, GM-CSF-single positive and IL-17A-GM-CSF-double positive cells.
Project description:Macrophages are known to be polarized into inflammatory (M1) and immunoregulatory (M2) cells when they are stimulated by agonists such as IFN-gamma and IL-4, respectively. If circulating monocytes may be polarized in response to T cell signals is often misguidedly deduced from macrophage results. Here the transcriptional responses of human CD14+ monocytes to IFN-gamma and IL-4 were analyzed using whole genome microarrays. A principal component analysis and hierarchical clustering showed that monocyte and macrophage responses were distinct. Monocytes stimulated with IFN-gamma and IL-4 for 6 hours exhibited some features of macrophage polarization. Indeed, when 80 genes considered as M1 and M2 genes were analyzed, we found that M1 genes were modulated in response to IFN-gamma and that M2 genes were modulated in response to IL-4. The M1 polarization of monocytes was transient because only M2 genes were modulated when monocytes were stimulated with IFN-gamma and IL-4 for 18 hours. However, the activation of monocytes by IFN-gamma and IL-4 could not be reduced to M1/M2 polarization status. Indeed, monocytes exhibited early specific signatures composed of 46 and 39 up-regulated genes in response to IFN-gamma and IL-4, respectively, and a late signature common to both molecules that consisted of 57 up-regulated genes. Taken together, these results demonstrated the extreme plasticity of human monocytes and suggested the existence of a core transcriptional termination program. Using early and late signatures might be pertinent to investigate monocyte activation in inflammatory or infectious diseases. Monocytes were stimulated with IFN-gamma (20ng/mL) or IL-4 (20ng/mL) for 6 and 18 hours or culture for 6 and 18 hours without agonist (Unstimulated samples). Monocytes-derived-macrophages (MDM) stimulated with IFN-gamma and IL-4 for 18 hours were used as controls. Each microarray is derived from a single biological sample.
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. Overall design: 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:Macrophage activation is required for the control of innate and adaptive immune responses. The classification in M1 and M2 macrophages based on a combination of small numbers of membrane and soluble markers is operational in murine and human macrophages. If this classification may be extended to circulating monocytes is not elucidated. To answer such question, human monocytes were stimulated for 6 and 18 hours with IFN-gamma and IL-4, two canonical agonists of M1/M2 polarization in macrophages, and gene expression programs were investigated with whole genome microarrays. The temporal analysis of these programs showed marked differences to both IFN-gamma and IL-4. In 6-h stimulated monocytes, gene categories related to inflammatory and immune responses were enriched, and these monocytes exhibited a M1 and M2 polarization in response to IFN-gamma and IL-4, respectively, as found in macrophages. In 18-h stimulated monocytes, the categories related to innate immunity and metabolic pathways were enriched in response to IFN-gamma and IL-4, whereas PPAR signaling pathway was specifically enriched in response to IL-4. In addition, the M1 and M2 polarization induced by IFN-gamma and IL-4, respectively, was replaced by an original transcriptional program that did not depend on IFN-gamma and IL-4. This program appeared as networks around chemokines, NF-kappaB/MAP kinase pathways and MHC class II molecules. These results clearly demonstrated that monocyte activation consisted of an early polarized stage likely involved in effector responses and a delayed stage that may regulate host responses. The establishment of databases on human circulating monocytes using high throughput methods may be critical for pathophysiological and clinical non-invasive studies. Peripheral blood mononuclear cells (PBMCs) were isolated from leukopacks from normal blood donor buffy coats (Etablissement Français du Sang, Marseille, France) by Ficoll density gradient
Project description:Human and murine studies showed that granulocyte macrophage colony-stimulating factor (GM-CSF) exerts beneficial effects in intestinal inflammation. To explore whether GM-CSF mediates its effects via monocytes, we analyzed effects of GM-CSF on monocytes in vitro and assessed the immunomodulatory potential of GM-CSF-activated monocytes (GMaM). We used microarray technology and functional assays to characterize GMaM in vitro and used a mouse model of colitis to study GMaM functions in vivo. Peripheral blood monocytes where cultured 16 h with media containing AB serum (control monocytes) or media containing 10 ng/mL GM-CSF and AB serum (GM-CSF activated monocytes). In three independent experiments, total RNA from GMaM and control monocytes was isolated and processed for microarray hybridization.
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. 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:Variation in individuals' responses to environmental factors is believed to influence susceptibility to complex diseases in humans. The genetic basis of such variation is poorly understood. We measured gene expression from resting and stimulated dendritic cells (DCs) derived from the peripheral blood of healthy individuals. We stimulated the primary DCs with E. coli lipopolysaccharide (LPS), influenza virus or the cytokine IFNβ, and associated genetic variation between individuals with the observed variation in gene expression and gene induction. We collected peripheral blood from each human donor. We isolated peripheral blood mononuclear cells by Ficoll, and magnetically sorted them for CD14+CD16- monocytes. We then differentiated the monocytes into monocyte-derived dendritic cells (MoDCs) by culturing the cells for 7 days with GM-CSF and IL-4. We stimulated the cells with E. coli lipopolysaccharide (LPS) for 2.5 hr or 5 hr, influenza (PR8 dNS1) for 10 hr, or recombinant IFN-beta for 6.5 hr. Finally, we lysed the cells and ran Nanostring on the lysates.
Project description:In this study we compared the response of human monocyte-derived macrophages differentiated with either granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF) to the most common activation stimuli: LPS plus interferon-γ to induce macrophage polarization towards the M1 type or IL-4 to induce macrophage polarization towards the M2a type. Additionally, IL-10 was used to drive M-CSF-primed macrophages into the M2c state. We used the the whole-human genome microarray to determine genes that were up- or downregulated by the activation stimuli in both macrophage lineages, with focus on genes implicated in immune response. Overall design: We generated 7 different macrophage subtypes in three biological replicates: Isolated monocytes of three healthy donors (biological replicates) were differentiated with either 25ng/ml GM-CSF or 50ng/ml M-CSF for 7d. GM-CSF-differentiated macrophages were then either mock-activated with culture medium only (control; condition 1) or activated with 100 ng/ml LPS + 25ng/ml IFNγ (condition 2), or 20 ng/ml IL-4 (condition 3) for 2d (48 h). This activation regime was also used to activate M-CSF-differentiated macrophages, which were in additionally activated with 20 ng/ml IL-10 (condition 4) for 2d (48 h).
Project description:Gene expression induced by IL-4 and IL-4 superkines on CD14+ monocytes cultured in the presence of GM-CSF. Super-4 and KFR signal preferentially through the type I and type II IL-4 receptor, respectively. Five biological replicates (n=5 healthy donors), four conditions: GM-CSF alone or in combination with IL-4, Super-4 or KFR. Two colors: Cy3 for GM-CSF alone, Cy5 for any combination. Cells were cultured for 6 hours with 50 ng/ml of GM-CSF and 20 ng/ml of IL-4, Super-4 or KFR.