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Toll-like receptor 4 engagement drives differentiation of human and murine dendritic cells from a pro- into an anti-inflammatory mode.

Luger R, Valookaran S, Knapp N, Vizzardelli C, Dohnal AM, Felzmann T - PLoS ONE (2013)

Bottom Line: T-cells, when contacted with DCs during their anti-inflammatory phase loose their proliferative capacity and develop regulatory T-cell (Treg) -like anti-inflammatory functions indicated by IL-10 secretion and elevated FoxP3 levels.When T-cells are separated from DCs within 24 hours, they are spared from the anti-inflammatory DC activity.We conclude that, in addition to differentiation of DCs into distinct subsets, the observed sequential functional phases of DC differentiation permit the fine-tuning of an immune response.

View Article: PubMed Central - PubMed

Affiliation: St. Anna Children's Cancer Research Institute, Laboratory of Tumor Immunology, Department of Pediatrics, Medical University Vienna, Austria.

ABSTRACT
The dendritic cell (DC) coordinates innate and adaptive immunity to fight infections and cancer. Our observations reveal that DCs exposed to the microbial danger signal lipopolysaccharide (LPS) in the presence of interferon-γ (IFN-γ) acquire a continuously changing activation/maturation phenotype. The DCs' initial mode of action is pro-inflammatory via up-regulation among others of the signaling molecule interleukin (IL) 12, which polarizes IFN-γ secreting type 1 helper T-cells (Th1). Within 24 hours the same DC switches from the pro- into an anti-inflammatory phenotype. This is mediated by autocrine IL-10 release and secretion of soluble IL-2 receptor alpha (sIL-2RA) molecules. T-cells, when contacted with DCs during their anti-inflammatory phase loose their proliferative capacity and develop regulatory T-cell (Treg) -like anti-inflammatory functions indicated by IL-10 secretion and elevated FoxP3 levels. Studying the kinetics of IL-12 and IL-10 expression from LPS/IFN-γ activated myeloid DCs on a single cell level confirmed these observations. When T-cells are separated from DCs within 24 hours, they are spared from the anti-inflammatory DC activity. We conclude that, in addition to differentiation of DCs into distinct subsets, the observed sequential functional phases of DC differentiation permit the fine-tuning of an immune response. A better understanding of time-kinetic DC features is required for optimally exploiting the therapeutic capacity of DCs in cancer immune therapy.

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Detection of immune-modifying molecules in maturing human DCs.(A) DC membrane molecule expression at 6 (dotted line) and 24 hours (black line) after LPS or LPS/IFN-γ exposure compared to un-stimulated human DCs (filled gray histograms). One representative out of 3 experiments is shown (donor C). (B) LPS or LPS/IFN-γ induced IL-12 (white bars) or IL-10 (grey bars) protein secretion was measured 48 hours after exposure to the different stimuli (p = 0.006). As a control, DCs were stimulated with IFN-γ or cultured without stimulation for 48 hours. Data are pooled from 4 experiments and depicted as median±SEM (donors A–D). Asterisks indicate cytokine levels below the detection limit of the assay.
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pone-0054879-g001: Detection of immune-modifying molecules in maturing human DCs.(A) DC membrane molecule expression at 6 (dotted line) and 24 hours (black line) after LPS or LPS/IFN-γ exposure compared to un-stimulated human DCs (filled gray histograms). One representative out of 3 experiments is shown (donor C). (B) LPS or LPS/IFN-γ induced IL-12 (white bars) or IL-10 (grey bars) protein secretion was measured 48 hours after exposure to the different stimuli (p = 0.006). As a control, DCs were stimulated with IFN-γ or cultured without stimulation for 48 hours. Data are pooled from 4 experiments and depicted as median±SEM (donors A–D). Asterisks indicate cytokine levels below the detection limit of the assay.

Mentions: Exposure of immature DCs to maturation agents triggers up-regulated expression density of characteristic DC membrane molecules in humans and mice. At 24 hours after initiation of maturation with LPS or LPS/IFN-γ we confirmed enhanced expression of the DC marker molecule CD83, the co-stimulatory molecules CD80 and CD86, the maturation molecule CD40, and of MHC I and II molecules in human monocyte derived DCs. The induction of these molecules became evident 6 hours after exposure to the maturation agents (figure 1A) and was found on bone-marrow derived murine DCs as well (BM-DCs, data not shown). Generally, addition of IFN-γ to the LPS stimulus caused more pronounced CD80, CD86 and MHC I/II expression, and enhanced CD83 expression. DCs, stimulated with a mediator cocktail comprised of tumor necrosis factor alpha (TNF-α), prostaglandin (PG) -E2, IL-1β, and IL-6 exhibited a membrane molecule expression pattern similar to LPS or LPS/IFN-γ exposed DCs (data not shown).


Toll-like receptor 4 engagement drives differentiation of human and murine dendritic cells from a pro- into an anti-inflammatory mode.

Luger R, Valookaran S, Knapp N, Vizzardelli C, Dohnal AM, Felzmann T - PLoS ONE (2013)

Detection of immune-modifying molecules in maturing human DCs.(A) DC membrane molecule expression at 6 (dotted line) and 24 hours (black line) after LPS or LPS/IFN-γ exposure compared to un-stimulated human DCs (filled gray histograms). One representative out of 3 experiments is shown (donor C). (B) LPS or LPS/IFN-γ induced IL-12 (white bars) or IL-10 (grey bars) protein secretion was measured 48 hours after exposure to the different stimuli (p = 0.006). As a control, DCs were stimulated with IFN-γ or cultured without stimulation for 48 hours. Data are pooled from 4 experiments and depicted as median±SEM (donors A–D). Asterisks indicate cytokine levels below the detection limit of the assay.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3569454&req=5

pone-0054879-g001: Detection of immune-modifying molecules in maturing human DCs.(A) DC membrane molecule expression at 6 (dotted line) and 24 hours (black line) after LPS or LPS/IFN-γ exposure compared to un-stimulated human DCs (filled gray histograms). One representative out of 3 experiments is shown (donor C). (B) LPS or LPS/IFN-γ induced IL-12 (white bars) or IL-10 (grey bars) protein secretion was measured 48 hours after exposure to the different stimuli (p = 0.006). As a control, DCs were stimulated with IFN-γ or cultured without stimulation for 48 hours. Data are pooled from 4 experiments and depicted as median±SEM (donors A–D). Asterisks indicate cytokine levels below the detection limit of the assay.
Mentions: Exposure of immature DCs to maturation agents triggers up-regulated expression density of characteristic DC membrane molecules in humans and mice. At 24 hours after initiation of maturation with LPS or LPS/IFN-γ we confirmed enhanced expression of the DC marker molecule CD83, the co-stimulatory molecules CD80 and CD86, the maturation molecule CD40, and of MHC I and II molecules in human monocyte derived DCs. The induction of these molecules became evident 6 hours after exposure to the maturation agents (figure 1A) and was found on bone-marrow derived murine DCs as well (BM-DCs, data not shown). Generally, addition of IFN-γ to the LPS stimulus caused more pronounced CD80, CD86 and MHC I/II expression, and enhanced CD83 expression. DCs, stimulated with a mediator cocktail comprised of tumor necrosis factor alpha (TNF-α), prostaglandin (PG) -E2, IL-1β, and IL-6 exhibited a membrane molecule expression pattern similar to LPS or LPS/IFN-γ exposed DCs (data not shown).

Bottom Line: T-cells, when contacted with DCs during their anti-inflammatory phase loose their proliferative capacity and develop regulatory T-cell (Treg) -like anti-inflammatory functions indicated by IL-10 secretion and elevated FoxP3 levels.When T-cells are separated from DCs within 24 hours, they are spared from the anti-inflammatory DC activity.We conclude that, in addition to differentiation of DCs into distinct subsets, the observed sequential functional phases of DC differentiation permit the fine-tuning of an immune response.

View Article: PubMed Central - PubMed

Affiliation: St. Anna Children's Cancer Research Institute, Laboratory of Tumor Immunology, Department of Pediatrics, Medical University Vienna, Austria.

ABSTRACT
The dendritic cell (DC) coordinates innate and adaptive immunity to fight infections and cancer. Our observations reveal that DCs exposed to the microbial danger signal lipopolysaccharide (LPS) in the presence of interferon-γ (IFN-γ) acquire a continuously changing activation/maturation phenotype. The DCs' initial mode of action is pro-inflammatory via up-regulation among others of the signaling molecule interleukin (IL) 12, which polarizes IFN-γ secreting type 1 helper T-cells (Th1). Within 24 hours the same DC switches from the pro- into an anti-inflammatory phenotype. This is mediated by autocrine IL-10 release and secretion of soluble IL-2 receptor alpha (sIL-2RA) molecules. T-cells, when contacted with DCs during their anti-inflammatory phase loose their proliferative capacity and develop regulatory T-cell (Treg) -like anti-inflammatory functions indicated by IL-10 secretion and elevated FoxP3 levels. Studying the kinetics of IL-12 and IL-10 expression from LPS/IFN-γ activated myeloid DCs on a single cell level confirmed these observations. When T-cells are separated from DCs within 24 hours, they are spared from the anti-inflammatory DC activity. We conclude that, in addition to differentiation of DCs into distinct subsets, the observed sequential functional phases of DC differentiation permit the fine-tuning of an immune response. A better understanding of time-kinetic DC features is required for optimally exploiting the therapeutic capacity of DCs in cancer immune therapy.

Show MeSH
Related in: MedlinePlus