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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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Related in: MedlinePlus

Blockade of CD40/CD40L signaling in short- versus long-term DC/T-cell Co-cultures.(A) CD40L expression on CD4+ T-cells activated after 2, 4 and 6 hours of CD3/CD28 cross-linking is shown. One representative out of 4 experiments is depicted. (B) Short- or long-term co-culture of CD3+ T-cells and DCs, activated with LPS/IFN-γ for 6 hours, in the presence of blocking CD40 and CD40L monoclonal antibodies (black bars) or isotype control immunoglobulins (white bars) is shown. Median±SEM of 7 to 12 experiments is depicted. DCs from Donors A, B and D were used in experiments (A) and (B).
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pone-0054879-g004: Blockade of CD40/CD40L signaling in short- versus long-term DC/T-cell Co-cultures.(A) CD40L expression on CD4+ T-cells activated after 2, 4 and 6 hours of CD3/CD28 cross-linking is shown. One representative out of 4 experiments is depicted. (B) Short- or long-term co-culture of CD3+ T-cells and DCs, activated with LPS/IFN-γ for 6 hours, in the presence of blocking CD40 and CD40L monoclonal antibodies (black bars) or isotype control immunoglobulins (white bars) is shown. Median±SEM of 7 to 12 experiments is depicted. DCs from Donors A, B and D were used in experiments (A) and (B).

Mentions: To better understand the critical mechanisms that cause enhanced T-cell proliferation under short-term co-culture conditions, we investigated the induction of CD40L expression on T-cells that may modulate the DCs’ function by interaction with CD40. On T-cells activated by use of α-CD3/α-CD28 monoclonal antibodies, CD40L expression reached maximum levels already after 6 hours (figure 4A); also we detected up-regulation of CD40 on DCs at early time points after stimulation (figure 1A). This suggests that engagement of CD40 with CD40L may take place during the 6 hours of short-term DC/T-cell contact and modulate the DC maturation signal, which in turn affects T-cell function.


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)

Blockade of CD40/CD40L signaling in short- versus long-term DC/T-cell Co-cultures.(A) CD40L expression on CD4+ T-cells activated after 2, 4 and 6 hours of CD3/CD28 cross-linking is shown. One representative out of 4 experiments is depicted. (B) Short- or long-term co-culture of CD3+ T-cells and DCs, activated with LPS/IFN-γ for 6 hours, in the presence of blocking CD40 and CD40L monoclonal antibodies (black bars) or isotype control immunoglobulins (white bars) is shown. Median±SEM of 7 to 12 experiments is depicted. DCs from Donors A, B and D were used in experiments (A) and (B).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569454&req=5

pone-0054879-g004: Blockade of CD40/CD40L signaling in short- versus long-term DC/T-cell Co-cultures.(A) CD40L expression on CD4+ T-cells activated after 2, 4 and 6 hours of CD3/CD28 cross-linking is shown. One representative out of 4 experiments is depicted. (B) Short- or long-term co-culture of CD3+ T-cells and DCs, activated with LPS/IFN-γ for 6 hours, in the presence of blocking CD40 and CD40L monoclonal antibodies (black bars) or isotype control immunoglobulins (white bars) is shown. Median±SEM of 7 to 12 experiments is depicted. DCs from Donors A, B and D were used in experiments (A) and (B).
Mentions: To better understand the critical mechanisms that cause enhanced T-cell proliferation under short-term co-culture conditions, we investigated the induction of CD40L expression on T-cells that may modulate the DCs’ function by interaction with CD40. On T-cells activated by use of α-CD3/α-CD28 monoclonal antibodies, CD40L expression reached maximum levels already after 6 hours (figure 4A); also we detected up-regulation of CD40 on DCs at early time points after stimulation (figure 1A). This suggests that engagement of CD40 with CD40L may take place during the 6 hours of short-term DC/T-cell contact and modulate the DC maturation signal, which in turn affects T-cell function.

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