Serum- and Glucocorticoid-Inducible Kinase 1 Sensitive NF-κB Signaling in Dendritic Cells (original) (raw)
Related papers
Journal of Cellular Biochemistry, 2001
NF-κB/Rel transcription factors have been implicated in the differentiation of monocytes to either dendritic cells (DCs) or macrophages, as well as in the maturation of DCs from antigen-processing to antigen-presenting cells. Recent studies of the expression pattern of Rel proteins and their inhibitors (IκBs) suggest that their regulation during this differentiation process is transcriptional. To investigate differential gene expression between macrophages and DCs, we used commercially available gene microarrays (GEArray KIT), which included four of the NF-κB/Rel family genes (p50/p105, p52/p100, RelB, and c-rel) and 32 additional genes either in the NF-κB signal transduction pathway or under transcriptional control of NF-κB/Rel factors. To generate macrophages and DCs, human adherent peripheral blood monocytes were cultured with M-CSF or GM-CSF + IL-4 respectively for up to 8 days. DCs (and in some experiments, macrophages) were treated with lipopolysaccharide (LPS) for the last 48 h of culture to induce maturation. Cells were harvested after 7 days, cDNA was prepared and radiolabeled with α-32P-dCTP, then hybridized to gene arrays containing specific gene probes. β-actin and GAPDH or PUC18 oligonucleotides served as positive or negative controls, respectively. The expression of all four NF-κB/Rel family genes examined was significantly upregulated in maturing DCs compared to macrophages. The strongest difference was observed for c-rel. RT-PCR determinations of c-rel, RelB, and p105 mRNAs confirmed these observations. Among the 32 NF-κB/Rel pathway genes, 14 were upregulated in mature DCs compared to macrophages. These genes were IκBα, IKK-β, NIK, ICAM-1, P-selectin, E-selectin, TNF-α, TNFR2, TNFAIP3, IL-1α, IL-1R1, IL-1R2, IRAK, and TANK. By contrast, only mcp-1 (monocyte chemotactic protein 1) was upregulated in macrophages compared to DCs. NF-κB pathway genes upregulated in DCs compared to macrophages were constitutively expressed in monocytes then selectively downregulated during macrophage but not DC differentiation. LPS did not induce expression of most of these genes in macrophages but LPS did induce upregulation of IL-8 in mature macrophages. We conclude that NF-κB/Rel family genes, especially c-rel, are selectively expressed during differentiation of monocytes towards DCs. Moreover, this differential expression is associated both with activation of different NF-κB signal transduction pathways in DCs and macrophages and with expression of a unique subset of genes in DCs that are transcriptionally targeted by NF-κB/Rel factors. The results illustrate the ability of the NF-κB pathway to respond to differentiation stimuli by activating in a cell-specific manner unique signalling pathways and subsets of NF-κB target genes. J. Cell. Biochem. 83: 281–290, 2001. © 2001 Wiley-Liss, Inc.
Modulation of cytokine expression in mouse dendritic cell clones
European Journal of Immunology, 1994
Dendritic cells (DC) play an essential role in the induction of primary immune responses; however, very little information is available on cytokine production by DC. Here we determined the cytokine gene expression profile of two immortalized DC clones, CB1 and D2SC/1, both generated from mouse spleen but differing in their activation requirements. Among the cytokines tested, only transforming growth factor-β1 was transcribed constitutively, but its production was detected only in D2SC/1 cells after treatment with granulocyte/macrophage colony-stimulating factor (GM-CSF). GM-CSF also promoted transcription and synthesis of interleukin (IL)-1β in CB1 cells that need pretreatment with GM-CSF to present major histocompatibility complex class II-restricted antigens efficiently in vitro. Lipopolysaccharide (LPS) up-regulated gene expression and induced release of tumor necrosis factor-α in both DC clones. In addition, LPS induced transcription of IL-1α and both gene expression and synthesis of IL-1β in D2SC/1 cells. Interferon-γ was ineffective in inducing cytokine gene expression, although it augmented the antigen-presentation capacity of DC. IL-4, IL-10 and IL-12 mRNA were not induced by any of the tested stimuli. The results suggest that DC have a limited cytokine gene expression pattern compared to macrophages and are heterogenous in some functional properties.
Regulation of NF-κB- and STAT1-mediated plasmacytoid dendritic cell functions by A20
PLOS ONE, 2019
Dendritic cells (DCs) are professional antigen presenting cells involved in the induction of T cell-mediated adaptive immunity. Plasmacytoid DCs (pDCs) originate from lymphoid precursors and produce type I interferons (IFNs) in response to pathogens. A20 is considered as a negative regulator of toll-like receptor (TLR) signaling pathways, in which Toxoplasma gondii-derived profilin (TgPRF) is a TLR11/12 ligand recognised by DCs to stimulate their maturation/activation. Little is known about contributions of A20 to changes in biological properties of pDCs. The present study, therefore, explored whether pDC functions are influenced by A20. To this end, bone marrow cells were isolated and cultured with Flt3L to attain CD8DCs, CD11bDCs and pDCs and followed by challenge with TgPRP in the presence or absence of A20 siRNA. Expression of maturation markers were analysed by flow cytometry, and secretion of inflammatory cytokines by ELISA, cell migration by a transwell migration assay and expression of signalling molecules by western blotting. As a result, treatment with A20 siRNA enhanced activations of IκB-α and STAT-1, leading to increases in expressions of maturation markers and cytokine productions as well as migration of TgPRP-treated pDCs, while mature CD11bDCs produced at higher levels of TNF-α and IL-6 only. In addition, functions of CD8DCs remained unaltered following A20 silencing. The effects of A20 on pDC maturation and activation were completely abolished by IKK inhibitor and partially blunted by fludarabine. In conclusion, the inhibitory effects of A20 on pDC functions are expected to affect the immune response in T. gondii infection.
The inflammatory cytokine, GM-CSF, alters the developmental outcome of murine dendritic cells
European Journal of Immunology, 2012
+ equivalent DCs or plasmacytoid DCs developed compared to cultures supplemented with Flt3L alone. The disappearance of these two cell subsets in GM-CSF + Flt3L culture was not a result of simple inhibition of their development, but a diversion of the original differentiation trajectory to form a new cell population. As a consequence, both DC progeny and their functions were altered. The effect of GM-CSF on DC subset development was confirmed in vivo. First, the CD8 + DC numbers were increased under GM-CSF deficiency (when either GM-CSF or its receptor was ablated). Second, this population was decreased under GM-CSF hyperexpression (by transgenesis or by Listeria infection). Our finding that GM-CSF dominantly changes the regulation of DC development in vitro and in vivo has important implications for inflammatory diseases or GM-CSF therapy.
Blood, 2001
Dendritic cells (DC) are highly specialized antigen-presenting cells that on activation by inflammatory stimuli (eg, tumor necrosis factor ␣ [TNF-␣] and interleukin-1 [IL-1]) or infectious agents (eg, lipopolysaccharide [LPS]), mature and migrate into lymphoid organs. During maturation, DC acquire the capacity to prime and polarize resting naive T lymphocytes. Maturation of monocyte-derived DC (MDDC) is inhibited by the p38 mitogenactivated protein kinase (MAPK) inhibitor SB203580. This study found that in the presence of the mitogen-activated protein kinase kinase 1-extracellular signal-regulated kinase (ERK) inhibitors PD98059 or U0126, TNF-␣-and LPS-induced phenotypic and functional maturation is enhanced. ERK pathway inhibitors increased expression of major histocompatibility complex and costimulatory molecules; loss of mannose-receptor-mediated endocytic activity; nuclear factor-B DNAbinding activity; release of IL-12 p40; and allogeneic T-cell proliferation induced by LPS or TNF-␣. Moreover, PD98059 and U0126 enhanced LPS-triggered production of IL-12 p70. In agreement with the effect of ERK inhibitors, maturation of MDDC was delayed in the presence of serum, an effect that was reversed by U0126. These results indicate that the ERK and p38 MAPK signaling pathways differentially regulate maturation of MDDC and suggest that their relative levels of activation might modulate the initial commitment of naive T-helper (Th) cells toward Th1 or Th2 subsets. The findings also suggest that maturation of MDDC might be pharmacologically modified by altering the relative levels of activation of both intracellular signaling routes. (Blood.
Journal of leukocyte biology, 2002
Functional roles of extracellular signal-related kinase (ERK) activation in dendritic-cell (DC) maturation have been unclear. In the present study, we investigated the ERK pathway in tumor necrosis factor (TNF)-alpha-induced maturation of murine spleen-derived DC. TNF-alpha increased surface expressions of major histocompatibility (MHC) and costimulatory molecules on DC in a dose-dependent manner. High (40 ng/ml) and low (0.4 ng/ml) concentrations of TNF-alpha markedly enhanced ERK1/2 activation in DC, and this activation was blocked completely by PD98059, a selective inhibitor of the ERK pathway. When DC were treated with TNF-alpha at a low but not a high concentration, PD98059 notably enhanced surface expressions of the MHC and costimulatory molecules and allostimulatory capability of the DC. Interleukin (IL)-12 production was enhanced significantly by PD98059 in DC treated with low or high concentration of TNF-alpha. These findings suggest that TNF-alpha-induced ERK activation ne...