Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dendritic cells (DC) are central to the immune response against invading pathogens. How DC translate different signals received from either other components of the immune system or from pathogens into a tailored immune response is not understood in detail. Using oligonucleotide microarray technology we performed a genome-wide analysis to investigate the transcriptional program in immature human monocyte-derived DC induced to mature with either CD40 ligand (CD40L), lipopolysaccharide (LPS) or a cocktail of inflammatory cytokines and prostaglandin (PG) E(2) (CyC). We identified elements of a sustained common response to LPS and CyC, as well as sets of transient and stimulus-specific gene expression changes. Interestingly, the transient LPS response as well as the sustained LPS-specific response included a high number of chemokines, suggesting that LPS stimulation of DC leads to enhanced recruitment of immune cells and potentially prolongs the immune response compared to an inflammatory signal mimicked by CyC. Of note, the core response common to both LPS and CyC comprised a high number of unknown genes as well as genes that have not been previously identified as part of the maturation response in DC. Since some of these genes have down-regulatory functions in other settings, they may have a regulatory role in DC maturation and immune response generation.
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PMID:The global transcriptional maturation program and stimuli-specific gene expression profiles of human myeloid dendritic cells. 1266 79

In this study we investigated whether berberine-mediated induction of interleukin-12 (IL-12) production in antigen-presenting cells could regulate a cytokine profile of antigen-primed CD4+ T helper (Th) cells. Pretreatment with berberine induced IL-12 production in both macrophages and dendritic cells, and significantly increased the levels of IL-12 production in lipopolysaccharide-stimulated macrophages and in CD40 ligand-stimulated dendritic cells. Importantly, berberine pretreatment of macrophages increased their ability to induce interferon-gamma (IFN-gamma) and reduced their ability to induce IL-4 in antigen-primed CD4+ T cells. Berberine did not influence the macrophage cell surface expression of the class II major histocompatibility complex molecule, the co-stimulatory molecules CD80 and CD86, and intracellular adhesion molecule-1. Addition of neutralizing anti-IL-12p40 monoclonal antibody to cultures of berberine-pretreated macrophages and CD4+ T cells restored IL-4 production in antigen-primed CD4+ T cells. The in vivo administration of berberine resulted in the enhanced induction of IL-12 production by macrophages when stimulated in vitro with lipopolysaccharide or heat-killed Listeria monocytogenes, leading to the inhibition of the Th type 2 cytokine profile (decreased IL-4 and increased IFN-gamma production) in antigen-primed CD4+ T cells. These findings may point to a possible therapeutic use of berberine or medicinal plants containing berberine in the Th type 2 cell-mediated immune diseases such as allergic diseases.
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PMID:Induction of interleukin-12 production in mouse macrophages by berberine, a benzodioxoloquinolizine alkaloid, deviates CD4+ T cells from a Th2 to a Th1 response. 1280 87

Inhibitors of cAMP-specific phosphodiesterase (PDE) 4 have been shown to inhibit inflammatory mediator release and T cell proliferation, and are considered candidate therapies for T(h)1-mediated diseases. However, little is known about how PDE4 inhibitors influence dendritic cells (DC), the cells responsible for the priming of naive T(h) cells. Therefore, we investigated the PDE profile of monocyte-derived DC, and whether PDE4 inhibitors modulate DC cytokine production and T cell-polarizing capacity. We mainly found cAMP-specific PDE4 enzymatic activity in both immature and mature DC. In contrast to monocytes that mainly express PDE4B, we found that PDE4A is the predominant PDE4 subtype present in DC. Immature DC showed reduced ability to produce IL-12p70 and tumor necrosis factor (TNF)-alpha upon lipopolysaccharide or CD40 ligand (CD40L) stimulation in the presence of PDE4 inhibitors, whereas cytokine production upon CD40L stimulation of fully mature DC in the presence of PDE4 inhibitors was not affected. Exposure to PDE4 inhibitors for 2 days during DC maturation did not influence T cell-stimulatory capacity or acquisition of a mature phenotype, but increased the expression of the chemokine receptor CXCR4. Furthermore, DC matured in the presence of PDE4 inhibitors showed reduced capacity to produce IL-12p70 and TNF-alpha upon subsequent CD40L stimulation. Using these PDE4 inhibitor-matured DC to stimulate naive T cells resulted in a reduction of IFN-gamma-producing (T(h)1) cells. These findings indicate that PDE4 inhibitors can affect T cell responses by acting at the DC level and may increase our understanding of the therapeutic implication of PDE4 inhibitors for T(h)1-mediated disorders.
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PMID:Phosphodiesterase 4 inhibitors reduce human dendritic cell inflammatory cytokine production and Th1-polarizing capacity. 1280 21

We have recently identified 2 patients with a rare autosomal recessive form of hyper IgM disease, known as HIGM3, caused by mutations in the CD40 gene. These patients had opportunistic infections observed on X-linked hyper IgM syndrome (HIGM), suggesting that the CD40-CD40 ligand interaction is important for promoting T-cell-mediated immunity. To evaluate whether innate immunity signals may substitute CD154 for inducing the maturation of dendritic cells (DCs), we analyzed monocyte-derived DCs in these patients. Monocyte-derived DCs of HIGM3 subjects on ex vivo stimulation with tumor necrosis factor-alpha (TNF-alpha) or lipopolysaccharide (LPS) combined with interferon-gamma (IFN-gamma) normally express all the markers of mature DCs, such as CD83 and DC-LAMP. However, cell surface levels of HLA-DR in mature DCs are reduced, as is costimulatory activity of these cells for allogeneic naive T cells. In addition, CD40-deficient DCs secrete lower amounts of interleukin-12 (IL-12) but larger quantities of IL-10 than control subjects. Finally, analysis of circulating plasmacytoid DCs demonstrates a normal percentage of this subset in CD40-deficient cells, but IFN-alpha secretion in response to herpes simplex virus 1 (HSV-1) infection is severely reduced in patients. These observations suggest that the severe impairment of DC maturation may contribute to the defect of T-cell-mediated immunity observed in HIGM3 patients.
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PMID:Functional defects of dendritic cells in patients with CD40 deficiency. 1289 49

Nitric oxide (NO) has an established role in the defense against bacterial infections and exerts multiple modulatory activities on both inflammatory and immune responses. However, the relevance of NO on dendritic cell (DC) functions has been poorly investigated. In this study, we found that addition of the NO donor S-nitrosoglutathione (GSNO) to monocyte-derived DCs matured by lipopolysaccharide (LPS) or soluble CD40 ligand led to a decreased capacity to activate naive allogeneic T cells but a more prominent Th1 polarization, with increased interferon-gamma (IFN-gamma) secretion and reduced interleukin-5 (IL-5) release. The presence of GSNO during maturation of DCs caused a reduced expression of surface CD86, whereas CD80, CD83, and MHC molecule expression was not affected. Moreover, GSNO induced a dose-dependent decrease of IL-10 and enhancement of tumor necrosis factor-alpha (TNF-alpha) release from mature DCs. In parallel, a marked reduced production of IL-12 p40 subunit but no significant perturbation of the bioactive IL-12 p70 production was observed. Finally, GSNO significantly reduced the release of IP-10/CXCL10 and RANTES/CCL5 but not IL-8/CXCL8 by mature DCs. Although GSNO can strengthen the capacity of mature DCs to induce type 1 polarization of T lymphocytes, our data suggest that it elicits distinct anti-inflammatory functions, eventually reducing T lymphocyte proliferation and recruitment.
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PMID:Regulatory role of nitric oxide on monocyte-derived dendritic cell functions. 1367 30

Dendritic cells (DC) are professional antigen-presenting cells that play a central role in the control of immunity. Mature DC are characterized by high expression levels of MHC and co-stimulatory molecules, and by the secretion of IL-12, a key cytokine for the priming of cytotoxic T lymphocytes. Here, we have compared different maturation stimuli to reproducibly generate stable mature DC secreting high amounts of bioactive IL-12p70. We have compared soluble human trimeric CD40 ligand (sCD40L) combined with IFN-gamma, poly(I:C), a cocktail of cytokines (IL-1beta, IL-6 and tumor necrosis factor-alpha) with prostaglandin E(2) and lipopolysaccharide. A major concern, however, is whether DC, that have already produced high amounts of IL-12p70 during the maturation step, are still capable of secreting IL-12p70 after in vivo administration at the time of interaction with the targeted T cells. To mimic that situation, mature DC generated by those methods were compared for their ability to secrete IL-12p70 in the absence of IFN-gamma, using sCD40L. We observed a second consistent secretion of bioactive IL-12p70 upon subsequent sCD40L stimulation only when poly(I:C) was used as the maturating agent. Our data suggest that, for clinical use, poly(I:C) may be one of the most appropriate agents to generate stable mature DC. These mature DC might generate in vivo effective immune responses after injection, because they retain the ability to secrete bioactive IL-12 after CD40 ligation.
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PMID:Poly(I:C) used for human dendritic cell maturation preserves their ability to secondarily secrete bioactive IL-12. 1509 80

B lymphocytes can be activated by many different stimuli. However, the mechanisms responsible for the signaling and functional specificities of individual stimuli remain to be elucidated. Here, we have compared the contribution of the type 1 (p50-dependent) and type 2 (p52-dependent) NF-kappaB activation pathways to cell survival, proliferation, homotypic aggregation, and specific gene regulation of murine primary B lymphocytes. Whereas lipopolysaccharide (LPS) and B cell activation factor (BAFF) mainly activate the type 1 or type 2 pathways, respectively, CD40 ligand (CD40L) strongly activates both. Rescue of spontaneous apoptosis is diminished in p52(-/-) B cells after BAFF stimulation and in p50(-/-)c-Rel(-/-) B cells after LPS stimulation. Interestingly, significant CD40-induced B cell survival is still observed even in p50(-/-)c-Rel(-/-)p65(-/+) B cells, which is correlated with the ability of CD40L to up-regulate Bcl-x(L) expression in these cells. CD40L- and LPS-induced B cell proliferation, as well as up-regulation of proliferation-related genes, however, are greatly reduced in c-Rel(-/-) and p50(-/-)c-Rel(-/-) B cells but are normal in p52(-/-) B cells. We have further demonstrated that both c-Rel and p52 are required for CD40-mediated B cell homotypic aggregation, which explains well why neither LPS nor BAFF has this function. Overall, our studies suggest that both type 1 and type 2 NF-kappaB pathways contribute to the gene expression and biological program unique for CD40 in B cell activation.
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PMID:Unique CD40-mediated biological program in B cell activation requires both type 1 and type 2 NF-kappaB activation pathways. 1514 78

Langerhans cells (LCs) represent an immature population of myeloid dendritic cells (DCs). As a result of their unique Birbeck granules (BGs), langerin expression, and heterogeneous maturation process, they differ from other immature DCs. Monocyte-derived LCs (MoLCs) mimic epidermal LCs. MoLCs with characteristic BGs are generated by culturing blood-derived monocytes with granulocyte macrophage-colony stimulating factor, interleukin (IL)-4, and transforming growth factor-beta1. Here, we compare maturation-induced antigen expression and cytokine release of LCs with MoLCs. To achieve comparable cell populations, LCs and MoLCs were isolated by CD1c cell sorting, resulting in high purity. In unstimulated cells, CD40 was expressed at equal levels. After stimulation with CD40 ligand (CD40L), LCs and MoLCs acquired CD83 and increased CD86. High CD80 expression was exclusively detected in CD1c-sorted MoLCs. Human leukocyte antigen-DR and CD54 expression was found in all cell populations, however, at different intensities. CD40 triggering increased the potency of LCs and MoLCs to stimulate CD4+ T cell proliferation. Activated MoLCs released IL-12p70 and simultaneously, anti-inflammatory IL-10. The application of the Toll-like receptor ligands peptidoglycan, flagellin, and in particular, lipopolysaccharide (LPS) increased the corelease of these cytokines. LCs secreted IL-10 at a comparable level with MoLCs but failed to produce high amounts of IL-12p70 after application of danger signals. These data indicate that MoLCs as well as LCs display no maturation arrest concerning CD83 and CD86 expression. In difference to MoLCs, LCs resisted activation by CD40L and LPS in terms of IL-12 production. This shows that natural and generated LCs share similar features but differ in relevant functions.
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PMID:Human epidermal Langerhans cells differ from monocyte-derived Langerhans cells in CD80 expression and in secretion of IL-12 after CD40 cross-linking. 1517 2

Two members of the NF-kappaB (nuclear factor kappaB)/Rel transcription factor family, NF-kappaB1 and NF-kappaB2, are produced as precursor proteins, NF-kappaB1 p105 and NF-kappaB2 p100 respectively. These are proteolytically processed by the proteasome to produce the mature transcription factors NF-kappaB1 p50 and NF-kappaB2 p52. p105 and p100 are known to function additionally as IkappaBs (inhibitors of NF-kappaB), which retain associated NF-kappaB subunits in the cytoplasm of unstimulated cells. The present review focuses on the latest advances in research on the function of NF-kappaB1 and NF-kappaB2 in immune cells. NF-kappaB2 p100 processing has recently been shown to be stimulated by a subset of NF-kappaB inducers, including lymphotoxin-beta, B-cell activating factor and CD40 ligand, via a novel signalling pathway. This promotes the nuclear translocation of p52-containing NF-kappaB dimers, which regulate peripheral lymphoid organogenesis and B-lymphocyte differentiation. Increased p100 processing also contributes to the malignant phenotype of certain T- and B-cell lymphomas. NF-kappaB1 has a distinct function from NF-kappaB2, and is important in controlling lymphocyte and macrophage function in immune and inflammatory responses. In contrast with p100, p105 is constitutively processed to p50. However, after stimulation with agonists, such as tumour necrosis factor-alpha and lipopolysaccharide, p105 is completely degraded by the proteasome. This releases associated p50, which translocates into the nucleus to modulate target gene expression. p105 degradation also liberates the p105-associated MAP kinase (mitogen-activated protein kinase) kinase kinase TPL-2 (tumour progression locus-2), which can then activate the ERK (extracellular-signal-regulated kinase)/MAP kinase cascade. Thus, in addition to its role in NF-kappaB activation, p105 functions as a regulator of MAP kinase signalling.
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PMID:Functions of NF-kappaB1 and NF-kappaB2 in immune cell biology. 1521 41

We previously demonstrated that tumor necrosis factor (TNF)-alpha-matured CD16- and CD16+ human monocyte-derived dendritic cells (16-mDC and 16+mDC) differentially stimulate naive CD4+ lymphocytes by inducing Th1- and Th2-like responses, respectively. Here, we further characterized the role of different DC maturation factors on Th polarization. Immature 16+mDC and 16-mDC (iDC) obtained by culture of purified monocytes with GM-CSF and IL-4 were maturated with (i) Toll-like receptor (TLR) ligands [lipopolysaccharide (LPS)], (ii) lymphocyte-derived (soluble CD40 ligand, IFN-gamma) and (iii) endogenous inflammatory stimuli [TNF-alpha, prostaglandin (PG)E2]. After activation with these stimuli, DC secrete IL-12 only in presence of LPS, and 16+mDC produced lower amounts of IL-12 and IL-10 than 16-mDC. Allogeneic CD4+CD45RO- lymphocytes co-cultured with 16+mDC secreted higher levels of IL-4 and IL-10 than those co-cultured with 16-mDC, regardless of the maturation stimuli. Results were similar when DC were activated with TLR-2 or TLR-3 ligands. The higher induction of IL-4 by 16+mDC was primarily dependent on IL-12, IL-4 and IL-10. IFN-gamma production by CD4+ T cells was similar with all the conditions except with LPS-16+mDC, which induced reduced amounts of this cytokine. Those differences were totally eliminated by neutralization of IL-12, IL-4 or IL-10. Finally, 16-mDC could reverse the Th2 phenotype of already committed lymphocytes toward a Th1 pattern in short-term cultures, whereas 16+mDC had less ability to skew this phenotype. These results indicate that 16+mDC elicit superior Th2 responses independently of the maturation factors that they received, and suggest that they could represent an important population of regulatory DC.
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PMID:CD16+ human monocyte-derived dendritic cells matured with different and unrelated stimuli promote similar allogeneic Th2 responses: regulation by pro- and anti-inflammatory cytokines. 1527 4


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