Effect of LPS, CpG, dexamethasone, Pam3Cys, poly I:C, zymosan, Schistosoma mansoni eggs, Schistosoma mansoni shistosomula, Listeria monocytogenes, Leishmania mexicana amastigotes and Leishmania mexicana promastigotes on dendritic cell gene transcription
Gene expression profiles identify inflammatory signatures in dendritic cells.
Sex, Specimen part, Cell line, Treatment, Compound, TimeView Samples
Mitochondrial biogenesis is under the control of two different genetic systems: the nuclear genome (nDNA) and the mitochondrial genome (mtDNA). mtDNA is a circular genome of 16.6 kb encoding 13 of the approximately 90 subunits that form the respiratory chain, the remaining ones being encoded by the nuclear genome (nDNA). Eukaryotic cells are able to monitor and respond to changes in mitochondrial function through alterations in nuclear gene expression, a phenomenon first defined in yeast and known as retrograde regulation. With this experiment we aimed to identify the set of nuclear genes that significantly change their expression level in response to depletion of mtDNA.
How do human cells react to the absence of mitochondrial DNA?
Cell lineView Samples
Gene expression profiling following different learning paradigms may help in defining the moleular pathways of memory formation. In this study we analyzed the gene expression pattern of murine hippocampus at different time points (0.5 h, 2h, 6h) after trace fear conditioning. We compared trained mice with naive mice that remained in their homecages.
Temporal gene expression profile of the hippocampus following trace fear conditioning.
Sex, Specimen partView Samples
Reduced or absent cytotrophoblast invasion of the maternal uterine spiral arteries is a common clinical finding in studies of pregnancies complicated by preeclampsia, suggesting that the mechanisms behind invasion of these cells is perturbed. The placenta initially develops in a low oxygen environment of 1-2% oxygen until after the 10th week of pregnancy. During this time oxygen concentration exerts a major influence over trophoblast activity and, in vitro, hypoxia inducible factors are proposed to be one of many key regulators of first trimester trophoblast behaviour. We used a global gene expression microarray approach to identify signalling pathways involved in invasion of the first trimester trophoblast cell line HTR8/SVneo under hypoxic conditions where HIF-1 was active. Additionally, first trimester placental samples from different gestational age groups were labelled with anti HIF-1 and HIF-2 to evaluate whether HIFs are differentially expressed and localised across the period of development characterised by hypoxia (6-8 weeks) and maternal blood perfusion (10-12 weeks). Eighty-eight genes were differentially expressed between cells cultured in 1% oxygen (where HIF-1 was localised to the nucleus) and 5% oxygen (where HIF-1 was cytoplasmic). 65% of the genes were predicted to contain HIF-1:ARNT transcription factor binding sites. Increased nuclear localisation of HIF-1 was seen in extravillous cytotrophoblasts in early first trimester compared with late, while cellular expression of HIF-2 in the villous stroma was higher in late first trimester. While HIFs and their downstream targets are clearly induced in trophoblasts during early placental development, and in vitro hypoxic conditions, the mechanism and pathways by which invasion is increased under hypoxic conditions is not clear from the gene expression profile. Further insight beyond the transcription level is required to fully understand this complex phenomenon.
Hypoxia induced HIF-1/HIF-2 activity alters trophoblast transcriptional regulation and promotes invasion.
Cell line, TreatmentView Samples
This study provides the dectin-1 and NFAT responsive genes for 2h and 4h of curdlan treatment.
NFATc2 mediates epigenetic modification of dendritic cell cytokine and chemokine responses to dectin-1 stimulation.
Specimen partView Samples
Dendritic cells (DCs) are crucial for sensing pathogens and triggering immune response. GM-CSF myeloid dendritic cells (GM-DCs) secrete several cytokines including IL-2 upon activation by pathogen associated molecular pattern (PAMP) ligands. DC IL-2 has been shown to be important for innate and adaptive immune responses, however its importance in DC physiology has never been demonstrated. This is due to ambiguity in expression of the CD122 subunit of the IL-2 trimeric receptor complex crucial for signaling. We show here that autocrine IL-2 signaling is functional in GM-DCs in early time window of stimulation with PAMPs. IL-2 signaling selectively activates the JAK/STAT5 pathway by assembling holo-receptor complexs at the cell surface. Autocrine IL-2 signaling inhibits survival of PAMP matured GM-DCs which is crucial for maintaining immune tolerance and preventing autoimmunity. Our findings suggest immune regulation by a novel autocrine signaling pathway that can potentially be exploited in DC immunotherapy.
Dendritic cell derived IL-2 inhibits survival of terminally mature cells via an autocrine signaling pathway.
Specimen partView Samples
Treatment of post-transplant patients with immunosuppressive drugs targeting the calcineurin-NFAT pathway, such as Cyclosporine A or Tacrolimus, are commonly associated with a higher incidence of opportunistic infections, such as Aspergillus fumigatus, which can lead to severe life-threating conditions. A component of the A. fumigatus cell wall, -glucan, is recognized by dendritic cells via the Dectin-1 receptor, triggering downstream signaling that leads to calcineurin-NFAT binding, NFAT translocation, and transcription of NFAT-regulated genes. Here, we address the question of whether calcineurin signaling in CD11c-expressing cells, such as DCs, has a specific role in the innate control of A. fumigatus. Impairment of calcineurin in CD11c-expressing cells (CD11ccrecnb1loxP) significantly increased susceptibility to systemic A. fumigatus infection and to intranasal infection in irradiated mice undergoing bone marrow transplant. Global expression profiling of bone marrow-derived DCs identified calcineurin-regulated processes in the immune response to infection, including expression of pentraxin-3, an important anti-fungal defense protein. These results suggest that calcineurin inhibition directly impairs important immunoprotective functions of myeloid cells, as shown by the higher susceptibility of CD11ccrecnbloxP mice in models of systemic and invasive pulmonary aspergillosis, including after allogeneic bone marrow transplantation. These findings are relevant to the clinical management of transplant patients with severe Aspergillus infections.
Impaired calcineurin signaling in myeloid cells results in downregulation of pentraxin-3 and increased susceptibility to aspergillosis.
Specimen partView Samples
Pattern recognition receptors (PRR) detect microbial products and induce cytokines which shape the immunological response. Interleukin-12 (IL-12), tumor necrosis factor alpha (TNF-) and IL-1 are proinflammatory cytokines which can be essential for resistance against infection, but if produced at high levels, may contribute to immunopathology. In contrast, IL-10 is an immunosuppressive cytokine which dampens proinflammatory responses, but can also lead to defective pathogen clearance. The regulation of these cytokines is therefore central to the generation of an effective but balanced immune response. Here, we show that macrophages derived from C57BL/6 mice produce low levels of IL-12, TNF- and IL-1, but high levels of IL-10 in response to TLR4 and TLR2 ligands LPS and PamCSK4, and Burkholderia pseudomallei a Gram-negative bacterium which activates TLR 2/4. In contrast, macrophages derived from BALB/c mice show a reciprocal pattern of cytokine production. Differential production of IL-10 in B. pseudomallei and LPS stimulated C57BL/6 and BALB/c macrophages was due to a type I IFN dependent, but IL-27 independent mechanism. Further, type I IFN contributed to differential IL-1 and IL-12 production in B. pseudomallei and LPS stimulated C57BL/6 and BALB/c macrophages, via both IL-10-dependent and independent mechanisms. These findings highlight key pathways responsible for the regulation of pro- and anti-inflammatory cytokines in macrophages and reveal how they may differ according to the genetic background of the host.
Differential Production of Type I IFN Determines the Reciprocal Levels of IL-10 and Proinflammatory Cytokines Produced by C57BL/6 and BALB/c Macrophages.
Sex, Specimen part, Treatment, TimeView Samples
Dendritic cells (DCs) are professional antigen-presenting cells whose activity is intrinsically linked to the microenvironment. Hypoxia is a condition of low oxygen tension occurring in inflammatory tissues that creates a special microenvironment conditioning cell physiology. We studied the effects of hypoxia on the differentiation of human monocytes into DCs. Immature DCs were differentiated in vitro from human monocytes under normoxic (iDCs) or hypoxic (Hi-DCs) conditions and the gene expression profile was determined. Hi-DCs expressed novel hypoxia-inducible genes and were characterized by up-regulation of pathways associated with cell movement/migration.
Transcriptome of hypoxic immature dendritic cells: modulation of chemokine/receptor expression.
No sample metadata fieldsView Samples
We have investigated the effects of cigarette smoke exposure in three different strains of mice. DBA/2 and C57Bl/6J are susceptible to smoke and develop different lung changes in response to chronic exposure, while ICR mice are resistant to smoke and do not develop emphysema. The present study was carried out to determine early changes in the gene expression profile of mice exposed to cigarette smoke with either a susceptible or resistant phenotype.
Early response of gene clusters is associated with mouse lung resistance or sensitivity to cigarette smoke.
No sample metadata fieldsView Samples