ABSTRACT: microRNAs are crucial post-transcriptional regulators which contribute to the effect of sulforaphane in cancer and are also involved in the modulation of of many aspects of DC biology, including development, maturation, surface molecule expression and released cytokines We used microarrays to detail the regulation of miRNAs in human DCs by sulforaphane, underlying the regulation of different crucial DCs regulatory molecules and signaling pathways
Project description:Dendritic cells (DCs) play a crucial role in the regulation of innate and adaptive immune responses. DCs initiate adaptive immune responses after their migration to secondary lymphoid organs, a process mainly driven by the expression of the chemokine receptor CCR7. LXR ligands/oxysterols released by tumors were shown to dampen DC migration to secondary lymphoid organs by the inhibition of CCR7 expression. We studied the gene expression modulation of DCs undergoing maturation (by LPS) in the presence of the oxysterol 22R-Hydroxycholesterol (22R-HC).
Project description:Purpose: DCIR is an inhibitory type of C-type lectin receptor that regulates DC functions. This study aimed to find the genes that could be regulated through DCIR. Method: Splenic DCs from WT and Dcir-/- mice were colutured with T cells that express specific TCR for MOG35-55 for 3 days in the presence of MOG peptide. CD11c+ cells were collected by an auto MACS. RNA profiles were generated by deep sequencing, in triplicate, using DNBSEQ-G400. Results: We detected xxx gense that were higher expression in Dcir-/- DCs, compared with WT DCs, with a fold change ≥1.5 and p value <0.05. Conclusion: Our data showed that Dcir deficiency in DCs changed the gene expression pattern, compared to WT DCs, in the coculture system of T cells. DCIR regulates the expression of DC genes that are associated with the functions of DCs.
Project description: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. Microarray technology was used to understand the role of IL-2 signaling in DC. Microarray was performed to investigate the role of IL-2 signaling in DC physiology. Hence Wt or IL-2-/- BMDCs were either treated or not with curdlan for 6h and taken for microarray.
Project description:DCs treated with PTX (PTX-DC) is able to induce EAE like PTX as adjuvant whereas neither LPS nor DCs treated with LPS (LPS-DC) fails to induce EAE. We want to identify genes that are responsible for EAE induction in DCs and genes that are able to toloerize EAE in DCs through the microarray.
Project description: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. Microarray technology was used to understand the role of IL-2 signaling in DC.
Project description:We investigated the influence of SCFAs on human, monocyte derived DCs that represent a reliable in vitro model to study circulating DCs, one of the key regulators of our immune system. We studied the individual effect exerted by SCFA, the main metabolic end-products of fermentation by anaerobic bacteria in the gut, on the gene expression of immature and mature DC, exploring the potential of circulating bacterial metabolites to directly influence immune system cells. We found that SCFAs have little effect on the transcriptome of immature DC, whereas the transcriptome of mature DC was highly perturbed especially by butyrate and propionate. Our findings show an overall down-regulation of LPS-induced inflammatory responses and provide new insights into host-microbiome interactions. In this dataset, we include the expression data obtained from immature and matured (via lipopolysaccharide, LPS) human monocyte-derived dendritic cells untreated and treated with 1mM of acetate, butyrate, or propionate.
Project description:DCs treated with PTX (PTX-DC) is able to induce EAE like PTX as adjuvant whereas neither LPS nor DCs treated with LPS (LPS-DC) fails to induce EAE. We want to identify genes that are responsible for EAE induction in DCs and genes that are able to toloerize EAE in DCs through the microarray. Bone marrow derived dendritic cells are either unstimulated or stimulated with LPS and PTX for 24h respectively. Cells are harveseted for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Transcriptome analysis of IFNγ-insensitive DCs IFNγ signaling drives dendritic cells (DCs) to promote type I T cell (Th1) immunity. Here, we show that activation of DCs by IFNγ is equally crucial for the differentiation of a population of T-bet+ regulatory T (Treg) cells specialized to inhibit Th1 immune responses. Conditional deletion of IFNγ receptor in DCs but not in Treg cells resulted in a severe defect in this specific Treg cell subset, leading to exacerbated immune pathology during parasitic infections. Mechanistically, IFNγ-unresponsive DCs failed to produce sufficient amount of IL-27, a cytokine required for optimal T-bet induction in Treg cells. Thus, IFNγ signalling endows DCs with the ability to efficiently control a specific type of T cell immunity through promoting a corresponding Treg cell population. We analyzed saliva from 3 WT DC samples and 3 IFNγR2 KO DC samples isolated from unmanipulated mice. In addition, we analyzed saliva from 3 WT DC samples and 3 IFNγR2 KO DC samples isolated from mixed BM chimeras (WT + IFNgR2KO) day 8 T. gondii infected.
Project description:Dendritic cells (DC) play a vital role in the induction of activation or tolerance of immune response. Histone deacetylase (HDAC) inhibitors potently modulate experimental graft-vs-host disease, allograft rejection, and autoimmune diseases, partly through the regulation of dendritic cells. The molecular mechanisms underpinning their immunosuppressive effects on DCs are not well understood. The functional relevance of acetylation in DC responses remains undefined. We used microarrays to detail the global program of gene expression in dendritic cells after treated with or without SAHA, a HDAC inhibitor utilized in clinic, to identify the upregulated and downregulated genes.
Project description:Gene expression profile of dendritic cells (DC) of mesenteric lymph node (mLN) and lamina propria of small intestine (SI-LP) of control mice and mice lacking RelB expression in DCs at steady state, four days and 14 days after infection with Heligmosomoides polygyrus bakeri (Hpb) Dendritic cells (DCs) are crucial for initiating protective immune responses and have also been implicated in the generation and regulation of Foxp3+ regulatory T cells (Tregs). Specific DC subsets or DC-intrinsic pathways regulate immunity against pathogens but also tolerance to harmless antigens derived from food or microbiota at barrier sites, but underlying mechanisms in the intestinal tract remain poorly defined. Here, we provide evidence that the alternative NF-B family member RelB controls a defined transcriptional program in migratory DC subsets of mesenteric lymph nodes and the small intestinal lamina propria. Functionally, ablation of RelB in dendritic cells result in increased Foxp3+ Treg cell numbers but decreased RORt peripheral Treg cell numbers maintained even under inflammatory conditions. Single-cell RNA-sequencing revealed a complete RelB dependency for the differentiation of cryptopatches and isolated lymphoid follicles-associated DCs (CIA-DCs) in the lamina propria of the small intestine. In addition, we show a RelB-dependent signature of migratory DCs in mesenteric lymph nodes favoring DC-Treg cell interaction by affecting the expression of chemokines (Ccl22, Ccl17), migration behavior (Cd63), co-stimulatory molecule (Cd80, Cd40, Cd200, Tnfsf4), and tolerance-related integrin (Itgb5, Itgb8) expression. Functionally, increased Treg cell numbers in DC-specific RelB knockout animals did not show any risk of increased reactions in a model of food allergy but instead prevented protective Th2 immune responses in the intestines after infection with Heligmosomoides polygyrus bakeri despite their slight steady-state type 2 immune bias. This protection was dependent on elevated Treg cell frequencies during primary infection as a result of bystander immune tolerance. Thus, RelB expression in conventional DCs acts as a rheostat to establish a tolerogenic set point that is maintained even during infection and strong type 2 immune conditions and thereby is a key regulator of intestinal homeostasis.