Project description:Dendritic cells (DC) are professional antigen presenting cells that develop from hematopoietic stem cells in bone marrow by successive steps of lineage commitment and differentiation. Different DC subsets were identified based on phenotype, localisation and function: (i) classical DC (cDC) and plasmacytoid DC (pDC) are found in lymphoid organs and (ii) migratory tissue DC are spread throughout peripheral organs, including Langerhans cells, the cutaneous contingent of DC. We have developed a two-step culture system that recapitulates DC development in vitro (Felker et al., J. Immunol. 185, 5326-5335, 2010). In this system multipotent hematopoietic progenitors (MPP) progress into DC-restricted common DC progenitors (CDP) and further into the two major DC subsets cDC and pDC. We employed chromatin immunoprecipitation (ChIP) with deep sequencing (ChIP-seq) to determine the dynamics of H3K27ac occupancy in MPP, CMP, cDC and pDC. Histone modification H3K27ac and RNA-Seq in MPP, CDP, cDC and pDC
Project description:Dendritic cells (DCs) are can be broadly divided into conventional (cDC) and plasmacytoid (pDC) subsets. Despite the importance of this lineage diversity, its genetic basis is not fully understood. ChIP-seq profiling of PU.1 binding sites in cDCs and pDCs revealed a key role for PU.1 in maintaining cDC identity.
Project description:Dendritic cells (DC) are professional antigen presenting cells that develop from hematopoietic stem cells in bone marrow by successive steps of lineage commitment and differentiation. Different DC subsets were identified based on phenotype, localisation and function: (i) classical DC (cDC) and plasmacytoid DC (pDC) are found in lymphoid organs and (ii) migratory tissue DC are spread throughout peripheral organs, including Langerhans cells, the cutaneous contingent of DC. We have developed a two-step culture system that recapitulates DC development in vitro (Felker et al., J. Immunol. 185, 5326-5335, 2010). In this system multipotent hematopoietic progenitors (MPP) progress into DC-restricted common DC progenitors (CDP) and further into the two major DC subsets cDC and pDC. We employed chromatin immunoprecipitation (ChIP) with deep sequencing (ChIP-seq) to determine the dynamics of H3K27ac occupancy in MPP, CDP, cDC and pDC. Additionally, we monitored changes in gene expression in MPP, CDP, cDC and pDC by RNA-seq.
Project description:In C. elegans cdc-48.2(-/-) mutant animals, ER stress-mediated expression of the UPR ckb-2::GFP reporter transgene is abolished. Here, we have used this phenotype in a genome-wide RNAi screen to identify genes involved in the CDC-48.2 mediated ER stress transcription. Combined with a comparative proteomic analysis, this approach has allowed us to identify the AAA+ ATPase RUVB-2 as a novel regulator of the ER stress response and a CDC-48 degradation target.
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive M-NM-1-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-M-NM-3-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response. Total 6 samples were examined. Splenic dendritic cells were treated with IL-21 and/or GM-CSF studying STAT3 and STAT5B binding in the genome
Project description:Classic dendritic cells (cDCs) play a central role in the immune system and consist of two major subsets: CD141+ cDC (cDC1) and CD1c+ cDC (cDC2). The pre-cDCs is the immediate precursors to both cDC subsets. Previous studies showed that there were two pre-committed pre-cDC subpopulations. However, the key molecular drivers of pre-commitment in human pre-cDCs were not investigated. To address this question, we performed both single cell and bulk RNA sequencing (RNA-seq) of two cDC subsets and pre-cDCs. We inferred a list of sixteen candidate master regulator transcriptional factors (TFs) that can indeed separate pre-cDCs into two sub-populations, with one close to cDC1 and the other close to cDC2. More importantly, these two pre-cDC sub-populations are correlated with ratio of IRF8 to IRF4 expression level more than their individual expression level. Our results suggest the concept that the ratio of antagonistic TFs and their competition determine cDC subset differentiation fate.