ABSTRACT: IRF8 transcription factor controls survival and function of terminally differentiated conventional and plasmacytoid dendritic cells respectively
Project description:Interferon regulatory factor-8 (IRF8) has been proposed to be essential for development of monocytes, plasmacytoid dendritic cells (pDCs) and type 1 conventional dendritic cells (cDC1s) and remains highly expressed in differentiated DCs. Transcription factors that are required to maintain the identity of terminally differentiated cells are designated “terminal selectors”. Using BM chimeras, conditional Irf8fl/fl mice and various promotors to target Cre recombinase to different stages of monocyte and DC development, we have identified IRF8 as a terminal selector of the cDC1 lineage controlling survival. In monocytes, IRF8 was necessary during early but not late development. Complete or late deletion of IRF8 had no effect on pDC development or survival but altered their phenotype and gene expression profile leading to increased T cell stimulatory function but decreased type 1 interferon production. Thus, IRF8 differentially controls the survival and function of terminally differentiated monocytes, cDC1s and pDCs.
Project description:The transcription factor IRF8 is a critical regulator of plasmacytoid dendritic cell (pDC) and classical dendritic cell (cDC) development in both mouse and man. Yet the downstream molecular targets that regulate DC homeostasis and development are largely unknown. A recent study using gene expression analysis of IRF8-deficient myeloid and lymphoid progenitors identified the Myc paralog Mycl1 as a potential transcriptional target of IRF8. We report here that Mycl1 is a mediator of DC homeostasis at steady state and during inflammation, and its expression is regulated by IRF8 in multiple DC lineages. We have further validated these observations with ChIP-Seq of IRF8 binding to the Mycl1 locus. Notably, IRF8 binding to Mycl1 locus is independent of an interaction with the AP1 factor, BATF3. Additionally, our genome-wide survey of IRF8 binding identified both EICE and AICE motifs. Examination of IRF8 binding in dendritic cells
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s.
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s.
Project description:The gene expression in conventional and plasmacytoid dendritic cells (cDC and pDC respectively) during Bluetongue virus (BTV) infection in sheep depends on the lymphoid compartment and suggest that these cell types have a role in the physiopathology
Project description:Cholangitis mouse models were characterised by selective intrahepatic expansion of type 2 conventional dendritic cells, whereas plasmacytoid and type 1 conventional dendritic cells were not expanded. Expansion of type 2 conventional dendritic cells in human PSC lesions was confirmed by histology. Depletion studies revealed a pro-inflammatory role of type 2 conventional dendritic cells. Single-cell transcriptomics confirmed inflammatory maturation of the intrahepatic type 2 conventional dendritic cells and identified dendritic cell-derived inflammatory mediators.
Project description:The functional diversification of dendritic cells (DCs) is a key step in establishing protective immune responses. Despite the importance of this lineage diversity, its genetic basis is not fully understood. DC-SCRIPT (Zfp366) is a poorly known transcription factor expressed in conventional DCs (cDCs) and their committed bone marrow progenitors but not in plasmacytoid DCs (pDCs). We show that mice lacking DC-SCRIPT displayed substantially impaired development of IRF8-dependent conventional DC1 (cDC1), while cDC2 differentiated normally. The residual DC-SCRIPT-deficient cDC1s had impaired CD8+ T-cell cross-priming, which could be in part explained by the direct control of DC-SCRIPT on IL-12p40 production. Genome-wide mapping of DC-SCRIPT binding and gene expression analyses revealed a key role for DC-SCRIPT in maintaining cDC1 identity via the direct regulation of cDC1 signature genes, including Irf8. Our study reveals DC-SCRIPT to be a critical component of the gene regulatory program shaping the functional attributes of cDC1s. This SuperSeries is composed of the SubSeries listed below.
Project description:The transcription factor IRF8 is a critical regulator of plasmacytoid dendritic cell (pDC) and classical dendritic cell (cDC) development in both mouse and man. Yet the downstream molecular targets that regulate DC homeostasis and development are largely unknown. A recent study using gene expression analysis of IRF8-deficient myeloid and lymphoid progenitors identified the Myc paralog Mycl1 as a potential transcriptional target of IRF8. We report here that Mycl1 is a mediator of DC homeostasis at steady state and during inflammation, and its expression is regulated by IRF8 in multiple DC lineages. We have further validated these observations with ChIP-Seq of IRF8 binding to the Mycl1 locus. Notably, IRF8 binding to Mycl1 locus is independent of an interaction with the AP1 factor, BATF3. Additionally, our genome-wide survey of IRF8 binding identified both EICE and AICE motifs.
Project description:Induction of the transcription factor Irf8 in the common dendritic cell progenitor (CDP) is required for classical type 1 dendritic cell (cDC1) fate specification, but the mechanisms controlling this induction are unclear. Here we identified Irf8 enhancers and used CRISPR/Cas9 genome editing to assess their roles in Irf8 regulation. An enhancer 32 kilobases downstream of the Irf8 transcriptional start site (+32 kb Irf8) that was active in mature cDC1s was required for the development of this lineage, but not for its specification. Instead, a +41 kb Irf8 enhancer previously thought to be active only in plasmacytoid DCs (pDCs) was found to also be transiently accessible in cDC1 progenitors. Deletion of this enhancer reduced Irf8 expression in pDCs as expected, but also surprisingly prevented the induction of Irf8 in CDPs and abolished cDC1 specification. Thus, cryptic activation of the +41 kb Irf8 enhancer in DC progenitors is responsible for cDC1 fate specification.
Project description:Induction of the transcription factor Irf8 in the common dendritic cell progenitor (CDP) is required for classical type 1 dendritic cell (cDC1) fate specification, but the mechanisms controlling this induction are unclear. Here we identified Irf8 enhancers and used CRISPR/Cas9 genome editing to assess their roles in Irf8 regulation. An enhancer 32 kilobases downstream of the Irf8 transcriptional start site (+32 kb Irf8) that was active in mature cDC1s was required for the development of this lineage, but not for its specification. Instead, a +41 kb Irf8 enhancer previously thought to be active only in plasmacytoid DCs (pDCs) was found to also be transiently accessible in cDC1 progenitors. Deletion of this enhancer reduced Irf8 expression in pDCs as expected, but also surprisingly prevented the induction of Irf8 in CDPs and abolished cDC1 specification. Thus, cryptic activation of the +41 kb Irf8 enhancer in DC progenitors is responsible for cDC1 fate specification.