Project description:Langerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC. Primary cells were isolated from peripheral blood (mDC1 and pDC), skin (epidermal Langerhans cells) and CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations. RNA was isolated from these cells ex vivo.
Project description:Langerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC.
Project description:An IRF8-dependent subset of classical dendritic cells (cDCs), termed DC1, effectively cross-primes CD8+ T cells and facilitates antitumor T cell responses. Etv6 is an ETS family transcription factor that controls hematopoietic stem and progenitor cell (HSPC) function. We report that like HSPC, cDCs express Etv6 but not its antagonist ETS1, whereas interferon-producing plasmacytoid dendritic cells (pDCs) express both factors. Deletion of Etv6 in the bone marrow reduced the generation of DC1-like cells in vitro and the differentiation of DC1 in vivo, including the loss of signature marker CD8a. Global expression and chromatin profiling of Etv6-deficient DCs revealed impaired lineage identity of DC1, including the reduction of cDC signature and upregulation of pDC signature. Accordingly, DC-specific Etv6 deletion impaired CD8+ T cell cross-priming and tumor-specific CD8+ T cell responses. These results identify Etv6 as a regulator of DC1 differentiation and functional fitness that indirectly facilitates T cell cross-priming and antitumor immunity.
Project description:An IRF8-dependent subset of classical dendritic cells (cDCs), termed DC1, effectively cross-primes CD8+ T cells and facilitates antitumor T cell responses. Etv6 is an ETS family transcription factor that controls hematopoietic stem and progenitor cell (HSPC) function. We report that like HSPC, cDCs express Etv6 but not its antagonist ETS1, whereas interferon-producing plasmacytoid dendritic cells (pDCs) express both factors. Deletion of Etv6 in the bone marrow reduced the generation of DC1-like cells in vitro and the differentiation of DC1 in vivo, including the loss of signature marker CD8a. Global expression and chromatin profiling of Etv6-deficient DCs revealed impaired lineage identity of DC1, including the reduction of cDC signature and upregulation of pDC signature. Accordingly, DC-specific Etv6 deletion impaired CD8+ T cell cross-priming and tumor-specific CD8+ T cell responses. These results identify Etv6 as a regulator of DC1 differentiation and functional fitness that indirectly facilitates T cell cross-priming and antitumor immunity.
Project description:Dendritic cells (DCs) are critical in mediating immunity to pathogens, vaccines, tumors and tolerance to self. Significant progress has been made in the study of DC subsets in murine models but the translation of these findings to human DC immunobiology has not been fully realized. Murine splenic CD8+ DC and CD103+ DC possess potent antigen cross-presenting capacity. Although recent evidence points to human blood CD141+ DCs as the functional equivalent of CD8+ DC, the precise identity of the human migratory cross-presenting DC has remained elusive. We performed phenotypic and functional analyses to interrogate the DC compartment of human non-lymphoid tissues and identified three distinct subsets: i) CD141high DCs, ii) CD1c DCs and iii) CD14+ DCs. Only CD141high DCs were capable of cross-presenting soluble antigen. Comparative transcriptome analysis of steady state monocyte and DC subsets between mouse and human confirmed conservation between species, aligning the following subsets together: i) human CD141high DCs with mouse CD8+ and CD103+ DCs, ii) human CD1c+ DCs with mouse CD4+ DCs and iii) human CD14+ DC with mouse monocyte subsets. The lack of positive association between human CD1c+ DCs and mouse non-lymphoid tissue CD11b+ DCs highlights heterogeneity and predicts the existence of a monocyte-like cell within the CD11b+ DCs. Gene expression analysis using total RNA from specific human and mouse monocyte and dendritic cell subsets purified by FACS.
Project description:Dendritic cells (DCs) are critical in mediating immunity to pathogens, vaccines, tumors and tolerance to self. Significant progress has been made in the study of DC subsets in murine models but the translation of these findings to human DC immunobiology has not been fully realized. Murine splenic CD8+ DC and CD103+ DC possess potent antigen cross-presenting capacity. Although recent evidence points to human blood CD141+ DCs as the functional equivalent of CD8+ DC, the precise identity of the human migratory cross-presenting DC has remained elusive. We performed phenotypic and functional analyses to interrogate the DC compartment of human non-lymphoid tissues and identified three distinct subsets: i) CD141high DCs, ii) CD1c DCs and iii) CD14+ DCs. Only CD141high DCs were capable of cross-presenting soluble antigen. Comparative transcriptome analysis of steady state monocyte and DC subsets between mouse and human confirmed conservation between species, aligning the following subsets together: i) human CD141high DCs with mouse CD8+ and CD103+ DCs, ii) human CD1c+ DCs with mouse CD4+ DCs and iii) human CD14+ DC with mouse monocyte subsets. The lack of positive association between human CD1c+ DCs and mouse non-lymphoid tissue CD11b+ DCs highlights heterogeneity and predicts the existence of a monocyte-like cell within the CD11b+ DCs. Gene expression analysis using total RNA from specific human and mouse monocyte and dendritic cell subsets purified by FACS.
Project description:This study showed that the oncogenic ligand Wnt1 silences chemokine genes in dendritic cells, leading to impaired cross-priming of T cells in lung adenocarcinoma. Blocking Wnt1 enhanced rejection of tumors by acting concomitantly at the cancer and immune cell level.
Project description:The IRF8-dependent subset of classical dendritic cells (cDC), termed cDC1, is important for cross-priming cytotoxic T cell responses against pathogens and tumors. Culture of hematopoietic progenitors with DC growth factor Flt3 ligand (Flt3L) yields very few cDC1 (in humans) or only immature "cDC1-like" cells (in the mouse). We report that OP9 stromal cells expressing Notch ligand Delta-like 1 (OP9-DL1) optimize Flt3L-driven development of cDC1 from murine immortalized progenitors and primary bone marrow cells. Co-culture with OP9-DL1 induced IRF8-dependent cDC1 with the phenotype (CD103+ Dec205+ CD8α+) and expression profile resembling ex vivo cDC1. OP9-DL1-induced cDC1 showed preferential migration towards Ccr7 ligands in vitro and superior T cell cross-priming and antitumor vaccination in vivo. Co-culture with OP9-DL1 also greatly increased the yield of IRF8-dependent CD141+ cDC1 from human bone marrow progenitors cultured with Flt3L. Thus, Notch signaling optimizes cDC generation in vitro and yields authentic cDC1 for functional studies and therapeutic applications.
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.