Project description:Dendritic cells (DCs) in lymphoid tissue comprise conventional DCs (cDCs) and plasmacytoid DCs (pDCs) that develop from common DC progenitors (CDPs). CDPs are Flt3+c-kitintM-CSFR+ and reside in bone marrow. Here we describe a two-step culture system that recapitulates DC development from c-kithiFlt3-/lo multipotent progenitors (MPPs) into CDPs and further into cDC and pDC subsets. MPPs and CDPs are amplified in vitro with Flt3 ligand, stem cell factor, hyper-IL-6 and insulin- like growth factor-1. The four-factor cocktail readily induces self-renewal of MPPs and their progression into CDPs and has no self-renewal activity on CDPs. The amplified CDPs respond to all known DC poietins and generate all lymphoid tissue DCs in vivo and in vitro. Additionally, in vitro CDPs recapitulate the cell surface marker and gene expression profile of in vivo CDPs and possess a DC-primed transcription profile. Transforming growth factor-β1 (TGF-β1) impacts on CDPs and directs their differentiation towards cDCs. Genome-wide gene expression profiling of TGF-β1-induced genes identified transcription factors, such as interferon regulatory factor-4 (IRF-4) and RelB, that are implicated as instructive factors for cDC subset specification. TGF-β1 also induced the transcription factor inhibitor of differentiation/DNA binding 2 (Id2) that suppresses pDC development. Thus, TGF-β1 directs CDP differentiation into cDC by inducing both cDC instructive factors and pDC inhibitory factors. 20 samples in total. Multipotent progenitor - MPP_1 - MPP_2 Common dendritic cell progenitor - CDP_1 - CDP_2 Plasmacytoid dendritic cell - pDC_1 - pDC_2 Conventional dendritic cell - cDC_1 - cDC_2 In vivo common dendritic cell progenitor - In vivo CDP_1 - In vivo CDP_2 Untreated common dendritic cell progenitor (CDP) - CDP_0h_1 - CDP_0h_2 TGF-beta1 treated (4 hours) CDP - CDP_4h_1 - CDP_4h_2 TGF-beta1 treated (8 hours) CDP - CDP_8h_1 - CDP_8h_2 TGF-beta1 treated (12 hours) CDP - CDP_12h_1 - CDP_12h_2 TGF-beta1 treated (24 hours) CDP - CDP_24h_1 - CDP_24h_2
Project description:Multipotent progenitors (MPP) and common dendritic cell progenitors (CDP) were obtained from mouse bone marrow, followed by in vitro culture with a specific cytokine cocktail and FACS sorting (Felker et al., 2010; Seré et al., 2012). Cells were treated with 10 ng/ml recombinant human TGF-β1 (R&D Systems, Minneapolis, USA) for 2, 4, 8, 12 and 24 h as described (Felker et al., 2010) or left untreated.
Project description:Dendritic cells (DC) develop from hematopoietic stem cells, which is guided by instructive signals through cytokines. DC development progresses from multipotent progenitors (MPP) via common DC progenitors (CDP) into DC. Flt3 ligand (Flt3L) signaling via the Flt3/Stat3 pathway is of pivotal importance for DC development under steady state conditions. Additional factors produced during steady state or inflammation, such as TGF-beta1 or GM-CSF, also influence the differentiation potential of MPP and CDP. Here, we studied how gp130, GM-CSF and TGF-beta1 signaling influence DC lineage commitment from MPP to CDP and further into DC. We observed that activation of gp130 signaling promotes expansion of MPP. Additionally, gp130 signaling inhibited Flt3L-driven DC differentiation, but had little effect on GM-CSF-driven DC development. The inflammatory cytokine GM-CSF induces differentiation of MPP into inflammatory DC and blocks steady state DC development. Global transcriptome analysis revealed a GM-CSF-driven gene expression repertoire that primes MPP for differentiation into inflammatory DC. Finally, TGF-beta1 induces expression of DC-lineage affiliated genes in MPP, including Flt3, Irf-4 and Irf-8. Under inflammatory conditions, however, the effect of TGF- beta1 is altered: Flt3 is not upregulated, indicating that an inflammatory environment inhibits steady state DC development. Altogether, our data indicate that distinct cytokine signals produced during steady state or inflammation have a different outcome on DC lineage commitment and differentiation. 6 samples in total. Multipotent progenitor - GM-MPP_1 - GM-MPP_2 Dendritic cell - GM-DC_1 - GM-DC_2 Dendritic cell plus TNFa - GM-TNFa-DC_1 - GM-TNFa-DC_2
Project description:TGF-β1 Accelerates Dendritic Cell Differentiation from Common Dendritic Cell Progenitors (CDPs) and Directs Subset Specification Towards Conventional Dendritic Cells
Project description:The development of dendritic cells (DCs) is regulated by complex transcriptional networks. DCs originate from the multipotent progenitors (MPPs) in the bone marrow, which could further give rise to common lymphoid progenitors (CLPs) and common dendritic cell progenitors (CDPs). Whereas CDPs, which could be further divided into CD115+ and CD115- populations, give rise to both conventional (cDC) and plasmacytoid DCs (pDCs), CLP is an addtional source of pDCs. Transcriptome profiling of wild type and Trim33-/- MPPs, CD115- CDPs, and CLPs revealed a critical role of TRIM33 in the development of DCs.
Project description:Pedro Vizán, Daniel S. J. Miller, Ilaria Gori, Debipriya Das, Bernhard Schmierer & Caroline S. Hill. Controlling long-term signaling: receptor dynamics determine attenuation and refractory behavior of the TGF-β pathway. Science Signaling 6, 305 (2013).
Understanding the complex dynamics of growth factor signaling requires both mechanistic and kinetic information. Although signaling dynamics have been studied for pathways downstream of receptor tyrosine kinases and G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors, they have not been investigated for the transforming growth factor-β (TGF-β) superfamily pathways. Using an integrative experimental and mathematical modeling approach, we dissected the dynamic behavior of the TGF-β to Smad pathway, which is mediated by type I and type II receptor serine/threonine kinases, in response to acute, chronic, and repeated ligand stimulations. TGF-β exposure produced a transient response that attenuated over time, resulting in desensitized cells that were refractory to further acute stimulation. This loss of signaling competence depended on ligand binding, but not on receptor activity, and was restored only after the ligand had been depleted. Furthermore, TGF-β binding triggered the rapid depletion of signaling-competent receptors from the cell surface, with the type I and type II receptors exhibiting different degradation and trafficking kinetics. A computational model of TGF-β signal transduction from the membrane to the nucleus that incorporates our experimental findings predicts that autocrine signaling, such as that associated with tumorigenesis, severely compromises the TGF-β response, which we confirmed experimentally. Thus, we have shown that the long-term signaling behavior of the TGF-β pathway is determined by receptor dynamics, does not require TGF-β-induced gene expression, and influences context-dependent responses in vivo.