Project description:Macrophages are hematopoietic cells critical for innate immune defense, but also control organ homeostasis in a tissue-specific manner. Tissue-resident macrophages, therefore, provide a well-defined model to study the impact of ontogeny and microenvironment on chromatin state. Here, we profile the dynamics of four histone modifications across seven tissue-resident macrophage populations, as well as monocytes and neutrophils. We identify 12,743 macrophage-specific enhancers and establish that tissue-resident macrophages have distinct enhancer landscapes. Our work suggests that a combination of tissue and lineage-specific transcription factors form the regulatory networks controlling chromatin specification in tissue-resident macrophages. The environment has the capacity to alter the chromatin landscape of macrophages derived from transplanted adult bone marrow in vivo and even differentiated macrophages are reprogrammed when transferred into a new tissue. Altogether, these data provide a comprehensive view of macrophage regulation and highlight the importance of microenvironment along with pioneer factors in orchestrating macrophage identity and plasticity. 7 tissue-resident macrophage populations were isolated, as well as monocytes and neutrophils, and transcriptome analysis was performed. Experiment was done in duplicates.
Project description:Macrophages are hematopoietic cells critical for innate immune defense, but also control organ homeostasis in a tissue-specific manner. Tissue-resident macrophages, therefore, provide a well-defined model to study the impact of ontogeny and microenvironment on chromatin state. Here, we profile the dynamics of four histone modifications across seven tissue-resident macrophage populations, as well as monocytes and neutrophils. We identify 12,743 macrophage-specific enhancers and establish that tissue-resident macrophages have distinct enhancer landscapes. Our work suggests that a combination of tissue and lineage-specific transcription factors form the regulatory networks controlling chromatin specification in tissue-resident macrophages. The environment has the capacity to alter the chromatin landscape of macrophages derived from transplanted adult bone marrow in vivo and even differentiated macrophages are reprogramed when transferred into a new tissue. Altogether, these data provide a comprehensive view of macrophage regulation and highlight the importance of microenvironment along with pioneer factors in orchestrating macrophage identity and plasticity.
Project description:Macrophages are hematopoietic cells critical for innate immune defense, but also control organ homeostasis in a tissue-specific manner. Tissue-resident macrophages, therefore, provide a well-defined model to study the impact of ontogeny and microenvironment on chromatin state. Here, we profile the dynamics of four histone modifications across seven tissue-resident macrophage populations, as well as monocytes and neutrophils. We identify 12,743 macrophage-specific enhancers and establish that tissue-resident macrophages have distinct enhancer landscapes. Our work suggests that a combination of tissue and lineage-specific transcription factors form the regulatory networks controlling chromatin specification in tissue-resident macrophages. The environment has the capacity to alter the chromatin landscape of macrophages derived from transplanted adult bone marrow in vivo and even differentiated macrophages are reprogramed when transferred into a new tissue. Altogether, these data provide a comprehensive view of macrophage regulation and highlight the importance of microenvironment along with pioneer factors in orchestrating macrophage identity and plasticity.
Project description:Macrophages are hematopoietic cells critical for innate immune defense, but also control organ homeostasis in a tissue-specific manner. Tissue-resident macrophages, therefore, provide a well-defined model to study the impact of ontogeny and microenvironment on chromatin state. Here, we profile the dynamics of four histone modifications across seven tissue-resident macrophage populations, as well as monocytes and neutrophils. We identify 12,743 macrophage-specific enhancers and establish that tissue-resident macrophages have distinct enhancer landscapes. Our work suggests that a combination of tissue and lineage-specific transcription factors form the regulatory networks controlling chromatin specification in tissue-resident macrophages. The environment has the capacity to alter the chromatin landscape of macrophages derived from transplanted adult bone marrow in vivo and even differentiated macrophages are reprogramed when transferred into a new tissue. Altogether, these data provide a comprehensive view of macrophage regulation and highlight the importance of microenvironment along with pioneer factors in orchestrating macrophage identity and plasticity.
Project description:Macrophages reside in essentially all tissues of the body and play key roles in innate and adaptive immune responses. Distinct populations of tissue macrophages also acquire context-specific functions that are important for normal tissue homeostasis. To investigate mechanisms responsible for tissue-specific functions, we analyzed the transcriptomes and enhancer landscapes of brain microglia and resident macrophages of the peritoneal cavity. In addition, we exploited natural genetic variation as a genome-wide “mutagenesis” strategy to identify DNA recognition motifs for transcription factors that promote common or subset-specific binding of the macrophage lineage-determining factor PU.1. We find that distinct tissue environments drive divergent programs of gene expression by differentially activating a common enhancer repertoire and by inducing the expression of divergent secondary transcription factors that collaborate with PU.1 to establish tissue-specific enhancers. These findings provide insights into molecular mechanisms by which tissue environment influences macrophage phenotypes that are likely to be broadly applicable to other cell types. Chromatin marks H3K4me2, H3K27Ac, and transcription factors PU.1 were assessed by ChIP-Seq and RNA-Seq were used to measure gene expression in 5 different macrophage subtypes.
Project description:Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. We now report that knock-down of MAFB impairs the acquisition of the anti-inflammatory profile of human macrophages, identify the MAFB-dependent gene signature in human macrophages and illustrate the co-expression of MAFB and MAFB-target genes in CD163+ tissue-resident and tumor associated macrophages. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene. Our results demonstrate that MAFB critically determines the acquisition of the anti-inflammatory transcriptional and functional profiles of human macrophages.
Project description:Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. We now report that knock-down of MAFB impairs the acquisition of the anti-inflammatory profile of human macrophages, identify the MAFB-dependent gene signature in human macrophages and illustrate the co-expression of MAFB and MAFB-target genes in CD163+ tissue-resident and tumor associated macrophages. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene. Our results demonstrate that MAFB critically determines the acquisition of the anti-inflammatory transcriptional and functional profiles of human macrophages.