Project description:We report that cavity macrophages from the pericardial, pleural and peritoneal cavities have distinct expression profile from cardiac macrophages
Project description:The goal of this study is to compare the transcriptome profile (RNA-seq) of peritoneal cavity macrophages of RXRa-deficient and WT mice to identify genes which are controlled by the expression of the TF RXRa
Project description:In mouse peritoneal and other serous cavities, the transcription factor Gata6 drives the identity of the major cavity resident population of macrophages, with a smaller subset of cavity-resident macrophages dependent on the transcription factor Irf4. Here we showed that GATA6+ macrophages in the human peritoneum were rare, regardless of age. Instead, more human peritoneal macrophages aligned with mouse CD206+ LYVE1+ cavity macrophages that represent a differentiation stage just preceding expression of Gata6. Low abundance of CD206+ macrophages was retained in C57BL/6J mice fed a high-fat diet or in wild-captured mice, suggesting that differences between serous cavity-resident macrophages in humans and mice were not environmental. Irf4-dependent mouse serous cavity macrophages aligned closely with human CD1c+CD14+CD64+ peritoneal cells that, in turn, resembled human peritoneal CD1c+CD14-CD64- cDC2. Thus, major populations of serous cavity-resident mononuclear phagocytes in humans and mice shared common features but the proportions of different macrophage differentiation stages greatly differ between the two species and DC2-like cells were especially prominent in humans.
Project description:We seeked to determine in vivo effects of IFNg and IFNa response in peritoneal cavity macrophages. These cells were part of ImmGen Interferon cytokine study and immunocytes were sorted according to Immgen's standard lineage panel. Profiles from peritoneal cavity macrophages were used to analyze cell specific responses to IFNg.
Project description:The recent revolution in tissue-resident macrophage biology has resulted largely from murine studies performed in the C57BL/6 strain. Here, we provide a comprehensive analysis of immune cells in the pleural cavity using both C57BL/6 and BALB/c mice. Unlike C57BL/6 mice, naïve tissue-resident Large Cavity Macrophages (LCM) of BALB/c mice failed to fully implement the tissue residency programme. Following infection with a pleural-dwelling nematode these pre-existing differences were accentuated with LCM expansion occurring in C57BL/6 but not BALB/c mice. While infection drove monocyte recruitment in both strains, only in C57BL/6 mice were monocytes able to integrate into the resident pool. Monocyte to macrophage conversion required both T cells and IL-4Rα signalling. Host genetics are therefore a key influence on tissue resident macrophage biology, and during nematode infection Th2 cells control the differentiation pathway of tissue resident macrophages.
Project description:The first macrophages that seed the developing heart originate from the yolk sac during fetal life. While murine studies reveal important homeostatic and reparative functions in adults, we know little about their roles in the earliest stages of human heart development due to a lack of accessible tissue. Generation of bioengineered human cardiac microtissues from pluripotent stem cells models these first steps in cardiac tissue development, however macrophages have not been included in these studies. To bridge these gaps, we differentiated human embryonic stem cells (hESCs) into primitive LYVE1+ macrophages (hESC-macrophages; akin to yolk sac macrophages) that stably engrafted within cardiac microtissues composed of hESC-cardiomyocytes and fibroblasts to study reciprocal interactions. Engraftment induced a tissue resident macrophage gene program resembling human fetal cardiac macrophages, enriched in efferocytic pathways. Functionally, hESC-macrophages induced production and maturation of cardiomyocyte sarcomeric proteins, and enhanced contractile force, relaxation kinetics, and electrical properties. Mechanistically, the primary effect of hESC-macrophages was during the stressful events surrounding early microtissue formation, where they engaged in phosphatidylserine dependent ingestion of apoptotic cardiomyocyte cargo, which reinforced core resident macrophage identity, reduced microtissue stress and drove hESC-cardiomyocytes to become more similar to human ventricular cardiomyocytes found in early development, both transcriptionally and metabolically. Inhibiting efferocytosis of hESC-cardiomyocytes by hESC-macrophages led to increased cell stress, impaired sarcomeric protein maturation and reduced cardiac microtissue function (contraction and relaxation). Taken together, macrophage-engineered human cardiac microtissues represent a considerably improved model for human heart development, and reveal a major beneficial, yet previously unappreciated role for human primitive macrophages in enhancing cardiac tissue function.
Project description:Tissue macrophages from peritoneal cavity, lung, liver, spleen, small intestine and adipose tissue and M-CSF derived bone marrow derived macrophages (BMDMs) were determined for gene expression. Macrophages from six different tissues and BMDMs were compared for gene expression.
Project description:Mononuclear phagocytes promote injury and repair following myocardial infarction but discriminating functions within mixed populations remains challenging. We utilized fate mapping and single cell RNA-sequencing to delineate fate specification trajectories of heterogeneous cardiac macrophage subpopulations. In steady state, TIMD4 expression tracked with a dominant resident cardiac macrophage subset that persisted via in situ self-renewal with minimal monocyte input. Following ischemic injury, monocytes displayed significant plasticity, ultimately adopting transcriptional states similar to resident macrophages, but also multiple unique states. Ischemic injury reduced resident macrophage abundance within infarct tissue, and despite transcriptional similarity, TIMD4 expression distinguished resident from recruited macrophages. Specific lineage-based depletion of resident cardiac macrophages resulted in depressed cardiac function and adverse remodeling primarily within the peri-infarct zone, the only region of the myocardium where resident macrophages expanded numerically following injury. Together, these data highlight a non-redundant, cardioprotective role of resident cardiac macrophages, and the diverse transcriptional fates recruited monocytes can adopt.
Project description:Tissue macrophages from peritoneal cavity, lung, liver, spleen, small intestine and adipose tissue and M-CSF derived bone marrow derived macrophages (BMDMs) were determined for gene expression.