Project description:Idiopathic pulmonary fibrosis (IPF) is a complex disease involving various cell types. Macrophages are essential in maintenance of physiological homeostasis, wound repair and fibrosis in the lung. Macrophages play a crucial role in repair and remodeling by altering their phenotype and secretory pattern in response to injury. The secretome of induced pluripotent stem cells (iPSC-cm) attenuates injury and fibrosis in bleomycin injured rat lungs. In the current study, we evaluate the effect of iPSC-cm on interstitial macrophage gene expression and phenotype in bleomycin injured rat lungs in vivo. Â iPSC-cm was intratracheally instilled 7 days after bleomycin induced lung injury and assessed 7 days later and single cell isolation was performed. Macrophages were FACS sorted and microarray analysis was performed. We characterized changes in the rat lung interstitial macrophages using transcriptional profiling.
Project description:Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is the leading cause of death in patients with systemic sclerosis (SSc) with unclear pathogenesis and limited treatment options. Evidence strongly supports an important role for profibrotic, SPP1-expressing macrophages in SSc-ILD. We sought to define the transcriptome and chromatin structural changes of SPP1 SSc-ILD macrophages, so as to better understand their role in promoting fibrosis and to identify transcription factors associated with open chromatin driving their altered phenotype.
Project description:We demonstrate that deficiency of IL-9 signaling inhibits lung tumor growth in multiple models. In defining the IL-9-responsive cells in the lung tumor models, we found IL-9 regulates lung heterogeneity by inhibiting alveolar macrophage and promoting the expansion of both CD11c+ and CD11c- interstitial macrophage populations. Interstitial macrophages are a critical IL-9-responsive population that is required to promote lung tumor growth. Mechanistically, the IL-9/macrophage axis requires arginase1 (Arg1) to mediate tumor growth. Adoptive transfer of Arg1+ but not Arg1- lung macrophages to Il9r-/- mice dramatically increases the tumor growth. In parallel, the elevated expression of IL-9R and Arg1 in human tumor associated macrophages is correlated with poor prognosis among lung cancer patients. Moreover, targeting IL-9 signaling in lung macrophages limited lung tumor growth.
Project description:This SuperSeries is composed of the following subset Series: GSE21369: Gene expression profiles of interstitial lung disease (ILD) patients GSE21394: MicroRNA expression profiles of interstitial lung disease (ILD) patients Refer to individual Series
Project description:In this study we demonstrate that the lung mononuclear phagocyte system comprises three interstitial macrophages (IMs), as well as alveolar macrophages (AMs), dendritic cells and few extravascular monocytes. Through cell sorting and RNAseq analysis we were able to identify transcriptional similarities and differences between the three pulmonary IM subtypes, with reference to the more well-characterized alveolar macrophage
Project description:Monocytes and macrophages play pivotal roles in tissue homeostasis and tumor progression. Here, we show that these cells express high levels of LAIR1, a known receptor for Collagen. Using a high throughput cell-based platform for interactome discovery, we identified Colec12, a protein expressed by stromal cells, as a novel high affinity LAIR1 ligand. Using a combination of genomic, phenotypic, global phosphoproteomics and transcriptomics assays, we corroborated the role of LAIR1 signaling in myeloid cells. Under homeostasis LAIR1 restrained proliferation and promoted survival of non-classical monocytes and dysregulation of this pathway led to an increase in classical monocytes and tissue-infiltrating macrophages in lungs. In tumors, LAIR1 deficiency in myeloid cells exacerbated metastasis to lungs and confirmed LAIR1 as a positive prognostic factor in human metastatic melanoma. Our study shows extracellular matrix provides monocytes and lung interstitial macrophages important homeostatic signals that are mediated via LAIR1. Methods: 10x single cell RNA sequencing was performed to characterize the differences between WT and LAIR1KO lung myeloid cells with and without tumor. Murine lungs were digested, cells were hashtagged and FACS-sorted for Interstitial macrophages, Alveolar macrophages, classical and nonclassical monocytes.
Project description:We developed a simplified flow cytometry strategy in order to discriminate monocytes and macrophages in the lung of C57BL/6 mice. Using this strategy, we identified autofluorescent F4/80+ CD11c+ alveolar macrophages, non-autofluorescent CD64+Ly-6C- interstitial macrophages and Ly-6Chi monocytes residing in the lung of WT mice. A fraction of these Ly-6Chi monocytes corresponded to classical blood monocytes associated with the lung vasculature, but another fraction did not depend on CCR2, the chemokine receptor required for monocytes to egress from the bone marrow, as a population of lung Ly-6Chi monocytes was also present in the lung of Ccr2-/- mice. A remaining question was whether lung monocytes represented a particular population of monocytes that could be distinguishable from the classical CCR2-dependent blood monocytes. To address this issue, we performed a transcriptomic comparison of Ly-6Chi monocytes recovered from flushed lung of WT mice (â60% of CCR2- dependent classical blood monocytes and â40% of lung monocytes) and Ccr2-/- mice (more than 95% of lung monocytes). In addition, we tested whether exposure to TLR ligands would affect interstitial macrophages, and we compared to transcriptome of IM at steady-state and IM 1 week after administration of 50 µg CpG-DNA intratracheally.
Project description:Macrophages are a heterogeneous cell population involved in tissue homeostasis, inflammation and in multiple pathologies. Although the major tissue-resident macrophage populations have been extensively studied, interstitial macrophages (IMs) residing within tissue parenchyma remain poorly defined. Here, we studied IMs from murine lung, fat, heart and dermis. We identified two independent IM subpopulations that are conserved across tissues: Lyve1loMHCIIhiCX3CR1hi (Lyve1loMHCIIhi) and Lyve1hiMHCIIloCX3CR1lo (Lyve1hiMHCIIlo) monocyte-derived IMs, with distinct gene expression profiles, phenotypes, functions, and localisation. Using a mouse model of inducible macrophage depletion (SLCO2B1-DTR), we found that the absence of Lyve1hiMHCIIlo IMs exacerbated experimental lung fibrosis. Thus, we demonstrate that two independent populations of IMs exist across tissues and exhibit conserved niche-dependent functional programming.