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Nature Communications Sep 2022Cellular metabolism underpins immune cell functionality, yet our understanding of metabolic influences in human dendritic cell biology and their ability to orchestrate...
Cellular metabolism underpins immune cell functionality, yet our understanding of metabolic influences in human dendritic cell biology and their ability to orchestrate immune responses is poorly developed. Here, we map single-cell metabolic states and immune profiles of inflammatory and tolerogenic monocytic dendritic cells using recently developed multiparametric approaches. Single-cell metabolic pathway activation scores reveal simultaneous engagement of multiple metabolic pathways in distinct monocytic dendritic cell differentiation stages. GM-CSF/IL4-induce rapid reprogramming of glycolytic monocytes and transient co-activation of mitochondrial pathways followed by TLR4-dependent maturation of dendritic cells. Skewing of the mTOR:AMPK phosphorylation balance and upregulation of OXPHOS, glycolytic and fatty acid oxidation metabolism underpin metabolic hyperactivity and an immunosuppressive phenotype of tolerogenic dendritic cells, which exhibit maturation-resistance and a de-differentiated immune phenotype marked by unique immunoregulatory receptor signatures. This single-cell dataset provides important insights into metabolic pathways impacting the immune profiles of human dendritic cells.
Topics: Cell Differentiation; Dendritic Cells; Glycolysis; Humans; Monocytes; Oxidative Phosphorylation
PubMed: 36056019
DOI: 10.1038/s41467-022-32849-1 -
International Journal of Molecular... Oct 2022In the last decade, there has been a tremendous revival of interest in monocyte and macrophages [...].
In the last decade, there has been a tremendous revival of interest in monocyte and macrophages [...].
Topics: Monocytes; Macrophages
PubMed: 36293261
DOI: 10.3390/ijms232012404 -
Immunology Jan 2020Monocyte-derived macrophages (MDMs) generated from peripheral blood monocytes are widely used to model human macrophages for in vitro studies. However, the possible... (Comparative Study)
Comparative Study
Monocyte-derived macrophages (MDMs) generated from peripheral blood monocytes are widely used to model human macrophages for in vitro studies. However, the possible impact of different isolation methods on the resulting MDM phenotype is poorly described. We aimed to investigate the effects of three commonly used monocyte isolation techniques on the resulting MDM phenotype. Plastic adhesion, negative selection, and CD14 selection were compared. Monocyte-derived macrophages were generated by 5-day culture with macrophage and granulocyte-macrophage colony-stimulating factors. We investigated monocyte and MDM yields, purity, viability, and cell phenotype. CD14 selection resulted in highest monocyte yield (19·8 × 10 cells, equivalent to 70% of total) and purity (98·7%), compared with negative selection (17·7 × 10 cells, 61% of total, 85·0% purity), and plastic adhesion (6·1 × 10 cells, 12·9% of total, 44·2% purity). Negatively selected monocytes were highly contaminated with platelets. Expression of CD163 and CD14 were significantly lower on CD14 selection and plastic adhesion monocytes, compared with untouched peripheral blood mononuclear cells. After maturation, CD14 selection also resulted in the highest MDM purity (98·2%) compared with negative selection (94·5%) and plastic adhesion (66·1%). Furthermore, MDMs from plastic adhesion were M1-skewed (CD80 HLA-DR CD163 ), whereas negative selection MDMs were M2-skewed (CD80 HLA-DR CD163 ). Choice of monocyte isolation method not only significantly affects yield and purity, but also impacts resulting phenotype of cultured MDMs. These differences may partly be explained by the presence of contaminating cells when using plastic adherence or negative selection. Careful considerations of monocyte isolation methods are important for designing in vitro assays on MDMs.
Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Biomarkers; Cell Adhesion; Cell Differentiation; Cell Separation; Cells, Cultured; Flow Cytometry; Humans; Interleukin-6; Lectins, C-Type; Lipopolysaccharide Receptors; Macrophages; Mannose Receptor; Mannose-Binding Lectins; Monocytes; Phenotype; Receptors, Cell Surface; Tumor Necrosis Factor-alpha
PubMed: 31573680
DOI: 10.1111/imm.13125 -
Cell Reports Mar 2023Inflammatory stimuli cause a state of emergency myelopoiesis leading to neutrophil-like monocyte expansion. However, their function, the committed precursors, or growth...
Inflammatory stimuli cause a state of emergency myelopoiesis leading to neutrophil-like monocyte expansion. However, their function, the committed precursors, or growth factors remain elusive. In this study we find that Ym1Ly6C monocytes, an immunoregulatory entity of neutrophil-like monocytes, arise from progenitors of neutrophil 1 (proNeu1). Granulocyte-colony stimulating factor (G-CSF) favors the production of neutrophil-like monocytes through previously unknown CD81CX3CR1 monocyte precursors. GFI1 promotes the differentiation of proNeu2 from proNeu1 at the cost of producing neutrophil-like monocytes. The human counterpart of neutrophil-like monocytes that also expands in response to G-CSF is found in CD14CD16 monocyte fraction. The human neutrophil-like monocytes are discriminated from CD14CD16 classical monocytes by CXCR1 expression and the capacity to suppress T cell proliferation. Collectively, our findings suggest that the aberrant expansion of neutrophil-like monocytes under inflammatory conditions is a process conserved between mouse and human, which may be beneficial for the resolution of inflammation.
Topics: Mice; Animals; Humans; Monocytes; Neutrophils; Myelopoiesis; Cell Differentiation; Granulocyte Colony-Stimulating Factor
PubMed: 36862552
DOI: 10.1016/j.celrep.2023.112165 -
Current Protocols Jun 2022Tissue-resident macrophages are present in all tissues where they perform homeostatic and immune surveillance functions. In many tissues, resident macrophages develop...
Tissue-resident macrophages are present in all tissues where they perform homeostatic and immune surveillance functions. In many tissues, resident macrophages develop from embryonic progenitors, which mature into a self-maintaining population through local proliferation. However, tissue-resident macrophages can be supported by recruited monocyte-derived macrophages during scenarios such as tissue growth, infection, or sterile inflammation. Circulating blood monocytes arise from hematopoietic stem cell progenitors and possess unique gene profiles that support additional functions within the tissue. Determining cell origins (ontogeny) and cellular turnover within tissues has become important to understanding monocyte and macrophage contributions to tissue homeostasis and disease. Fate mapping, or lineage tracing, is a promising approach to tracking cells based on unique gene expression driving reporter systems, often downstream of a Cre-recombinase-mediated excision event, to express a fluorescent protein. This approach is typically deployed temporally with developmental stage, disease onset, or in association with key stages of inflammation resolution. Importantly, myeloid fate mapping can be combined with many emerging technologies, including single-cell RNA-sequencing and spatial imaging. The application of myeloid cell fate mapping approaches has allowed for impactful discoveries regarding myeloid ontogeny, tissue residency, and monocyte fate within disease models. This protocol outline will discuss a variety of myeloid fate mapping approaches, including constitutive and inducible labeling approaches in adult and embryo tissues. This article outlines basic approaches and models used in mice for fate mapping macrophages. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Adult Fate Mapping Basic Protocol 2: Embryonic Fate Mapping.
Topics: Animals; Cell Differentiation; Hematopoietic Stem Cells; Inflammation; Macrophages; Mice; Monocytes
PubMed: 35687806
DOI: 10.1002/cpz1.456 -
Nature Communications Sep 2019Resident tissue macrophages (RTM) can fulfill various tasks during development, homeostasis, inflammation and repair. In the lung, non-alveolar RTM, called interstitial...
Resident tissue macrophages (RTM) can fulfill various tasks during development, homeostasis, inflammation and repair. In the lung, non-alveolar RTM, called interstitial macrophages (IM), importantly contribute to tissue homeostasis but remain little characterized. Here we show, using single-cell RNA-sequencing (scRNA-seq), two phenotypically distinct subpopulations of long-lived monocyte-derived IM, i.e. CD206 and CD206IM, as well as a discrete population of extravasating CD64CD16.2 monocytes. CD206 IM are peribronchial self-maintaining RTM that constitutively produce high levels of chemokines and immunosuppressive cytokines. Conversely, CD206IM preferentially populate the alveolar interstitium and exhibit features of antigen-presenting cells. In addition, our data support that CD64CD16.2 monocytes arise from intravascular Ly-6C patrolling monocytes that enter the tissue at steady-state to become putative precursors of CD206IM. This study expands our knowledge about the complexity of lung IM and reveals an ontogenic pathway for one IM subset, an important step for elaborating future macrophage-targeted therapies.
Topics: Animals; Flow Cytometry; Lung; Macrophages, Alveolar; Mice, Inbred C57BL; Monocytes; Phenotype; Sequence Analysis, RNA; Single-Cell Analysis
PubMed: 31481690
DOI: 10.1038/s41467-019-11843-0 -
Theranostics 2022Monocytes belong to the mononuclear phagocyte system and are immune responders to tissue injury and infection. There were also reports of monocytes transforming to...
Monocytes belong to the mononuclear phagocyte system and are immune responders to tissue injury and infection. There were also reports of monocytes transforming to microglia-like cells. Here we explore the roles of monocytes in microglia ontogeny and the pathogenesis of neonatal cerebral hypoxic-ischemic (HI) brain injury in mice. We used three genetic methods to track the development of monocytes, including CX3CR1; CCR2 reporter mice, adoptive transfer of GFP monocytes, and fate-mapping with CCR2-CreER mice, in neonatal mouse brains with or without lipopolysaccharide (LPS, 0.3 mg/kg)-sensitized Vannucci HI. We also used genetic (CCR2, CCR2 knockout) and pharmacological methods (RS102895, a CCR2 antagonist) to test the roles of monocytic influx in LPS/HI brain injury. CCR2 monocytes entered the late-embryonic brains via choroid plexus, but rapidly became CX3CR1 amoeboid microglial cells (AMCs). The influx of CCR2 monocytes declined after birth, but recurred after HI or LPS-sensitized HI (LPS/HI) brain injury, particularly in the hippocampus. The CCR2-CreER-based fate-mapping showed that CCR2 monocytes became CD68 TNFα macrophages within 4 d after LPS/HI, and maintained as TNFα MHCII macrophages or persisted as Tmem119 Sall1 P2RY12 ramified microglia for at least five months after injury. Genetic deletion of the chemokine receptor CCR2 markedly diminished monocytic influx, the expression of pro- and anti-inflammatory cytokines, and brain damage. Post-LPS/HI application of RS102895 also reduced inflammatory responses and brain damage, leading to better cognitive functions. These results suggest that monocytes promote acute inflammatory responses and may become pathological microglia long after the neonatal LPS/HI insult. Further, blocking the influx of monocytes may be a potential therapy for neonatal brain injury.
Topics: Adoptive Transfer; Animals; Animals, Newborn; Brain Injuries; Cell Movement; Cells, Cultured; Choroid Plexus; Female; Hypoxia-Ischemia, Brain; Inflammation; Male; Mice, Inbred C57BL; Microglia; Monocytes; Neuroinflammatory Diseases; Receptors, CCR2; Mice
PubMed: 34976198
DOI: 10.7150/thno.64033 -
Aging Mar 2021
Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Aging; COVID-19; Humans; Immunosenescence; Middle Aged; Monocytes; SARS-CoV-2; Young Adult
PubMed: 33795524
DOI: 10.18632/aging.202918 -
International Journal of Molecular... Jun 2022Cell fusion (fusogenesis) occurs in natural and pathological conditions in prokaryotes and eukaryotes. Cells of monocyte-macrophage lineage are highly fusogenic. They... (Review)
Review
Cell fusion (fusogenesis) occurs in natural and pathological conditions in prokaryotes and eukaryotes. Cells of monocyte-macrophage lineage are highly fusogenic. They create syncytial multinucleated giant cells (MGCs) such as osteoclasts (OCs), MGCs associated with the areas of infection/inflammation, and foreign body-induced giant cells (FBGCs). The fusion of monocytes/macrophages with tumor cells may promote cancer metastasis. We describe types and examples of monocyte-macrophage lineage cell fusion and the role of actin-based structures in cell fusion.
Topics: Cell Differentiation; Cell Fusion; Giant Cells; Giant Cells, Foreign-Body; Monocytes; Osteoclasts
PubMed: 35742997
DOI: 10.3390/ijms23126553 -
Cells Jun 2023Monocytes are highly plastic innate immune cells that display significant heterogeneity during homeostasis, inflammation, and tumorigenesis. Tumor-induced systemic and... (Review)
Review
Monocytes are highly plastic innate immune cells that display significant heterogeneity during homeostasis, inflammation, and tumorigenesis. Tumor-induced systemic and local microenvironmental changes influence the phenotype, differentiation, and distribution of monocytes. Meanwhile, monocytes and their related cell subsets perform an important regulatory role in the development of many cancers by affecting tumor growth or metastasis. Thanks to recent advances in single-cell technologies, the nature of monocyte heterogeneity and subset-specific functions have become increasingly clear, making it possible to systematically analyze subset-specific roles of monocytes in tumorigenesis. In this review, we discuss recent discoveries related to monocytes and tumorigenesis, and new strategies for tumor biomarker identification and anti-tumor immunotherapy.
Topics: Humans; Monocytes; Carcinogenesis; Neoplasms; Cell Transformation, Neoplastic; Immunotherapy; Biomarkers, Tumor
PubMed: 37443711
DOI: 10.3390/cells12131673