scholarly journals Amphiregulin Aggravates Glomerulonephritis via Recruitment and Activation of Myeloid Cells

2020 ◽  
Vol 31 (9) ◽  
pp. 1996-2012 ◽  
Author(s):  
Simon Melderis ◽  
Julia Hagenstein ◽  
Matthias Tobias Warkotsch ◽  
Julien Dang ◽  
Georg Rudolf Herrnstadt ◽  
...  
Keyword(s):  
Egf Receptor ◽  
Inflammatory Diseases ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Antibody Treatment ◽  
Treatment Dose ◽  
Egfr Ligand ◽  
Significant Amelioration ◽  
M1 Phenotype

BackgroundRecent studies have identified the EGF receptor (EGFR) ligand amphiregulin (AREG) as an important mediator of inflammatory diseases. Both pro- and anti-inflammatory functions have been described, but the role of AREG in GN remains unknown.MethodsThe nephrotoxic nephritis model of GN was studied in AREG−/− mice after bone marrow transplantation, and in mice with myeloid cell–specific EGFR deficiency. Therapeutic utility of AREG neutralization was assessed. Furthermore, AREG's effects on renal cells and monocytes/macrophages (M/M) were analyzed. Finally, we evaluated AREG expression in human renal biopsies.ResultsRenal AREG mRNA was strongly upregulated in murine GN. Renal resident cells were the most functionally relevant source of AREG. Importantly, the observation that knockout mice showed significant amelioration of disease indicates that AREG is pathogenic in GN. AREG enhanced myeloid cell responses via inducing chemokine and colony stimulating factor 2 (CSF2) expression in kidney resident cells. Furthermore, AREG directly skewed M/M to a proinflammatory M1 phenotype and protected them from apoptosis. Consequently, anti-AREG antibody treatment dose-dependently ameliorated GN. Notably, selective abrogation of EGFR signaling in myeloid cells was sufficient to protect against nephritis. Finally, strong upregulation of AREG expression was also detected in kidneys of patients with two forms of crescentic GN.ConclusionsAREG is a proinflammatory mediator of GN via (1) enhancing renal pathogenic myeloid cell infiltration and (2) direct effects on M/M polarization, proliferation, and cytokine secretion. The AREG/EGFR axis is a potential therapeutic target for acute GN.

Abstract 641: The Role of Interleukin-23 in the Development of Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Aliia Fatkhullina ◽  
Iuliia Peshkova ◽  
Ekaterina Koltsova
Keyword(s):  
T Cells ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Chronic Inflammatory Disease ◽  
Lymphoid Cells ◽  
Efficient Manner ◽  
Mediators Of Inflammation

Atherosclerosis is lipid-driven chronic inflammatory disease of the arterial wall mediated by innate and adaptive immune responses. Inflammation promotes the development atherosclerotic plaques. Cytokines are soluble mediators of inflammation and important players in the pathogenesis of atherosclerosis. IL-23, a cytokine of IL-6/IL-12 cytokines superfamily is produced by myeloid cells and regulates the production of IL-17 and IL-22 by T helper IL-17 producing (Th17) cells, innate lymphoid cells of type 3 (ILC3) and gamma delta T cells in various auto-inflammatory diseases. IL-23R expression was also detected on myeloid cells but its role in regulation of myeloid cell function is not well defined. The level of IL-23 was shown to be upregulated in cardiovascular pathologies. Therefore, we decided to address the role of IL-23 in atherosclerosis using Il23p19 and Il23(R) receptor deficient mice. Surprisingly, atherosclerosis prone, Ldlr -/- mice transplanted with Il23p19 -/- or Il23r -/- bone marrow and fed with Western diet (WD) for 14 weeks demonstrated acceleration of atherosclerosis progression, which was characterized by increased accumulation of various hematopoietic cells in the aortas. Analysis of cytokine production unexpectedly revealed no changes in IL-17A and IFN-gamma production among CD4 T cells in the aortas. This effect was specific to aortas, as IL-17A production in the intestine of Il23p19 -/- mice was reduced, similarly to previously published observations. On the other hand, macrophages from Il23p19 -/- mice were able to uptake oxLDL in more efficient manner compared to wt controls, suggesting the regulatory role of IL-23 in foam cells formation. We also found enhanced inflammatory gene expression in aortas of Il23p19 -/- -> Ldlr -/- and Il23r -/- -> Ldlr -/- mice compared to wt controls. Overall our data suggest IL-17 independent atheroprotective role of IL-23.

scholarly journals Endothelial cell-derived CD95 ligand serves as a chemokine in induction of neutrophil slow rolling and adhesion

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Liang Gao ◽  
Gülce Sila Gülcüler ◽  
Lieke Golbach ◽  
Helena Block ◽  
Alexander Zarbock ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Cecal Ligation ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Flow Chamber ◽  
Integrin Activation ◽  
Cd95 Ligand ◽  
Slow Rolling

Integrin activation is crucial for the regulation of leukocyte rolling, adhesion and trans-vessel migration during inflammation and occurs by engagement of myeloid cells through factors presented by inflamed vessels. However, endothelial-dependent mechanisms of myeloid cell recruitment are not fully understood. Here we show using an autoperfused flow chamber assay of whole blood neutrophils and intravital microscopy of the inflamed cremaster muscle that CD95 mediates leukocyte slow rolling, adhesion and transmigration upon binding of CD95-ligand (CD95L) that is presented by endothelial cells. In myeloid cells, CD95 triggers activation of Syk-Btk/PLCγ2/Rap1 signaling that ultimately leads to integrin activation. Excitingly, CD95-deficient myeloid cells exhibit impaired bacterial clearance in an animal model of sepsis induced by cecal ligation and puncture (CLP). Our data identify the cellular and molecular mechanisms underlying the chemoattractant effect of endothelial cell-derived CD95L in induction of neutrophil recruitment and support the use of therapeutic inhibition of CD95’s activity in inflammatory diseases.

scholarly journals C/EBPα initiates primitive myelopoiesis in pluripotent embryonic cells

Blood ◽  
2009 ◽  
Vol 114 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Yaoyao Chen ◽  
Ricardo M. B. Costa ◽  
Nick R. Love ◽  
Ximena Soto ◽  
Martin Roth ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Embryonic Cells ◽  
Single Factor ◽  
Pluripotent Cells ◽  
Highly Active ◽  
Vertebrate Embryos ◽  
Necessary And Sufficient

Abstract The molecular mechanisms that underlie the development of primitive myeloid cells in vertebrate embryos are not well understood. Here we characterize the role of cebpa during primitive myeloid cell development in Xenopus. We show that cebpa is one of the first known hematopoietic genes expressed in the embryo. Loss- and gain-of-function studies show that it is both necessary and sufficient for the development of functional myeloid cells. In addition, we show that cebpa misexpression leads to the precocious induction of myeloid cell markers in pluripotent prospective ectodermal cells, without the cells transitioning through a general mesodermal state. Finally, we use live imaging to show that cebpa-expressing cells exhibit many attributes of terminally differentiated myeloid cells, such as highly active migratory behavior, the ability to quickly and efficiently migrate toward wounds and phagocytose bacteria, and the ability to enter the circulation. Thus, C/EPBα is the first known single factor capable of initiating an entire myelopoiesis pathway in pluripotent cells in the embryo.

Angiopoietin-2 promotes myeloid cell infiltration in a β2-integrin–dependent manner

Blood ◽  
2011 ◽  
Vol 118 (18) ◽  
pp. 5050-5059 ◽  
Author(s):  
Alexander Scholz ◽  
Victoria Lang ◽  
Reinhard Henschler ◽  
Marcus Czabanka ◽  
Peter Vajkoczy ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Delayed Type Hypersensitivity ◽  
Cell Infiltration ◽  
Dependent Manner ◽  
Specific Expression ◽  
Β2 Integrin ◽  
Angiopoietin 2

Abstract In human inflammatory diseases, we identified endothelial angiopoietin-2 (Ang-2) expression to be strongly associated with inflammations mediated by myeloid cells but not lymphocytes. To identify the underlying mechanism, we made use of a transgenic mouse model with inducible endothelial cell-specific expression of Ang-2. In this model, in the absence of inflammatory stimuli, long-term expression of Ang-2 led to a time-dependent accumulation of myeloid cells in numerous organs, suggesting that Ang-2 is sufficient to recruit myeloid cells. In models of acute inflammation, such as delayed-type hypersensitivity and peritonitis, Ang-2 transgenic animals showed an increased responsiveness. Intravital fluorescence video microscopy revealed augmented cell adhesion as an underlying event. Consequently, we demonstrated that Ang-2 is able to induce strong monocyte adhesion under shear in vitro, which could be blocked by antibodies to β2-integrin. Taken together, our results describe Ang-2 as a novel, endothelial-derived regulator of myeloid cell infiltration that modulates β2-integrin–mediated adhesion in a paracrine manner.

Abstract 590: Loss of Myeloid Cell Prostaglandin E Receptor 4 Does Not Alter Diabetes-Accelerated Atherosclerosis in a Murine Model of Type 1 Diabetes

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Sara N Vallerie ◽  
Farah Kramer ◽  
Jenny E Kanter ◽  
Shelley Barnhart ◽  
Richard M Breyer ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Mouse Model ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Prostaglandin E ◽  
Lesion Area ◽  
Accelerated Atherosclerosis ◽  
Anti Inflammatory

Diabetes is associated with an increased risk of cardiovascular disease, largely due to increased atherosclerosis. Our studies have suggested myeloid cell prostaglandin E 2 (PGE 2 ) production as a possible mediator of diabetes-accelerated atherosclerosis in a virally-induced mouse model of type 1 diabetes. Prostaglandin E Receptor 4 (EP4; Ptger4 ) is a major PGE 2 receptor in myeloid cells. We hypothesized that generation of a mouse model of myeloid cell-targeted EP4-deficiency would allow us to test the role of myeloid EP4 in diabetes-accelerated atherosclerosis. Thus, we generated a Ptger4 flox/flox LysM-Cre tg/tg mouse model. Peritoneal macrophages isolated from these myeloid cell EP4-deficient (EP4 M-/- ) mice expressed <90% Ptger4 mRNA compared to LysM-Cre tg/tg controls (n=10; p<0.0001). To analyze the role of myeloid cell EP4 in diabetes-accelerated atherosclerosis, we transplanted bone marrow from EP4 M-/- mice and littermate controls into lethally irradiated Ldlr -/- RIP-LCMV mice (the model of type 1 diabetes) and, after 7 weeks of recovery, induced diabetes by viral infection and fed the mice a low-fat semi-purified diet for an additional 12 weeks. Diabetic EP4 M-/- mice had similar blood glucose (568 ± 15 vs. 569 ± 15 mg/dl), blood cholesterol (531 ± 29 vs. 510 ± 37 mg/dl), and plasma triglycerides (249 ± 49 vs. 247 ± 44 mg/dl) as diabetic controls (n=15 all groups; mean ± SEM). At the endpoint, aortas were harvested for lesion area quantification. Diabetic EP4 M-/- and diabetic wild type mice had similar lesion area (1.9% ± 0.2 vs. 1.7% ± 0.2), which were both increased (p < 0.01; n=9-15) as compared to their non-diabetic controls. Additionally, we analyzed the role of EP4 in inflammatory activation of myeloid cells ex vivo. EP4-deficiency had no significant effect on basal or lipopolysaccharide (LPS)-induced inflammatory gene expression in the absence of PGE 2 . Pretreatment of the cells with PGE 2 (10 nM) followed by LPS stimulation resulted in a significant reduction of Tnfa and Il6 mRNA compared to LPS alone, and this anti-inflammatory effect of PGE 2 was completely blocked in EP4-deficient cells. These results suggest that myeloid cell EP4 mediates anti-inflammatory actions of PGE 2 but that it is not involved in diabetes-accelerated atherosclerosis.

scholarly journals Myeloid Cells in the Tumor Microenvironment: Modulation of Tumor Angiogenesis and Tumor Inflammation

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Michael C. Schmid ◽  
Judith A. Varner
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Angiogenesis ◽  
Malignant Tumors ◽  
Critical Role ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Promote Tumor Growth ◽  
Bone Marrow Derived Cells

Myeloid cells are a heterogeneous population of bone marrow-derived cells that play a critical role during growth and metastasis of malignant tumors. Tumors exhibit significant myeloid cell infiltrates, which are actively recruited to the tumor microenvironment. Myeloid cells promote tumor growth by stimulating tumor angiogenesis, suppressing tumor immunity, and promoting metastasis to distinct sites. In this review, we discuss the role of myeloid cells in promoting tumor angiogenesis. Furthermore, we describe a subset of myeloid cells with immunosuppressive activity (known as myeloid-derived suppressor cells). Finally, we will comment on the mechanisms regulating myeloid cell recruitment to the tumor microenvironment and on the potential of myeloid cells as new targets for cancer therapy.

scholarly journals Toll-Like Receptor 9 Inactivation Alleviated Atherosclerotic Progression and Inhibited Macrophage Polarized to M1 Phenotype in ApoE−/−Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chunmei Ma ◽  
Qiufang Ouyang ◽  
Ziyang Huang ◽  
Xiaoqing Chen ◽  
Ye Lin ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Macrophage Polarization ◽  
Immunohistochemical Analysis ◽  
Plaque Burden ◽  
Toll Like Receptor ◽  
Plaque Vulnerability ◽  
M1 Phenotype ◽  
Functional Inactivation ◽  
Atherosclerosis Development

Objective. Toll-like receptor 9 (TLR9) is involved in many inflammatory diseases, but its role in atherosclerosis remains controversial. This study aimed to investigate the role of TLR9 in atherosclerosis development and macrophage polarization.Methods. ApoE−/−mice were treated with vehicle or IRS869 for 12 weeks. Plaque vulnerability was assessed with immunohistochemical analysis, picro-sirius red, and oil red O staining. The expressions of M1- and M2-associated markers in plaques were detected by RT-PCR and immunofluorescence. The aorta TLR9 and its downstream molecules including myeloid differentiation protein 88 (MyD88), phosphorylated nuclear factor-kappa B (p-NF-κB), and interferon regulatory factor 7 (IRF7) were determined by western blot analysis. The frequency of M1 and M2 subtype in RAW264.7 cells treated with IRS869 and/or ODN1826 was evaluated with flow cytometry.Results. In ApoE−/−mice, functional inactivation of TLR9 pathway resulted in attenuated atherosclerosis development, as manifested by reduced plaque burden and by decreased plaque vulnerability. Mechanistically, TLR9 inhibition prevented the activation of MyD88/NF-κB pathway and shifted the balance of M1/M2 toward M2 macrophages that were involved.Conclusions. Our data indicated that TLR9 inactivation ameliorated atherosclerosis via skewing macrophage plasticity to M2 phenotype in ApoE-deficient mice. These findings may provide a promising therapeutic strategy for atherosclerosis.

scholarly journals Immune Suppression by Myeloid Cells in HIV Infection: New Targets for Immunotherapy

2014 ◽  
Vol 8 (1) ◽  
pp. 66-78 ◽  
Author(s):  
Vikram Mehraj ◽  
Mohammad-Ali Jenabian ◽  
Kishanda Vyboh ◽  
Jean-Pierre Routy
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Cell Function ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Immune Dysfunction ◽  
Hiv Pathogenesis ◽  
Host Restriction

Over thirty years of extensive research has not yet solved the complexity of HIV pathogenesis leading to a continued need for a successful cure. Recent immunotherapy-based approaches are aimed at controlling the infection by reverting immune dysfunction. Comparatively less appreciated than the role of T cells in the context of HIV infection, the myeloid cells including macrophages monocytes, dendritic cells (DCs) and neutrophils contribute significantly to immune dysfunction. Host restriction factors are cellular proteins expressed in these cells which are circumvented by HIV. Guided by the recent literature, the role of myeloid cells in HIV infection will be discussed highlighting potential targets for immunotherapy. HIV infection, which is mainly characterized by CD4 T cell dysfunction, also manifests in a vicious cycle of events comprising of inflammation and immune activation. Targeting the interaction of programmed death-1 (PD-1), an important regulator of T cell function; with PD-L1 expressed mainly on myeloid cells could bring promising results. Macrophage functional polarization from pro-inflammatory M1 to anti-inflammatory M2 and vice versa has significant implications in viral pathogenesis. Neutrophils, recently discovered low density granular cells, myeloid derived suppressor cells (MDSCs) and yolk sac macrophages provide new avenues of research on HIV pathogenesis and persistence. Recent evidence has also shown significant implications of neutrophil extracellular traps (NETs), antimicrobial peptides and opsonizing antibodies. Further studies aimed to understand and modify myeloid cell restriction mechanisms have the potential to contribute in the future development of more effective anti-HIV interventions that may pave the way to viral eradication.

scholarly journals A novel mouse model of conditional IRAK-M deficiency in myeloid cells: application in lung Pseudomonas aeruginosa infection

2016 ◽  
Vol 23 (2) ◽  
pp. 206-215 ◽  
Author(s):  
Di Jiang ◽  
Jennifer Matsuda ◽  
Reena Berman ◽  
Niccolette Schaefer ◽  
Connor Stevenson ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mouse Model ◽  
Bacterial Infection ◽  
Knockout Mice ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Conditional Knockout ◽  
Negative Regulator ◽  
Innate Defense

Myeloid cells such as macrophages are critical to innate defense against infection. IL-1 receptor-associated kinase M (IRAK-M) is a negative regulator of TLR signaling during bacterial infection, but the role of myeloid cell IRAK-M in bacterial infection is unclear. Our goal was to generate a novel conditional knockout mouse model to define the role of myeloid cell IRAK-M during bacterial infection. Myeloid cell-specific IRAK-M knockout mice were generated by crossing IRAK-M floxed mice with LysM–Cre knock-in mice. The resulting LysM–Cre+/IRAK-Mfl/wt and control (LysM–Cre–/IRAK-Mfl/wt) mice were intranasally infected with Pseudomonas aeruginosa (PA). IRAK-M deletion, inflammation, myeloperoxidase (MPO) activity and PA load were measured in leukocytes, bronchoalveolar lavage (BAL) fluid and lungs. PA killing assay with BAL fluid was performed to determine mechanisms of IRAK-M-mediated host defense. IRAK-M mRNA and protein levels in alveolar and lung macrophages were significantly reduced in LysM–Cre+/IRAK-Mfl/wt mice compared with control mice. Following PA infection, LysM–Cre+/IRAK-Mfl/wt mice have enhanced lung neutrophilic inflammation, including MPO activity, but reduced PA load. The increased lung MPO activity in LysM–Cre+/IRAK-Mfl/wt mouse BAL fluid reduced PA load. Generation of IRAK-M conditional knockout mice will enable investigators to determine precisely the function of IRAK-M in myeloid cells and other types of cells during infection and inflammation.

scholarly journals Myeloid cells, BAFF, and IFN-γ establish an inflammatory loop that exacerbates autoimmunity in Lyn-deficient mice

2010 ◽  
Vol 207 (8) ◽  
pp. 1757-1773 ◽  
Author(s):  
Patrizia Scapini ◽  
Yongmei Hu ◽  
Ching-Liang Chu ◽  
Thi-Sau Migone ◽  
Anthony L. DeFranco ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
B Lymphocyte ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cell Clones ◽  
B Lymphocyte Stimulator ◽  
Ifn Γ ◽  
Deficient Mice

Autoimmunity is traditionally attributed to altered lymphoid cell selection and/or tolerance, whereas the contribution of innate immune cells is less well understood. Autoimmunity is also associated with increased levels of B cell–activating factor of the TNF family (BAFF; also known as B lymphocyte stimulator), a cytokine that promotes survival of self-reactive B cell clones. We describe an important role for myeloid cells in autoimmune disease progression. Using Lyn-deficient mice, we show that overproduction of BAFF by hyperactive myeloid cells contributes to inflammation and autoimmunity in part by acting directly on T cells to induce the release of IFN-γ. Genetic deletion of IFN-γ or reduction of BAFF activity, achieved by either reducing myeloid cell hyperproduction or by treating with an anti-BAFF monoclonal antibody, reduced disease development in lyn−/− mice. The increased production of IFN-γ in lyn−/− mice feeds back on the myeloid cells to further stimulate BAFF release. Expression of BAFF receptor on T cells was required for their full activation and IFN-γ release. Overall, our data suggest that the reciprocal production of BAFF and IFN-γ establishes an inflammatory loop between myeloid cells and T cells that exacerbates autoimmunity in this model. Our findings uncover an important pathological role of BAFF in autoimmune disorders.

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