scholarly journals Myeloid-Derived Suppressor Cells and Pulmonary Hypertension

2018 ◽  
Vol 19 (8) ◽  
pp. 2277
Author(s):  
Andrew Bryant ◽  
Borna Mehrad ◽  
Todd Brusko ◽  
James West ◽  
Lyle Moldawer
Keyword(s):  
Pulmonary Hypertension ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Myeloid Derived Suppressor Cells ◽  
Pulmonary Vascular Remodeling ◽  
Adaptive Immune ◽  
Cell Changes ◽  
Transcription Factor Signaling

Myeloid–derived suppressor cells (MDSCs) comprised a heterogeneous subset of bone marrow–derived myeloid cells, best studied in cancer research, that are increasingly implicated in the pathogenesis of pulmonary vascular remodeling and the development of pulmonary hypertension. Stem cell transplantation represents one extreme interventional strategy for ablating the myeloid compartment but poses a number of translational challenges. There remains an outstanding need for additional therapeutic targets to impact MDSC function, including the potential to alter interactions with innate and adaptive immune subsets, or alternatively, alter trafficking receptors, metabolic pathways, and transcription factor signaling with readily available and safe drugs. In this review, we summarize the current literature on the role of myeloid cells in the development of pulmonary hypertension, first in pulmonary circulation changes associated with myelodysplastic syndromes, and then by examining intrinsic myeloid cell changes that contribute to disease progression in pulmonary hypertension. We then outline several tractable targets and pathways relevant to pulmonary hypertension via MDSC regulation. Identifying these MDSC-regulated effectors is part of an ongoing effort to impact the field of pulmonary hypertension research through identification of myeloid compartment-specific therapeutic applications in the treatment of pulmonary vasculopathies.

501 VISTA regulates the differentiation and suppressive function of myeloid-derived suppressor cells

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A536-A536
Author(s):  
Juan Dong ◽  
Cassandra Gilmore ◽  
Hieu Ta ◽  
Keman Zhang ◽  
Sarah Stone ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
Immune Checkpoint ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Myeloid Derived Suppressor Cells ◽  
Checkpoint Protein ◽  
Suppressive Function

BackgroundV-domain immunoglobulin suppressor of T cell activation (VISTA) is a B7 family inhibitory immune checkpoint protein and is highly expressed on myeloid cells and T cells.1 VISTA acts as both an inhibitory ligand when expressed on antigen-presenting cells and a receptor when expressed on T cells. Our recent study has shown that VISTA is a myeloid cell-specific immune checkpoint and that blocking VISTA can reprogram suppressive myeloid cells and promote a T cell-stimulatory tumor microenvironment.2 In this study, we further demonstrate that VISTA blockade directly alters the differentiation and the suppressive function of myeloid-derived suppressor cells (MDSC).MethodsFlow cytometry was performed to examine VISTA expression on MDSCs in multiple murine tumor models including the B16BL6 melanoma model, MC38 colon cancer model, and the KPC pancreatic cancer models. To examine the role of VISTA in controlling the differentiation and suppressive function of MDSCs, we cultured wild type (WT) and VISTA.KO bone marrow progenitor cells with GM-CSF and IL-6 to induce BM -derived MDSCs.ResultsOur preliminary results show that VISTA is highly expressed on M-MDSCs in B16BL6, MC38 and KPC tumors. In BM-derived MDSCs, VISTA deletion significantly altered the signaling pathways and the differentiation of MDSCs. Multiple inflammatory signaling pathways were downregulated in VISTA KO MDSCs, resulting in decreased production of cytokines such as IL1 and chemokines such as CCL2/4/9, as well as significantly impaired their ability to suppress the activation of CD8+ T cells. The loss of suppressive function in VISTA KO MDSCs is correlated with significantly reduced expression of iNOS. To validate the results from BM-MDSCs, we sorted CD11b+CD11c-Ly6C+Ly6G- M-MDSCs and CD11b+CD11c-Ly6G+ G-MDSCs from B16BL6 tumor tissues and tested the ability of a VISTA-blocking mAb to reverse the suppressive effects of tumor-derived MDSCs. Our results show that blocking VISTA impaired the suppressive function of tumor-derived M-MDSC but not G-MDSCs.ConclusionsTaken together, these results demonstrate a crucial role of VISTA in regulating the differentiation and function of MDSCs, and that blocking VISTA abolishes MDSC-mediated T cell suppression, thereby boosting.Ethics ApprovalAll in vivo studies were reviewed and approved by Institutional Animal Care and Use Committee (Approval number 2019-2142).ReferencesXu W, Hire T, Malarkannan, S. et al. The structure, expression, and multifaceted role of immune-checkpoint protein VISTA as a critical regulator of anti-tumor immunity, autoimmunity, and inflammation. Cell Mol Immunol 2018;15:438–446.Xu W, Dong J, Zheng Y, et al. Immune-checkpoint protein VISTA regulates antitumor immunity by controlling myeloid cell-mediated inflammation and immunosuppression. Cancer Immunol Res 2019;7:1497–510.

scholarly journals Myeloid-Derived Suppressor Cells in Sepsis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Dengming Lai ◽  
Chaojin Qin ◽  
Qiang Shu
Keyword(s):  
Secondary Infection ◽  
Suppressor Cells ◽  
Antimicrobial Activities ◽  
Therapeutic Benefit ◽  
Myeloid Derived Suppressor Cells ◽  
Innate Immune Responses ◽  
Suspected Infection ◽  
Adaptive Immune ◽  
Immature Myeloid Cells

Sepsis is a systemic, deleterious host response to widespread infection. Patients with sepsis will have documented or suspected infection which can progress to a state of septic shock or acute organ dysfunction. Since sepsis is responsible for nearly 3 million cases per year in China and severe sepsis is a common, expensive fatal condition in America, developing new therapies becomes a significant and worthwhile challenge. Clinical research has shown that sepsis-associated immunosuppression plays a central role in patient mortality, and targeted immune-enhancing therapy may be an effective treatment approach in these patients. As part of the inflammatory response during sepsis, there are elevations in the number of myeloid-derived suppressor cells (MDSCs). MDSCs are a heterogeneous population of immature myeloid cells that possess immunosuppressive activities via suppressing T-cell proliferation and activation. The role of MDSCs in sepsis remains uncertain. Some believe activated MDSCs are beneficial to the sepsis host by increasing innate immune responses and antimicrobial activities, while others think expansion of MDSCs leads to adaptive immune suppression and secondary infection. Herein, we discuss the complex role of MDSCs in immune regulation during sepsis, as well as the potential to target these cells for therapeutic benefit.

scholarly journals Characterization of Myeloid-Derived Suppressor Cells and Tumor Associated Macrophages Using MultiOmyxTM Hyperplexed Immunofluorescence Assay in Hodgkin Lymphoma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4135-4135
Author(s):  
Qingyan Au ◽  
Jun Fang ◽  
Anna Juncker-Jensen ◽  
Judy Kuo ◽  
Eric Leones ◽  
...  
Keyword(s):  
Hodgkin Lymphoma ◽  
Hematological Malignancies ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Myeloid Derived Suppressor Cells ◽  
M2 Macrophages ◽  
Tumor Associated Macrophages ◽  
Hla Dr

Abstract Tumor microenvironment (TME) consists of heterogeneous subsets of myeloid cells and plays a crucial role in promoting cancer development and metastasis. Tumor associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) all contribute to an immunologically permissive microenvironment for cancer cells. On basis of the expression of surface markers, MDSC can be further subdivided into granulocytic MDSC (G-MDSC, polymorphonuclear MDSC) and monocytic MDSC (M-MDSC). In solid tumors, these different myeloid cell populations are well characterized and extensively studied. However, in hematological malignancies the role of myeloid cell subsets has been less studied. A recent study showed increase in MDSC in the bone marrow (BM) at time of diagnosis in acute myeloid leukemia (AML) patients (Sun H. et al. Int J Hematol. 2015). Significantly higher numbers of G-MDSC and M-MDSC were present at diagnosis in classic Hodgkin lymphoma (cHL) (Romano A. et al. Br J Haematol. 2015). The accumulation of TAMs was also reported to be associated with poor prognosis in cHL (Steidl C. et al. N Engl J Med. 2010). Collectively, these results indicate that the tumor-resident myeloid cells play an important clinical role, thus highlighting the need for monitoring and deeper characterization of various myeloid subsets in hematological malignancies, especially in the tumor FFPE sections. Herein, we report an analysis of MDSCs and 'protumoral' M2 macrophages using MultiOmyx hyperplexed immunofluorescence (IF) assay in 9 clinical samples diagnosed with HL. MultiOmyx is a proprietary multi 'omic' technology that enables detection and visualization of up to 60 biomarkers on a single 4µM FFPE slide (Gerdes MJ. et al. PNAS 2013). The HL FFPE sections were stained with a 13-marker panel including Arginase 1, CD11b, CD14, CD15, CD16, CD33, CD68, CD163, HLA-DR, CD3, CD4, CD8 and FOXP3. We observed that both M-MDSC (Fig 1A, characterized as CD11b+CD14+CD15-CD33+HLA-DR-) and G-MDSC (Fig 1B, identified as CD11b+CD14-CD15+CD33+HLA-DR-) accumulated within the TME in all 9 HL samples, with higher frequency of G-MDSCs over M-MDSCs. Arg1 expression was detected exclusively in G-MDSC population (Fig 1C). The data also revealed an abundant M2 macrophages (Fig 1D, characterized as CD68+CD163+) present in all HL samples. The detection of both MDSCs and M2 macrophages in HL samples supports the hypothesis that these cells contribute to the establishment of an immunosuppressive TME. Using the MultiOmyx proprietary algorithm, which takes into account the staining patterns, we will next quantify the counts and density of different tumor-resident myeloid subsets and measure the spatial distance between each subset of tumor-resident myeloid cells to the neoplastic Reed-Sternberg cells. Correlation study will also be performed to determine if significant correlations exist between MDSCs and TAMs and how these immunosuppressive myeloid cells are related to the Regulatory T cells (CD3+CD4+FOXP3+) in HL samples. In addition to HL samples, the same 13-plexed panel will be utilized to characterize the myeloid cell population from AML patients. TAMs and MDSCs are emerging as potential biomarkers for diagnosis and prognosis of cancer as well as therapeutic targets. The comprehensive myeloid cells phenotyping offered by MultiOmyx 13-plexed panel has the potential to monitor the changes of immunosuppressive myeloid cells in response to immune modulating drugs such as MDSC-targeting drugs (e.g. PDE-5 inhibitors, COX-2 inhibitors), TAM-targeting agents (e.g. anti-CSF1R) and combined therapy in treatment of lymphoma and leukemia. Disclosures No relevant conflicts of interest to declare.

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 Phenotypic and Functional Diversities of Myeloid-Derived Suppressor Cells in Autoimmune Diseases

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huijuan Ma ◽  
Chang-Qing Xia
Keyword(s):  
Autoimmune Diseases ◽  
Tumor Development ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Beneficial Effects ◽  
Adaptive Immune ◽  
The Past ◽  
Animal Tumor ◽  
Promote Tumor Development

Myeloid-derived suppressor cells (MDSCs) are identified as a heterogeneous population of cells with the function to suppress innate as well as adaptive immune responses. The initial studies of MDSCs were primarily focused on the field of animal tumor models or cancer patients. In cancer, MDSCs play the deleterious role to inhibit tumor immunity and to promote tumor development. Over the past few years, an increasing number of studies have investigated the role of MDSCs in autoimmune diseases. The beneficial effects of MDSCs in autoimmunity have been reported by some studies, and thus, immunosuppressive MDSCs may be a novel therapeutic target in autoimmune diseases. There are some controversial findings as well. Many questions such as the activation, differentiation, and suppressive functions of MDSCs and their roles in autoimmune diseases remain unclear. In this review, we have discussed the current understanding of MDSCs in autoimmune diseases.

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 Mechanisms and Functional Significance of Human Tumor-infiltrating Myeloid Cells

2019 ◽  
Vol 4 (2) ◽  
pp. 41-49
Author(s):  
Amin Ramezani ◽  
Fatemeh Sadat Toghraie
Keyword(s):  
Stromal Cells ◽  
Cancer Biology ◽  
Critical Role ◽  
Myeloid Cells ◽  
Human Tumor ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Myeloid Derived Suppressor Cells ◽  
Patient Prognosis ◽  
Tumor Associated Neutrophils

Myeloid cells as the major components of tumor-infiltrating leukocytes play critical roles in anti-tumor immunity. However, emerging evidences have revealed that soluble factors produced by tumor/stromal cells skew myeloid cells toward a tumor-promoting phenotype. Tumor-infiltrating myeloid cells (TIMs) including tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), myeloid-derived suppressor cells (MDSCs), and tumor-associated dendritic cells (TADCs) are considered as the key mediators of tumor microenvironment (TME). TIMs have been shown to play important roles in various aspects of cancer biology and their presence is often linked to altered patient prognosis and survival. Regarding their critical role in TME, TIMs have been proposed as relevant targets of therapeutic strategies aimed at expanding immunostimulatory myeloid cell populations and depleting or modulating immunosuppressive ones. In this review, we briefly describe TIMs subsets and discuss the mechanisms by which TIMs induce immunosuppression, angiogenesis, and metastasis.

scholarly journals Defining the emergence of myeloid-derived suppressor cells in breast cancer using single-cell transcriptomics

2019 ◽  
Author(s):  
Hamad Alshetaiwi ◽  
Nicholas Pervolarakis ◽  
Laura Lynn McIntyre ◽  
Dennis Ma ◽  
Quy Nguyen ◽  
...  
Keyword(s):  
Single Cell ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Gene Signature ◽  
Specific Gene ◽  
Surface Markers ◽  
Myeloid Derived Suppressor Cells ◽  
Adaptive Immune ◽  
Molecular Features ◽  
Immunosuppressive Cell

AbstractMyeloid-derived suppressor cells (MDSCs) are innate immune cells that acquire the capacity to suppress adaptive immune responses during cancer. It remains elusive how MDSCs differ from their normal myeloid counterparts, which limits our ability to specifically detect and therapeutically target MDSCs during cancer. Here, we used single-cell RNAseq to compare MDSC-containing splenic myeloid cells from breast tumor-bearing mice to wildtype controls. Our computational analysis of 14,646 single-cell transcriptomes reveals that MDSCs emerge through a previously unrealized aberrant neutrophil maturation trajectory in the spleen giving rise to a unique chemokine-responsive, immunosuppressive cell state that strongly differs from normal myeloid cells. We establish the first MDSC-specific gene signature and identify novel surface markers for improved detection and enrichment of MDSCs in murine and human samples. Our study provides the first single-cell transcriptional map defining the development of MDSCs, which will ultimately enable us to specifically target these cells in cancer patients.One Sentence SummaryWe used single cell transcriptomics to identify the unique molecular features distinguishing myeloid-derived suppressor cells (MDSCs) from their normal, myeloid counterparts, which enabled us to reveal distinct transitory gene expression changes during their maturation in the spleen, and to identify novel cell surface markers for improved detection and isolation of MDSCs.

scholarly journals EXPRESS: Pulmonary Hypertension Associated With Neurofibromatosis Type 2

2021 ◽  
pp. 204589402110295
Author(s):  
Hirohisa Taniguchi ◽  
Tomoya Takashima ◽  
Ly Tu ◽  
Raphaël Thuillet ◽  
Asuka Furukawa ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Neurofibromatosis Type ◽  
Pulmonary Vascular Remodeling ◽  
Life Threatening ◽  
History Of ◽  
Pulmonary Arterial ◽  
First Time

Although precapillary pulmonary hypertension (PH) is a rare but severe complication of patients with neurofibromatosis type 1 (NF1), its association with NF2 remains unknown. Herein, we report a case of a 44-year-old woman who was initially diagnosed with idiopathic pulmonary arterial hypertension (IPAH) and treated with PAH-specific combination therapy. However, a careful assessment for a relevant family history of the disease and genetic testing reveal that this patient had a mutation in the NF2 gene. Using immunofluorescence and Western blotting, we demonstrated a decrease in endothelial NF2 protein in lungs from IPAH patients compared to control lungs, suggesting a potential role of NF2 in PAH development. To our knowledge, this is the first time that precapillary PH has been described in a patient with NF2. The altered endothelial NF2 expression pattern in PAH lungs should stimulate work to better understand how NF2 is contributing to the pulmonary vascular remodeling associated to these severe life-threatening conditions.

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