scholarly journals Disruption of MyD88 signaling suppresses hemophagocytic lymphohistiocytosis in mice

Blood ◽  
2011 ◽  
Vol 117 (24) ◽  
pp. 6582-6588 ◽  
Author(s):  
Philippe Krebs ◽  
Karine Crozat ◽  
Daniel Popkin ◽  
Michael B. Oldstone ◽  
Bruce Beutler
Keyword(s):  
T Cells ◽  
Hemophagocytic Lymphohistiocytosis ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Elevated Serum ◽  
Cytokine Signaling ◽  
Cell Contact ◽  
Inflammatory Disorder ◽  
Immune Cell Activation

AbstractHemophagocytic lymphohistiocytosis (HLH) is a rare inflammatory disorder with a poor prognosis for affected individuals. To find a means of suppressing the clinical phenotype, we investigated the cellular and molecular mechanisms leading to HLH in Unc13djinx/jinx mice, in which cytolytic function of NK and CD8+ T cells is impaired. Unc13djinx/jinx mutants infected with lymphochoriomeningitis virus (LCMV) present typical clinical features of HLH, including splenomegaly, elevated serum IFNγ, and anemia. Proteins mediating cell-cell contact, cytokine signaling or Toll-like receptor (TLR) signaling were analyzed. We show that neither the integrin CD18, which is involved in adhesion between antigen-presenting cells and effector T cells, nor tumor necrosis factor (TNF) made nonredundant contributions to the disease phenotype. Disruption of IFNγ signaling reduced immune cell activation in Unc13djinx/jinx mice, but also resulted in uncontrolled viral proliferation and exaggerated release of inflammatory cytokines. Abrogating the function of myeloid differentiation primary response gene 88 (MyD88) in Unc13djinx/jinx mice suppressed immune cell activation and controlled cytokine production in an IL-1 receptor 1 (IL-1R1)–independent way. Our findings implicate MyD88 as the key initiator of myeloid and lymphoid proliferation in HLH, and suggest that blockade of this signaling molecule may reduce immunopathology in patients.

scholarly journals A bi-directional dialog between vascular cells and monocytes/macrophages regulates tumor progression

2021 ◽  
Author(s):  
Victor Delprat ◽  
Carine Michiels
Keyword(s):  
Tumor Progression ◽  
Cancer Progression ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
The Body ◽  
Vascular Cells ◽  
Tumor Associated Macrophage ◽  
Immune Cell Activation ◽  
The Impact

AbstractCancer progression largely depends on tumor blood vessels as well on immune cell infiltration. In various tumors, vascular cells, namely endothelial cells (ECs) and pericytes, strongly regulate leukocyte infiltration into tumors and immune cell activation, hence the immune response to cancers. Recently, a lot of compelling studies unraveled the molecular mechanisms by which tumor vascular cells regulate monocyte and tumor-associated macrophage (TAM) recruitment and phenotype, and consequently tumor progression. Reciprocally, TAMs and monocytes strongly modulate tumor blood vessel and tumor lymphatic vessel formation by exerting pro-angiogenic and lymphangiogenic effects, respectively. Finally, the interaction between monocytes/TAMs and vascular cells is also impacting several steps of the spread of cancer cells throughout the body, a process called metastasis. In this review, the impact of the bi-directional dialog between blood vascular cells and monocytes/TAMs in the regulation of tumor progression is discussed. All together, these data led to the design of combinations of anti-angiogenic and immunotherapy targeting TAMs/monocyte whose effects are briefly discussed in the last part of this review.

scholarly journals The Role of T Cells and Macrophages in Asthma Pathogenesis: A New Perspective on Mutual Crosstalk

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xueyi Zhu ◽  
Jie Cui ◽  
La Yi ◽  
Jingjing Qin ◽  
Wuniqiemu Tulake ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Activation ◽  
Immune Cell ◽  
Immune Microenvironment ◽  
Innate And Adaptive Immunity ◽  
Immune Cell Activation ◽  
Inflammatory Signals ◽  
Macrophage Dysfunction ◽  
New Perspective

Asthma is associated with innate and adaptive immunity mediated by immune cells. T cell or macrophage dysfunction plays a particularly significant role in asthma pathogenesis. Furthermore, crosstalk between them continuously transmits proinflammatory or anti-inflammatory signals, causing the immune cell activation or repression in the immune response. Consequently, the imbalanced immune microenvironment is the major cause of the exacerbation of asthma. Here, we discuss the role of T cells, macrophages, and their interactions in asthma pathogenesis.

Hypertension

2021 ◽  
Vol 128 (7) ◽  
pp. 908-933
Author(s):  
Meena S. Madhur ◽  
Fernando Elijovich ◽  
Matthew R. Alexander ◽  
Ashley Pitzer ◽  
Jeanne Ishimwe ◽  
...  
Keyword(s):  
Blood Pressure ◽  
T Cells ◽  
Cardiovascular Risk ◽  
Cell Activation ◽  
Viral Infections ◽  
Immune Cell ◽  
Vascular Dysfunction ◽  
Dietary Salt ◽  
Activated T Cells ◽  
Immune Cell Activation

Elevated cardiovascular risk including stroke, heart failure, and heart attack is present even after normalization of blood pressure in patients with hypertension. Underlying immune cell activation is a likely culprit. Although immune cells are important for protection against invading pathogens, their chronic overactivation may lead to tissue damage and high blood pressure. Triggers that may initiate immune activation include viral infections, autoimmunity, and lifestyle factors such as excess dietary salt. These conditions activate the immune system either directly or through their impact on the gut microbiome, which ultimately produces chronic inflammation and hypertension. T cells are central to the immune responses contributing to hypertension. They are activated in part by binding specific antigens that are presented in major histocompatibility complex molecules on professional antigen-presenting cells, and they generate repertoires of rearranged T-cell receptors. Activated T cells infiltrate tissues and produce cytokines including interleukin 17A, which promote renal and vascular dysfunction and end-organ damage leading to hypertension. In this comprehensive review, we highlight environmental, genetic, and microbial associated mechanisms contributing to both innate and adaptive immune cell activation leading to hypertension. Targeting the underlying chronic immune cell activation in hypertension has the potential to mitigate the excess cardiovascular risk associated with this common and deadly disease.

9 METABOLIC UTILIZATION OF PROPANEDIOL BY ADHERENT-INVASIVE E. COLI REGULATES INTESTINAL TISSUE IMMUNITY

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S33-S33
Author(s):  
Monica Viladomiu ◽  
Maeva Metz ◽  
Svetlana Lima ◽  
Chun-Jun Guo ◽  
Kenneth Simpson ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Th17 Cells ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Mononuclear Phagocytes ◽  
Secretion Systems ◽  
E Coli ◽  
Immune Cell Activation

Abstract While the molecular mechanisms by which the microbiome modulates mucosal immunity in Crohn’s disease (CD) are still largely unknown, recent data highlight the involvement of specific diet- and bacterial-derived metabolites in the regulation of intestinal immune cell activation and differentiation. We have recently shown that Adherent-Invasive E.coli (AIEC), which are enriched in CD patients, are sufficient to induce intestinal Th17 cells. Although AIEC lack pathogenic factors including type III secretion systems, many CD-derived isolates express virulence-associated metabolic enzymes including propanediol dehydratase (PduC), which enables AIEC to use fucose-derived propanediol as an alternate carbon source in the gut. We found that pduC is enriched in the microbiome and among E. coli genomes in CD patients compared to healthy controls. With fucosylated oligosaccharides on the surface of intestinal epithelial cells, we hypothesized that this propanediol utilization pathway provides AIEC a competitive advantage for epithelial cell adherence and intestinal immune cell activation. To evaluate the physiologic contribution of pduC to mucosal Th17 induction, we generated a pduC-deficient (ΔpduC) mutant of a CD-derived, AIEC isolate. Deletion of pduC resulted in reduced inflammatory Th17 cells and attenuated weight loss following T cell transfer colitis. Using genetic mouse models, we found that CX3CR1+ mononuclear phagocytes are required for this AIEC-mediated Th17 induction and IL-10 is required to restrain pduC-dependent dextran sodium sulfate (DSS)-induced colitis. Using a catalytically-inactive mutant, we determined that PduC metabolic activity was required for this immune phenotype. Cell-free supernatants from WT AIEC (but not the isogenic, pduC-deficient clone) promoted ex vivo Th17 cell polarization and metabolomics analysis (LC-MS) of these supernatants defined PduC-dependent metabolites capable of promoting Th17 polarization. These studies reveal a link between AIEC microbial metabolism and inflammatory Th17 cells with the potential to serve as a therapeutic target in the treatment of Crohn’s disease.

scholarly journals Exploiting aneuploidy-imposed stresses and coping mechanisms to battle cancer

Open Biology ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200148
Author(s):  
Lin Zhou ◽  
Laura J. Jilderda ◽  
Floris Foijer
Keyword(s):  
Cancer Cells ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Metabolic Stress ◽  
Coping Mechanisms ◽  
Immune Cell Activation ◽  
Cycle Arrest ◽  
Biological Responses ◽  
And Coping

Aneuploidy, an irregular number of chromosomes in cells, is a hallmark feature of cancer. Aneuploidy results from chromosomal instability (CIN) and occurs in almost 90% of all tumours. While many cancers display an ongoing CIN phenotype, cells can also be aneuploid without displaying CIN. CIN drives tumour evolution as ongoing chromosomal missegregation will yield a progeny of cells with variable aneuploid karyotypes. The resulting aneuploidy is initially toxic to cells because it leads to proteotoxic and metabolic stress, cell cycle arrest, cell death, immune cell activation and further genomic instability. In order to overcome these aneuploidy-imposed stresses and adopt a malignant fate, aneuploid cancer cells must develop aneuploidy-tolerating mechanisms to cope with CIN. Aneuploidy-coping mechanisms can thus be considered as promising therapeutic targets. However, before such therapies can make it into the clinic, we first need to better understand the molecular mechanisms that are activated upon aneuploidization and the coping mechanisms that are selected for in aneuploid cancer cells. In this review, we discuss the key biological responses to aneuploidization, some of the recently uncovered aneuploidy-coping mechanisms and some strategies to exploit these in cancer therapy.

scholarly journals 685 A highly selective and potent HPK1 inhibitor enhances immune cell activation and induces robust tumor growth inhibition in a murine syngeneic tumor model

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A724-A724
Author(s):  
David Ciccone ◽  
Vad Lazari ◽  
Ian Linney ◽  
Michael Briggs ◽  
Samantha Carreiro ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Activation ◽  
Immune Cell ◽  
Tumor Model ◽  
Tumor Growth Inhibition ◽  
Immune Cell Activation ◽  
Syngeneic Tumor ◽  
Human T Cells

BackgroundHPK1, a member of the MAP4K family of protein serine/threonine kinases, is involved in regulating signal transduction cascades in cells of hematopoietic origin. Recent data from HPK1 knockout animals and kinase-inactive knock-in animals underscores the role of HPK1 in negatively regulating immune cell activation. This negative-feedback role of HPK1 combined with its restricted expression in cells of hematopoietic origin, make it a compelling drug target for enhancing anti-tumor immunity.MethodsA structure-based drug design approach was used to identify potent and selective inhibitors of HPK1. Biochemical assays, as well as primary human and mouse immune cell-based activation assays, were utilized for multiple iterations of structure-activity relationship (SAR) studies. In vivo efficacy, target engagement and pharmacodynamic data were generated using murine syngeneic tumor models.ResultsA highly potent, HPK1 inhibitor was identified, that showed high selectivity against T cell-specific kinases and kinases in the MAP4K family. In vitro, HPK1 small molecule inhibition resulted in enhanced IL-2 production in primary mouse and human T cells, enhanced IL-6 and IgG production in primary human B cells, and enhanced mouse dendritic cell activation and antigen presentation capacity. Furthermore, HPK1 inhibition alleviated the immuno-suppressive effects of PGE2 on naïve human T cells and restored the proliferative capacity of exhausted human T cells. In vivo, HPK1 inhibitionHPK1 inhibition abrogated T cell receptor-stimulated phospho-SLP-76, enhanced cytokine production, and mediated robust tumor growth inhibition in a murine syngeneic tumor model.ConclusionsPharmacological blockade of HPK1 kinase activity represents a novel and potentially valuable immunomodulatory approach for anti-tumor immunity.

438 Synergy between SEA-CD40 and chemotherapeutics drives curative antitumor activity in preclinical models

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A464-A464
Author(s):  
Weiping Zeng ◽  
Haley Neff-LaFord ◽  
Sahar Ansari ◽  
Celine Jacquemont ◽  
Michael Schmitt ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Tumor Microenvironment ◽  
Antitumor Activity ◽  
Cell Activation ◽  
Tumor Antigens ◽  
Immune Cell ◽  
Chemotherapeutic Agents ◽  
Clinical Development ◽  
Immune Cell Activation

BackgroundCD40 is a co-stimulatory receptor of the TNF receptor superfamily expressed on antigen presenting cells (APCs). Antibodies targeting CD40 may have antitumor therapeutic benefit by driving innate immune cell activation that supports generation of antigen-specific T cell responses. Multiple CD40-directed antibodies are in clinical development in both solid and hematologic indications and differ according to immunoglobulin isotype, affinity to CD40, and differential FcγR-binding. SEA-CD40 is an agonistic nonfucosylated, humanized IgG1 monoclonal antibody directed against CD40. SEA-CD40 is distinct from other CD40 targeted agents in clinical development as it binds with increased affinity to FcγRIIIa resulting in enhanced effector function and CD40 agonism. This unique composition of SEA-CD40 could amplify immune stimulation and antitumor activity relative to other CD40-directed therapeutics.MethodsEffective immunity requires the presence of diverse antigens to drive generation of distinct antigen-specific memory T cells. SEA-CD40 in many ways works like a vaccine as it can increase active acquired immunity against endogenous tumor antigens. A potential limiting factor for maximal SEA-CD40 antitumor activity across multiple tumor types may be the limited level and diversity of tumor-associated antigens within the tumor microenvironment (TME). Chemotherapeutic agents drive tumor cell death resulting in the release and increase of tumor antigens locally within the TME. Combining chemotherapeutic agents with SEA-CD40 could facilitate robust antigen release and amplified presentation of those antigens to CD8+ T cells. Antitumor activity and immune cell changes of SEA-CD40 in combination with chemotherapeutic agents was evaluated in vitro and in vivo using human CD40 transgenic mice.ResultsIn preclinical mouse models, SEA-CD40 combined with chemotherapeutic agents to drive robust anti-tumor activity. The nature of the chemotherapeutic agent influenced immune cell activation within the tumor microenvironment (TME) and extent of combinability with SEA-CD40. Preclinical assessment indicates that chemotherapeutics which induce immunogenic cell death (ICD) combine with SEA-CD40 to increase curative activity compared to non-ICD-inducing chemotherapeutics. The preferred partnership of SEA-CD40 with ICD-inducing agents, such as a monomethyl auristatin E (MMAE) antibody-drug conjugate, increased curative antitumor activity in mouse models. The combination of SEA-CD40 and chemotherapeutic agents with a T cell targeted anti-PD1 antibody could deepen and extend these anti-tumor responses.ConclusionsThese data support continued clinical evaluation of SEA-CD40 in combination with chemotherapeutic agents and potentially in the future MMAE based ADCs. A phase 1 clinical trial is actively enrolling (NCT02376699) and includes a cohort in pancreatic cancer assessing the combination of SEA-CD40, gemcitabine, nab-paclitaxel, and pembrolizumab.Ethics ApprovalStudies with human samples were performed according to institutional ethics standards. Animals studies were approved by and conducted in accordance with Seattle Genetics Institutional Care and Use Committee protocol #SGE-029.

scholarly journals Neuroinflammatory Basis of Depression: Learning From Experimental Models

2021 ◽  
Vol 15 ◽  
Author(s):  
Ruqayya Afridi ◽  
Kyoungho Suk
Keyword(s):  
Cell Activation ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Brain Regions ◽  
Experimental Models ◽  
Sterile Inflammation ◽  
Immune Cell Activation ◽  
Glial Cell Activation ◽  
Intensive Investigation

The neuroinflammatory basis of depression encompasses the detrimental role of otherwise supportive non-neuronal cells and neuroinflammation in hampering neuronal function, leading to depressive behavior. Animals subjected to different stress paradigms show glial cell activation and a surge in proinflammatory cytokines in various brain regions. The concept of sterile inflammation observed in animal models of depression has intrigued many researchers to determine the possible triggers of central immune cell activation. Notably, microglial activation and subsequent phenotypic polarization in depression have been strongly advocated by the wealth of recent preclinical studies; however, findings from human studies have shown contradictory results. Despite intensive investigation, many research gaps still exist to elucidate the molecular mechanisms of neuroinflammatory cascades underlying the pathophysiology of depression. In this mini-review, recent progress in understanding neuroinflammatory mechanisms in light of experimental models of depression will be thoroughly discussed. The challenges of mirroring depression in animal and in vitro models will also be highlighted. Furthermore, prospects of targeting neuroinflammation to treat depressive disorder will be covered.

Oxidized Haemoglobin–Driven Endothelial Dysfunction and Immune Cell Activation: Novel Therapeutic Targets for Atherosclerosis

2013 ◽  
Vol 20 (37) ◽  
pp. 4806-4814 ◽  
Author(s):  
Brigitta Buttari ◽  
Elisabetta Profumo ◽  
Rita Businaro ◽  
Luciano Saso ◽  
Raffaele Capoano ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Cell Activation ◽  
Immune Cell ◽  
Therapeutic Targets ◽  
Immune Cell Activation ◽  
Novel Therapeutic

scholarly journals Neuronal guidance proteins in cardiovascular inflammation

2021 ◽  
Vol 116 (1) ◽  
Author(s):  
Marius Keller ◽  
Valbona Mirakaj ◽  
Michael Koeppen ◽  
Peter Rosenberger
Keyword(s):  
Cell Activation ◽  
Immune Cell ◽  
Vascular Endothelial ◽  
Therapeutic Approaches ◽  
Immune Cell Activation ◽  
Cytokines And Chemokines ◽  
The Future ◽  
Cardiovascular Pathologies ◽  
Neuronal Guidance

AbstractCardiovascular pathologies are often induced by inflammation. The associated changes in the inflammatory response influence vascular endothelial biology; they complicate the extent of ischaemia and reperfusion injury, direct the migration of immune competent cells and activate platelets. The initiation and progression of inflammation is regulated by the classical paradigm through the system of cytokines and chemokines. Therapeutic approaches have previously used this knowledge to control the extent of cardiovascular changes with varying degrees of success. Neuronal guidance proteins (NGPs) have emerged in recent years and have been shown to be significantly involved in the control of tissue inflammation and the mechanisms of immune cell activation. Therefore, proteins of this class might be used in the future as targets to control the extent of inflammation in the cardiovascular system. In this review, we describe the role of NGPs during cardiovascular inflammation and highlight potential therapeutic options that could be explored in the future.

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