scholarly journals Fibg390-396A Limits Metastatic Potential Via a Mechanism Independent of Fibrin-Myeloid Cell Interactions, but Prospectively through the Disruption of FXIII-Mediated Fibrin Crosslinking

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2385-2385
Author(s):  
Brenton J Francisco ◽  
Balkrishan Sharma ◽  
Leah A. Rosenfeldt ◽  
Duaa Mureb ◽  
Joseph S. Palumbo
Keyword(s):  
Factor Xiii ◽  
Germ Line ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Metastatic Potential ◽  
Binding Motif ◽  
Experimental Metastasis ◽  
Cell Functions ◽  
Polymer Formation ◽  
Immunocompetent Mice

Previous studies have shown that fibrin(ogen) supports metastasis. In order to better define the mechanisms coupling fibrin(ogen) to metastasis, we compared metastatic potential in immunocompetent mice carrying specific structure/function alterations in fibrinogen and controls. FibrinogenAEK mice, which have a germ-line mutation in the thrombin cleavage site that essentially "locks" fibrinogen in its soluble state, exhibited diminished metastatic potential relative to FibWT mice. Notably, previous studies have established that factor XIII is also a significant determinant of metastasis. Taken together, these studies suggest that stable fibrin polymer formation is important in the metastatic process. However, FibAEK retained significant metastatic potential relative to mice with complete fibrinogen deficiency, indicating that fibrinogen possesses prometastatic properties in the absence of polymer formation. Fibrin(ogen) has also been shown to mediate inflammatory cell functions through direct engagement of leukocyte integrins independently of its role in platelet aggregation. Given previous studies demonstrating that myeloid cells are promote metastatic potential, we hypothesized that fibrin(ogen)-mediated leukocyte engagement represents one mechanism by which fibrinogen drives metastasis. Consistent with this view, mice expressing a mutant fibrinogen lacking the y chain binding motif for the leukocyte integrin αMβ2 (Fibγ390-396A) had diminished metastatic potential in both spontaneous and experimental metastasis assays. Furthermore, fate analyses revealed that Fibγ390-396A results in diminished survival of newly-formed metastatic foci. The early reduction in metastatic potential observed in Fibγ390-396A mice suggests that fibrin(ogen) promotes metastasis by recruiting myeloid cells to the early metastatic niche. In order to explore this hypothesis, we performed experimental metastasis assays in immunocompetent mice in which macrophages or neutrophils were specifically depleted using either clodronate or an anti-Ly6G antibody. In contrast to mice carrying the Fibγ390-396A mutation, depletion of macrophages or neutrophils had no significant impact on the early survival of metastatic foci. These studies suggest that expression Fibγ390-396A limits metastatic potential via a mechanism independent of interactions with myeloid cells. In addition to disrupting fibrin-αMβ2 interactions, elimination of the γ chain 390-396a binding motif has also been shown to limit factor XIII binding to fibrinogen. Given the established importance of FXIII in metastasis, it is conceivable that even subtle alterations in the kinetics of fibrin cross-linking resulting from expression of Fibγ390-396A limits metastatic potential. Disclosures Palumbo: Ionis Pharmaceuticals: Research Funding.

scholarly journals Myeloid Cell Function in MRP-14 (S100A9) Null Mice

2003 ◽  
Vol 23 (7) ◽  
pp. 2564-2576 ◽  
Author(s):  
Josie A. R. Hobbs ◽  
Richard May ◽  
Kiki Tanousis ◽  
Eileen McNeill ◽  
Margaret Mathies ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Cell Function ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cytosolic Calcium ◽  
In Vivo Model ◽  
Maximal Response ◽  
Cell Functions ◽  
The Stability

ABSTRACT Myeloid-related protein 14 (MRP-14) and its heterodimeric partner, MRP-8, are cytosolic calcium-binding proteins, highly expressed in neutrophils and monocytes. To understand the function of MRP-14, we performed targeted disruption of the MRP-14 gene in mice. MRP-14−/− mice showed no obvious phenotype and were fertile. MRP-8 mRNA but not protein is present in the myeloid cells of these mice, suggesting that the stability of MRP-8 protein is dependent on MRP-14 expression. A compensatory increase in other proteins was not detected in cells lacking MRP-8 and MRP-14. Although the morphology of MRP-14−/− myeloid cells was not altered, they were significantly less dense. When Ca2+ responses were investigated, there was no change in the maximal response to the chemokine MIP-2. At lower concentrations, however, there was reduced responsiveness in MRP-14−/− compared with MRP-14+/+ neutrophils. This alteration in the ability to flux Ca2+ did not impair the ability of the MRP-14−/− neutrophils to respond chemotactically to MIP-2. In addition, the myeloid cell functions of phagocytosis, superoxide burst, and apoptosis were unaffected in MRP-14−/− cells. In an in vivo model of peritonitis, MRP-14−/− mice showed no difference from wild-type mice in induced inflammatory response. The data indicate that MRP-14 and MRP-8 are dispensable for many myeloid cell functions.

scholarly journals The Metabolic Control of Myeloid Cells in the Tumor Microenvironment

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2960
Author(s):  
Eloise Ramel ◽  
Sebastian Lillo ◽  
Boutaina Daher ◽  
Marina Fioleau ◽  
Thomas Daubon ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Single Cell ◽  
Phenotypic Diversity ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Mass Cytometry ◽  
Cell Functions ◽  
Metabolic Checkpoints ◽  
The Impact

Myeloid cells are a key determinant of tumor progression and patient outcomes in a range of cancers and are therefore being actively pursued as targets of new immunotherapies. The recent use of high-dimensional single-cell approaches, e.g., mass cytometry and single-cell RNA-sequencing (scRNA-seq) has reinforced the predominance of myeloid cells in the tumor microenvironment and uncovered their phenotypic diversity in different cancers. The cancerous metabolic environment has emerged as a critical modulator of myeloid cell functions in anti-tumor immunity versus immune suppression and immune evasion. Here, we discuss mechanisms of immune-metabolic crosstalk in tumorigenesis, with a particular focus on the tumor-associated myeloid cell’s metabolic programs. We highlight the impact of several metabolic pathways on the pro-tumoral functions of tumor-associated macrophages and myeloid-derived suppressor cells and discuss the potential myeloid cell metabolic checkpoints for cancer immunotherapy, either as monotherapies or in combination with other immunotherapies.

188 Novel Anti-SIRpalpha antibodies with differentiated characteristics as promising cancer therapeutics

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A202-A202
Author(s):  
Swati Jalgaonkar ◽  
George Huang ◽  
Erin Filbert ◽  
Christine Tan ◽  
Ryan Alvarado ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Immunity ◽  
Cell Activation ◽  
Regulatory Protein ◽  
Cancer Therapeutics ◽  
Myeloid Cell ◽  
Therapeutic Window ◽  
Close Relative ◽  
Cell Functions ◽  
Tumor Clearance

BackgroundTherapeutically targeting tumor myeloid cells has emerged as a novel and complementary strategy to existing cancer immunotherapy approaches. The interaction of tumor expressed CD47 with SIRP alpha (signal regulatory protein-alphaa, SIRPA) on macrophages, dendritic cells and neutrophils inhibits key immune effector mechanisms. Targeting SIRPa-CD47 represents a novel approach to enhance anti-tumor immunity by augmenting or reactivating critical tumor clearance mechanisms.H5F9, an antibody against CD47, has shown promising therapeutic activities in patients with MSD, AML and NHL. However, agents targeting CD47 present hematological toxicities and present a huge antigen sink leading to not achieving an optimum therapeutic window. Our approach is to target SIRP alpha, the receptor of CD47 and focus therapeutic targeting to relevant mechanisms related to phagocytosis and myeloid cell activation and at the same time avoid undesired effects of blocking CD47. SIRP gamma, a very close relative of SIRP alpha is expressed on T cells and also binds to CD47. It has been shown that blockade of SIRP gamma-CD47 interaction inhibits T cell proliferation and blocks trans-endothelial T cell migration. Hence, our aim is to generate SIRP alpha selective antibodies that do not cross-react with SIRP gamma and have minimal impact on T cell functions.MethodsUsing Apexigen’s APXiMAB™ proprietary antibody discovery platform, we have generated two novel anti-SIRP alpha antibodies (APX701 & APX702) with differentiated properties as compared to other approaches targeting the CD47/SIRP alpha axis. We have used ELISA, FACS based cell binding and blocking assays, and functional assays including in vitro phagocytosis and antibody-dependent cell phagocytosis (ADCP) in combination with tumor-opsonizing antibody to select APX701 & APX702.ResultsOur novel preclinical-stage APX701 & APX702 antibodies have demonstrated the following attributes: high binding affinity to human SIRP alpha (APX701 Kd = 0.95nM, APX702 Kd = 0.88nM), no binding to SIRP gamma, efficient blockade of SIRP alpha binding to CD47(APX701 IC50 = 1.04nM, APX702 IC50 = 0.80nM), potent macrophage mediated phagocytosis, enhancement of ADCP mediated by tumor-opsonizing antibody and favorable developability CMC profiles. In comparison with the benchmark antibody OSE-172, APX701 & APX702 showed potent phagocytosis activity and ADCP enhancement in all donors tested while OSE-172 induced phagocytosis in only 50% of the donors. This may result from the fact that APX701 and APX702 bind to all major SIRP alpha variants (V1, V2 & V8; covering ~92% population) while OSE 172 only binds to SIRPalpha V1 (~50% population).ConclusionsAPX701 and APX702 demonstrate differentiated anti-SIRPalpha activities by enhancing myeloid cell-mediated anti-tumor immunity and reactivating critical tumor clearance mechanisms within the tumor microenvironment.

scholarly journals A novel transcript encoding an N-terminally truncated AML1/PEBP2 alphaB protein interferes with transactivation and blocks granulocytic differentiation of 32Dcl3 myeloid cells.

1997 ◽  
Vol 17 (7) ◽  
pp. 4133-4145 ◽  
Author(s):  
Y W Zhang ◽  
S C Bae ◽  
G Huang ◽  
Y X Fu ◽  
J Lu ◽  
...  
Keyword(s):  
Fetal Liver ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Protein Product ◽  
Terminal Region ◽  
Human Leukemia ◽  
Granulocytic Differentiation ◽  
Runt Domain ◽  
Rnase Protection ◽  
Novel Transcript

The gene AML1/PEBP2 alphaB encodes the alpha subunit of transcription factor PEBP2/CBF and is essential for the establishment of fetal liver hematopoiesis. Rearrangements of AML1 are frequently associated with several types of human leukemia. Three types of AML1 cDNA isoforms have been described to date; they have been designated AML1a, AML1b, and AML1c. All of these isoforms encode the conserved-Runt domain, which harbors the DNA binding and heterodimerization activities. We have identified a new isoform of the AML1 transcript, termed AML1 deltaN, in which exon 1 is directly connected to exon 4 by alternative splicing. The AML1 deltaN transcript was detected in various hematopoietic cell lines of lymphoid to myeloid cell origin, as revealed by RNase protection and reverse transcriptase PCR analyses. The protein product of AML1 deltaN lacks the N-terminal region of AML1, including half of the Runt domain, and neither binds to DNA nor heterodimerizes with the beta subunit. However, AML1 deltaN was found to interfere with the transactivation activity of PEBP2, and the molecular region responsible for this activity was identified. Stable expression of AML1 deltaN in 32Dcl3 myeloid cells blocked granulocytic differentiation in response to granulocyte colony-stimulating factor. These results suggest that AML1 deltaN acts as a modulator of AML1 function and serves as a useful tool to dissect the functional domains in the C-terminal region of AML1.

Receptor and Molecular Mechanism of AGGF1 Signaling in Endothelial Cell Functions and Angiogenesis

2021 ◽  
Author(s):  
Jingjing Wang ◽  
Huixin Peng ◽  
Ayse Anil Timur ◽  
Vinay Pasupuleti ◽  
Yufeng Yao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Endothelial Cell ◽  
Neutralizing Antibodies ◽  
Molecular Mechanisms ◽  
Capillary Tube ◽  
Therapeutic Angiogenesis ◽  
Angiogenic Factor ◽  
Single Amino Acid ◽  
Binding Motif ◽  
Cell Functions

Objective: Angiogenic factor AGGF1 (angiogenic factor and G-patch and FHA [Forkhead-associated] domain 1) promotes angiogenesis as potently as VEGFA (vascular endothelial growth factor A) and regulates endothelial cell (EC) proliferation, migration, specification of multipotent hemangioblasts and venous ECs, hematopoiesis, and vascular development and causes vascular disease Klippel-Trenaunay syndrome when mutated. However, the receptor for AGGF1 and the underlying molecular mechanisms remain to be defined. Approach and Results: Using functional blocking studies with neutralizing antibodies, we identified α5β1 as the receptor for AGGF1 on ECs. AGGF1 interacts with α5β1 and activates FAK (focal adhesion kinase), Src, and AKT. Functional analysis of 12 serial N-terminal deletions and 13 C-terminal deletions by every 50 amino acids mapped the angiogenic domain of AGGF1 to a domain between amino acids 604-613 (FQRDDAPAS). The angiogenic domain is required for EC adhesion and migration, capillary tube formation, and AKT activation. The deletion of the angiogenic domain eliminated the effects of AGGF1 on therapeutic angiogenesis and increased blood flow in a mouse model for peripheral artery disease. A 40-mer or 15-mer peptide containing the angiogenic domain blocks AGGF1 function, however, a 15-mer peptide containing a single amino acid mutation from −RDD- to −RGD- (a classical RGD integrin-binding motif) failed to block AGGF1 function. Conclusions: We have identified integrin α5β1 as an EC receptor for AGGF1 and a novel AGGF1-mediated signaling pathway of α5β1-FAK-Src-AKT for angiogenesis. Our results identify an FQRDDAPAS angiogenic domain of AGGF1 crucial for its interaction with α5β1 and signaling.

Targeting Trained Innate Immunity With Nanobiologics to Treat Cardiovascular Disease

2021 ◽  
Author(s):  
Abraham J.P. Teunissen ◽  
Mandy M.T. van Leent ◽  
Geoffrey Prevot ◽  
Eliane E.S. Brechbuhl ◽  
Carlos Pérez-Medina ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Apolipoprotein A1 ◽  
New Paradigm ◽  
Trained Immunity ◽  
Atherosclerosis Progression ◽  
Cardiovascular Patients ◽  
Cellular Pathways

The innate immune system plays a key role in atherosclerosis progression and the pathogenesis of cardiovascular disease. Trained immunity, an epigenetically regulated hyperresponsive state of myeloid cells, is a driving force underlying chronic inflammation in atherosclerosis. Therapeutically targeting innate trained immunity therefore may mature into a compelling new paradigm for the effective treatment of cardiovascular patients, which would require effective engagement of myeloid cells. For over a decade, we have worked on apolipoprotein A1-based nanomaterials, referred to as nanobiologics, which we have utilized for myeloid cell-directed immunotherapy. Here, we review the application of our nanobiologic immunotherapies in treating vascular disease. The design of nanobiologic therapeutics, as well as their use in targeting myeloid cells and cellular pathways related to trained immunity, is discussed. Furthermore, we show that nanobiologic biocompatibility and in vivo behavior are conserved across species, from mice to larger animals, including rabbits, pigs, and nonhuman primates. Last, we deliberate on the hurdles that currently prevent widespread translation of trained immunity targeting cardiovascular nanotherapies.

scholarly journals Inflammation and Cancer: Extra- and Intracellular Determinants of Tumor-Associated Macrophages as Tumor Promoters

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Gabor J. Szebeni ◽  
Csaba Vizler ◽  
Klara Kitajka ◽  
Laszlo G. Puskas
Keyword(s):  
Tumor Microenvironment ◽  
Macrophage Polarization ◽  
Myeloid Cells ◽  
Therapeutic Interventions ◽  
Tumor Associated Macrophages ◽  
Poor Survival ◽  
Cell Functions ◽  
Intracellular Signals ◽  
Ontogenetic Diversity ◽  
Cell Dissemination

One of the hallmarks of cancer-related inflammation is the recruitment of monocyte-macrophage lineage cells to the tumor microenvironment. These tumor infiltrating myeloid cells are educated by the tumor milieu, rich in cancer cells and stroma components, to exert functions such as promotion of tumor growth, immunosuppression, angiogenesis, and cancer cell dissemination. Our review highlights the ontogenetic diversity of tumor-associated macrophages (TAMs) and describes their main phenotypic markers. We cover fundamental molecular players in the tumor microenvironment including extra- (CCL2, CSF-1, CXCL12, IL-4, IL-13, semaphorins, WNT5A, and WNT7B) and intracellular signals. We discuss how these factors converge on intracellular determinants (STAT3, STAT6, STAT1, NF-κB, RORC1, and HIF-1α) of cell functions and drive the recruitment and polarization of TAMs. Since microRNAs (miRNAs) modulate macrophage polarization key miRNAs (miR-146a, miR-155, miR-125a, miR-511, and miR-223) are also discussed in the context of the inflammatory myeloid tumor compartment. Accumulating evidence suggests that high TAM infiltration correlates with disease progression and overall poor survival of cancer patients. Identification of molecular targets to develop new therapeutic interventions targeting these harmful tumor infiltrating myeloid cells is emerging nowadays.

scholarly journals Triggering receptor expressed on myeloid cells-2 expression in the brain is required for maximal phagocytic activity and improved neurological outcomes following experimental stroke

2018 ◽  
Vol 39 (10) ◽  
pp. 1906-1918 ◽  
Author(s):  
Kota Kurisu ◽  
Zhen Zheng ◽  
Jong Youl Kim ◽  
Jian Shi ◽  
Atsushi Kanoke ◽  
...  
Keyword(s):  
Cell Activation ◽  
Infarct Volume ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cerebrovascular Diseases ◽  
Stroke Recovery ◽  
Experimental Stroke ◽  
Neurological Outcomes ◽  
Intact Brain ◽  
The Brain

Triggering receptor expressed on myeloid cells-2 (TREM2) is an innate immune receptor that promotes phagocytosis by myeloid cells such as microglia and macrophages. We previously showed that TREM2 deficiency worsened outcomes from experimental stroke and impeded phagocytosis. However, myeloid cells participating in stroke pathology include both brain resident microglia and circulating macrophages. We now clarify whether TREM2 on brain microglia or circulating macrophages contribute to its beneficial role in ischemic stroke by generating bone marrow (BM) chimeric mice. BM chimera mice from TREM2 knockout (KO) or wild type (Wt) mice were used as donor and recipient mice. Mice were subjected to experimental stroke, and neurological function and infarct volume were assessed. Mice with intact TREM2 in brain microglia showed better neurological recovery and reduced infarct volumes, compared with mice lacking microglial TREM2. Myeloid cell activation and numbers of phagocytes were decreased in mice lacking brain TREM2, compared with mice with intact brain TREM2. These results suggest that TREM2 expression is important for post-stroke recovery, and that TREM2 expression on brain resident microglia is more essential to this recovery, than that of circulating macrophages. These findings might suggest a new therapeutic target for cerebrovascular diseases.

scholarly journals Identification of a ras-activated enhancer in the mouse osteopontin promoter and its interaction with a putative ETS-related transcription factor whose activity correlates with the metastatic potential of the cell.

1995 ◽  
Vol 15 (1) ◽  
pp. 476-487 ◽  
Author(s):  
X Guo ◽  
Y P Zhang ◽  
D A Mitchell ◽  
D T Denhardt ◽  
A F Chambers
Keyword(s):  
Transcription Factor ◽  
Protein Binding ◽  
Uv Light ◽  
Metastatic Potential ◽  
Binding Motif ◽  
Binding Assays ◽  
Mobility Shift ◽  
Related Transcription Factor ◽  
Altered Gene ◽  
Alpha V Beta 3

The role of RAS in transducing signals from an activated receptor into altered gene expression is becoming clear, though some links in the chain are still missing. Cells possessing activated RAS express higher levels of osteopontin (OPN), an alpha v beta 3 integrin-binding secreted phosphoprotein implicated in a number of developmental, physiological, and pathological processes. We report that in T24 H-ras-transformed NIH 3T3 cells enhanced transcription contributes to the increased expression of OPN. Transient transfection studies, DNA-protein binding assays, and methylation protection experiments have identified a novel ras-activated enhancer, distinct from known ras response elements, that appears responsible for part of the increase in OPN transcription in cells with an activated RAS. In electrophoretic mobility shift assays, the protein-binding motif GGAGGCAGG was found to be essential for the formation of several complexes, one of which (complex A) was generated at elevated levels by cell lines that are metastatic. Southwestern blotting and UV light cross-linking studies indicated the presence of several proteins able to interact with this sequence. The proteins that form these complexes have molecular masses estimated at approximately 16, 28, 32, 45, 80, and 100 kDa. Because the approximately 16-kDa protein was responsible for complex A formation, we have designated it MATF for metastasis-associated transcription factor. The GGANNNAGG motif is also found in some other promoters, suggesting that they may be similarly controlled by MATF.

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.

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