Publications by authors named "Whitty G"

Aim: Pilot clinical trial of NY-ESO-1 (ESO) protein in ISCOMATRIX™ adjuvant pulsed onto peripheral blood dendritic cells (PBDC), to ascertain feasibility, evaluate toxicity and assess induction of ESO-specific immune responses.

Patients & Methods: Eligible participants had resected cancers expressing ESO or LAGE-1 and were at high risk of relapse. PBDC were produced using CliniMACSplus, with initial depletion of CD1c B cells followed by positive selection of CD1c PBDC.

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Osteopontin (OPN), a multifunctional acidic glycoprotein, expressed by osteoblasts within the endosteal region of the bone marrow (BM) suppresses the proliferation of hemopoietic stem and progenitor cells and also regulates their lodgment within the BM after transplantation. Herein we demonstrate that OPN cleavage fragments are the most abundant forms of this protein within the BM. Studies aimed to determine how hemopoietic stem cells (HSCs) interact with OPN revealed for the first time that murine and human HSCs express alpha(9)beta(1) integrin.

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How diverse stimuli control hemopoietic lineage development is unknown. An early event during induction of macrophage differentiation in the myeloblastic leukemia M1 cell line by different stimuli, such as leukemia inhibitory factor (LIF) and interleukin-6 (IL-6), is expression of the colony-stimulating factor-1 receptor (CSF-1R). We report that expression of active CSF-1R in M1 cells accelerated their subsequent terminal differentiation into macrophages in response to LIF and IL-6 when compared with cells lacking the CSF-1R or expressing the receptor with compromised kinase activity; however, there was no requirement for signaling through the CSF-1R, for example, via endogenous CSF-1, during the actual LIF-induced and IL-6-induced differentiation stage.

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Previous studies revealed that mAb BB9 reacts with a subset of CD34(+) human BM cells with hematopoietic stem cell (HSC) characteristics. Here we map BB9 expression throughout hematopoietic development and show that the earliest definitive HSCs that arise at the ventral wall of the aorta and surrounding endothelial cells are BB9(+). Thereafter, BB9 is expressed by primitive hematopoietic cells in fetal liver and in umbilical cord blood (UCB).

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It is now evident that hemopoietic stem cells (HSC) are located in close proximity to bone lining cells within the endosteum. Accordingly, it is unlikely that the traditional method for harvesting bone marrow (BM) from mice by simply flushing long bones would result in optimal recovery of HSC. With this in mind, we have developed improved methodologies based on sequential grinding and enzymatic digestion of murine bone tissue to harvest higher numbers of BM cells and HSC from the endosteal and central marrow regions.

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Proteases and their serpin inhibitors are abundantly expressed in haemopoietic and peripheral blood cells. There is, however, relatively little information about the role played by serpins in the control of protease activity within these cells and in the pericellular region. The observation that mutations in the neutrophil elastase gene, which cause cyclic and severe congenital neutropenia, are associated with protease maldistribution gives some clue as to the potential importance of inhibitor proteins.

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Although recent data suggests that osteoblasts play a key role within the hematopoietic stem cell (HSC) niche, the mechanisms underpinning this remain to be fully defined. The studies described herein examine the role in hematopoiesis of Osteopontin (Opn), a multidomain, phosphorylated glycoprotein, synthesized by osteoblasts, with well-described roles in cell adhesion, inflammatory responses, angiogenesis, and tumor metastasis. We demonstrate a previously unrecognized critical role for Opn in regulation of the physical location and proliferation of HSCs.

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Infusions of ex vivo-expanded (EXE) mobilized blood cells have been explored to enhance haematopoietic recovery following high dose chemotherapy (HDT). However, prior studies have not consistently demonstrated improvements in trilineage haematopoietic recovery. Three cohorts of three patients with breast cancer received three cycles of repetitive HDT supported by either unmanipulated (UM) and/or EXE cells.

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Macrophage colony-stimulating factor (M-CSF or CSF-1) controls the development of macrophage lineage cells via activation of its tyrosine kinase receptor, c-Fms. After adding CSF-1 to M1 myeloid cells expressing CSF-1R (CSF-1 receptor), tyrosine phosphorylation of many cellular proteins occurs, which might be linked to subsequent macrophage differentiation. The biological significance and characterization of such proteins were explored by a dual strategy comprising two-dimensional SDS/PAGE analysis of cell lysates of CSF-1-treated M1 cells expressing the wild-type or a mutated receptor, together with an enrichment strategy involving a tyrosine-phosphorylated receptor construct.

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Microglial cells, macrophage-lineage cells in the brain, are increased in amyloid-containing plaques in Alzheimer's disease (AD) and in the lesions of prion diseases. Recent studies suggest that microglia have a central role in turnover of amyloid in these diseases. We report here that synthetic amyloid beta (Abeta) 1-42 and prion protein (PrP) 106-126 peptides promote macrophage survival; they also induce macrophage DNA synthesis, particularly in the presence of sub-optimal concentrations of the growth factor, macrophage-colony stimulating factor (M-CSF or CSF-1).

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Osteoclasts form when hematopoietic cells are stimulated by macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-kappaB ligand (RANKL) or tumor necrosis factor-alpha (TNFalpha). Osteoclast precursors derive from M-CSF-dependent proliferating hematopoietic cells but cannot yet be purified from mixed populations. M-CSF stimulation of bone marrow cells results in large numbers of nonadherent, proliferating macrophage precursors.

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M1 myeloid cells transfected with the wild-type (WT) colony-stimulating factor-1 (CSF-1) receptor (CSF-1R; M1/WT cells) undergo CSF-1-dependent macrophage differentiation. By mutation studies, we have provided prior evidence that tyrosine 559 in the CSF-1R cytoplasmic domain governs the Src-dependent differentiation pathway. Further components of this pathway were then sought.

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The interaction of particulates with resident macrophages is a consistent feature in certain forms of crystal-induced inflammation, for example, in synovial tissues, lung, and the peritoneum. The mitogenic activity of basic calcium phosphate (BCP) crystals and calcium pyrophosphate dihydrate (CPPD) crystals on synovial fibroblasts has been considered relevant to the synovial hyperplasia observed in crystal-induced arthritis. The aim of the study was to determine whether microcrystals such as these could enhance macrophage survival and induce DNA synthesis, thus indicating that they may contribute to the tissue hyperplasia.

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Macrophage colony stimulating factor (M-CSF or CSF-1) acts to regulate the development and function of cells of the macrophage lineage. Murine myeloid FDC-P1 cells transfected with the CSF-1 receptor (FD/WT) adopt a macrophage-like morphology when cultured in CSF-1. This process is abrogated in FDC-P1 cells transfected with the CSF-1 receptor with a tyrosine to phenyalanine substitution at position 807 (FD/807), suggesting that a molecular interaction critical to differentiation signaling is lost (Bourette, R.

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Human atherosclerotic plaque contains a partially characterized range of normal and oxidized lipids formed mainly from free and esterified cholesterol and phospholipids, some of which can be located in macrophage-derived "foam" cells. Oxidation of low-density lipoprotein (LDL) is often considered as an important event leading to subsequent foam-cell development, which may also include enhanced cell survival and/or proliferation. The active component(s) in oxidized LDL (ox.

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Modification of low-density lipoprotein (LDL), for example by oxidation, could be involved in foam cell formation and proliferation observed in atherosclerotic lesions. Macrophage colony-stimulating factor (CSF-1 or M-CSF) has been implicated in foam cell development. It has been reported previously that oxidized LDL (ox.

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The mode of action of immunological adjuvants is not yet completely understood. Many are particulate. Certain antigen-presenting (dendritic) cell populations belong to the monocyte/macrophage lineage and, like other members of the lineage, in some tissues appear to be short-lived.

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Modification of low density lipoprotein (LDL), eg, by oxidation, has been proposed as being important for the formation of foam cells and therefore for the development of atherosclerotic plaques. There are a number of reports showing that macrophage-derived foam cells can proliferate in both human and animal lesions, particularly in the early phase of the disease and possibly involving macrophage-colony stimulating factor (M-CSF, or CSF-1). We studied the in vitro effects of oxidized LDL (ox-LDL) on murine bone marrow-derived macrophages (BMMs), a cell population with a high proliferative capacity in vitro in response to CSF-1 and a dependence for survival on the presence of this growth factor.

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There are differing views regarding the roles of phosphatidylinositol 3-kinases (PI3-kinases) and p70 S6 kinase (p70s6k) in growth factor-induced cellular responses. One approach that is widely employed to investigate these roles is to use the inhibitors, wortmannin and rapamycin, respectively. This approach is used here to study the responses in macrophages to colony stimulating factor-1 (CSF-1).

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There is currently much interest in the mechanisms of action of antiproliferative agents and their effects on cell cycle machinery. In the present study we examined the mechanisms of action of four unrelated agents known to inhibit proliferation of CSF-1-stimulated bone marrow-derived macrophages (BMM). We report that 8-bromo-cAMP (8Br-cAMP) and lipopolysaccharide (LPS) potently reduced CSF-1-stimulated cyclin D1 protein, and cyclin-dependent kinase (cdk) 4 mRNA and protein levels, while the inhibitory effects of the Na+/ H+ antiport inhibitor 5-(N',N'-dimethyl) amiloride (DMA) and interferon gamma (IFN gamma ) were only weak.

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Murine bone marrow-derived macrophages (BMM) are widely used as a suitable model to study the proliferative response to macrophage-CSF or CSF-1. We report here that the amount of DNA synthesis observed in BMM cultures in response to CSF-1 can be masked quite significantly by low levels of IFN-alpha beta produced in the cultures. It was found that Ab to IFN-alpha beta could enhance the proliferative response in CSF-treated BMM that were able to respond to endogenous IFN-alpha beta; however, BMM from mice lacking a component of the type I IFN receptor did not show any enhancement of CSF-1-dependent DNA synthesis on addition of the Ab.

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To examine the in vivo role(s) of type I interferons (IFNs) and to determine the role of a component of the type I IFN receptor (IFNAR1) in mediating responses to these IFNs, we generated mice with a null mutation (-/-) in the IFNAR1 gene. Despite compelling evidence for modulation of cell proliferation and differentiation by type I IFNs, there were no gross signs of abnormal fetal development or morphological changes in adult IFNAR1-/- mice. However, abnormalities of hemopoietic cells were detected in IFNAR1 -/- mice.

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Macrophage colony-stimulating factor (M-CSF or CSF-1) and granulocyte-macrophage CSF (GM-CSF) have been shown to increase human monocyte urokinase-type plasminogen-activator (u-PA) activity with possible consequences for cell migration and tissue remodeling; because monocyte u-PA activity is likely to be controlled in part also by the PA inhibitors (PAIs) made by the cell, the effect of M-CSF and GM-CSF on human monocyte PAI-2 and PAI-1 synthesis was investigated. To this end, elutriation-purified human monocytes were treated in vitro with purified recombinant human M-CSF and GM-CSF, and PAI-2 and PAI-1 antigen and mRNA levels measured by specific enzyme-linked immunosorbent assays and Northern blot, respectively. Each CSF could enhance the protein and mRNA levels of PAI-2 and PAI-1 at similar concentrations for each product.

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