Search results for "Haematopoiesis"
showing 10 items of 183 documents
Bone Marrow Derived Mesenchymal Cells Secrete Granulopoietic Cytokines upon Danger Signaling
2014
Abstract Granulopoietic homeostasis is regulated at steady-state to supply sufficient numbers of pooled and circulating neutrophils to maintain barrier function against commensal flora. In addition, upon pathogenic microbial challenge, an increased formation of neutrophils is induced, termed ‘emergency granulopoiesis’. Antibody-mediated reduction of neutrophil numbers in steady-state induces a feedback loop leading to an increase of bone marrow granulopoiesis with expansion of hematopoetic stem and progenitor cells. This feedback loop was demonstrated to depend on TLR4 and TRIF, but not MyD88 signaling (Bugl et al. Blood 2013). In contrast, emergency granulopoiesis was shown to be dependent…
Study of the role of “gatekeeper” mutations V654A and T670I of c-kit kinase in the interaction with inhibitors by means mixed molecular dynamics/dock…
2011
The over-expression of c-kit proto-oncogene has been reported in hematopoietic cells, small cell lung cancer, and gastrointestinal stromal tumors. The clinical importance of c-kit expression in tumors focused the research towards inhibitors of this tyrosine kinase. Imatinib (Gleevec®) was the first compound used in therapy, but mutations on c-kit led to reduced effectiveness or ineffectiveness of this treatment. Other compounds are likely to be effective against mutants, such as Sunitinib (Sutent®), but the need for new and most effective inhibitors against mutants is still critical. We report mixed Molecular Dynamics/Docking study with the aim to unveil the molecular mechanism involved in …
Evidence against a key role for transforming growth factor-beta1 in cytomegalovirus-induced bone marrow aplasia.
1998
During immunodeficiency after sublethal haematoablative treatment, cytomegalovirus (CMV) infection interferes with haematopoietic reconstitution and can cause lethal bone marrow (BM) aplasia. The in vivo model of murine CMV infection has identified the BM stroma as the principal target site of CMV in the haematopoietic cord. The infected cell type is the reticular stromal cell which forms the stromal network and produces essential haemopoietins, such as stem-cell factor (SCF). The expression of SCF was found to be reduced in the infected stroma, but the stromal network was not disrupted and the number of infected stromal cells was too low to explain the functional deficiency. These facts ca…
Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells
1993
Abstract nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and…
Hematopoietic stem cell quiescence and function are controlled by the CYLD–TRAF2–p38MAPK pathway
2015
Tesio at al. identify a novel pathway controlled by the tumor suppressor and deubiquitinase cylindromatosis (CYLD), which is involved in the regulation of hematopoietic stem cell quiescence and repopulation potential.
Transcriptional regulation of the stem cell leukemia gene by PU.1 and Elf-1.
1998
Abstract The SCL gene, also known astal-1, encodes a basic helix-loop-helix transcription factor that is pivotal for the normal development of all hematopoietic lineages. SCL is expressed in committed erythroid, mast, and megakaryocytic cells as well as in hematopoietic stem cells. Nothing is known about the regulation of SCL transcription in mast cells, and in other lineages GATA-1 is the only tissue-specific transcription factor recognized to regulate the SCL gene. We have therefore analyzed the molecular mechanisms underlyingSCL expression in mast cells. In this paper, we demonstrate that SCL promoter 1a was regulated by GATA-1 together with Sp1 and Sp3 in a manner similar to the situati…
186: Superior antitumor in vitro responses of allogeneic matched sibling compared to autologous patient CD8+ T cells
2007
Allogeneic cell therapy as a means to break immunotolerance to solid tumors is increasingly used for cancer treatment. To investigate cellular alloimmune responses in a human tumor model, primary cultures were established from renal cell carcinoma (RCC) tissues of 56patients. In three patients with stable RCC line and human leukocyte antigen (HLA)-identical sibling donor available, allogeneic and autologous RCC reactivities were compared using mixed lymphocyte/ tumor cell cultures (MLTC). Responding lymphocytes were exclusively CD8 + T cells, whereas CD4 + T cells or natural killer cells were never observed. Sibling MLTC populations showed higher proliferative and cytolytic antitumor respon…
Tif1gamma Is Essential for Macrophage Differentiation
2011
Abstract Abstract 2370 TIF1gamma (or TRIM33) is an ubiquitous nuclear protein that belongs to the transcriptional intermediary factor 1 family. Human and mouse TIF1gamma are closely related to zebrafish moonshine (mon), a gene whose mutations disrupt embryonic and adult hematopoiesis with severe red blood cell aplasia. Targeted deletion of Tif1gamma is embryonic lethal in mice. In zebrafish and human CD34+ cells, TIF1gamma functionally links positive elongation factors such as p-TEFb and FACT to blood specific transcription complexes (e.g. the SCL/TAL1 complex) to regulate elongation of genes by antagonizing Pol II pausing. TIF1gamma also affects the human hematopoietic progenitor cell resp…
From the oxygen to the organ protection: Erythropoietin as protagonist in internal medicine
2006
Erythropoietin (EPO), already known as the stimulating hormone for erythropoiesis, has shown different and interesting pleiotropic actions. It does not only affect erythroid cells, but also myeloid cells, lymphocytes and megakaryocytes. This hormone can also enhance phagocytic function of the polymorphonuclear cells and reduce the activation of macrophages, thus modulating the inflammatory process.Moreover, hematopoietic and endothelial cells probably have the same cellular origin, and the discovery of erythropoietin receptors (EPO-R) also on mesangial and myocardial cells, smooth muscle fibrocells and neurons has prompted the study of the non-erythropoietic functions of this hormone.The in…
Efficient retrovirus-mediated gene transfer to transplantable human bone marrow cells in the absence of fibronectin
2000
Abstract The low frequency of transplantable hematopoietic stem cells in adult human bone marrow (BM) and other differences from cord blood stem cells have impeded studies to optimize the retroviral transduction of stem cells from adult sources. To address this problem, first a cytokine combination was defined that would both maximize the kinetics of adult BM CD34+CD38− cell mitogenesis and minimize the period of prestimulation required for the transduction of these cells by a MSCV-GFP/neor virus in tissue culture dishes in the absence of fibronectin. Three days of stimulation with flt3-ligand, Steel factor, interleukin (IL)-3, and hyper-IL-6 proved both necessary and sufficient to obtain 8…