Search results for "Haematopoiesi"
showing 10 items of 183 documents
Bio-inorganic Nanomaterials for Biomedical Applications (Bio-silica and Polyphosphate)
2014
Bio-silica represents the main mineral component of the sponge skeletal elements (siliceous spicules), while bio-polyphosphate (polyP), a multifunctional polymer existing in microorganisms and animals, acts, among others, as reinforcement for pores in cell membranes. These natural inorganic bio-polymers, which can be readily prepared, either by recombinant enzymes (bio-silica and polyP) or chemically (polyP), are promising materials/substances for the amelioration and/or treatment of human bone diseases and dysfunctions. Bone defects in human, caused by fractures/nonunions or trauma, have an increasing impact and have become a medical challenge in the present-day aging population. Frequentl…
Mast Cell–deficient KitW-sh “Sash” Mutant Mice Display Aberrant Myelopoiesis Leading to the Accumulation of Splenocytes That Act as Myeloid-Derived S…
2013
Abstract Mast cell-deficient KitW-sh “sash” mice are widely used to investigate mast cell functions. However, mutations of c-Kit also affect additional cells of hematopoietic and nonimmune origin. In this study, we demonstrate that KitW-sh causes aberrant extramedullary myelopoiesis characterized by the expansion of immature lineage-negative cells, common myeloid progenitors, and granulocyte/macrophage progenitors in the spleen. A consistent feature shared by these cell types is the reduced expression of c-Kit. Populations expressing intermediate and high levels of Ly6G, a component of the myeloid differentiation Ag Gr-1, are also highly expanded in the spleen of sash mice. These cells are …
Rapid Differentiation of a Rare Subset of Adult Human Lin−CD34−CD38− Cells Stimulated by Multiple Growth Factors In Vitro
1999
Recently, several reports of lineage-negative (lin(-)) CD34(-) cells with in vivo hematopoietic activity have focused interest on the properties and growth factor response characteristics of these cells. We have now identified a combination of 5 growth factors that are necessary and sufficient to stimulate a marked mitogenic and differentiation response by a subset of human lin(-)CD34(-)CD38(-) cells present in normal adult human marrow and granulocyte colony-stimulating factor (G-CSF)-mobilized blood. Less than 0.1% of the cells in highly purified (including doubly sorted) lin(-)CD34(-)CD38(-) cells from these 2 sources formed colonies directly in semisolid medium or generated such cells a…
Candida albicans triggers proliferation and differentiation of hematopoietic stem and progenitor cells by a MyD88-dependent signaling.
2009
As TLRs are expressed by hematopoietic stem and progenitor cells, these receptors may play a role in hematopoiesis in response to pathogens during infection. We showed here that inactivated yeasts and hyphae of Candida albicans induce in vitro the proliferation of purified murine hematopoietic stem and progenitor cells (Lin(-)c-Kit(+) Sca-1(+)) as well as their differentiation to lineage positive cells, through a MyD88-dependent pathway. These results indicate that TLR-mediated recognition of C. albicans by hematopoietic stem and progenitor cells may augment the host capability for rapidly replenishing the innate immune system during candidiasis.
Hyper-IL-6 (H-IL-6), a Fusion Protein of Soluble IL-6 Receptor (Sil-6R), and Interleukin-6 (IL-6), Acts Synergistic with Thrombopoietin (TPO) and Ste…
1999
It has been shown that signalings from c-kit and gpl30, the signal-transducing receptor component of the IL6 receptor, act synergistic for the ex-vivo expansion of multipotential hematopoietic progenitors. A similar synergistic effect has been demonstrated for signalings from c-kit, c-mpl, and flt3. While c-kit is activated by stem cell factor (SCF), gpl30 can be activated by the complex of soluble IL-6 receptor (sIL-6R) and interleukin-6 (IL-6). Recently, a bioactive designer cytokine, H-IL-6, a fusion protein consisting of SIL-6R and IL-6 linked by a flexible peptide chain has been shown to expand human hematopoietic colony-forming cells. We tested the activity of H-IL-6 alone and in comb…
Interleukins
1994
With interleukins (IL), a new class of potential drugs has been introduced into clinical research. These signal peptides are involved in the regulation of many physiological and pathophysiological processes. IL-1, -2, -3, -4, -6 and -11 have been tested in clinical trials. The growth promoting, growth inhibiting or immunomodulatory activities of interleukins represent the theoretical basis for large scale clinical testing, predominantly in malignant disease. Dose-dependent effects on numbers of peripheral blood cells and recovery from bone marrow failure have been demonstrated for IL-1, -3, -6 and -11. Phase III trials are in progress to determine their value for clinical practice. However,…
Hematopoietins: New Tools in the Treatment of Hematopoietic Insufficiency
1993
The number of circulating blood cells and their function are regulated by a variety of peptide hormones, the so-called hematopoietic growth factors (HGFs) or hematopoietins. In a complex regulatory network of stimulating and inhibiting peptide hormones [1], the number of circulating blood cells is kept at a physiological level. Because many of these blood cells have a relatively short half-life, the bone marrow is in a state of constant active proliferation in order to produce the necessary blood cells. For instance, granulocytes are made at a rate of 5 × 107–10 × 107 cells/s. It is unclear whether additional, hematopoietin-independent regulatory mechanisms exist, which might be responsible…
High Expression of Cannabinoid Receptor 2 on Cytokine-Induced Killer Cells and Multiple Myeloma Cells
2020
Multiple myeloma (MM) is characterized by aberrant bone marrow plasma cell (PC) proliferation and is one of the most common hematological malignancies. The potential effect of cannabinoids on the immune system and hematological malignancies has been poorly characterized. Cannabidiol (CBD) may be used to treat various diseases. CBD is known to exert immunomodulatory effects through the activation of cannabinoid receptor 2 (CB2), which is expressed in high levels in the hematopoietic system. Cytokine-induced killer (CIK) cells are a heterogeneous population of polyclonal T lymphocytes obtained via ex vivo sequential incubation of peripheral blood mononuclear cells (PBMCs) with interferon-&gam…
In vivo fate mapping with SCL regulatory elements identifies progenitors for primitive and definitive hematopoiesis in mice.
2009
10 páginas, 6 figuras.-- et al.
Rapid Expansion of Acute Myeloid Leukemia-Reactive Cytotoxic T Cells from CD8+CD62L+ Blood Lymphocytes of HLA-Matched Healthy Donors In Vitro
2006
Abstract Allogeneic cytotoxic T-lymphocyte (CTL) therapy in acute myeloid leukemia (AML) is hampered by the poor efficiency of growing leukemia-reactive CTLs from healthy donors in vitro. We established an allogeneic mini-mixed lymphocyte-leukemia culture (MLLC) approach by stimulating comparably small numbers (104/well) of CD8+ T cells isolated from healthy donors against irradiated primary AML blasts in 96-well plates. Prior to use, CD8+ T cells were immunomagnetically separated into a CD62L(high)+ subset enriched for naive precursors and central memory cells as well as a CD62L(low)+/negative subset containing effector memory cells. The culture medium contained IL-7, IL-12, and IL-15. Aft…