Search results for " STEM"
showing 10 items of 2170 documents
The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of human hematopoietic progenitor cells capable to differentiate into funct…
2000
Abstract Objective . Hyper-IL-6, a fusion protein of interleukin-6 and its specific receptor, together with stem cell factor leads to the proliferation of primitive hematopoietic progenitor cells. Based on these findings, the current study examined whether hyper-IL-6 promotes the growth of precursor cells that can be further differentiated into dendritic cells in the presence of additional cytokines. Methods . Dendritic cell cultures were generated from CD34 + hematopoietic progenitor cells derived either from bone marrow or from peripheral blood. CD34 + cells were cultured in the presence of cytokines for 2 weeks and then used for phenotyping and T-cell stimulation assays. Results . Hyper-…
Induction of cytokine production in naive CD4+ T cells by antigen-presenting murine liver sinusoidal endothelial cells but failure to induce differen…
1999
Abstract Background & Aims: Murine liver sinusoidal endothelial cells (LSECs) constitutively express accessory molecules and can present antigen to memory Th1 CD4+ T cells. Using a T-cell receptor transgenic mouse line, we addressed the question whether LSECs can prime naive CD4+ T cells. Methods: Purified LSECs were investigated for their ability to induce activation and differentiation of naive CD4+ T cells in comparison with bone marrow–derived antigen-presenting cells and macrovascular endothelial cells. Activation of T cells was determined by cytokine production. LSECs were further studied for expression of interleukin (IL)-12 by reverse-transcription polymerase chain reaction, and the…
CD8+ cytotoxic T lymphocytes isolated from allogeneic healthy donors recognize HLA class Ia/Ib–associated renal carcinoma antigens with ubiquitous or…
2004
AbstractAllogeneic hematopoietic stem cell transplantation can induce considerable tumor remissions in metastatic renal-cell carcinoma (RCC) patients. The precise effector mechanisms mediating these graft-versus-tumor reactions are unknown. We studied RCC-directed CD8+ T-cell responses in blood lymphocytes of healthy individuals matched with established RCC cell lines for HLA-class I. In 21 of 22 allogeneic mixed lymphocyte/tumor-cell cultures (MLTCs), RCC-reactive cytotoxic T-lymphocytes (CTLs) were readily obtained. From MLTCs, 121 CD8+ CTL clones with memory phenotype were isolated. Their anti–RCC reactivity was restricted by multiple classical HLA-Ia molecules, in particular by HLA-A2, …
TLR2 and Dectin-1 Signaling in Mouse Hematopoietic Stem and Progenitor Cells Impacts the Ability of the Antigen Presenting Cells They Produce to Acti…
2020
Microbial recognition by pattern recognition receptors (PRRs) expressed on hematopoietic stem and progenitor cells (HSPCs) not only activates myelopoiesis but also programs the function of the monocytes and macrophages they produce. For instance, changes in HSPC programming modify the ability of macrophages derived from them to produce inflammatory cytokines. While HSPCs exposed to a TLR2 agonist give rise to tolerized macrophages (lower proinflammatory cytokine production), HSPCs treated with Dectin-1 ligands produce trained macrophages (higher proinflammatory cytokine production). However, nothing is known about the impact of HSPC exposure to microbes on the function of antigen presenting…
Reconstitution of CD52-Negative CD4 T Cells after Alemtuzumab-Based T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation
2008
Abstract The human CD52 molecule is the target of the monoclonal antibody Alemtuzumab, which is used for treating patients with chemo-refractory chronic lymphocytic leukemia as well as for T cell depletion (TCD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT). The molecule is expressed on the surface of lymphocytes, dendritic cells and to a lesser extent on blood-derived monocytes. Previously, investigators have demonstrated that the surface expression of CD52 on T cells is down-regulated after in vitro incubation with Alemtuzumab. By treating purified human CD4 T cells over 4 hours with 10 μg/mL Alemtuzumab in medium supplemented with 10% human AB serum in vitro…
Functionally Altered GPI-Anchor Negative Treg Following Alemtuzumab-Based T-Cell Depletion Are Associated with Acute Gvhd.
2012
Abstract Abstract 3059 Introduction: The monoclonal anti-CD52antibody Alemtuzumab is frequently used for T-cell depletion (TCD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT) to prevent graft versus host disease (GVHD). We previously demonstrated the long term persistence of functionally impaired glycosylphosphatidylinositol (GPI)-anchor negative effector T-cells in patients receiving high dose (100mg) Alemtuzumab in combination with a dose reduced conditioning regimen (Fludarabin + Melpahlan) (Meyer, Wagner et al. BMT 2010). Despite of Alemtuzumab-mediated TCD, half of our patients developed acute GVHD. Since regulatory T cells (Treg) play a major role for cont…
Evidence of alloreactive T lymphocytes in fetal liver: implications for fetal hematopoietic stem cell transplantation
2000
The use of hematopoietic stem cells for in utero transplantation to create permanent hematochimerism represents a new concept in fetal therapy, although this approach has provided heterogeneous results. In this paper we have undertaken molecular, phenotypic and functional studies aimed at identifying the presence of fully competent T lymphocytes in samples of fetal livers and cord blood. We found mature VDJ TCR beta chain transcripts in fetal liver cells taken from 7 to 16 weeks of gestation and a similar pattern was detected in cord blood cells sampled from 13.5 to 20.5 weeks of gestation. A Vbeta8 gene sequence comparable to that detected in adult PBMC was found in fetal liver samples at …
Safety and efficacy outcomes after intranasal administration of neural stem cells in cerebral palsy : a randomized phase 1/2 controlled trial
2023
Abstract Background Neural stem cells (NSCs) are believed to have the most therapeutic potential for neurological disorders because they can differentiate into various neurons and glial cells. This research evaluated the safety and efficacy of intranasal administration of NSCs in children with cerebral palsy (CP). The functional brain network (FBN) analysis based on electroencephalogram (EEG) and voxel-based morphometry (VBM) analysis based on T1-weighted images were performed to evaluate functional and structural changes in the brain. Methods A total of 25 CP patients aged 3–12 years were randomly assigned to the treatment group (n = 15), which received an intranasal infusion of NSCs loade…
Crystallized nano-sized alpha-tricalcium phosphate from amorphous calcium phosphate: microstructure, cementation and cell response
2015
New insight on the conversion of amorphous calcium phosphate (ACP) to nano-sized alpha tricalcium phosphate (α-TCP) provides a faster pathway to calcium phosphate bone cements. In this work, synthesized ACP powders were treated with either water or ethanol, dried, crystallized between 700 and 800 °C, and then cooled at different cooling rates. Particle size was measured in a scanning electron microscope, but crystallite size calculated by Rietveld analysis. Phase composition and bonding in the crystallized powder was assessed by x-ray diffraction and Fourier-transform infrared spectroscopy. Results showed that 50 nm sized α-TCP formed after crystallization of lyophilized powders. Water trea…
Amorphous polyphosphate/amorphous calcium carbonate implant material with enhanced bone healing efficacy in a critical-size defect in rats
2016
In this study the effect of amorphous calcium carbonate (ACC) microparticles and amorphous calcium polyphosphate (polyP) microparticles (termed aCa-polyP-MP) on bone mineral forming cells/tissue was investigated in vitro and in vivo. The ACC particles (termed ACC-P10-MP) were prepared in the presence of Na-polyP. Only the combinations of polyP and ACC microparticles enhanced the proliferation rate of human mesenchymal stem cells (MSCs). Gene expression studies revealed that ACC causes an upregulation of the expression of the cell membrane-associated carbonic anhydrase IX (CA IX; formation of ACC), while the transcript level of the alkaline phosphatase (ALP; liberation of orthophosphate from…