搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Pre-clinical research on B and NK cell development relies on murine stromal cell-based systems with reduced physiological relevance and clinical applicability. A serum-free,fully humanized co-culture system utilizing human bone marrow-derived mesenchymal stromal cells (BM-MSCs) was developed to differentiate CB-CD34+ cells towards B and NK cell lineages. Differentiation dynamics were monitored via flow cytometry,with immunophenotypic analysis tracking progression from progenitors to mature cells. The system generated CD19+ IgM+ immature B cells and CD56+ CD16+ NK cells,recapitulating fetal stages of human lymphopoiesis. Serum-free media conditions ensured reproducibility and high overall yield of CD19+ B (35 ± 5.32%) and CD56+ NK (28.46 ± 7.01%) cell progenitors. Flow cytometry identified distinct population peaks,confirming temporal control over differentiation. This clinically relevant platform addresses the limitations of traditional models by providing a more physiologically accurate human microenvironment. The serum-free system supports applications in disease modeling,genotoxic compound screening,and mutational studies of hematopoiesis. By enabling scalable production of B and NK cells it aims to accelerate translational research for immunodeficiencies,cancer immunotherapy,and hematopoietic disorders. View Publication

The regulatory pathways necessary for the maintenance of adult hematopoietic stem cells (HSCs) remain poorly defined. By using loss-of-function approaches,we report a selective and cell-autonomous requirement for the p300/CBP-binding transcriptional coactivator Cited2 in adult HSC maintenance. Conditional deletion of Cited2 in the adult mouse results in loss of HSCs causing multilineage bone marrow failure and increased lethality. In contrast,conditional ablation of Cited2 after lineage specification in lymphoid and myeloid lineages has no impact on the maintenance of these lineages. Additional deletion of Ink4a/Arf (encoding p16(Ink4a) and p19(Arf)) or Trp53 (encoding p53,a downstream target of p19(Arf)) in a Cited2-deficient background restores HSC functionality and rescues mice from bone marrow failure. Furthermore,we show that the critical role of Cited2 in primitive hematopoietic cells is conserved in humans. Taken together,our studies provide genetic evidence that Cited2 selectively maintains adult HSC functions,at least in part,via Ink4a/Arf and Trp53. View Publication

The generation of hematopoietic cells from human embryonic stem cells (hESC) has raised the possibility of using hESC as an alternative donor source for transplantation. However,functional defects identified in hESC-derived cells limit their use for full lymphohematopoietic reconstitution. The purpose of the present study was to define and quantitate key functional and molecular differences between CD34(+) hematopoietic progenitor subsets derived from hESC and CD34(+) subsets from umbilical cord blood (UCB) representing definitive hematopoiesis. Two distinct sub-populations were generated following mesodermal differentiation from hESC,a CD34(bright) (hematoendothelial) and CD34(dim) (hematopoietic-restricted) subset. Limiting dilution analysis revealed profound defects in clonal proliferation relative to UCB particularly in B lymphoid conditions. Transcription factors normally expressed at specific commitment stages during B lymphoid development from UCB-CD34(+) cells were aberrantly expressed in hESC-derived CD34(+) cells. Moreover,strong negative regulators of lymphopoiesis such as the adaptor protein LNK and CCAAT/enhancer-binding protein-α (CEBPα),were exclusively expressed in hESC-CD34(+) subsets. Knockdown of LNK lead to an increase in hematopoietic progenitors generated from hESCs. The aberrant molecular profile seen in hESC-CD34(+) cells represents persistence of transcripts first expressed in undifferentiated hESC and/or CD326-CD56(+) mesoderm progenitors,and may contribute to the block in definitive hematopoiesis from hESC. View Publication

Gene therapy has proven its potential to cure diseases of the hematopoietic system. However,severe adverse events observed in clinical trials have demanded improved gene-transfer conditions. Whereas progress has been made to reduce the genotoxicity of integrating gene vectors,the role of pretransplantation cultivation is less well investigated. We observed that the STIF (stem cell factor [SCF],thrombopoietin [TPO],insulin-like growth factor-2 [IGF-2],and fibroblast growth factor-1 [FGF-1]) cytokine cocktail developed to effectively expand murine hematopoietic stem cells (HSCs) also supports the expansion of leukemia-initiating insertional mutants caused by gammaretroviral gene transfer. We compared 4 protocols to examine the impact of prestimulation and posttransduction culture in STIF in the context of lentiviral gene transfer. Observing 56 transplanted mice for up to 9.5 months,we found consistent engraftment and gene-marking rates after prolonged ex vivo expansion. Although a lentiviral vector with a validated insertional-mutagenic potential was used,longitudinal analysis identifying textgreater 7000 integration sites revealed polyclonal fluctuations,especially in expanded" groups� View Publication

A population of CD133(+)Lin(-)CD45(-) very small embryonic/epiblast-like stem cells (VSELs) has been purified by multiparameter sorting from umbilical cord blood (UCB). To speed up isolation of these cells,we employed anti-CD133-conjugated paramagnetic beads followed by staining with Aldefluor to detect aldehyde dehydrogenase (ALDH) activity; we subsequently sorted CD45(-)/GlyA(-)/CD133(+)/ALDH(high) and CD45(-)/GlyA(-)/CD133(+)/ALDH(low) cells,which are enriched for VSELs,and CD45(+)/GlyA /CD133(+)/ALDH(high) and CD45(+)/GlyA(-)/CD133(+)/ALDH(low) cells,which are enriched for hematopoietic stem/progenitor cells (HSPCs). Although freshly isolated CD45(-) VSELs did not grow hematopoietic colonies,the same cells,when activated/expanded over OP9 stromal support,acquired hematopoietic potential and grew colonies composed of CD45(+) hematopoietic cells in methylcellulose cultures. We also observed that CD45(-)/GlyA(-)/CD133(+)/ALDH(high) VSELs grew colonies earlier than CD45(-)/GlyA(-)/CD133(+)/ALDH(low) VSELs,which suggests that the latter cells need more time to acquire hematopoietic commitment. In support of this possibility,real-time polymerase chain reaction analysis confirmed that,whereas freshly isolated CD45(-)/GlyA(-)/CD133(+)/ALDH(high) VSELs express more hematopoietic transcripts (for example,c-myb),CD45(-)/GlyA(-)/CD133(+)/ALDH(low) VSELs exhibit higher levels of pluripotent stem cell markers (for example,Oct-4). More importantly,hematopoietic cells derived from VSELs that were co-cultured over OP9 support were able to establish human lympho-hematopoietic chimerism in lethally irradiated non-obese diabetic/severe combined immunodeficiency mice 4-6 weeks after transplantation. Overall,our data suggest that UCB-VSELs correspond to the most primitive population of HSPCs in UCB. View Publication

Excessive accumulation of smooth-muscle cells (SMCs) has a key role in the pathogenesis of vascular diseases. It has been assumed that SMCs derived from the outer medial layer migrate,proliferate and synthesize extracellular matrix components on the luminal side of the vessel. Although much effort has been devoted to targeting migration and proliferation of medial SMCs,there is no effective therapy that prevents occlusive vascular remodeling. We show here that in models of post-angioplasty restenosis,graft vasculopathy and hyperlipidemia-induced atherosclerosis,bone-marrow cells give rise to most of the SMCs that contribute to arterial remodeling. Notably,purified hematopoietic stem cells differentiate into SMCs in vitro and in vivo. Our findings indicate that somatic stem cells contribute to pathological remodeling of remote organs,and may provide the basis for the development of new therapeutic strategies for vascular diseases through targeting mobilization,homing,differentiation and proliferation of bone marrow-derived vascular progenitor cells. View Publication

OBJECTIVE: We examined the effect of the vasoactive agents carbon monoxide (CO) and nitric oxide (NO) : n the phosphorylation and intracellular redistribution of vasodilator-stimulated phosphoprotein (VASP),a critical actin motor protein required for cell migration that also controls vasodilation and platelet aggregation. RESEARCH DESIGN AND METHODS: We examined the effect of donor-released CO and NO in endothelial progenitor cells (EPCs) and platelets from nondiabetic and diabetic subjects and in human microvascular endothelial cells (HMECs) cultured under low (5.5 mmol/l) or high (25 mmol/l) glucose conditions. VASP phosphorylation was evaluated using phosphorylation site-specific antibodies. RESULTS: In control platelets,CO selectively promotes phosphorylation at VASP Ser-157,whereas NO promotes phosphorylation primarily at Ser-157 and also at Ser-239,with maximal responses at 1 min with both agents on Ser-157 and at 15 min on Ser-239 with NO treatment. In diabetic platelets,neither agent resulted in VASP phosphorylation. In nondiabetic EPCs,NO and CO increased phosphorylation at Ser-239 and Ser-157,respectively,but this response was markedly reduced in diabetic EPCs. In endothelial cells cultured under low glucose conditions,both CO and NO induced phosphorylation at Ser-157 and Ser-239; however,this response was completely lost when cells were cultured under high glucose conditions. In control EPCs and in HMECs exposed to low glucose,VASP was redistributed to filopodia-like structures following CO or NO exposure; however,redistribution was dramatically attenuated under high glucose conditions. CONCLUSIONS: Vasoactive gases CO and NO promote cytoskeletal changes through site- and cell type-specific VASP phosphorylation,and in diabetes,blunted responses to these agents may lead to reduced vascular repair and tissue perfusion. View Publication

BACKGROUND: Conventional gene-therapy applications of hematopoietic stem cells (HSCs) involve purification of CD34+ progenitor cells from the mobilized peripheral blood,ex vivo transduction of the gene of interest into them,and reinfusion of the transduced CD34+ progenitor cells into patients. Eliminating the process of purification would save labor,time and money,while enhancing HSCs viability,transplantability and pluripotency. Lentiviral vectors have been widely used in gene therapy because they infect both dividing and nondividing cells and provide sustained transgene expression. One of the exceptions to this rule is quiescent primary lymphocytes,in which reverse transcription of viral DNA is not completed. METHODS: In the present study,we tested the possibility of targeting CD34+ progenitor cells within nonpurified human mobilized peripheral blood mononuclear cells (mPBMCs) utilizing vesicular stomatitis virus G (VSV-G) pseudotyped lentiviral vectors,based on the assumption that the CD34+ progenitor cells would be preferentially transduced. To further enhance the specificity of vector transduction,we also examined utilizing a modified Sindbis virus envelope (2.2) pseudotyped lentiviral vector,developed in our laboratory,that allows targeted transduction to specific cell receptors via antibody recognition. RESULTS: Both the VSV-G and 2.2 pseudotyped vectors achieved measurable results when they were used to target CD34+ progenitor cells in nonpurified mPBMCs. CONCLUSIONS: Overall,the data obtained demonstrate the potential of ex vivo targeting of CD34+ progenitor cells without purification. View Publication

Infection with Anaplasma phagocytophilum,a gram-negative,lipopolysaccharide (LPS)-negative,obligate intracellular bacterium,results in multiple peripheral blood cytopenias. We hypothesized that infection with this organism would result in decreased bone marrow (BM) function and shifts in hematopoietic progenitor cells (HPCs) and lineage-committed cells in a well-established murine model of infection. HPCs and lineage-committed progenitors were enumerated in the BM and spleen during acute infection. BM cytokine production and BM CXCL12 expression were determined. Infection resulted in peripheral blood bicytopenia,marked decreases in the number of lineage-committed HPCs in the BM along with concurrent increases in the number of lineage-committed HPCs in the spleen,and a mixed,predominantly myelosuppressive BM cytokine environment. There was significant downregulation of CXCL12 in BM cells that may have been partially responsible for changes in HPC trafficking observed. Changes occurred in the absence of direct pathogen infection of BM cells. Hematopoietic lineage assessment demonstrated that there was loss of erythrocytes and B lymphocytes from the BM along with increased granulopoiesis. These changes were accompanied by splenomegaly due to lymphoid hyperplasia and increased hematopoiesis,most notably erythropoiesis. These changes largely mimic well-described inflammation and endotoxin-mediated effects on the BM and spleen; however,the numbers of peripheral blood neutrophils appear to be independently modulated as granulocytic hyperplasia does not result in neutrophilia. Our findings highlight a well-conserved series of events that we demonstrate can be instigated by an LPS-negative pathogen in the absence of an endotoxin-mediated acute proinflammatory response. View Publication

The future use of adult mesenchymal stem cells (MSCs) for human therapies depends on the establishment of preclinical studies with other mammals such as mouse. Surprisingly,purification and characterisation of murine MSCs were only poorly documented. The aim of this study was to purify mouse MSCs from adult bone marrow and to functionally characterise their abilities to differentiate along diverse lineages. Adherent cells from adult C57Bl/6J mouse bone marrow were depleted of granulo-monocytic cells and subsequently allowed to grow on fibronectin-coated dishes in presence of fetal bovine serum and growth factors. The growing fibroblastoid cell population primarily consisted of spindle- and star-shaped cells with significant renewal capacity as they were cultured until 30 passages (about 60 doubling population). We fully demonstrated the MSC phenotype of these cells by inducing them to differentiate along osteoblastic,adipocytic,and chondrocytic pathways. Mouse MSCs (mMSCs) sharing the same morphological and functional characteristics as human MSCs can be successfully isolated from adult bone marrow without previous mouse or bone marrow treatment. Therefore,mMSCs will be an important tool to study the in vivo behaviour and fate of this cell type after grafting in mouse pathology models. View Publication