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

Reliable,scalable and time-efficient culture methods are required to fully realize the clinical and industrial applications of human pluripotent stem (hPS) cells. Here we present a completely defined,xeno-free medium that supports long-term propagation of hPS cells on uncoated tissue culture plastic. The medium consists of the Essential 8 (E8) formulation supplemented with inter-α-inhibitor (IαI),a human serum-derived protein,recently demonstrated to activate key pluripotency pathways in mouse PS cells. IαI efficiently induces attachment and long-term growth of both embryonic and induced hPS cell lines when added as a soluble protein to the medium at seeding. IαI supplementation efficiently supports adaptation of feeder-dependent hPS cells to xeno-free conditions,clonal growth as well as single-cell survival in the absence of Rho-associated kinase inhibitor (ROCKi). This time-efficient and simplified culture method paves the way for large-scale,high-throughput hPS cell culture,and will be valuable for both basic research and commercial applications. View Publication

The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) systems have evolved as an adaptive surveillance and defense mechanism in bacteria and archaea that uses short RNAs to direct degradation of foreign genetic elements. Here,we present our protocol for utilizing the S. pyogenes type II bacterial CRISPR system to achieve sequence-specific genome alterations in human cells. In principle,any genomic sequence of the form N(19)NGG can be targeted with the generation of custom guide RNA (gRNA) which functions to direct the Cas9 protein to genomic targets and induce DNA cleavage. Here,we describe our methods for designing and generating gRNA expression constructs either singly or in a multiplexed manner,as well as optimized protocols for the delivery of Cas9-gRNA components into human cells. Genomic alterations at the target site are then introduced either through nonhomologous end joining (NHEJ) or through homologous recombination (HR) in the presence of an appropriate donor sequence. This RNA-guided editing tool offers greater ease of customization and synthesis in comparison to existing sequence-specific endonucleases and promises to become a highly versatile and multiplexable human genome engineering platform. View Publication

[3H]thymidine uptake by NFS-60 cells in microcultures was found to increase in a linear fashion with the increasing doses of purified recombinant human granulocyte colony-stimulating factor (rhG-CSF). Such increases were found neither with rhG-CSF samples pretreated with rabbit anti-rhG-CSF serum nor with other human colony-stimulating factors such as granulocyte-macrophage colony-stimulating factor (hGM-CSF) or macrophage colony-stimulating factor (hM-CSF). Based on these findings,sera from normal persons and patients with severe infections or various hematological disorders were tested after dialysis using this system in order to determine whether G-CSF levels in sera can be estimated or not. In ten normal persons,five patients with acute myelogenous leukemia (AML M1,M2,and M3),five with myelodysplastic syndrome,and four with chronic myelogenous leukemia,no increases in [3H]thymidine uptake were found within the dose range of 0.4 microliters to 50 microliters. In contrast,linear dose responses parallel to a G-CSF standard curve were observed in one patient with a severe bacterial infection,four with aplastic anemia,two with acute myelomonocytic leukemia (AMMoL) (M4),and two with idiopathic neutropenia tested. From the standard curve,the probable levels of G-CSF were calculated as follows: approximately 200 pg/ml with infection,130-220 pg/ml with aplastic anemia,150 and 200 pg/ml with AMMoL,and 1120 and 1200 pg/ml with idiopathic neutropenia. The activities of sera were reduced by the anti-rhG-CSF serum pretreatment in the same way as documented in the case of rhG-CSF. Furthermore,the level in a patient with a severe infection became undetectable soon after elimination of the infection and blood neutrophil counts had returned to normal. These findings indicate that the microbioassay system will be useful for measuring circulating G-CSF levels which would fluctuate in accord with requirements for stimulating neutrophil production or with abnormal production of hG-CSF. View Publication

Aurora kinases play an important role in chromosome alignment,segregation,and cytokinesis during mitosis. We have recently shown that hematopoietic malignant cells including those from acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) aberrantly expressed Aurora A and B kinases,and ZM447439,a potent inhibitor of Aurora kinases,effectively induced growth arrest and apoptosis of a variety of leukemia cells. The present study explored the effect of AZD1152,a highly selective inhibitor of Aurora B kinase,on various types of human leukemia cells. AZD1152 inhibited the proliferation of AML lines (HL-60,NB4,MOLM13),ALL line (PALL-2),biphenotypic leukemia (MV4-11),acute eosinophilic leukemia (EOL-1),and the blast crisis of chronic myeloid leukemia K562 cells with an IC50 ranging from 3 nM to 40 nM,as measured by thymidine uptake on day 2 of culture. These cells had 4N/8N DNA content followed by apoptosis,as measured by cell-cycle analysis and annexin V staining,respectively. Of note,AZD1152 synergistically enhanced the antiproliferative activity of vincristine,a tubulin depolymerizing agent,and daunorubicin,a topoisomerase II inhibitor,against the MOLM13 and PALL-2 cells in vitro. Furthermore,AZD1152 potentiated the action of vincristine and daunorubicin in a MOLM13 murine xenograft model. Taken together,AZD1152 is a promising new agent for treatment of individuals with leukemia. The combined administration of AZD1152 and conventional chemotherapeutic agent to patients with leukemia warrants further investigation. View Publication

The pathogenesis of malarial anemia is multifactorial,and the mechanisms responsible for its high mortality are poorly understood. Studies indicate that host mediators produced during malaria infection may suppress erythroid progenitor development (Miller,K.L.,J.C. Schooley,K.L. Smith,B. Kullgren,L.J. Mahlmann,and P.H. Silverman. 1989. Exp. Hematol. 17:379-385; Yap,G.S.,and M.M. Stevenson. 1991. Ann. NY Acad. Sci. 628:279-281). We describe an intrinsic role for macrophage migration inhibitory factor (MIF) in the development of the anemic complications and bone marrow suppression that are associated with malaria infection. At concentrations found in the circulation of malaria-infected patients,MIF suppressed erythropoietin-dependent erythroid colony formation. MIF synergized with tumor necrosis factor and gamma interferon,which are known antagonists of hematopoiesis,even when these cytokines were present in subinhibitory concentrations. MIF inhibited erythroid differentiation and hemoglobin production,and it antagonized the pattern of mitogen-activated protein kinase phosphorylation that normally occurs during erythroid progenitor differentiation. Infection of MIF knockout mice with Plasmodium chabaudi resulted in less severe anemia,improved erythroid progenitor development,and increased survival compared with wild-type controls. We also found that human mononuclear cells carrying highly expressed MIF alleles produced more MIF when stimulated with the malarial product hemozoin compared with cells carrying low expression MIF alleles. These data suggest that polymorphisms at the MIF locus may influence the levels of MIF produced in the innate response to malaria infection and the likelihood of anemic complications. View Publication

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder,with no effective treatment currently available. Recently,non-pharmacological therapy,especially gamma frequency stimulation has shown promising therapeutic effects in Alzheimer’s disease (AD) mouse models. Electric field (EF) is a non-invasive biophysical approach for neuronal protection. However,whether EF is beneficial in AD neuropathology remains unknown. In this study,we exposed the P301S tauopathy mouse model to EF at gamma frequency on the head. We demonstrated that EF treatment significantly improved the cognitive impairments in the P301S mice. This was accompanied by reduced tau pathologies,suppressed microglial activation,neuroinflammation and oxidative stress in the tauopathy mouse brain. Moreover,EF treatment induced cell-specific responses in neural cells,with neurons being more susceptible,followed by microglia and oligodendrocytes. EF also had favorable effects on synaptic protein in neurons,inflammatory response and complement signaling in microglia,and myelination in oligodendrocytes. This study provides strong evidence that EF at gamma frequency may have great potential to be a novel therapeutic intervention for P301S by attenuating neuropathology and offering neuroprotection.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13195-025-01859-8. View Publication

Hematopoietic stem cell transplantation (HSCT) is a curative treatment for many diverse blood and immune diseases. However,HSCT regimens currently commonly utilize genotoxic chemotherapy and/or total body irradiation (TBI) conditioning which causes significant morbidity and mortality through inducing broad tissue damage triggering infections,graft vs. host disease,infertility,and secondary cancers. We previously demonstrated that targeted monoclonal antibody (mAb)-based HSC depletion with anti(α)-CD117 mAbs could be an effective alternative conditioning approach for HSCT without toxicity in severe combined immunodeficiency (SCID) mouse models,which has prompted parallel clinical αCD117 mAbs to be developed and tested as conditioning agents in clinical trials starting with treatment of patients with SCID. Subsequent efforts have built upon this work to develop various combination approaches,though none are optimal and how any of these mAbs fully function is unknown. To improve efficacy of mAb-based conditioning as a stand-alone conditioning approach for all HSCT settings,it is critical to understand the mechanistic action of αCD117 mAbs on HSCs. Here,we compare the antagonistic properties of αCD117 mAb clones including ACK2,2B8,and 3C11 as well as ACK2 fragments in vitro and in vivo in both SCID and wildtype (WT) mouse models. Further,to augment efficacy,combination regimens were also explored. We confirm that only ACK2 inhibits SCF binding fully and prevents HSC proliferation in vitro. Further,we verify that this corresponds to HSC depletion in vivo and donor engraftment post HSCT in SCID mice. We also show that SCF-blocking αCD117 mAb fragment derivatives retain similar HSC depletion capacity with enhanced engraftment post HSCT in SCID settings,but only full αCD117 mAb ACK2 in combination with αCD47 mAb enables enhanced donor HSC engraftment in WT settings,highlighting that the Fc region is not required for single-agent efficacy in SCID settings but is required in immunocompetent settings. This combination was the only non-genotoxic conditioning approach that enabled robust donor engraftment post HSCT in WT mice. These findings shed new insights into the mechanism of αCD117 mAb-mediated HSC depletion. Further,they highlight multiple approaches for efficacy in SCID settings and optimal combinations for WT settings. This work is likely to aid in the development of clinical non-genotoxic HSCT conditioning approaches that could benefit millions of people world-wide. The online version contains supplementary material available at 10.1186/s13287-024-03981-0. View Publication

Resting CD4+ T cells are primary targets of early HIV infection events in vivo,but do not readily support HIV replication in vitro. This barrier to infection can be overcome by exposing resting CD4+ T cells to endothelial cells (ECs). ECs line blood vessels and direct T cell trafficking into inflamed tissues. Cell trafficking pathways have been shown to have overlapping roles in facilitating HIV replication,but their relevance to EC-mediated enhancement of HIV susceptibility in resting CD4+ T cells has not previously been examined. We characterized the phenotype of primary human resting CD4+ T cells that became productively infected with HIV when cocultured with primary human blood and lymphatic ECs. The infected CD4+ T cells were primarily central memory cells enriched for high expression of the integrins LFA-1 and VLA-4. ICAM-1 and VCAM-1,the cognate ligands for LFA-1 and VLA-4,respectively,were expressed by the ECs in the coculture. Blocking LFA-1 and VLA-4 on resting CD4+ T cells inhibited infection by 65.4%-96.9%,indicating that engagement of these integrins facilitates EC-mediated enhancement of productive HIV infection in resting CD4+ T cells. The demonstration that ECs influence cellular HIV susceptibility of resting memory CD4+ T cells through cell trafficking pathways engaged during the transmigration of T cells into tissues highlights the physiological relevance of these findings for HIV acquisition and opportunities for intervention. View Publication

The multifunctional signaling protein p75 neurotrophin receptor (p75(NTR)) is a central regulator and major contributor to the highly invasive nature of malignant gliomas. Here,we show that neurotrophin-dependent regulated intramembrane proteolysis (RIP) of p75(NTR) is required for p75(NTR)-mediated glioma invasion,and identify a previously unnamed process for targeted glioma therapy. Expression of cleavage-resistant chimeras of p75(NTR) or treatment of animals bearing p75(NTR)-positive intracranial tumors with clinically applicable gamma-secretase inhibitors resulted in dramatically decreased glioma invasion and prolonged survival. Importantly,proteolytic processing of p75(NTR) was observed in p75(NTR)-positive patient tumor specimens and brain tumor initiating cells. This work highlights the importance of p75(NTR) as a therapeutic target,suggesting that gamma-secretase inhibitors may have direct clinical application for the treatment of malignant glioma. View Publication