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

Trisomy 21 is associated with hematopoietic abnormalities in the fetal liver,a preleukemic condition termed transient myeloproliferative disorder,and increased incidence of acute megakaryoblastic leukemia. Human trisomy 21 pluripotent cells of various origins,human embryonic stem (hES),and induced pluripotent stem (iPS) cells,were differentiated in vitro as a model to recapitulate the effects of trisomy on hematopoiesis. To mitigate clonal variation,we isolated disomic and trisomic subclones from the same parental iPS line,thereby generating subclones isogenic except for chromosome 21. Under differentiation conditions favoring development of fetal liver-like,γ-globin expressing,definitive hematopoiesis,we found that trisomic cells of hES,iPS,or isogenic origins exhibited a two- to fivefold increase in a population of CD43(+)(Leukosialin)/CD235(+)(Glycophorin A) hematopoietic cells,accompanied by increased multilineage colony-forming potential in colony-forming assays. These findings establish an intrinsic disturbance of multilineage myeloid hematopoiesis in trisomy 21 at the fetal liver stage. View Publication

Recent evidence suggests human embryonic stem cell (hESC) and induced pluripotent stem (iPS) cell lines have differences in their epigenetic marks and transcriptomes,yet the impact of these differences on subsequent terminally differentiated cells is less well understood. Comparison of purified,homogeneous populations of somatic cells derived from multiple independent human iPS and ES lines will be required to address this critical question. Here,we report a differentiation protocol based on embryonic development that consistently yields large numbers of endothelial cells (ECs) derived from multiple hESCs or iPS cells. Mesoderm differentiation of embryoid bodies was maximized,and defined growth factors were used to generate KDR+ EC progenitors. Magnetic purification of a KDR+ progenitor subpopulation resulted in an expanding,homogeneous pool of ECs that expressed EC markers and had functional properties of ECs. Comparison of the transcriptomes revealed limited gene expression variability between multiple lines of human iPS-derived ECs or between lines of ES- and iPS-derived ECs. These results demonstrate a method to generate large numbers of pure human EC progenitors and differentiated ECs from pluripotent stem cells and suggest individual lineages derived from human iPS cells may have significantly less variance than their pluripotent founders. STEM Cells2013;31:92–103 View Publication

Many studies have compared the genetic and epigenetic profiles of human induced pluripotent stem cells (hiPSCs) to human embryonic stem cells (hESCs) and yet the picture remains unclear. To address this,we derived a population of neural precursor cells (NPCs) from the H1 (WA01) hESC line and generated isogenic iPSC lines by reprogramming. The gene expression and methylation profile of three lines were compared to the parental line and intermediate NPC population. We found no gene probe with expression that differed significantly between hESC and iPSC samples under undifferentiated or differentiated conditions. Analysis of the global methylation pattern also showed no significant difference between the two PSC populations. Both undifferentiated populations were distinctly different from the intermediate NPC population in both gene expression and methylation profiles. One point to note is that H1 is a male line and so extrapolation to female lines should be cautioned. However,these data confirm our previous findings that there are no significant differences between hESCs and hiPSCs at the gene expression or methylation level. View Publication

Insulin resistance is central to diabetes and metabolic syndrome. To define the consequences of genetic insulin resistance distinct from those secondary to cellular differentiation or in vivo regulation,we generated induced pluripotent stem cells (iPSCs) from individuals with insulin receptor mutations and age-appropriate control subjects and studied insulin signaling and gene expression compared with the fibroblasts from which they were derived. iPSCs from patients with genetic insulin resistance exhibited altered insulin signaling,paralleling that seen in the original fibroblasts. Insulin-stimulated expression of immediate early genes and proliferation were also potently reduced in insulin resistant iPSCs. Global gene expression analysis revealed marked differences in both insulin-resistant iPSCs and corresponding fibroblasts compared with control iPSCs and fibroblasts. Patterns of gene expression in patients with genetic insulin resistance were particularly distinct in the two cell types,indicating dependence on not only receptor activity but also the cellular context of the mutant insulin receptor. Thus,iPSCs provide a novel approach to define effects of genetically determined insulin resistance. This study demonstrates that effects of insulin resistance on gene expression are modified by cellular context and differentiation state. Moreover,altered insulin receptor signaling and insulin resistance can modify proliferation and function of pluripotent stem cell populations. View Publication

Human embryonic stem cells (hESCs) are capable of extensive self-renewal and expansion and can differentiate into any somatic tissue,making them useful for regenerative medicine applications. Allogeneic transplantation of hESC-derived tissues from results in immunological rejection absent adjunctive immunosuppression. The goal of our study was to generate a universal pluripotent stem cell source by nucleofecting a mutated human leukocyte antigen G (mHLA-G) gene into hESCs using the PiggyBac transposon. We successfully generated stable mHLA-G(EF1$\$)-hESC lines using chEF1$\$ system that stably expressed mHLA-G protein during prolonged undifferentiated proliferation andin differentiated embryoid bodies as well as teratomas. Morphology,karyotype,and telomerase activity of mHLA-G expressing hESC were normal. Immunofluorescence staining and flow cytometry analysis revealed persistent expression of pluripotent markers,OCT-3/4 and SSEA-4,in undifferentiated mHLA-G(EF1$\$)-hESC. Nucleofected hESC formed teratomas and when directed to differentiate into epidermal precursors,expressed high levels of mHLA-G and keratinocyte markers K14 and CD29. Natural killer cell cytotoxicity assays demonstrated a significant decrease in lysis of mHLA-G(EF1a)-hESC targets relative to control cells. Similar results were obtained with mHLA-G(EF1$\$)-hESC-derived epidermal progenitors (hEEP). One way mixed T lymphocyte reactions unveiled that mHLA-G(EF1a)-hESC and -hEEP restrained the proliferative activity of mixed T lymphocytes. We conclude that heterologous expression of mHLA-G decreases immunogenicity of hESCs and their epidermal differentiated derivatives. View Publication

CRISPR/Cas9 has demonstrated a high-efficiency in site-specific gene targeting. However,potential off-target effects of the Cas9 nuclease represent a major safety concern for any therapeutic application. Here,we knock out the Tafazzin gene by CRISPR/Cas9 in human-induced pluripotent stem cells with 54% efficiency. We combine whole-genome sequencing and deep-targeted sequencing to characterise the off-target effects of Cas9 editing. Whole-genome sequencing of Cas9-modified hiPSC clones detects neither gross genomic alterations nor elevated mutation rates. Deep sequencing of in silico predicted off-target sites in a population of Cas9-treated cells further confirms high specificity of Cas9. However,we identify a single high-efficiency off-target site that is generated by a common germline single-nucleotide variant (SNV) in our experiment. Based on in silico analysis,we estimate a likelihood of SNVs creating off-target sites in a human genome to be ˜1.5-8.5%,depending on the genome and site-selection method,but also note that mutations might be generated at these sites only at low rates and may not have functional consequences. Our study demonstrates the feasibility of highly specific clonal ex vivo gene editing using CRISPR/Cas9 and highlights the value of whole-genome sequencing before personalised CRISPR design. View Publication

OBJECTIVE Long-term treatment with tyrosine kinase inhibitors (TKI) represents an effective cure for chronic myeloid leukemia (CML) patients and discontinuation of TKI therapy is now proposed to patient with deep molecular responses. However,evidence demonstrating that TKI are unable to fully eradicate dormant leukemic stem cells (LSC) indicate that new therapeutic strategies are needed to control LSC and to prevent relapse. In this study we investigated the metabolic pathways responsible for CML surviving to imatinib exposure and its potential therapeutic utility to improve the efficacy of TKI against stem-like CML cells. METHODS Using complementary cell-based techniques,metabolism was characterized in a large panel of BCR-ABL+ cell lines as well as primary CD34+ stem-like cells from CML patients exposed to TKI and L-Asparaginases. Colony forming cell (CFC) assay and flow cytometry were used to identify CML progenitor and stem like-cells. Preclinical models of leukemia dormancy were used to test the effect of treatments. RESULTS Although TKI suppressed glycolysis,compensatory glutamine-dependent mitochondrial oxidation supported ATP synthesis and CML cell survival. Glutamine metabolism was inhibited by L-asparaginases such as Kidrolase or Erwinase without inducing predominant CML cell death. However,clinically relevant concentrations of TKI render CML cells susceptible to Kidrolase. The combination of TKI with Lasparaginase reactivates the intinsic apoptotic pathway leading to efficient CML cell death. CONCLUSION Targeting glutamine metabolism with the FDA-approved drug,Kidrolase in combination with TKI that suppress glycolysis represents an effective and widely applicable therapeutic strategy for eradicating stem-like CML cells. View Publication

BACKGROUND Adoptive cell therapy (ACT) using genetically modified T cells has evolved into a promising treatment option for patients with cancer. However,even for the best-studied and clinically validated CD19-targeted chimeric antigen receptor (CAR) T-cell therapy,many patients face the challenge of lack of response or occurrence of relapse. There is increasing need to improve the efficacy of ACT so that durable,curative outcomes can be achieved in a broad patient population. METHODS Here,we investigated the impact of indomethacin (indo),a non-steroidal anti-inflammatory drug (NSAID),on the efficacy of ACT in multiple preclinical models. Mice with established B-cell lymphoma received various combinations of preconditioning chemotherapy,infusion of suboptimal dose of tumor-reactive T cells,and indo administration. Donor T cells used in the ACT models included CD4+ T cells expressing a tumor-specific T cell receptor (TCR) and T cells engineered to express CD19CAR. Mice were monitored for tumor growth and survival. The effects of indo on donor T cell phenotype and function were evaluated. The molecular mechanisms by which indo may influence the outcome of ACT were investigated. RESULTS ACT coupled with indo administration led to improved tumor growth control and prolonged mouse survival. Indo did not affect the activation status and tumor infiltration of the donor T cells. Moreover,the beneficial effect of indo in ACT did not rely on its inhibitory effect on the immunosuppressive cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) axis. Instead,indo-induced oxidative stress boosted the expression of death receptor 5 (DR5) in tumor cells,rendering them susceptible to donor T cells expressing TNF-related apoptosis-inducing ligand (TRAIL). Furthermore,the ACT-potentiating effect of indo was diminished against DR5-deficient tumors,but was amplified by donor T cells engineered to overexpress TRAIL. CONCLUSION Our results demonstrate that the pro-oxidative property of indo can be exploited to enhance death receptor signaling in cancer cells,providing rationale for combining indo with genetically modified T cells to intensify tumor cell killing through the TRAIL-DR5 axis. These findings implicate indo administration,and potentially similar use of other NSAIDs,as a readily applicable and cost-effective approach to augment the efficacy of ACT. View Publication

OBJECTIVES We sought to develop medium throughput standard operating procedures for screening cryopreserved human peripheral blood mononuclear cells (PBMCs) for CD4+ and CD8+ T cell responses to potential autoantigens. METHODS Dendritic cells were loaded with a peptide cocktail from ubiquitous viruses or full-length viral protein antigens and cocultured with autologous T cells. We measured expression of surface activation markers on T cells by flow cytometry and cytometry by time of flight 24-72 h later. We tested responses among T cells freshly isolated from healthy control PBMCs,cryopreserved T cells,and T cells derived from a variety of T cell expansion protocols. We also compared the transcriptional profile of CD8+ T cells rested with interleukin (IL)7 for 48 h after 1) initial thawing,2) expansion,and 3) secondary cryopreservation/thawing of expanded cells. To generate competent antigen presenting cells from PBMCs,we promoted differentiation of PBMCs into dendritic cells with granulocyte macrophage colony stimulating factor and IL-4. RESULTS We observed robust dendritic cell differentiation from human PBMCs treated with 50 ng/mL GM-CSF and 20 ng/mL IL-4 in as little as 3 days. Dendritic cell purity was substantially increased by magnetically enriching for CD14+ monocytes prior to differentiation. We also measured antigen-dependent T cell activation in DC-T cell cocultures. However,polyclonal expansion of T cells with anti-CD3/antiCD28 abolished antigen-dependent upregulation of CD69 in our assay despite minimal transcriptional differences between rested CD8+ T cells before and after expansion. Furthermore,resting these expanded T cells in IL-2,IL-7 or IL-15 did not restore the antigen dependent responses. In contrast,T cells that were initially expanded with IL-2 + IL-7 rather than plate bound anti-CD3 + anti-CD28 retained responsiveness to antigen stimulation and these responses strongly correlated with responses measured at initial thawing. SIGNIFICANCE While screening techniques for potential pathological autoantibodies have come a long way,comparable full-length protein target assays for screening patient T cells at medium throughput are noticeably lacking due to technical hurdles. Here we advance techniques that should have broad applicability to translational studies investigating cell mediated immunity in infectious or autoimmune diseases. Future studies are aimed at investigating possible CD8+ T cell autoantigens in MS and other CNS autoimmune diseases. View Publication

PURPOSE We investigated the effect of the racemic $\beta$-hydroxybutyrate precursor,R,S-1,3-butanediol (BD),on T-cell-related cytokine gene expression within stimulated peripheral blood mononuclear cells (PBMC) following prolonged,strenuous exercise. METHODS A repeated-measures,randomised,crossover study was conducted in nine healthy,trained male cyclists (age,26.7 ± 5.2 years; VO2peak,63.9 ± 2.5 mL kg-1 min-1). Participants ingested 0.35 g kg-1 of BD or placebo 30 min before and 60 min during 85 min of steady-state (SS) exercise,which preceded a {\~{}} 30 min time-trial (TT) (7 kJ kg-1). Blood samples were collected at pre-supplement,pre-exercise,post-SS,post-TT and 1-h post-TT. Whole blood cultures were stimulated with Staphylococcal enterotoxin B (SEB) for 24 h to determine T-cell-related interleukin (IL)-4,IL-10 and interferon (IFN)-$\gamma$ mRNA expression within isolated PBMCs in vitro. RESULTS Serum cortisol,total circulating leukocyte and lymphocyte,and T-cell subset concentrations were similar between trials during exercise and recovery (all p {\textgreater} 0.05). BD ingestion increased T-cell-related IFN-$\gamma$ mRNA expression compared with placebo throughout exercise and recovery (p = 0.011); however,IL-4 and IL-10 mRNA expression and the IFN-$\gamma$/IL-4 mRNA expression ratio were unaltered (all p {\textgreater} 0.05). CONCLUSION Acute hyperketonaemia appears to transiently amplify the initiation of the pro-inflammatory T-cell-related IFN-$\gamma$ response to an immune challenge in vitro during and following prolonged,strenuous exercise; suggesting enhanced type-1 T-cell immunity at the gene level. View Publication

Angelman syndrome (AS) and Prader-Willi syndrome (PWS),two distinct neurodevelopmental disorders,result from loss of expression from imprinted genes in the chromosome 15q11-13 locus most commonly caused by a megabase-scale deletion on either the maternal or paternal allele,respectively. Each occurs at an approximate incidence of 1/15,000 to 1/30,000 live births and has a range of debilitating phenotypes. Patient-derived induced pluripotent stem cells (iPSCs) have been valuable tools to understand human-relevant gene regulation at this locus and have contributed to the development of therapeutic approaches for AS. Nonetheless,gaps remain in our understanding of how these deletions contribute to dysregulation and phenotypes of AS and PWS. Variability across cell lines due to donor differences,reprogramming methods,and genetic background make it challenging to fill these gaps in knowledge without substantially increasing the number of cell lines used in the analyses. Isogenic cell lines that differ only by the genetic mutation causing the disease can ease this burden without requiring such a large number of cell lines. Here,we describe the development of isogenic human embryonic stem cell (hESC) lines modeling the most common genetic subtypes of AS and PWS. These lines allow for a facile interrogation of allele-specific gene regulation at the chromosome 15q11-q13 locus. Additionally,these lines are an important resource to identify and test targeted therapeutic approaches for patients with AS and PWS. View Publication

In this study,we explore the therapeutic feasibility of globotriaosylceramide (Gb3) synthase (A4GALT)-specific siRNA-loaded polyhistidine (pHis)-incorporated lipid nanoparticles (HLNPs) for Fabry disease (FD). HLNPs were developed to deliver siRNAs targeting A4GALT using a microfluidic device,with pHis aiding in endosome escape. The therapy was tested on GLA-knockout human-induced pluripotent-stem-cell-derived endothelial cells (GLA-KO-hiPSC-ECs) and podocytes (GLA-KO-hiPSC-PCs). GLA-KO-hiPSCs-ECs or -PCs,upon differentiation,were treated with A4GALT-siRNA-HLNP. Successful intracellular uptake of A4GALT-siRNA-HLNP was confirmed through fluorescence and electron microscopy in both cell types. A4GALT-siRNA-HLNP treatment confirmed both cell types’ stability at 5 ?g/mL. Increased Gb3 deposition and zebra body formation were detected in both cell types,but A4GALT-siRNA-HLNP treatment attenuated these FD phenotypes,demonstrating reduced expression of A4GALT through western blot analysis. RNA sequencing analysis revealed that the expression of transcripts associated with FD was restored by A4GALT-siRNA-HLNP treatment in GLA-KO-hiPSCs-ECs,whereas in GLA-KO-hiPSCs-PCs,this effect was relatively less pronounced. Suppression of A4GALT via siRNA/HLNP treatment significantly rescued FD phenotypes especially in EC,presenting a novel therapeutic approach for FD. Graphical abstract This study highlights the therapeutic potential of A4GALT-siRNA delivered via HLNPs for Fabry disease (FD). In GLA-KO-hiPSC-derived endothelial cells and podocytes,treatment reduced Gb3 accumulation,restored transcriptomic changes,and mitigated FD phenotypes,with stronger effects in endothelial cells,supporting its promise as a novel FD therapy. View Publication