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

Gamma-delta (??) T cells recognize antigens in a major histocompatibility complex (MHC) independent and have cytotoxic capability. Human immunodeficiency virus (HIV) infection reduces the proportion of the V?2 cell subset compared to the V?1 cell subset of ?? T cells in the blood in most infected individuals,except for elite controllers. The capacity of V?2 T cells to kill HIV-infected targets has been demonstrated in vitro,albeit in vivo confirmatory studies are lacking. Here,we provide the first characterization of ?? T cell-HIV interactions in bone marrow-liver-thymus (BLT) humanized mice and examined the immunotherapeutic potential of V?2 T cells in controlling HIV replication in vivo. We demonstrate a reduced proportion of V?2 T cells and an increased proportion of V?1 T cells in HIV-infected BLT humanized mice,like in HIV-positive individuals. HIV infection in BLT humanized mice also impaired the ex vivo expansion of V?2 T cells,like in HIV-positive individuals. Adoptive transfer of activated V?2 T cells did not control HIV replication during cell-associated HIV transmission in BLT humanized mice but instead exacerbated viremia,suggesting that V?2 T cells may serve as early targets for HIV replication. Our findings demonstrate that BLT humanized mice can model ?? T cell-HIV interactions in vivo. View Publication

Adoptive cell therapy is an emerging treatment strategy for a number of serious diseases. Regulatory T (Treg) cells represent 1 cell type of particular interest for therapy of inflammatory conditions,as they are responsible for controlling unwanted immune responses. Initial clinical trials of adoptive transfer of Treg cells in patients with graft-versus-host disease were shown to be safe. However,obtaining sufficient numbers of highly pure and functional Treg cells with minimal contamination remains a challenge. We developed a novel approach to isolate untouched" human Treg cells from healthy donors on the basis of negative selection using the surface markers CD49d and CD127. This procedure� View Publication

Increasing evidence suggests that the deposition of amyloid plaques,composed primarily of the amyloid-beta protein (Abeta),within the cerebrovasculature is a frequent occurrence in Alzheimer's disease and may play a significant role in disease progression. Accordingly,the pathogenic mechanisms by which Abeta can alter vascular function may have therapeutic implications. Despite observations that Abeta elicits a number of physiological responses in endothelial cells,ranging from alteration of protein expression to cell death,the Abeta species accountable for these responses remains unexplored. In the current study,we show that isolated soluble Abeta aggregation intermediates activate human brain microvascular endothelial cells for both adhesion and subsequent transmigration of monocyte cells in the absence of endothelial cell death and monolayer disruption. In contrast,unaggregated Abeta monomer and mature Abeta fibril fail to induce any change in endothelial adhesion or transmigration. Correlations between average Abeta aggregate size and observed increases in adhesion illustrate that smaller soluble aggregates are more potent activators of endothelium. These results support previous studies demonstrating heightened neuronal activity of soluble Abeta aggregates,including Abeta-derived diffusible ligands,oligomers,and protofibrils,and further show that soluble aggregates also selectively exhibit activity in a vascular cell model. View Publication

Proof of drug-target engagement in physiologically-relevant contexts is a key pillar of successful therapeutic target validation. We developed two orthogonal technologies,the cellular thermal shift assay (CETSA) and a covalent chemical probe reporter approach (harnessing sulfonyl fluoride tyrosine labeling and subsequent click chemistry) to measure the occupancy of the mRNA-decapping scavenger enzyme DcpS by a small molecule inhibitor in live cells. Enzyme affinity determined using isothermal dose response fingerprinting (ITDRFCETSA) and the concentration required to occupy 50% of the enzyme (OC50) using the chemical probe reporter assay were very similar. In this case,the chemical probe method worked well due to the long offset kinetics of the reversible inhibitor (determined using a fluorescent dye-tagged probe). This work suggests that CETSA could become the first choice assay to determine in-cell target engagement due to its simplicity. View Publication

Inhibition of cytosolic DNA sensing represents a strategy that tumor cells use for immune evasion,but the underlying mechanisms are unclear. Here we have shown that CD47-signal regulatory protein α (SIRPα) axis dictates the fate of ingested DNA in DCs for immune evasion. Although macrophages were more potent in uptaking tumor DNA,increase of DNA sensing by blocking the interaction of SIRPα with CD47 preferentially occurred in dendritic cells (DCs) but not in macrophages. Mechanistically,CD47 blockade enabled the activation of NADPH oxidase NOX2 in DCs,which in turn inhibited phagosomal acidification and reduced the degradation of tumor mitochondrial DNA (mtDNA) in DCs. mtDNA was recognized by cyclic-GMP-AMP synthase (cGAS) in the DC cytosol,contributing to type I interferon (IFN) production and antitumor adaptive immunity. Thus,our findings have demonstrated how tumor cells inhibit innate sensing in DCs and suggested that the CD47-SIRPα axis is critical for DC-driven antitumor immunity. View Publication

Prostate cancer (PCa) contains a small population of cancer stem cells (CSCs) that contribute to its initiation and progression. The development of specific markers for identification of the CSCs may lead to new diagnostic strategies of PCa. Increased aldehyde dehydrogenase 1A1 (ALDH1A1) activity has been found in the stem cell populations of leukemia and some solid tumors. The aim of the study was to investigate the stem-cell-related function and clinical significance of the ALDH1A1 in human PCa. ALDEFLUOR assay was used to isolate ALDH1A1(+) cells from PCa cell lines. Stem cell characteristics of the ALDH1A1(+) cells were then investigated by in vitro and in vivo approaches. The ALDH1A1 expression was also analyzed by immunohistochemistry in 18 normal prostate and 163 PCa tissues. The ALDH1A1(+) PCa cells showed high clonogenic and tumorigenic capacities,and serially reinitiated transplantable tumors that resembled histopathologic characteristics and heterogeneity of the parental PCa cells in mice. Immunohistochemical analysis of human prostate tissues showed that ALDH1A1(+) cells were sparse and limited to the basal component in normal prostates. However,in tumor specimens,increased ALDH1A1 immunopositivity was found not only in secretory type cancer epithelial cells but also in neuroendocrine tumor populations. Furthermore,the high ALDH1A1 expression in PCa was positively correlated with Gleason score (P=0.01) and pathologic stage (P=0.01),and inversely associated with overall survival and cancer-specific survival of the patients (P=0.00093 and 0.00017,respectively). ALDH1A1 could be a prostate CSC-related marker. Measuring its expression might provide a potential approach to study tumorigenesis of PCa and predict outcome of the disease. View Publication

The utility of measuring real-time cellular bioenergetics of peripheral blood mononuclear cells (PBMCs) as biomarkers in disease monitoring,such as the bioenergetic health index,is of emerging interest. However,various experimental factors can impact the accuracy and reproducibility of these measurements. Methods: : PBMC bioenergetics were probed in real-time using extracellular flux analysis to identify optimal seeding density and injection protocol. Using a modified protocol,we assessed the extent to which blood processing time and isolation method (SepMate™ vs. EasySep™ Direct) influence PBMC bioenergetics under basal and stimulated conditions. Advanced metabolic control analysis including mitochondrial and glycolytic ATP supply flux,respiratory control ratio,bioenergetic health index,and mitochondrial toxicity index were used to identify and quantify PBMC bioenergetics. Results: Measures of metabolic profiling such as mitochondrial respiration,glycolytic activity,ATP supply flux,and respiratory control ratio were significantly diminished in PBMCs due to blood processing delay (48–72 hours) and were influenced by isolation method. Extended blood processing time significantly lowered T cell activation capacity in PBMCs,evidenced by decreased responses of mitochondrial and glycolytic ATP supply to CD3/CD28 activation. Discussion/Conclusion: This study demonstrates that key experimental variables including blood processing time and isolation method critically affect the reliability and biological relevance of PBMC metabolic assessments,highlighting the importance of protocol standardisation for accurate bioenergetic biomarker measurements. View Publication

The purpose of this study was to examine the in vitro and in vivo osteogenic potential of human induced pluripotent stem cells (hiPSCs) against that of human bone marrow mesenchymal stem cells (hBMMSCs). Embryoid bodies (EBs),which were formed from undifferentiated hiPSCs,were dissociated into single cells and underwent osteogenic differentiation using the same medium as hBMMSCs for 14 days. Osteoinduced hiPSCs were implanted on the critical-size calvarial defects and long bone segmental defects in rats. The healing of defects was evaluated after 8 weeks and 12 weeks of implantation,respectively. Osteoinduced hiPSCs showed relatively lower and delayed in vitro expressions of the osteogenic marker COL1A1 and bone sialoprotein,as well as a weaker osteogenic differentiation through alkaline phosphatase staining and mineralization through Alizarin red staining compared with hBMMSCs. Calvarial defects treated with osteoinduced hiPSCs had comparable quality of new bone formation,including full restoration of bone width and robust formation of trabeculae,to those treated with hBMMSCs. Both osteoinduced hiPSCs and hBMMSCs persisted in regenerated bone after 8 weeks of implantation. In critical-size long bone segmental defects,osteoinduced hiPSC treatment also led to healing of segmental defects comparable to osteoinduced hBMMSC treatment after 12 weeks. In conclusion,despite delayed in vitro osteogenesis,hiPSCs have an in vivo osteogenic potential as good as hBMMSCs. View Publication

The human peripheral B-cell compartment displays a large population of immunoglobulin M-positive,immunoglobulin D-positive CD27(+) (IgM(+)IgD(+)CD27(+)) memory" B cells carrying a mutated immunoglobulin receptor. By means of phenotypic analysis� View Publication

We have previously shown that coculture of human embryonic stem cells (hESCs) for 14 days with immortalized fetal hepatocytes yields CD34(+) cells that can be expanded in serum-free liquid culture into large numbers of megaloblastic nucleated erythroblasts resembling yolk sac-derived cells. We show here that these primitive erythroblasts undergo a switch in hemoglobin (Hb) composition during late terminal erythroid maturation with the basophilic erythroblasts expressing predominantly Hb Gower I (zeta(2)epsilon(2)) and the orthochromatic erythroblasts hemoglobin Gower II (alpha(2)epsilon(2)). This suggests that the switch from Hb Gower I to Hb Gower II,the first hemoglobin switch in humans is a maturation switch not a lineage switch. We also show that extending the coculture of the hESCs with immortalized fetal hepatocytes to 35 days yields CD34(+) cells that differentiate into more developmentally mature,fetal liver-like erythroblasts,that are smaller,express mostly fetal hemoglobin,and can enucleate. We conclude that hESC-derived erythropoiesis closely mimics early human development because the first 2 human hemoglobin switches are recapitulated,and because yolk sac-like and fetal liver-like cells are sequentially produced. Development of a method that yields erythroid cells with an adult phenotype remains necessary,because the most mature cells that can be produced with current systems express less than 2% adult beta-globin mRNA. View Publication

Human embryonic stem cells (hESCs) are considered a potential alternative to cadaveric islets as a source of transplantable cells for treating patients with diabetes. We previously described a differentiation protocol to generate pancreatic progenitor cells from hESCs,composed of mainly pancreatic endoderm (PDX1/NKX6.1-positive),endocrine precursors (NKX2.2/synaptophysin-positive,hormone/NKX6.1-negative),and polyhormonal cells (insulin/glucagon-positive,NKX6.1-negative). However,the relative contributions of NKX6.1-negative versus NKX6.1-positive cell fractions to the maturation of functional β-cells remained unclear. To address this question,we generated two distinct pancreatic progenitor cell populations using modified differentiation protocols. Prior to transplant,both populations contained a high proportion of PDX1-expressing cells (˜85%-90%) but were distinguished by their relatively high (˜80%) or low (˜25%) expression of NKX6.1. NKX6.1-high and NKX6.1-low progenitor populations were transplanted subcutaneously within macroencapsulation devices into diabetic mice. Mice transplanted with NKX6.1-low cells remained hyperglycemic throughout the 5-month post-transplant period whereas diabetes was reversed in NKX6.1-high recipients within 3 months. Fasting human C-peptide levels were similar between groups throughout the study,but only NKX6.1-high grafts displayed robust meal-,glucose- and arginine-responsive insulin secretion as early as 3 months post-transplant. NKX6.1-low recipients displayed elevated fasting glucagon levels. Theracyte devices from both groups contained almost exclusively pancreatic endocrine tissue,but NKX6.1-high grafts contained a greater proportion of insulin-positive and somatostatin-positive cells,whereas NKX6.1-low grafts contained mainly glucagon-expressing cells. Insulin-positive cells in NKX6.1-high,but not NKX6.1-low grafts expressed nuclear MAFA. Collectively,this study demonstrates that a pancreatic endoderm-enriched population can mature into highly functional β-cells with only a minor contribution from the endocrine subpopulation. View Publication