Jeffery LE et al. (NOV 2009)
Journal of immunology (Baltimore,Md. : 1950) 183 9 5458--67
1,25-Dihydroxyvitamin D3 and IL-2 combine to inhibit T cell production of inflammatory cytokines and promote development of regulatory T cells expressing CTLA-4 and FoxP3.
The active form of vitamin D,1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)),has potent immunomodulatory properties that have promoted its potential use in the prevention and treatment of infectious disease and autoimmune conditions. A variety of immune cells,including macrophages,dendritic cells,and activated T cells express the intracellular vitamin D receptor and are responsive to 1,25(OH)(2)D(3.) Despite this,how 1,25(OH)(2)D(3) regulates adaptive immunity remains unclear and may involve both direct and indirect effects on the proliferation and function of T cells. To further clarify this issue,we have assessed the effects of 1,25(OH)(2)D(3) on human CD4(+)CD25(-) T cells. We observed that stimulation of CD4(+)CD25(-) T cells in the presence of 1,25(OH)(2)D(3) inhibited production of proinflammatory cytokines including IFN- gamma,IL-17,and IL-21 but did not substantially affect T cell division. In contrast to its inhibitory effects on inflammatory cytokines,1,25(OH)(2)D(3) stimulated expression of high levels of CTLA-4 as well as FoxP3,the latter requiring the presence of IL-2. T cells treated with 1,25(OH)(2)D(3) could suppress proliferation of normally responsive T cells,indicating that they possessed characteristics of adaptive regulatory T cells. Our results suggest that 1,25(OH)(2)D(3) and IL-2 have direct synergistic effects on activated T cells,acting as potent anti-inflammatory agents and physiologic inducers of adaptive regulatory T cells.
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产品类型：
产品号#：
14052
产品名：
(Oct 2024)
Viruses 16 10
The HIV-1 vpr R77Q Mutant Induces Apoptosis, G2 Cell Cycle Arrest, and Lower Production of Pro-Inflammatory Cytokines in Human CD4+ T Cells
Acquired immunodeficiency syndrome (AIDS) occurs when HIV depletes CD4+ helper T cells. Some patients develop AIDS slowly or not at all,and are termed long-term non-progressors (LTNP),and while mutations in the HIV-1 Viral Protein R (vpr) gene such as R77Q are associated with LTNP,mechanisms for this correlation are unclear. This study examines the induction of apoptosis,cell cycle arrest,and pro-inflammatory cytokine release in the HUT78 T cell line following infection with replication-competent wild-type strain NL4-3,the R77Q mutant,or a vpr Null mutant. Our results show a significant enhancement of apoptosis and G2 cell cycle arrest in HUT78 cells infected with R77Q,but not with WT NL4-3 or the vpr Null strain. Conversely,HUT78 cells infected with the WT virus show higher levels of necrosis. We also detected lower TNF and IL-6 release after infection with R77Q vs. WT. The apoptotic phenotype was also seen in the CEM cell line and in primary CD4+ T cells. Protein expression of the R77Q vpr variant was low compared to WT vpr,but expression levels alone cannot explain these phenotypes because the Null virus did not show apoptosis or G2 arrest. These results suggest that R77Q triggers a non-inflammatory apoptotic pathway that attenuates inflammation,possibly contributing to LTNP.
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产品类型：
产品号#：
17852
17852RF
100-0693
产品名：
EasySep™人CD4正选试剂盒II
RoboSep™ 人CD4正选试剂盒II
EasySep™人CD4正选试剂盒II
Ailles LE et al. (OCT 1997)
Blood 90 7 2555--64
Detection and characterization of primitive malignant and normal progenitors in patients with acute myelogenous leukemia using long-term coculture with supportive feeder layers and cytokines.
Analysis of the mitogenic activity of interleukin-3 (IL-3),Steel factor (SF),and flt-3 ligand (FL) on acute myelogenous leukemia (AML) blasts using the short-term endpoints of proliferation in 3H-thymidine (3H-Tdr) incorporation assays or methylcellulose cultures (colony assays) showed that greater than 90% of samples contained cells that were responsive to one or more of these cytokines. With this information,culture conditions that were known to support normal long-term culture-initiating cells (LTC-IC) were tested,with or without supplements of one or more of these three growth factors,for their ability to support primitive progenitors from 10 cell samples from patients with AML. In all cases cytogenetically abnormal colony forming cells (CFC) were detected after 5 weeks when AML peripheral blood or marrow cells were cocultured on preestablished,normal human marrow feeders (HMF) and/or SI/SI mouse fibroblast feeders and the number of CFC detected in these 5-week-old LTC maintained a linear relationship to the number of input AML cells. Limiting dilution analysis,performed on 6 of the 10 samples,showed the frequency of AML cells initiating LTC (AML LTC-IC) to be 5- to 300-fold lower than the frequency of AML-CFC in the same cell sample,whereas the average number of CFC produced per LTC-IC varied from 1 to 13. Surprisingly,in each case the concentration of cytogenetically normal LTC-IC detected in AML patient blood was at least 10-fold higher than that previously observed in the blood of normal individuals. Mixed" mouse fibroblast feeders engineered to produce human G-CSF
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产品类型：
产品号#：
05150
05350
产品名：
MyeloCult™H5100
Vandenabeele P et al. (JAN 1990)
Lymphokine research 9 3 381--9
Response of murine cell lines to an IL-1/IL-2-induced factor in a rat/mouse T hybridoma (PC60): differential induction of cytokines by human IL-1 alpha and IL-1 beta and partial amino acid sequence of rat GM-CSF.
We analyzed the proliferative response of the growth factor-dependent murine cell lines FDCp1,DA1-a,32DC1,Ea3.15,7TD1,BCL1 and of femural bone marrow cells for their sensitivity to various cytokines,viz. rhIL-1 beta,rhTNF,rhIL-2,mIL-3,rmIL-4,rmIL-5,rhIL-6,rhG-CSF and rmGM-CSF. We also tested for IL-1 and TNF-mediated cytokine secretion by several T cell lines and thymocytes. In all T cell systems,IL-1 alpha and IL-1 beta were equally active in the induction of cytokine production,except for the rat/mouse T cell hybridoma PC60. This cell line exhibited a 10-fold difference in specific activity for the induction of cytokine secretion between rhIL-1 alpha and the other human or murine IL-1 species. Furthermore,IL-1 and IL-2 synergistically induced PC60 cells to produce a factor,which was preferentially active on FDCp1-cells,provisionally called FDCp1-growth factor. SDS-PAGE analysis of partially purified FDCp1-GF showed 19 kDa and 24 kDa-associated biological activities. Amino-terminal and internal amino acid sequences of both bands were determined and on this basis,we identified FDCp1-GF as rat GM-CSF.
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Meivar-Levy I et al. (JAN 1997)
The Journal of biological chemistry 272 3 1558--64
The role of sphingolipids in the maintenance of fibroblast morphology. The inhibition of protrusional activity, cell spreading, and cytokinesis induced by fumonisin B1 can be reversed by ganglioside GM3.
Previous studies demonstrated that inhibition of sphingolipid synthesis by the mycotoxin fumonisin B1 (FB1) disrupts axonal growth in cultured hippocampal neurons (Harel,R.,and Futerman,A. H. (1993) J. Biol. Chem. 268,14476-14481) by affecting the formation or stabilization of axonal branches (Schwarz,A.,Rapaport,E.,Hirschberg,K.,and Futerman,A.H. (1995) J. Biol. Chem. 270,10990-10998). We now demonstrate that long term incubation with FB1 affects fibroblast morphology and proliferation. Incubation of Swiss 3T3 cells with FB1 resulted in a decrease in synthesis of ganglioside GM3,the major glycosphingolipid in 3T3 fibroblasts and of sphingomyelin. The projected cell area of FB1-treated cells was approximately 45% less than control cells. FB1 had no affect on the organization of microtubules or intermediate filaments,but fewer actin-rich stress fibers were observed,and there was a loss of actin-rich lamellipodia at the leading edge. Three other processes involving the actin cytoskeleton,cytokinesis,microvilli formation,and the formation of long processes induced by protein kinase inhibitors,were all disrupted by FB1. All the effects of FB1 on cell morphology could be reversed by addition of ganglioside GM3 even in the presence of FB1,whereas the bioactive intermediates,sphinganine,sphingosine,and ceramide,were without effect. Finally,FB1 blocked cell proliferation and DNA synthesis in a reversible manner,although ganglioside GM3 could not reverse the effects of FB1 on cell proliferation. Together,these data suggest that ongoing sphingolipid synthesis is required for the assembly of both new membrane and of the underlying cytoskeleton.
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产品类型：
产品号#：
73682
73684
产品名：
Fumonisin B1
Fumonisin B1
Baksh D et al. (NOV 2005)
Blood 106 9 3012--9
Soluble factor cross-talk between human bone marrow-derived hematopoietic and mesenchymal cells enhances in vitro CFU-F and CFU-O growth and reveals heterogeneity in the mesenchymal progenitor cell compartment.
The homeostatic adult bone marrow (BM) is a complex tissue wherein physical and biochemical interactions serve to maintain a balance between the hematopoietic and nonhematopoietic compartments. To focus on soluble factor interactions occurring between mesenchymal and hematopoietic cells,a serum-free adhesion-independent culture system was developed that allows manipulation of the growth of both mesenchymal and hematopoietic human BM-derived progenitors and the balance between these compartments. Factorial experiments demonstrated a role for stem cell factor (SCF) and interleukin 3 (IL-3) in the concomitant growth of hematopoietic (CD45+) and nonhematopoietic (CD45-) cells,as well as their derivatives. Kinetic tracking of IL-3alpha receptor (CD123) and SCF receptor (CD117) expression on a sorted CD45- cell population revealed the emergence of CD45-CD123+ cells capable of osteogenesis. Of the total fibroblast colony-forming units (CFU-Fs) and osteoblast colony-forming units (CFU-O),approximately 24% of CFU-Fs and about 22% of CFU-Os were recovered from this population. Cell-sorting experiments demonstrated that the CD45+ cell population secreted soluble factors that positively affect the survival and proliferation of CFU-Fs and CFU-Os generated from the CD45- cells. Together,our results provide insight into the intercellular cytokine network between hematopoietic and mesenchymal cells and provide a strategy to mutually culture both mesenchymal and hematopoietic cells in a defined scalable bioprocess.
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产品类型：
产品号#：
09850
产品名：
Moulding DA et al. (SEP 2007)
The Journal of experimental medicine 204 9 2213--24
Unregulated actin polymerization by WASp causes defects of mitosis and cytokinesis in X-linked neutropenia.
Specific mutations in the human gene encoding the Wiskott-Aldrich syndrome protein (WASp) that compromise normal auto-inhibition of WASp result in unregulated activation of the actin-related protein 2/3 complex and increased actin polymerizing activity. These activating mutations are associated with an X-linked form of neutropenia with an intrinsic failure of myelopoiesis and an increase in the incidence of cytogenetic abnormalities. To study the underlying mechanisms,active mutant WASp(I294T) was expressed by gene transfer. This caused enhanced and delocalized actin polymerization throughout the cell,decreased proliferation,and increased apoptosis. Cells became binucleated,suggesting a failure of cytokinesis,and micronuclei were formed,indicative of genomic instability. Live cell imaging demonstrated a delay in mitosis from prometaphase to anaphase and confirmed that multinucleation was a result of aborted cytokinesis. During mitosis,filamentous actin was abnormally localized around the spindle and chromosomes throughout their alignment and separation,and it accumulated within the cleavage furrow around the spindle midzone. These findings reveal a novel mechanism for inhibition of myelopoiesis through defective mitosis and cytokinesis due to hyperactivation and mislocalization of actin polymerization.
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Pessina A et al. (FEB 2009)
Toxicology in vitro : an international journal published in association with BIBRA 23 1 194--200
Application of human CFU-Mk assay to predict potential thrombocytotoxicity of drugs.
Megakaryocytopoiesis gives rise to platelets by proliferation and differentiation of lineage-specific progenitors,identified in vitro as Colony Forming Unit-Megakaryocytes (CFU-Mk). The aim of this study was to refine and optimize the in vitro Standard Operating Procedure (SOP) of the CFU-Mk assay for detecting drug-induced thrombocytopenia and to prevalidate a model for predicting the acute exposure levels that cause maximum tolerated decreases in the platelets count,based on the correlation with the maximal plasma concentrations (C max) in vivo. The assay was linear under the SOP conditions,and the in vitro endpoints (percentage of colonies growing) were reproducible within and across laboratories. The protocol performance phase was carried out testing 10 drugs (selected on the base of their recognised or potential in vivo haematotoxicity,according to the literature). Results showed that a relationship can be established between the maximal concentration in plasma (C max) and the in vitro concentrations that inhibited the 10-50-90 percent of colonies growth (ICs). When C max is lower than IC10,it is possible to predict that the chemicals have no direct toxicity effect on CFU-Mk and could not induce thrombocytopenia due to bone marrow damage. When the C max is higher than IC90 and/or IC50,thrombocytopenia can occur due to direct toxicity of chemicals on CFU-Mk progenitors.
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产品类型：
产品号#：
04960
04902
04900
04963
04962
04970
产品名：
MegaCult™-C胶原蛋白和不含细胞因子的培养基
胶原蛋白溶液
MegaCult™-C培养基无细胞因子
双室载玻片试剂盒
MegaCult™-C cfu染色试剂盒
MegaCult™-C不含细胞因子完整试剂盒
Malerba I et al. (OCT 2002)
Toxicological sciences : an official journal of the Society of Toxicology 69 2 433--8
In vitro myelotoxicity of propanil and 3,4-dichloroaniline on murine and human CFU-E/BFU-E progenitors.
Because of the wide use of pesticides for domestic and industrial purposes,the evaluation of their potential effects is of major concern for public health. The myelotoxicity of the herbicide propanil (3,4-dichloroproprioanilide) and its metabolite 3,4-dichloroaniline (DCA) is well documented in mice,but evidence that pesticides may severely compromise hematopoiesis in humans is lacking. In this study,an interspecies comparison of in vitro toxicity of these two compounds on murine and human burst- and colony-forming unit-erythrocyte (BFU-E,CFU-E) and colony-forming unit-granulocyte/macrophage (CFU-GM) progenitors,has been carried out. Murine bone marrow progenitors and human cord blood cells were exposed to propanil or DCA in doses ranging from 10 micro M to 1000 micro M,and the toxic effect was detected by a clonogenic assay with continuous exposure to the compounds. The results on murine cells indicate that the erythrocytic lineage is the most sensitive target for propanil and DCA. On the other hand,human progenitors seem to be less sensitive to the toxic effects of both compounds than murine progenitors at the same concentrations (IC(50) values are 305.2 +/- 22.6 micro M [total erythroid colonies] and textgreater500 micro M [CFU-GM] for propanil). Propanil was significantly more toxic to human erythroid progenitors than to human CFU-GM progenitors,as was found for the murine cells,emphasizing the role of the heme pathway as the target for propanil. These data confirm the evidence that the compounds investigated interfere with erythroid colony formation at different stages of the differentiation pathway and have different effects according to the dose.
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EasySep™小鼠TIL（CD45）正选试剂盒
产品手册STEMvision™ 为脐血库提供的自动化和 标准化CFU检测计数
技术窍门CFU检测中造血祖细胞的培养与分析
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