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

In preclinical studies on the T-cell engager MP0533,the authors show that targeting multiple tumor-associated antigens may lead to better selectivity and efficacy in eliminating leukemic stem cells and blasts,representing a promising therapeutic strategy for AML. View Publication

Both antitumor and protumor property of mesenchymal stem cells (MSCs) have been demonstrated. We hypothesize that this contradiction is due to the heterogeneity of MSC subsets and that extracellular vesicles (EVs) from distinct MSC subsets can transfer the corresponding antitumor activities. Here we evaluated the antitumor activities of two subsets of adipose-derived mesenchymal stem cells (ADSCs) and ADSC-derived EVs (ADSC-EVs) in immunocompetent syngeneic mouse models of breast cancer. We identified CD90high and CD90low ADSC subsets and demonstrated that CD90high ADSCs could be converted into CD90low ADSCs by stimulation with LPS. CD90low ADSCs and its derived EVs significantly inhibited tumor growth in tumor-bearing mice. Benefit of tumor control were associated with decreased tumor cell proliferation and migration,and enhanced tumor cell apoptosis mediated by ADSC-EVs. Antioncogenic miRNA-16-5p loaded CD90low ADSC-EVs further significantly enhanced antitumor activities. Taken together,this study represents the first attempt to apply our newly identified antitumor ADSCs and its derived EVs in preclinical treatment of breast cancer. This study also provides the evidence that EVs can serve as a novel and effective therapeutics or drug delivery vesicle. This new therapeutic approach could be potentially applicable to breast cancer and many other types of cancer. View Publication

Overcoming drug resistance and targeting cancer stem cells remain challenges for curative cancer treatment. To investigate the role of miRNAs in regulating drug resistance and leukemic stem cell (LSCs) fate,we performed global transcriptome profiling in treatment-na{\{i}}ve chronic myeloid leukemia (CML) stem/progenitor cells and identified that miR-185 levels anticipate their response to ABL tyrosine kinase inhibitors (TKIs). miR-185 functions as a tumor suppressor; its restored expression impaired survival of drug-resistant cells sensitized them to TKIs in vitro and markedly eliminated long-term repopulating LSCs and infiltrating blast cells conferring a survival advantage in pre-clinical xenotransplantation models. Integrative analysis with mRNA profiles uncovered PAK6 as a crucial target of miR-185 and pharmacological inhibition of PAK6 perturbed the RAS/MAPK pathway and mitochondrial activity sensitizing therapy-resistant cells to TKIs. Thus miR-185 presents as a potential predictive biomarker and dual targeting of miR-185-mediated PAK6 activity and BCR-ABL may provide a valuable strategy for overcoming drug resistance in patients." View Publication

Aim To analyse the ability of mesenchymal stem cells (MSCs) to regulate interleukin 6 (IL-6) and transforming growth factor (TGF-$\beta$) expression in vitro under co-culture conditions in human systemic lupus erythematosus (SLE). Method This study used a post-test group design that used peripheral blood mononuclear cells (PBMCs) from SLE patients at Kariadi Hospital,Semarang,Indonesia,and MSCs from a human umbilical cord. The cells were divided into two groups. The control group of PBMCs was treated with a standard medium,and the treatment group was co-cultured with the MSCs at a 1:40 ratio. Following 24 h incubation,the levels of IL-6 and TGF-$\beta$ released in the culture medium were measured using a specific ELISA assay. Results This study showed a significant decrease in IL-6 level (p{\textless}0.05) and a significant increase in TGF-$\beta$ level (p{\textless}0.001) following 24 h of co-culture incubation of human SLE PBMCs cells and MSCs. Conclusion The PBMCs-to-MSCs ratio of 1:40 can regulate the IL-6 and TGF-$\beta$ levels in human SLE PBMCs. View Publication

Francisella tularensis (Ft),a Gram-negative bacterium that causes tularemia,possesses a non-inflammatory atypical LPS (LPSFt) that is highly immunogenic through unknown mechanism. We previously showed that immunization with LPSFt,a type 2 T-independent (TI) antigen,elicits protective LPSFt-specific IgM (IgMFt) and IgG3Ft by B1 cells in a mechanism dependent on the IL-5 produced by innate lymphoid cells type 2 (ILC2). Here,we examined the role of complement in the B1 cells’ response against LPSFt. C3-/-,C1q-/- and C4-/- mice immunized with LPSFt failed to produce IgMFt and IgG3Ft. In contrast,the response of Cfb-/- and Mbl1/Mbl2-/- mice was comparable to that of WT mice. Thus,activation of the classical complement cascade,but not the alternative or the Mannose Binding Lectin pathway,is required for activation of B1 cells and production of LPSFt-specific antibodies. Complement activation generates the C3d fragment,which opsonizes antigens for recognition by complement receptor-2 (CR2),and the C3a and C5a anaphylatoxins. Our results show that C3d opsonized LPSFt and that the response to immunization was dependent on CR2 expression by B1 cells. Importantly,the response to LPSFt immunization was also drastically decreased in C3ar1-/-,but not in C5ar1-/- mice. C3a induced IL-5 in ILC2,which supported B1 cells activation. Decreased antibody production in C3ar1-/- and Cr2-/- mice correlated with increased susceptibility to tularemia. Together,these results demonstrate that the high immunogenicity of LPSFt depends on two effector mechanisms triggered by activation of the classical complement pathway: 1) tagging of LPSFt with C3d fragment,leading to its interaction with CR2 expressed by B1 cells; 2) production of the anaphylatoxin C3a that stimulated IL-5 secretion by ILC2. Our study increases our understanding of the B1 cells’ response to TI-2 antigens and identifies two complement effector mechanisms that can be harnessed for therapeutic interventions. Author summaryThe lipopolysaccharide (LPS) of the bacterium Francisella tularensis strongly stimulates B cells for antibody production independently of T cell help through unknown mechanism. In the present study we examined the role of the complement cascade in this process. We found that production of antibodies against this LPS depends on activation of the classical complement pathway but not the MBL-dependent lectin or the alternative pathways. Following complement activation,LPS became tagged with the C3d complement fragment leading to its interaction with the complement receptor CR2 expressed by B cells. Complement activation also resulted in production of the anaphylatoxin C3a that was required for B cells activation,possibly through induction of IL-5 by innate lymphoid cells 2. Our study increases our understanding of the B cells’ response to T-independent antigens and identifies two complement effector mechanisms that can be harnessed for therapeutic interventions. View Publication

Background: Lenalidomide is an immunomodulatory drug approved in the treatment of autoimmune disease,inflammation,and cancer. Its impact continues to grow due to its diverse spectrum of effects hampered only by toxicities and reduced efficacy. Therefore,development of strategies that enhance function while reducing drawbacks remains a prime goal. Objective and Hypothesis: The mechanisms of action of lenalidomide on the activity of natural killer cells (NK cells) remains understudied yet could be critical for the development of strategies to enhance its efficacy. These cells are critical drivers of anti-tumor immune responses which are often functionally suppressed in malignancies. NK cell and T cell survival and function is driven by the IL-2 family of cytokines (IL-2 or IL-15) and work has shown that lenalidomide potentially works by increasing the secretion of IL-2 by other lymphocytes,such as CD4+ T helper cells. Thus,we hypothesized that improving NK activity with IL-2 family of cytokines could lead to enhanced lenalidomide-induced responses of these cells. Results: We show that lenalidomide does not affect NK cell viability but reduces their proliferation through cell cycle arrest which could be overcome by exogenous addition of IL-2 family of cytokines. Moreover,lenalidomide induced the secretion of IL-2 on isolated NK cells although it also modulated NK receptor expression,such as NKp46,trough downregulation of PI3K/AKT pathway reduction. This was overcome by exogeneous addition of IL-2 family of cytokines increasing natural cytotoxicity,through higher perforin and granzyme expression. Mechanistically,this increased gene and protein expression occurred through the activation of STAT5 by lenalidomide which was also enhanced through the exogenous addition of IL-2 family of cytokines and modulation of IL-2R subunit changes. Conclusions: These data provide a rationale for the combination of lenalidomide with IL-2 family of cytokines to enhance the effectiveness of NK cells. View Publication

Human embryonic stem cells (hESCs) require specific niches for adhesion,expansion,and lineage-specific differentiation. In this study,we showed that a membrane substrate offers better tissue niches for hESC attachment,spreading,proliferation,and differentiation. The cell doubling time was shortened from 46.3±5.7 h for hESCs grown on solid substrates to 25.6±2.6 h for those on polyester (PE) membrane substrates with pore size of 0.4 μm. In addition,we observed an increase of approximately five- to ninefold of definitive endoderm marker gene expression in hESCs differentiated on PE or polyethylene terephthalate membrane substrates. Global gene expression analysis revealed upregulated expressions of a number of extracellular matrix and cell adhesion molecules in hESCs grown on membrane substrates. Further,an enhanced nuclear translocation of β-catenin was detected in these cells. These observations suggested the augmentation of Wnt signaling in hESCs grown on membrane substrates. These results also demonstrated that a membrane substrate can offer better physicochemical cues for enhancing in vitro hESC attachment,proliferation,and differentiation. View Publication

Early studies in exercise immunology suggested acute bouts of exercise had an immunosuppressive effect in human subjects. However,recent data,show acute bouts of combined aerobic and resistance training increase both lymphocyte activation and proliferation. We quantified resistance exercise-induced changes in the activation state of CD4+ T lymphocytes via surface protein expression and using a medically relevant model of infection (HIV-1). Using a randomized cross-over design,10 untrained subjects completed a control and exercise session. The control session consisted of 30-min seated rest while the exercise session entailed 3 sets × 10 repetitions of back squat,leg press,and leg extensions at 70{\%} 1-RM with 2-min rest between each set. Venous blood samples were obtained pre/post each session. CD4+ T lymphocytes were isolated from whole blood by negative selection. Expression of activation markers (CD69 {\&} CD25) in both nonstimulated and stimulated (costimulation through CD3+ CD28) cells were assessed by flow cytometry. Resistance exercised-induced effects on intracellular activation was further evaluated via in vitro infection with HIV-1. Nonstimulated CD4+ T lymphocytes obtained postexercise exhibited elevated CD25 expression following 24 h in culture. Enhanced HIV-1 replication was observed in cells obtained postexercise. Our results demonstrate that an acute bout of resistance exercise increases the activation state of CD4+ T lymphocytes and results in a greater susceptibility to HIV-1 infection in vitro. These findings offer further evidence that exercise induces activation of T lymphocytes and provides a foundation for the use of medically relevant pathogens as indirect measures of intracellular activation. View Publication

The small cytokine-inducible SH2 domain-containing protein (CIS) has been implicated in the negative regulation of signaling through cytokine receptors. CIS reduces growth of erythropoietin receptor (EpoR)-dependent cell lines,but its role in proliferation,differentiation,and survival of erythroid progenitor cells has not been resolved. To dissect the function of CIS in cell lines and erythroid progenitor cells,we generated green fluorescent protein (GFP)-tagged versions of wild type CIS,a mutant harboring an inactivated SH2 domain (CIS R107K),and a mutant with a deletion of the SOCS Box (CISDeltaBox). Retroviral expression of the GFP fusion proteins in BaF3-EpoR cells revealed that both Tyr-401 in the EpoR and an intact SH2 domain within CIS are prerequisites for receptor recruitment. As a consequence,both are essential for the growth inhibitory effect of CIS,whereas the CIS SOCS box is dispensable. Accordingly,the retroviral expression of GFP-CIS but not GFP-CIS R107K impaired proliferation of erythroid progenitor cells in colony assays. Erythroid differentiation was unaffected by either protein. Interestingly,apoptosis of erythroid progenitor cells was increased upon GFP-CIS expression and this required the presence both of an intact SH2 domain and the SOCS box. Thus,CIS negatively regulates signaling at two levels,apoptosis and proliferation,and thereby sets a threshold for signal transduction. View Publication

Lymphocyte activation is regulated by costimulatory and inhibitory receptors,of which both B and T lymphocyte attenuator (BTLA) and CD160 engage herpesvirus entry mediator (HVEM). Notably,it remains unclear how HVEM functions with each of its ligands during immune responses. In this study,we show that HVEM specifically activates CD160 on effector NK cells challenged with virus-infected cells. Human CD56(dim) NK cells were costimulated specifically by HVEM but not by other receptors that share the HVEM ligands LIGHT,Lymphotoxin-α,or BTLA. HVEM enhanced human NK cell activation by type I IFN and IL-2,resulting in increased IFN-γ and TNF-α secretion,and tumor cell-expressed HVEM activated CD160 in a human NK cell line,causing rapid hyperphosphorylation of serine kinases ERK1/2 and AKT and enhanced cytolysis of target cells. In contrast,HVEM activation of BTLA reduced cytolysis of target cells. Together,our results demonstrate that HVEM functions as a regulator of immune function that activates NK cells via CD160 and limits lymphocyte-induced inflammation via association with BTLA. View Publication

Cancer-initiating cells (CICs) that are responsible for tumor initiation,propagation,and resistance to standard therapies have been isolated from human solid tumors,including colorectal cancer (CRC). The aim of this study was to obtain an immunological profile of CRC-derived CICs and to identify CIC-associated target molecules for T cell immunotherapy. We have isolated cells with CIC properties along with their putative non-CIC autologous counterparts from human primary CRC tissues. These CICs have been shown to display tumor-initiating/stemness" properties� View Publication