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

The ability of acute myeloid leukemic (AML) blasts to differentiate into leukemic dendritic cells (DC) thus acquiring the potential to present known and unknown leukemic antigens efficiently,holds promise as a possible new treatment for AML patients with minimal residual disease. Recent advances in culture methods have made the clinical use of leukemic DC feasible. However,additional measures appear to be essential in order to potentiate vaccines and to overcome the intrinsic tolerant state of the patients immune system. This review describes ways to improve AML-DC vaccines and discusses critical aspects concerning the development of clinical vaccination protocols. View Publication

A commonly activated signaling cascade in many human malignancies,including glioblastoma multiforme,is the Akt pathway. This pathway can be activated via numerous upstream alterations including genomic amplification of epidermal growth factor receptor,PTEN deletion,or PIK3CA mutations. In this study,we screened phosphatidylinositol 3-kinase/Akt small-molecule inhibitors in an isogenic cell culture system with an activated Akt pathway secondary to a PIK3CA mutation. One small molecule,A-443654,showed the greatest selective inhibition of cells with the mutant phenotype. Based on these findings,this inhibitor was screened in vitro against a panel of glioblastoma multiforme cell lines. All cell lines tested were sensitive to A-443654 with a mean IC(50) of approximately 150 nmol/L. An analogue of A-443654,methylated at a region that blocks Akt binding,was on average 36-fold less active. Caspase assays and dual flow cytometric analysis showed an apoptotic mechanism of cell death. A-443654 was further tested in a rat intracranial model of glioblastoma multiforme. Animals treated intracranially with polymers containing A-443654 had significantly extended survival compared with control animals; animals survived 79% and 43% longer than controls when A-443654-containing polymers were implanted simultaneously or in a delayed fashion,respectively. This small molecule also inhibited glioblastoma multiforme stem-like cells with similar efficacy compared with traditionally cultured glioblastoma multiforme cell lines. These results suggest that local delivery of an Akt small-molecule inhibitor is effective against experimental intracranial glioma,with no observed resistance to glioblastoma multiforme cells grown in stem cell conditions. View Publication

Human U1 small nuclear (sn)RNA,required for splicing of pre-mRNA,is encoded by genes on chromosome 1 (1p36). Imperfect copies of these U1 snRNA genes,also located on chromosome 1 (1q12-21),were thought to be pseudogenes. However,many of these variant" (v)U1 snRNA genes produce fully processed transcripts. Using antisense oligonucleotides to block the activity of a specific vU1 snRNA in HeLa cells� View Publication

Progestins play a deleterious role in the onset of breast cancer,yet their influence on existing breast cancer and tumor progression is not well understood. In luminal estrogen receptor (ER)- and progesterone receptor (PR)-positive breast cancer,progestins induce a fraction of cells to express cytokeratin 5 (CK5),a marker of basal epithelial and progenitor cells in the normal breast. CK5(+) cells lose expression of ER and PR and are relatively quiescent,increasing their resistance to endocrine and chemotherapy compared to intratumoral CK5(-)ER(+)PR(+) cells. Characterization of live CK5(+) cells has been hampered by a lack of means for their direct isolation. Here,we describe optical (GFP) and bioluminescent (luciferase) reporter models to quantitate and isolate CK5(+) cells in luminal breast cancer cell lines utilizing the human KRT5 gene promoter and a viral vector approach. Using this system,we confirmed that the induction of GFP(+)/CK5(+) cells is specific to progestins,is dependent on PR,can be blocked by antiprogestins,and does not occur with other steroid hormones. Progestin-induced,fluorescence-activated cell sorting-isolated CK5(+) cells had lower ER and PR mRNA,were slower cycling,and were relatively more invasive and sphere forming than their CK5(-) counterparts in vitro. Repeated progestin treatment and selection of GFP(+) cells enriched for a persistent population of CK5(+) cells,suggesting that this transition can be semi-permanent. These data support that in PR(+) breast cancers,progestins induce a subpopulation of CK5(+)ER(-)PR(-) cells with enhanced progenitor properties and have implications for treatment resistance and recurrence in luminal breast cancer. View Publication

Available methods for differentiating human embryonic stem cells (ESCs) and induced pluripotent cells (iPSCs) into neurons are often cumbersome,slow,and variable. Alternatively,human fibroblasts can be directly converted into induced neuronal (iN) cells. However,with present techniques conversion is inefficient,synapse formation is limited,and only small amounts of neurons can be generated. Here,we show that human ESCs and iPSCs can be converted into functional iN cells with nearly 100% yield and purity in less than 2weeks by forced expression of a single transcription factor. The resulting ES-iN or iPS-iN cells exhibit quantitatively reproducible properties independent of the cell line of origin,form mature pre- and postsynaptic specializations,and integrate into existing synaptic networks when transplanted into mouse brain. As illustrated by selected examples,our approach enables large-scale studies of human neurons for questions such as analyses of human diseases,examination of human-specific genes,and drug screening View Publication

In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented,but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally,the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor,such as microbial agents,pollutants,or allergens. Briefly,nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates,and then transferred onto cell culture inserts. Upon reaching confluency,cells continue to be cultured at the air-liquid interface (ALI),for several weeks,which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium,with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents,transduction with lentiviral vectors,exposure to gases,or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways,functional changes,morphology,etc. In vitro models of differentiated human nasal epithelial cells will enable investigators to address novel and important research questions by using organotypic experimental models that largely mimic the nasal epithelium in vivo. View Publication

Production of human embryonic stem cell (hESC)-derived lung progenitors has broad applicability for drug screening and cell therapy; however,this is complicated by limitations in demarcating phenotypic changes with functional validation of airway cell types. In this paper,we reveal the potential of hESCs to produce multipotent lung progenitors using a combined growth factor and physical culture approach,guided by the use of novel markers LIFRα and NRP1. Lung specification of hESCs was achieved by priming differentiation via matrix-specific support,followed by air-liquid interface to allow generation of lung progenitors capable of in vitro maturation into airway epithelial cell types,resulting in functional characteristics such as secretion of pulmonary surfactant,ciliation,polarization,and acquisition of innate immune activity. This approach provided a robust expansion of lung progenitors,allowing in vivo assessment,which demonstrated that only fully differentiated hESC-derived airway cells were retained in the distal airway,where they aided in physiological recovery in immunocompromised mice receiving airway injury. Our study provides a basis for translational applications of hESCs for lung diseases. View Publication

Generation of surrogate sources of insulin-producing β-cells remains a goal of diabetes therapy. While most efforts have been directed at differentiating embryonic or induced pluripotent stem (iPS) cells into β-like-cells through endodermal progenitors,we have shown that gut endocrine progenitor cells of mice can be differentiated into glucose-responsive,insulin-producing cells by ablation of transcription factor Foxo1. Here we show that FOXO1 is present in human gut endocrine progenitor and serotonin-producing cells. Using gut organoids derived from human iPS cells,we show that FOXO1 inhibition using a dominant-negative mutant or lentivirus-encoded small hairpin RNA promotes generation of insulin-positive cells that express all markers of mature pancreatic β-cells,release C-peptide in response to secretagogues and survive in vivo following transplantation into mice. The findings raise the possibility of using gut-targeted FOXO1 inhibition or gut organoids as a source of insulin-producing cells to treat human diabetes. View Publication

The enteric nervous system (ENS) is composed of neural crest-derived neurons (also known as ganglion cells) the cell bodies of which are located in the submucosal and myenteric plexuses of the intestinal wall. Intramucosal ganglion cells are known to exist but are rare and often considered ectopic. Also derived from the neural crest are enteric glial cells that populate the ganglia and the associated nerves,as well as the lamina propria of the intestinal mucosa. In Hirschsprung disease (HSCR),ganglion cells are absent from the distal gut because of a failure of neural crest-derived progenitor cells to complete their rostrocaudal migration during embryogenesis. The fate of intramucosal glial cells in human HSCR is essentially unknown. We demonstrate a network of intramucosal cells that exhibit dendritic morphology typical of neurons and glial cells. These dendritic cells are present throughout the human gut and express Tuj1,S100,glial fibrillary acidic protein,CD56,synaptophysin,and calretinin,consistent with mixed or overlapping neuroglial differentiation. The cells are present in aganglionic colon from patients with HSCR,but with an altered immunophenotype. Coexpression of Tuj1 and HNK1 in this cell population supports a neural crest origin. These findings extend and challenge the current understanding of ENS microanatomy and suggest the existence of an intramucosal population of neural crest-derived cells,present in HSCR,with overlapping immunophenotype of neurons and glia. Intramucosal neuroglial cells have not been previously recognized,and their presence in HSCR poses new questions about ENS development and the pathobiology of HSCR that merit further investigation. View Publication

Development of non-invasive and accurate methods to track cell fate after delivery will greatly expedite transition of embryonic stem (ES) cell therapy to the clinic. In this protocol,we describe the in vivo monitoring of stem cell survival,proliferation and migration using reporter genes. We established stable ES cell lines constitutively expressing double fusion (DF; enhanced green fluorescent protein and firefly luciferase) or triple fusion (TF; monomeric red fluorescent protein,firefly luciferase and herpes simplex virus thymidine kinase (HSVtk)) reporter genes using lentiviral transduction. We used fluorescence-activated cell sorting to purify these populations in vitro,bioluminescence imaging and positron emission tomography (PET) imaging to track them in vivo and fluorescence immunostaining to confirm the results ex vivo. Unlike other methods of cell tracking,such as iron particle and radionuclide labeling,reporter genes are inherited genetically and can be used to monitor cell proliferation and survival for the lifetime of transplanted cells and their progeny. View Publication

Since the derivation of human embryonic stem (hES) cells,their translation to clinical therapies has been met with several challenges,including the need for large-scale expansion and controlled differentiation processes. Suspension bioreactors are an effective alternative to static culture flasks as they enable the generation of clinically relevant cell numbers with greater efficacy in a controlled culture system. We,along with other groups,have developed bioreactor protocols for the expansion of pluripotent murine ES cells. Here we present a novel bioreactor protocol that yields a 25-fold expansion of hES cells over 6 days. Using immunofluorescence,flow cytometry,and teratoma formation assays,we demonstrated that these bioreactor cultures retained high levels of pluripotency and a normal karyotype. Importantly,the use of bioreactors enables the expansion of hES cells in the absence of feeder layers or matrices,which will facilitate the adaptation of good manufacturing process (GMP) standards to the development of hES cell therapies. View Publication

AIMS: Endothelial progenitor cells (EPC) have been shown to repair pulmonary endothelium,although they can also migrate into the arterial intima and differentiate into smooth muscle-like (mesenchymal) cells contributing to intimal hyperplasia. The molecular mechanisms by which this process proceeds have not been fully elucidated. Here,we study whether genes involved in the endothelial-to-mesenchymal transition (EnMT) may contribute to the mesenchymal phenotype acquisition of EPC and we evaluate whether transforming growth factor β1 (TGFβ1) is involved in this process. METHODS AND RESULTS: Our results show that co-culture of EPC with smooth muscle cells (SMC) increases the expression of the mesenchymal cell markers α-smooth muscle actin,sm22-α,and myocardin,and decreases the expression of the endothelial cell marker CD31. In the same conditions,we also observed a concomitant increase in the gene expression of the EnMT-related transcription factors: slug,snail,zeb1,and endothelin-1. This indicates that mesenchymal phenotype acquisition occurred through an EnMT-like process. Inhibition of TGFβ receptor I (TGFβRI) downregulated snail gene expression,blocked the EnMT,and facilitated the differentiation of EPC to the endothelial cell lineage. Furthermore,TGFβRI inhibition decreased migration of EPC stimulated by SMC without affecting their functionality and adhesion capacity. CONCLUSION: These results indicate that EPC may differentiate into SMC-like cells through an EnMT-like process and that TGFβI plays an important role in the fate of EPC. View Publication