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

Glioblastoma (GBM) is associated with poor prognosis despite aggressive surgical resection,chemotherapy,and radiation therapy. Unfortunately,this standard therapy does not target glioma cancer stem cells (GCSCs),a subpopulation of GBM cells that can give rise to recurrent tumors. GBMs express human cytomegalovirus (HCMV) proteins,and previously we found that the level of expression of HCMV immediate-early (IE) protein in GBMs is a prognostic factor for poor patient survival. In this study,we investigated the relation between HCMV infection of GBM cells and the presence of GCSCs. Primary GBMs were characterized by their expression of HCMV-IE and GCSCs marker CD133 and by patient survival. The extent to which HCMV infection of primary GBM cells induced a GCSC phenotype was evaluated in vitro. In primary GBMs,a large fraction of CD133-positive cells expressed HCMV-IE,and higher co-expression of these two proteins predicted poor patient survival. Infection of GBM cells with HCMV led to upregulation of CD133 and other GSCS markers (Notch1,Sox2,Oct4,Nestin). HCMV infection also promoted the growth of GBM cells as neurospheres,a behavior typically displayed by GCSCs,and this phenotype was prevented by either chemical inhibition of the Notch1 pathway or by treatment with the anti-viral drug ganciclovir. GBM cells that maintained expression of HCMV-IE failed to differentiate into neuronal or astrocytic phenotypes. Our findings imply that HCMV infection induces phenotypic plasticity of GBM cells to promote GCSC features and may thereby increase the aggressiveness of this tumor. View Publication

Variants of phospholipase C gamma 2 (PLCG2),a key microglial immune signaling protein,are genetically linked to Alzheimer's disease (AD) risk. Understanding how PLCG2 variants alter microglial function is critical for identifying mechanisms that drive neurodegeneration or resiliency in AD. Induced pluripotent stem cell (iPSC) –derived microglia carrying the protective PLCG2 P522R or risk‐conferring PLCG2 M28L variants,or loss of PLCG2,were generated to ascertain the impact on microglial transcriptome and function. Protective PLCG2 P522R microglia showed significant transcriptomic similarity to isogenic controls. In contrast,risk‐conferring PLCG2 M28L microglia shared similarities with PLCG2 KO microglia,with functionally reduced TREM2 expression,blunted inflammatory responses,and increased proliferation and cell death. Uniquely,PLCG2 P522R microglia showed elevated cytokine secretion after lipopolysaccharide (LPS) stimulation and were protected from apoptosis. These findings demonstrate that PLCG2 variants drive distinct microglia transcriptomes that influence microglial functional responses that could contribute to AD risk and protection. Targeting PLCG2‐mediated signaling may represent a powerful therapeutic strategy to modulate neuroinflammation. The impact of Alzheimer's disease protective‐ and risk‐associated variants of phospholipase C gamma 2 (PLCG2) on the transcriptome and function of induced pluripotent stem cell (iPSC) –derived microglia was investigated. PLCG2 risk variant microglia exhibited a basal transcriptional profile similar to PLCG2‐deficient microglia but significantly different from isotype control and the transcriptionally similar PLCG2 protective variant microglia. PLCG2 risk variant and PLCG2‐deficient microglia show decreased levels of triggering receptor expressed on myeloid cells 2 (TREM2). The differential transcriptional pathways of protective and risk‐associated PLCG2 variant microglia functionally affect proliferation,apoptosis,and immune response. Protective PLCG2 microglia show resilience to apoptosis and increased cytokine/chemokine secretion upon exposure to lipopolysaccharide (LPS). View Publication

The airway epithelium provides a first line of defense against pathogens by release of antimicrobial factors and neutrophil-attracting chemokines. Pseudomonas (P.) aeruginosa,a Gram-negative bacterium that expresses flagellin as an important virulence factor,is a common cause of injurious airway inflammation. The aim of our study was to determine the contribution of flagellin to the inflammatory,antimicrobial,and metabolic responses of the airway epithelium to P. aeruginosa . Furthermore,as we previously showed that targeting mTOR limited the glycolytic and inflammatory response induced by flagellin,we assessed the effect of rapamycin on human bronchial epithelial (HBE) cells stimulated with flagellated and non-flagellated P. aeruginosa. Primary pseudostratified HBE cells,cultured on an air-liquid-interface,were treated on the basolateral side with medium,vehicle or rapamycin,exposed on the apical side with flagellated or flagellin-deficient P. aeruginosa,and analyzed for their inflammatory,antimicrobial,and glycolytic responses. Flagellin augmented the P. aeruginosa -induced expression of antimicrobial factors and secretion of chemokines by HBE cells but did not further increase the glycolytic response. Treatment of HBE cells with rapamycin inhibited mTOR activation in general and flagellin-augmented mTOR activation in particular,but did not affect the glycolytic response. Rapamycin,however,diminished the flagellin-augmented inflammatory and antimicrobial response induced by Pseudomonas . These results demonstrate that flagellin is a significant factor that augments the inflammatory and antimicrobial response of human airway epithelial cells upon exposure to P. aeruginosa and suggest that mTOR inhibition by rapamycin in the airway epithelium diminishes these exaggerated responses. View Publication

Recently,it has been shown that certain combinations of TLR ligands act in synergy to induce the release of IL-12 by DCs. In this study,we sought to define the critical parameters underlying TLR synergy. Our data show that TLR ligands act synergistically if MyD88- and TRIF-dependent ligands are combined. TLR4 uses both of these adaptor molecules,thus activation via TLR4 proved to be a synergistic event on its own. TLR synergy did not affect all aspects of DC activation but enhanced primarily the release of certain cytokines,particularly IL-12,whereas the expression of costimulatory molecules remained unchanged. Consequently,synergistic activation of DC did not affect their ability to induce T cell proliferation but resulted in T(H)1-biased responses in vitro and in vivo. Furthermore,we examined the impact of TLR ligand combinations on primary DC in vitro but observed only modest effects with a combination of CpG + Poly (I:C). However,noticeable synergy in terms of IL-12 production by DCs was detectable in vivo after systemic administration of CpG + Poly (I:C). Finally,we show that synergy is partially dependent on IFNAR signaling but does not require the release of IFNs to the enviroment,suggesting an autocrine action of type I IFNs. View Publication

The in vitro 3D culture of intestinal epithelium is a valuable resource in the study of its function. Organoid culture exploits stem cells' ability to regenerate and produce differentiated epithelium. Intestinal organoid models from rodent or human tissue are widely available whereas large animal models are not. Livestock enteric and zoonotic diseases elicit significant morbidity and mortality in animal and human populations. Therefore,livestock species-specific models may offer novel insights into host-pathogen interactions and disease responses. Bovine and porcine jejunum were obtained from an abattoir and their intestinal crypts isolated,suspended in Matrigel,cultured,cryopreserved and resuscitated. 'Rounding' of crypts occurred followed by budding and then enlargement of the organoids. Epithelial cells were characterised using immunofluorescent staining and confocal microscopy. Organoids were successfully infected with Toxoplasma gondii or Salmonella typhimurium. This 3D organoid model offers a long-term,renewable resource for investigating species-specific intestinal infections with a variety of pathogens. View Publication

Inappropriate activation of the Hedgehog (Hh) signaling pathway has been implicated in a diverse spectrum of cancers,and its pharmacological blockade has emerged as an anti-tumor strategy. While nearly all known Hh pathway antagonists target the transmembrane protein Smoothened (Smo),small molecules that suppress downstream effectors could more comprehensively remediate Hh pathway-dependent tumors. We report here four Hh pathway antagonists that are epistatic to the nucleocytoplasmic regulator Suppressor of Fused [Su(fu)],including two that can inhibit Hh target gene expression induced by overexpression of the Gli transcription factors. Each inhibitor has a unique mechanism of action,and their phenotypes reveal that Gli processing,Gli activation,and primary cilia formation are pharmacologically targetable. We further establish the ability of certain compounds to block the proliferation of cerebellar granule neuron precursors expressing an oncogenic form of Smo,and we demonstrate that Hh pathway inhibitors can have tissue-specific activities. These antagonists therefore constitute a valuable set of chemical tools for interrogating downstream Hh signaling mechanisms and for developing chemotherapies against Hh pathway-related cancers. View Publication

The ability to stimulate mammalian cells with light has significantly changed our understanding of electrically excitable tissues in health and disease,paving the way toward various novel therapeutic applications. Here,we demonstrate the potential of optogenetic control in cardiac cells using a hybrid experimental/computational technique. Experimentally,we introduced channelrhodopsin-2 into undifferentiated human embryonic stem cells via a lentiviral vector,and sorted and expanded the genetically engineered cells. Via directed differentiation,we created channelrhodopsin-expressing cardiomyocytes,which we subjected to optical stimulation. To quantify the impact of photostimulation,we assessed electrical,biochemical,and mechanical signals using patch-clamping,multielectrode array recordings,and video microscopy. Computationally,we introduced channelrhodopsin-2 into a classic autorhythmic cardiac cell model via an additional photocurrent governed by a light-sensitive gating variable. Upon optical stimulation,the channel opens and allows sodium ions to enter the cell,inducing a fast upstroke of the transmembrane potential. We calibrated the channelrhodopsin-expressing cell model using single action potential readings for different photostimulation amplitudes,pulse widths,and frequencies. To illustrate the potential of the proposed approach,we virtually injected channelrhodopsin-expressing cells into different locations of a human heart,and explored its activation sequences upon optical stimulation. Our experimentally calibrated computational toolbox allows us to virtually probe landscapes of process parameters,and identify optimal photostimulation sequences toward pacing hearts with light. ?? 2011 Biophysical Society. View Publication