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Sample records for cell surface expression

  1. Calreticulin: Roles in Cell-Surface Protein Expression

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    Yue Jiang

    2014-09-01

    Full Text Available In order to perform their designated functions, proteins require precise subcellular localizations. For cell-surface proteins, such as receptors and channels, they are able to transduce signals only when properly targeted to the cell membrane. Calreticulin is a multi-functional chaperone protein involved in protein folding, maturation, and trafficking. However, evidence has been accumulating that calreticulin can also negatively regulate the surface expression of certain receptors and channels. In these instances, depletion of calreticulin enhances cell-surface expression and function. In this review, we discuss the role of calreticulin with a focus on its negative effects on the expression of cell-surface proteins.

  2. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard; Skov, Søren

    2009-01-01

    We show that inhibition of HDAC activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC inhibitor-mediated Hsp70 surface expression was confined to the apoptotic Annexin V...... activity selectively induces surface expression of Hsp70 on hematopoietic cancer cells and that this may increase immunorecognition of these cells.......-positive cells and blocked by inhibition of apoptosis. Other chemotherapeutic inducers of apoptosis such as etoposide and camptothecin also led to a robust induction of Hsp70 surface expression. Hsp70 expression was, however, not caused by induction of apoptosis per se, as activated CD4 T cells remained Hsp70...

  3. The cell surface expressed nucleolin is a glycoprotein that triggers calcium entry into mammalian cells

    International Nuclear Information System (INIS)

    Nucleolin is an ubiquitous nucleolar phosphoprotein involved in fundamental aspects of transcription regulation, cell proliferation and growth. It has also been described as a shuttling molecule between nucleus, cytosol and the cell surface. Several studies have demonstrated that surface nucleolin serves as a receptor for various extracellular ligands implicated in cell proliferation, differentiation, adhesion, mitogenesis and angiogenesis. Previously, we reported that nucleolin in the extranuclear cell compartment is a glycoprotein containing N- and O-glycans. In the present study, we show that glycosylation is an essential requirement for surface nucleolin expression, since it is prevented when cells are cultured in the presence of tunicamycin, an inhibitor of N-glycosylation. Accordingly, surface but not nuclear nucleolin is radioactively labeled upon metabolic labeling of cells with [3H]glucosamine. Besides its well-demonstrated role in the internalization of specific ligands, here we show that ligand binding to surface nucleolin could also induce Ca2+ entry into cells. Indeed, by flow cytometry, microscopy and patch-clamp experiments, we show that the HB-19 pseudopeptide, which binds specifically surface nucleolin, triggers rapid and intense membrane Ca2+ fluxes in various types of cells. The use of several drugs then indicated that Store-Operated Ca2+ Entry (SOCE)-like channels are involved in the generation of these fluxes. Taken together, our findings suggest that binding of an extracellular ligand to surface nucleolin could be involved in the activation of signaling pathways by promoting Ca2+ entry into cells

  4. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle

    frequently express Hsp70 on their cell surface, whereas the corresponding normal tissues do not. In addition, several clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 cell surface expression on cancer...... cells. We have found that inhibition of histone deacetylase (HDAC) activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC-inhibitor mediated Hsp70 cell surface expression was confined to...... transport and cell surface binding of Hsp70 after HDAC-inhibitor treatment remains elusive. Our data suggest that inhibition of HDAC activity selectively induces cell surface expression of Hsp70 on hematopoietic cancer cells, and this may increase the immunorecognition of these cells. It could be envisaged...

  5. Short-chain ceramides depress integrin cell surface expression and function in colorectal cancer cells.

    Science.gov (United States)

    Morad, Samy A F; Bridges, Lance C; Almeida Larrea, Alex D; Mayen, Anthony L; MacDougall, Matthew R; Davis, Traci S; Kester, Mark; Cabot, Myles C

    2016-07-01

    Colorectal cancer (CRC) is highly metastatic, significantly so to liver, a characteristic that embodies one of the most challenging aspects of treatment. The integrin family of cell-cell and cell-matrix adhesion receptors plays a central role in migration and invasion, functions that underlie metastatic potential. In the present work we sought to determine the impact of ceramide, which plays a key modulatory role in cancer suppression, on integrin cell surface expression and function in CRC cells in order to reveal possible ceramide-centric effects on tumor cell motility. Human CRC cells LoVo, HT-29, and HCT-116 were employed, which represent lines established from primary and metastatic sites. A cell-permeable, short-chain analog, C6-ceramide, was used as ceramide mimic. Exposure of cells to C6-ceramide (24 h) promoted a dose-dependent (2.5-10 µM) decrease in the expression of cell surface β1 and β4 integrin subunits in all cell lines; at 10 µM C6-ceramide, the decreases ranged from 30 to 50% of the control. Expression of cell surface αVβ6 integrin, which is associated with advanced invasion in CRC, was also suppressed by C6-ceramide. Decreases in integrin expression translated to diminished cellular adhesion, 50% of the control at 5 µM C6-ceramide, and markedly reduced cellular migration, approximately 30-40% of the control in all cell lines. Physicochemical examination revealed potent efficacy of nano-formulated C6-ceramide, but inferior activity of dihydro-C6-ceramide and L-C6-ceramide, compared to the unsaturated counterpart and the natural d-enantiomer, respectively. These studies demonstrate novel actions of ceramides that may have application in suppression of tumor metastasis, in addition to their known tumor suppressor effects. PMID:27045476

  6. Glioma Cell Proliferation Controlled by ERK Activity-Dependent Surface Expression of PDGFRA

    OpenAIRE

    Dongfeng Chen; Duo Zuo; Cheng Luan; Min Liu; Manli Na; Liang Ran; Yingyu Sun; Annette Persson; Elisabet Englund; Leif G Salford; Erik Renström; Xiaolong Fan; Enming Zhang

    2014-01-01

    Increased PDGFRA signaling is an essential pathogenic factor in many subtypes of gliomas. In this context the cell surface expression of PDGFRA is an important determinant of ligand sensing in the glioma microenvironment. However, the regulation of spatial distribution of PDGFRA in glioma cells remains poorly characterized. Here, we report that cell surface PDGFRA expression in gliomas is negatively regulated by an ERK-dependent mechanism, resulting in reduced proliferation of glioma cells. G...

  7. Glioma cell proliferation controlled by ERK activity-dependent surface expression of PDGFRA.

    Science.gov (United States)

    Chen, Dongfeng; Zuo, Duo; Luan, Cheng; Liu, Min; Na, Manli; Ran, Liang; Sun, Yingyu; Persson, Annette; Englund, Elisabet; Salford, Leif G; Renström, Erik; Fan, Xiaolong; Zhang, Enming

    2014-01-01

    Increased PDGFRA signaling is an essential pathogenic factor in many subtypes of gliomas. In this context the cell surface expression of PDGFRA is an important determinant of ligand sensing in the glioma microenvironment. However, the regulation of spatial distribution of PDGFRA in glioma cells remains poorly characterized. Here, we report that cell surface PDGFRA expression in gliomas is negatively regulated by an ERK-dependent mechanism, resulting in reduced proliferation of glioma cells. Glioma tumor tissues and their corresponding cell lines were isolated from 14 patients and analyzed by single-cell imaging and flow cytometry. In both cell lines and their corresponding tumor samples, glioma cell proliferation correlated with the extent of surface expression of PDGFRA. High levels of surface PDGFRA also correlated to high tubulin expression in glioma tumor tissue in vivo. In glioma cell lines, surface PDGFRA declined following treatment with inhibitors of tubulin, actin and dynamin. Screening of a panel of small molecule compounds identified the MEK inhibitor U0126 as a potent inhibitor of surface PDGFRA expression. Importantly, U0126 inhibited surface expression in a reversible, dose- and time-dependent manner, without affecting general PDGFRA expression. Treatment with U0126 resulted in reduced co-localization between PDGFRA and intracellular trafficking molecules e.g. clathrin, RAB11 and early endosomal antigen-1, in parallel with enhanced co-localization between PDGFRA and the Golgi cisternae maker, Giantin, suggesting a deviation of PDGFRA from the endosomal trafficking and recycling compartment, to the Golgi network. Furthermore, U0126 treatment in glioma cells induced an initial inhibition of ERK1/2 phosphorylation, followed by up-regulated ERK1/2 phosphorylation concomitant with diminished surface expression of PDGFRA. Finally, down-regulation of surface PDGFRA expression by U0126 is concordant with reduced glioma cell proliferation. These findings

  8. Glioma cell proliferation controlled by ERK activity-dependent surface expression of PDGFRA.

    Directory of Open Access Journals (Sweden)

    Dongfeng Chen

    Full Text Available Increased PDGFRA signaling is an essential pathogenic factor in many subtypes of gliomas. In this context the cell surface expression of PDGFRA is an important determinant of ligand sensing in the glioma microenvironment. However, the regulation of spatial distribution of PDGFRA in glioma cells remains poorly characterized. Here, we report that cell surface PDGFRA expression in gliomas is negatively regulated by an ERK-dependent mechanism, resulting in reduced proliferation of glioma cells. Glioma tumor tissues and their corresponding cell lines were isolated from 14 patients and analyzed by single-cell imaging and flow cytometry. In both cell lines and their corresponding tumor samples, glioma cell proliferation correlated with the extent of surface expression of PDGFRA. High levels of surface PDGFRA also correlated to high tubulin expression in glioma tumor tissue in vivo. In glioma cell lines, surface PDGFRA declined following treatment with inhibitors of tubulin, actin and dynamin. Screening of a panel of small molecule compounds identified the MEK inhibitor U0126 as a potent inhibitor of surface PDGFRA expression. Importantly, U0126 inhibited surface expression in a reversible, dose- and time-dependent manner, without affecting general PDGFRA expression. Treatment with U0126 resulted in reduced co-localization between PDGFRA and intracellular trafficking molecules e.g. clathrin, RAB11 and early endosomal antigen-1, in parallel with enhanced co-localization between PDGFRA and the Golgi cisternae maker, Giantin, suggesting a deviation of PDGFRA from the endosomal trafficking and recycling compartment, to the Golgi network. Furthermore, U0126 treatment in glioma cells induced an initial inhibition of ERK1/2 phosphorylation, followed by up-regulated ERK1/2 phosphorylation concomitant with diminished surface expression of PDGFRA. Finally, down-regulation of surface PDGFRA expression by U0126 is concordant with reduced glioma cell proliferation

  9. Regulation of ADAM12 cell-surface expression by protein kinase C epsilon

    DEFF Research Database (Denmark)

    Sundberg, Christina; Thodeti, Charles Kumar; Kveiborg, Marie;

    2004-01-01

    constitutively active protein. However, little is known about the regulation of ADAM12 cell-surface translocation. Here, we used human RD rhabdomyosarcoma cells, which express ADAM12 at the cell surface, in a temporal pattern. We report that protein kinase C (PKC) epsilon induces ADAM12 translocation to the cell......The ADAM (a disintegrin and metalloprotease) family consists of multidomain cell-surface proteins that have a major impact on cell behavior. These transmembrane-anchored proteins are synthesized as proforms that have (from the N terminus): a prodomain; a metalloprotease-, disintegrin......-immunoprecipitated from membrane-enriched fractions of PMA-treated cells, 3) RD cells transfected with EGFP-tagged, myristoylated PKCepsilon expressed more ADAM12 at the cell surface than did non-transfected cells, and 4) RD cells transfected with a kinase-inactive PKCepsilon mutant did not exhibit ADAM12 cell...

  10. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard;

    small HSPs). Hsp70 belongs to the HSP70 family and is expressed at low levels in normal non-stressed cells. Its expression is however induced by different cellular stresses, such as heat shock and oxidative stress. The function of Hsp70 depends on its cellular location: Intracellular it has...... normal ER/Golgi transport did not affect Hsp70 surface expression. Intracellular Calcium and the transcription factor Sp1, that has previously been shown to be important for the intracellular stress mediated by HDAC-inhibitors, were not involved in Hsp70 surface expression. We also found that HDAC...... cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer-derived antigenic peptides, a function which is currently explored in immunotherapeutic approaches against cancer. Additionally...

  11. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad;

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  12. Variability in expression of cell surface antigens of Candida albicans during morphogenesis.

    OpenAIRE

    Brawner, D L; Cutler, J. E.

    1986-01-01

    The location and expression of two different cell surface antigens on germinating and nongerminating Candida albicans cells was examined by using transmission electron microscopy after labeling with monoclonal antibodies (H9 or C6) and immunocolloidal gold. Immunodeterminant expression of the two carbohydrate antigens was followed from early germination events through 20 h of development. The determinant detected by H9 antibody, which was initially lost from the mother cell surface and prefer...

  13. Surface expressed nucleolin is constantly induced in tumor cells to mediate calcium-dependent ligand internalization.

    Directory of Open Access Journals (Sweden)

    Ara G Hovanessian

    Full Text Available BACKGROUND: Nucleolin is one of the major proteins of the nucleolus, but it is also expressed on the cell surface where is serves as a binding protein for variety of ligands implicated in tumorigenesis and angiogenesis. Emerging evidence suggests that the cell-surface expressed nucleolin is a strategic target for an effective and nontoxic cancer therapy. METHODOLOGY/PRINCIPAL FINDINGS: By monitoring the expression of nucleolin mRNA, and by measuring the level of nucleolin protein recovered from the surface and nucleus of cells, here we show that the presence of nucleolin at the cell surface is dependent on the constant induction of nucleolin mRNA. Indeed, inhibitors of RNA transcription or translation block expression of surface nucleolin while no apparent effect is observed on the level of nucleolin in the nucleus. The estimated half-life of surface nucleolin is less than one hour, whereas that of nuclear nucleolin is more than 8 hours. Nucleolin mRNA induction is reduced markedly in normal fibroblasts that reach confluence, while it occurs continuously even in post-confluent epithelial tumor cells consistent with their capacity to proliferate without contact inhibition. Interestingly, cold and heat shock induce nucleolin mRNA concomitantly to enhanced mRNA expression of the heat shock protein 70, thus suggesting that surface nucleolin induction also occurs in response to an environmental insult. At the cell surface, one of the main functions of nucleolin is to shuttle specific extracellular ligands by an active transport mechanism, which we show here to be calcium dependent. CONCLUSION/SIGNIFICANCE: Our results demonstrate that the expression of surface nucleolin is an early metabolic event coupled with tumor cell proliferation and stress response. The fact that surface nucleolin is constantly and abundantly expressed on the surface of tumor cells, makes them a preferential target for the inhibitory action of anticancer agents that target

  14. Model system for the analysis of cell surface expression of human ABCA1

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    Sarkadi Balázs

    2009-12-01

    Full Text Available Abstract Background The ABCA1 protein plays a pivotal role in reverse cholesterol transport, by mediating the generation of HDL particles and removing cellular cholesterol. Both the proper expression of ABCA1 in the plasma membrane and the internalization along with apoA-I are required for function. Therefore, we developed a model system to investigate the effect of clinically relevant drugs on the cell surface appearance of ABCA1. Results By retroviral transduction system, we established stable mammalian cell lines expressing functional and non-functional ABCA1 variants, tagged with an extracellular hemagglutinin epitope. After characterization of the expression, proper localization and function of different ABCA1 variants, we followed quantitatively their cell surface expression by immunofluorescent staining, using flow cytometry. As expected, we found increased cell surface expression of ABCA1 after treatment with a calpain inhibitor, and observed a strong decrease in plasma membrane ABCA1 expression upon treatment with a trans-Golgi transport inhibitor, Brefeldin A. We tested cholesterol level lowering drugs and other potential inhibitors of ABCA1. Here we demonstrate that ezetimibe affects ABCA1 cell surface expression only in the case of a functional ABCA1. Conclusions Our model system allows a quantitative detection of cell surface expression of ABCA1, screening of substrates or specific inhibitors, and investigating transport regulation.

  15. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanjuan; Zhang, Shaolian; Wen, Qingqing; Huang, Hongxing; Yang, Peihui, E-mail: typh@jnu.edu.cn

    2015-06-30

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 10{sup 6} cells mL{sup −1} with a detection limit of 40 cells mL{sup −1} was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 10{sup 5} with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening.

  16. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    International Nuclear Information System (INIS)

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 106 cells mL−1 with a detection limit of 40 cells mL−1 was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 105 with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening

  17. Cell surface modulation of gene expression in brain cells by down regulation of glucocorticoid receptors

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, J.F.; de Vellis, J.

    1981-02-01

    The concentration of glycerol-3-phosphate dehydrogenase (GPDH; sn-glycerol-3-phosphate:NAD/sup +/ 2-oxidoreductase, EC 1.1.1.8) had previously been determined to be regulated by glucocorticoids in rat brain cells in vivo and in cell culture. We now demonstrate that concanavalin A (Con A) can inhibit the induction of GPDH in a dose-dependent manner in C6 rat glioma cells and in primary cultures of rat brain oligodendrocytes. The inhibition specifically prevents the appearance of new molecules of GPDH, although Con A does not significantly inhibit protein synthesis in these cells, nor does it affect the activity of another solube enzyme, lactate dehydrogenase. The ability to block enzyme induction is not limited to Con A, because other lectins also inhibit induction. The molecular mechanism by which Con A inhibits GPDH induction appears to be by the down regulation of the cytoplasmic glucocorticoid receptors, because exposure to Con A results in the loss of more than 90% of the receptor activity. Con A does not inhibit the receptor assay and no direct interaction between the receptor and Con A could be demonstrated. This down regulation is not tumor cell specific and appears to be a general phenomenon, because it occurs in normal oligodendrocytes and even in normal astrocytes (a cell type in which the gene for GPDH is not expressed). The down regulation of glucocorticoid receptors in normal brain cells suggests two important corollaries. First, it demonstrates the existence of a rate-limiting step controlling the glucocorticoid-dependent gene expression in brain cells and possibly represents a regulatory site common to all glucocorticoid target cells. Second, it suggests that the response to glucocorticoids of oligodendrocytes and astrocytes can be regulated in vivo by cell surface contact with endogenous lectins, neighboring cells, or both.

  18. Oxygen Modulates Human Decidual Natural Killer Cell Surface Receptor Expression and Interactions with Trophoblasts1

    Science.gov (United States)

    Wallace, Alison E.; Goulwara, Sonu S.; Whitley, Guy S.; Cartwright, Judith E.

    2014-01-01

    Decidual natural killer (dNK) cells have been shown to both promote and inhibit trophoblast behavior important for decidual remodeling in pregnancy and have a distinct phenotype compared to peripheral blood NK cells. We investigated whether different levels of oxygen tension, mimicking the physiological conditions of the decidua in early pregnancy, altered cell surface receptor expression and activity of dNK cells and their interactions with trophoblast. dNK cells were isolated from terminated first-trimester pregnancies and cultured in oxygen tensions of 3%, 10%, and 21% for 24 h. Cell surface receptor expression was examined by flow cytometry, and the effects of secreted factors in conditioned medium (CM) on the trophoblast cell line SGHPL-4 were assessed in vitro. SGHPL-4 cells treated with dNK cell CM incubated in oxygen tensions of 10% were significantly more invasive (P oxygen tensions of 3% or 21%. After 24 h, a lower percentage of dNK cells expressed CD56 at 21% oxygen (P oxygen (P oxygen tensions, with large patient variation. This study demonstrates dNK cell phenotype and secreted factors are modulated by oxygen tension, which induces changes in trophoblast invasion and endovascular-like differentiation. Alterations in dNK cell surface receptor expression and secreted factors at different oxygen tensions may represent regulation of function within the decidua during the first trimester of pregnancy. PMID:25232021

  19. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors.

    Directory of Open Access Journals (Sweden)

    Adiba Isa

    Full Text Available HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced a 9-42 fold increase of all six HLA-A,-B,-C gene transcripts. Interestingly, prior to stimulation, gene transcripts for all but two alleles were present in similar amounts suggesting that post-transcriptional mechanisms regulate the constitutive expression of HLA-A,-B, and -C. Locus-restricted expression of HLA-A, -B and -C challenges our current understanding of the function of these molecules as regulators of CD8(+ T-cell and NK-cell function and should lead to further inquiries into their expression on other cell types.

  20. Cell surface expression and turnover of the alpha-subunit of the epithelial sodium channel.

    Science.gov (United States)

    Kleyman, T R; Zuckerman, J B; Middleton, P; McNulty, K A; Hu, B; Su, X; An, B; Eaton, D C; Smith, P R

    2001-08-01

    The renal epithelial cell line A6, derived from Xenopus laevis, expresses epithelial Na(+) channels (ENaCs) and serves as a model system to study hormonal regulation and turnover of ENaCs. Our previous studies suggest that the alpha-subunit of Xenopus ENaC (alpha-xENaC) is detectable as 150- and 180-kDa polypeptides, putative immature and mature alpha-subunit heterodimers. The 150- and 180-kDa alpha-xENaC were present in distinct fractions after sedimentation of A6 cell lysate through a sucrose density gradient. Two anti-alpha-xENaC antibodies directed against distinct domains demonstrated that only 180-kDa alpha-xENaC was expressed at the apical cell surface. The half-life of cell surface-expressed alpha-xENaC was 24-30 h, suggesting that once ENaC matures and is expressed at the plasma membrane, its turnover is similar to that reported for mature cystic fibrosis transmembrane conductance regulator. No significant changes in apical surface expression of alpha-xENaC were observed after treatment of A6 cells with aldosterone for 24 h, despite a 5.3-fold increase in short-circuit current. This lack of change in surface expression is consistent with previous observations in A6 cells and suggests that aldosterone regulates ENaC gating and increases channel open probability. PMID:11457713

  1. Altered expression of epithelial cell surface glycoconjugates and intermediate filaments at the margins of mucosal wounds

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Grøn, B; Mandel, U;

    1998-01-01

    Alterations in cell to cell adhesion are necessary to enable the type of cell movements that are associated with epithelial wound healing and malignant invasion. Several studies of transformed cells have related epithelial cell movement to changes in the cell surface expression of the carbohydrate...... structures represented by the ABO blood group antigens and, in particular, by Lewis antigens and their biosynthetic precursors. To study further the relationship between cell surface carbohydrates and keratinocyte cell movement, experimental wounds were created in human oral mucosa and examined by...... immunohistochemical methods for their expression of selected cytokeratins (K5, K16, K19), basement membrane components (laminin alpha5 and gamma2-chains, BP180, collagen IV and collagen VII), and blood group antigen precursor structures Le(x), sialosyl-Le(x), Le(y), H antigen, N-acetyllactosamine, and sialosyl...

  2. Ultrastructural and biochemical studies of two dynamically expressed cell surface determinants on Candida albicans.

    OpenAIRE

    Brawner, D L; Cutler, J E

    1986-01-01

    Variability in the expression of two different cell surface carbohydrate determinants was examined with two agglutinating immunoglobulin M monoclonal antibodies (H9 and C6) and immunoelectron microscopy during growth of three strains of Candida albicans. A single strain of Candida parapsilosis did not express either antigen at any time during growth. Antigens were detected on the surface of C. albicans by agglutination tests with either H9 or C6 over a 48-h growth period. The difference in sp...

  3. Anti-obesity phenotypic screening looking to increase OBR cell surface expression.

    Science.gov (United States)

    Kim, Tae-Hee; Choi, Dong-Hwa; Vauthier, Virginie; Dam, Julie; Li, Xiaolan; Nam, Yeon-Ju; Ko, YoonAe; Kwon, Ho Jeong; Shin, Sang Hoon; Cechetto, Jonathan; Soloveva, Veronica; Jockers, Ralf

    2014-01-01

    The leptin receptor, OBR, is involved in the regulation of whole-body energy homeostasis. Most obese people are resistant to leptin and do not respond to the hormone. The prevention and reversal of leptin resistance is one of the major current goals of obesity research. We showed previously that increased OBR cell surface expression concomitantly increases cellular leptin signaling and prevents obesity development in mice. Improvement of OBR cell surface expression can thus be considered as an interesting anti-obesity therapeutic strategy. To identify compounds that increase the surface expression of OBR, we developed a cell-based, phenotypic assay to perform a high-content screen (HCS) against a library of 50,000 chemical compounds. We identified 67 compounds that increased OBR cell surface expression with AC50 values in the low micromolar range and no effect on total OBR expression and cellular toxicity. Compounds were classified into 16 chemical clusters, of which 4 potentiated leptin-promoted signaling through the JAK2/STAT3 pathway. In conclusion, development of a robust phenotypic screening approach resulted in the discovery of four new scaffolds that demonstrate the desired biological activity and could constitute an original therapeutic solution against obesity and associated disorders. PMID:23958651

  4. IL-4 enhances expression and function of surface IgM in CLL cells.

    Science.gov (United States)

    Aguilar-Hernandez, Maria M; Blunt, Matthew D; Dobson, Rachel; Yeomans, Alison; Thirdborough, Stephen; Larrayoz, Marta; Smith, Lindsay D; Linley, Adam; Strefford, Jonathan C; Davies, Andrew; Johnson, Peter M W; Savelyeva, Natalia; Cragg, Mark S; Forconi, Francesco; Packham, Graham; Stevenson, Freda K; Steele, Andrew J

    2016-06-16

    Kinase inhibitors targeting the B-cell receptor (BCR) are now prominent in the treatment of chronic lymphocytic leukemia (CLL). We have focused here on interleukin 4 (IL-4), a cytokine that protects normal and malignant B cells from apoptosis and increases surface immunoglobulin M (sIgM) expression on murine splenic B cells. First, we have demonstrated that IL-4 treatment increased sIgM expression in vitro on peripheral blood B cells obtained from healthy individuals. In CLL, IL-4 target genes are overexpressed in cells purified from the lymph nodes of patients compared with cells derived from matched blood and bone marrow samples. As for normal B cells, IL-4 increased sIgM expression on CLL cells in vitro, especially in samples expressing unmutated V-genes. IL-4-induced sIgM expression was associated with increased receptor signalling activity, measured by anti-IgM-induced calcium mobilization, and with increased expression of CD79B messenger RNA and protein, and the "mature" glycoform of sIgM. Importantly, the ability of the BCR-associated kinase inhibitors idelalisib and ibrutinib, approved for treatment of CLL and other B-cell malignancies, to inhibit anti-IgM-induced signalling was reduced following IL-4 pretreatment in samples from the majority of patients. In contrast to stimulatory effects on sIgM, IL-4 decreased CXCR4 and CXCR5 expression; therefore, CLL cells, particularly within the progressive unmutated V-gene subset, may harness the ability of IL-4 to promote BCR signalling and B-cell retention within lymph nodes. Effects of IL-4 were mediated via JAK3/STAT6 and we propose a potential role for JAK inhibitors in combination with BCR kinase inhibitors for the treatment of CLL. PMID:27002119

  5. Cell-surface serglycin promotes adhesion of myeloma cells to collagen type I and affects the expression of matrix metalloproteinases.

    Science.gov (United States)

    Skliris, Antonis; Labropoulou, Vassiliki T; Papachristou, Dionysios J; Aletras, Alexios; Karamanos, Nikos K; Theocharis, Achilleas D

    2013-05-01

    Serglycin (SG) is mainly expressed by hematopoetic cells as an intracellular proteoglycan. Multiple myeloma cells constitutively secrete SG, which is also localized on the cell surface in some cell lines. In this study, SG isolated from myeloma cells was found to interact with collagen type I (Col I), which is a major bone matrix component. Notably, myeloma cells positive for cell-surface SG (csSG) adhered significantly to Col I, compared to cells lacking csSG. Removal of csSG by treatment of the cells with chondroitinase ABC or blocking of csSG by an SG-specific polyclonal antibody significantly reduced the adhesion of myeloma cells to Col I. Significant up-regulation of expression of the matrix metalloproteinases MMP-2 and MMP-9 at both the mRNA and protein levels was observed when culturing csSG-positive myeloma cells on Col I-coated dishes or in the presence of soluble Col I. MMP-9 and MMP-2 were also expressed in increased amounts by myeloma cells in the bone marrow of patients with multiple myeloma. Our data indicate that csSG of myeloma cells affects key functional properties, such as adhesion to Col I and the expression of MMPs, and imply that csSG may serve as a potential prognostic factor and/or target for pharmacological interventions in multiple myeloma. PMID:23387827

  6. Kv7.1 surface expression is regulated by epithelial cell polarization

    DEFF Research Database (Denmark)

    Andersen, Martin N; Olesen, Søren-Peter; Rasmussen, Hanne Borger

    2011-01-01

    deafness, and several mutations have been described as trafficking mutations. To learn more about the basic mechanisms that regulate K(V)7.1 surface expression, we have investigated the trafficking of K(V)7.1 during the polarization process of the epithelial cell line Madin-Darby Canine Kidney (MDCK) using...

  7. Cell surface polypeptides of murine T-cell clones expressing cytolytic or amplifier activity.

    OpenAIRE

    Sarmiento, M.; Glasebrook, A L; Fitch, F. W.

    1980-01-01

    Murine cytolytic T-cell and amplifier T-cell clones derived from secondary unidirectional mixed leukocyte cultures were labeled with 125I by the lactoperoxidase method and their polypeptide profiles were analyzed by NaDodSO4/polyacrylamide gel electrophoresis. All cytolytic T-cell clones derived from the same mouse strain yeilded similar cell surface polypeptide profiles. However, profiles obtained with three amplifier T-cell clones were strikingly different from each other as well as from th...

  8. Developmental expression of a cell surface protein involved in sea urchin skeleton formation

    International Nuclear Information System (INIS)

    The authors have previously used a monoclonal antibody (1223) to identify a 130 Kd cell surface protein involved in skeleton formation is sea urchin embryos. In the current study the authors have examined the expression of the 1223 antigen over the course of development of embryos of two species, Strongylocentrotus purpuratus and Lytechinus pictus. The 130 Kd protein is detected in S. purp eggs on immunoblots. Labeling with [3H] leucine and immunoaffinity chromatography show that it also is synthesized shortly after fertilization. Immunofluroescence reveals that at this early stage the 1223 antigen is uniformly distributed on all of the cells. Synthesis decreases to a minimum by the time of hatching (18 h), as does the total amount of antigen present in the embryo. A second period of synthesis commences at the mesenchyme blastula stage, when the spicule-forming primary mesenchyme cells (PMCs) have appeared. During this later stage, synthesis and cell surface expression are restricted to the PMCs. In contrast to S. purp., in L. pictus the 130 Kd protein does not appear until the PMCs are formed. Hybrid embryos demonstrate a pattern of expression of the maternal species. These results suggest that early expression of 1223 antigen in S. purp. is due to utilization of maternal transcripts present in the egg. In both species later expression in PMCs appears to be the result of cell-type specific synthesis, perhaps encoded by embryonic transcripts

  9. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    D. Mesquita Júnior

    2014-08-01

    Full Text Available Regulatory T (TREG cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE. TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/highCD127Ø/lowFoxP3+, and effector T cells were defined as CD25+CD127+FoxP3Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163. In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

  10. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita Júnior, D. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cruvinel, W.M. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Departamento de Biomedicina, Universidade Católica de Goiás, Goiânia, GO (Brazil); Araujo, J.A.P. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Salmazi, K.C.; Kallas, E.G. [Disciplina de Imunologia Clínica e Alergia, Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Andrade, L.E.C. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-08-22

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25{sup +/high}CD127{sup Ø/low}FoxP3{sup +}, and effector T cells were defined as CD25{sup +}CD127{sup +}FoxP3{sup Ø}. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4{sup +}TREG and CD28{sup +}TREG cells and an increased frequency of CD40L{sup +}TREG cells. There was a decrease in the TREG/effector-T ratio for GITR{sup +}, HLA-DR{sup +}, OX40{sup +}, and CD45RO{sup +} cells, and an increased ratio of TREG/effector-T CD40L{sup +} cells in patients with SLE. In addition, CD40L{sup +}TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

  11. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/highCD127Ø/lowFoxP3+, and effector T cells were defined as CD25+CD127+FoxP3Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease

  12. Cytomegalovirus m154 hinders CD48 cell-surface expression and promotes viral escape from host natural killer cell control.

    Directory of Open Access Journals (Sweden)

    Angela Zarama

    2014-03-01

    Full Text Available Receptors of the signalling lymphocyte-activation molecules (SLAM family are involved in the functional regulation of a variety of immune cells upon engagement through homotypic or heterotypic interactions amongst them. Here we show that murine cytomegalovirus (MCMV dampens the surface expression of several SLAM receptors during the course of the infection of macrophages. By screening a panel of MCMV deletion mutants, we identified m154 as an immunoevasin that effectively reduces the cell-surface expression of the SLAM family member CD48, a high-affinity ligand for natural killer (NK and cytotoxic T cell receptor CD244. m154 is a mucin-like protein, expressed with early kinetics, which can be found at the cell surface of the infected cell. During infection, m154 leads to proteolytic degradation of CD48. This viral protein interferes with the NK cell cytotoxicity triggered by MCMV-infected macrophages. In addition, we demonstrate that an MCMV mutant virus lacking m154 expression results in an attenuated phenotype in vivo, which can be substantially restored after NK cell depletion in mice. This is the first description of a viral gene capable of downregulating CD48. Our novel findings define m154 as an important player in MCMV innate immune regulation.

  13. Surface expression of Mo3e antigen by activated human monocytes and U-937 cells

    Energy Technology Data Exchange (ETDEWEB)

    Todd R.F. III; Bury, M.J.; Liu, D.Y.

    1986-03-05

    The surface expression of a protease-sensitive antigen, Mo3e, by activated human monocytes and U-937 cells is a plasma membrane feature of the activated state. Mo3e, which is an 80 kD protein on Western blot analysis, may represent the surface receptor for migration inhibitory factor (MIF), as evidenced by inhibition of MIF responsiveness produced by anti-Mo3e monoclonal antibody. Mo3e is barely detectable (by surface immunofluorescence) on freshly isolated monocytes but becomes expressed in high antigen density during 18-24 hrs culture in medium containing E. coli lipopolysaccharide (> 1 ng/ml), 4..beta..-phorbol 12-myristate 13-acetate (PMA) (5-10 nM), or muramyl dipeptide (0.1-1 ..mu..M). In U-937 cells, Mo3e surface expression is detectable after 24 hrs exposure to PMA and other pharmacological activators of protein kinase C: 4..beta..-phorbol 12, 13 dibutyrate, 4..beta..-phorbol 12, 13 didecanoate, mezerein, or Sn-1,2-dioctanoylglycerol. The biologically-inactivate phorbol compounds, 4..cap alpha..-phorbol 12, 13 didecanoate and 4/sub ..beta../-phorbol do not stimulate Mo3e expression. The calcium ionophore, ionomycin, has a synergistic effect on Mo3e expression stimulated by PMA; conversely, calcium antagonists block PMA-induced Mo3e expression. These results suggest the involvement of protein kinase C activation and intracellular calcium mobilization in the stimulated expression of Mo3e by activated human mononuclear phagocytes.

  14. Cutaneous T cell lymphoma expresses immunosuppressive CD80 (B7-1) cell surface protein in a STAT5-dependent manner

    DEFF Research Database (Denmark)

    Zhang, Qian; Wang, Hong Yi; Wei, Fang;

    2014-01-01

    In this article, we report that cutaneous T cell lymphoma (CTCL) cells and tissues ubiquitously express the immunosuppressive cell surface protein CD80 (B7-1). CD80 expression in CTCL cells is strictly dependent on the expression of both members of the STAT5 family, STAT5a and STAT5b, as well as...

  15. Investigation of integrin expression on the surface of osteoblast-like cells by atomic force microscopy

    International Nuclear Information System (INIS)

    The transforming growth factor β1 (TGF-β1) is a human cytokine which has been demonstrated to modulate cell surface integrin repertoire. In this work integrin expression in response to TGF-β1 stimulation has been investigated on the surface of human osteoblast-like cells. We used atomic force microscopy (AFM) and confocal laser scanning microscopy to assess integrin expression and to evaluate their distribution over the dorsal side of the plasma membrane. AFM probes have been covalently functionalised with monoclonal antibodies specific to the β1 integrin subunit. Force curves have been collected in order to obtain maps of the interaction between the immobilized antibody and the respective cell membrane receptors. Adhesion peaks have been automatically detected by means of an ad hoc developed data analysis software. The specificity of the detected interactions has been assessed by adding free antibody in the solution and monitoring the dramatic decrease in the recorded interactions. In addition, the effect of TGF-β1 treatment on both the fluorescence signal and the adhesion events has been tested. The level of expression of the β1 integrin subunit was enhanced by TGF-β1. As a further analysis, the adhesion force of the single living cells to the substrate was measured by laterally pushing the cell with the AFM tip and measuring the force necessary to displace it. The treatment with TGF-β1 resulted in a decrease of the cell/substrate adhesion force. Results obtained by AFM have been validated by confocal laser scanning microscopy thus demonstrating the high potential of the AFM technique for the investigation of cell surface receptors distribution and trafficking at the nanoscale.

  16. Expression of cancer stem cell surface markers after chemotherapeutic drug treatment to reflect breast cancer cell regrowth

    Institute of Scientific and Technical Information of China (English)

    Qing Liu; Wings Tjing Yung Loo; Louis Wing Cheong Chow; Kelly Wei Yu Rui

    2014-01-01

    Objective To detect the cell viability and the expressions of stem cell surface markers after chemotherapeutic drug treatment. Methods We observed the cytotoxic effects of three chemotherapeutic agents [ epirubicin ( Epi ) , fluorouracil ( 5-FU ) and cyclophosphamide ( Cyc ) ] in three cell lines, and the cell viabilities after removed these chemotherapeutic agents. Expressions of stem cell surface markers CD44, CD24, CD90, CD14 and aldehyde dehydrogenase1(ALDH1) in breast cancer cells were analyzed by real-time PCR. The post hoc analysis (Tukey’s tests) in conjunction with one-way ANOVA was used for statistical analysis. Results The initial cytotoxic efficacy was most notable. After the treatment of the same therapeutic agents, cell viability was decreased by 64. 8% 35. 14%, 32. 25% in BT-483 cells, 66. 4%, 22. 94% and 45. 88% in MDA-MB-231 cells, 97. 1%, 99. 5% and 76. 4% in MCF cells. The difference was significant compared with that before treatment ( P=0. 000 ) . However, the inhibitory effects were diminished after chemotherapeutic agent withdrawal. Cell viabilities were increased to 167. 9%, 212. 04% and 188. 66% in MDA-MB-231 cells at 48 h after withdrawal. At 72 h after withdrawal, cell viability was increased with a significant difference in three cell lines (all P values=0. 000). Expressions of CD44 and ALDH1 were most prevalent for MDA-MB-231, BT-483 and MCF-7 cells. ALDH1 mRNA level was significant higher in BT-483 ( HER-2 overexpression cell line) than MDA-MB-231 ( triple negative cell line ) ( P = 0. 012 ) . CD14 mRNA level in MCF-7 cells were significantly lower than that in MDA-MB-231 and BT-483 (P=0. 003, 0. 001). BT-483 showed significantly higher level of CD44 than MDA-MB-231 and MCF-7 cell line (P= 0.013, 0.020), and no significant difference was detected between MDA-MB-231 and MCF-7 breast cancer cells ( P=0. 955 ) . CD90 mRNA expressions were detected in MDA-MB-231 cells and MCF-7 cells, but not in BT-483 cells. Conclusion Some malignant

  17. High Cell Surface Death Receptor Expression Determines Type I Versus Type II Signaling*

    Science.gov (United States)

    Meng, Xue Wei; Peterson, Kevin L.; Dai, Haiming; Schneider, Paula; Lee, Sun-Hee; Zhang, Jin-San; Koenig, Alexander; Bronk, Steve; Billadeau, Daniel D.; Gores, Gregory J.; Kaufmann, Scott H.

    2011-01-01

    Previous studies have suggested that there are two signaling pathways leading from ligation of the Fas receptor to induction of apoptosis. Type I signaling involves Fas ligand-induced recruitment of large amounts of FADD (FAS-associated death domain protein) and procaspase 8, leading to direct activation of caspase 3, whereas type II signaling involves Bid-mediated mitochondrial perturbation to amplify a more modest death receptor-initiated signal. The biochemical basis for this dichotomy has previously been unclear. Here we show that type I cells have a longer half-life for Fas message and express higher amounts of cell surface Fas, explaining the increased recruitment of FADD and subsequent signaling. Moreover, we demonstrate that cells with type II Fas signaling (Jurkat or HCT-15) can signal through a type I pathway upon forced receptor overexpression and that shRNA-mediated Fas down-regulation converts cells with type I signaling (A498) to type II signaling. Importantly, the same cells can exhibit type I signaling for Fas and type II signaling for TRAIL (TNF-α-related apoptosis-inducing ligand), indicating that the choice of signaling pathway is related to the specific receptor, not some other cellular feature. Additional experiments revealed that up-regulation of cell surface death receptor 5 levels by treatment with 7-ethyl-10-hydroxy-camptothecin converted TRAIL signaling in HCT116 cells from type II to type I. Collectively, these results suggest that the type I/type II dichotomy reflects differences in cell surface death receptor expression. PMID:21865165

  18. GABA Acts as a Ligand Chaperone in the Early Secretory Pathway to Promote Cell Surface Expression of GABAA Receptors

    OpenAIRE

    Eshaq, Randa S.; Stahl, Letha D.; Stone, Randolph; Smith, Sheryl S.; Robinson, Lucy C.; Leidenheimer, Nancy J.

    2010-01-01

    GABA (γ-aminobutyric acid) is the primary inhibitory neurotransmitter in brain. The fast inhibitory effect of GABA is mediated through the GABAA receptor, a postsynaptic ligand-gated chloride channel. We propose that GABA can act as a ligand chaperone in the early secretory pathway to facilitate GABAA receptor cell surface expression. Forty-two hrs of GABA treatment increased the surface expression of recombinant receptors expressed in HEK 293 cells, an effect accompanied by an increase in GA...

  19. Aged mice have increased inflammatory monocyte concentration and altered expression of cell-surface functional receptors

    Indian Academy of Sciences (India)

    Kelley Strohacker; Whitney L Breslin; Katie C Carpenter; Brian K McFarlin

    2012-03-01

    The expression of monocyte cell-surface receptors represents one index of immune dysfunction, which is common with aging. Although mouse models of aging are prevalent, monocyte subset assessment is rare. Our purpose was to compare cell receptor expression on classic (CD115+/Gr-1high) and non-classic (CD115+/Gr-1low) monocytes from 80- or 20-week-old CD-1 mice. Three-colour flow cytometry was used to determine the concentration of monocyte subsets and their respective cell-surface expression of TLR2, TLR4, CD80, CD86, MHC II and CD54. These receptors were selected because they have been previously associated with altered monocyte function. Data were analysed with independent -tests; significance was set at < 0.05. Old mice had a greater concentration of both classic (258%, =0.003) and non-classic (70%, =0.026) monocytes. The classic : non-classic monocyte ratio doubled in old as compared with that in young mice (=0.006), indicating a pro-inflammatory shift. TLR4 ($\\downarrow$27%, =0.001) and CD80 ($\\downarrow$37%, =0.004) were decreased on classic monocytes from old as compared with those from young mice. TLR2 ($\\uparrow$24%, =0.002) and MHCII ($\\downarrow$21%, =0.026) were altered on non-classic monocytes from old as compared with those from young mice. The increased classic : non-classic monocyte ratio combined with changes in the cell-surface receptor expression on both monocyte subsets is indicative of immune dysfunction, which may increase age-associated disease risk.

  20. Genetic analysis of the SARS-coronavirus spike glycoprotein functional domains involved in cell-surface expression and cell-to-cell fusion

    International Nuclear Information System (INIS)

    The SARS-coronavirus (SARS-CoV) is the etiological agent of severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. To delineate functional domains of the SARS-CoV S glycoprotein, single point mutations, cluster-to-lysine and cluster-to-alanine mutations, as well as carboxyl-terminal truncations were investigated in transient expression experiments. Mutagenesis of either the coiled-coil domain of the S glycoprotein amino terminal heptad repeat, the predicted fusion peptide, or an adjacent but distinct region, severely compromised S-mediated cell-to-cell fusion, while intracellular transport and cell-surface expression were not adversely affected. Surprisingly, a carboxyl-terminal truncation of 17 amino acids substantially increased S glycoprotein-mediated cell-to-cell fusion suggesting that the terminal 17 amino acids regulated the S fusogenic properties. In contrast, truncation of 26 or 39 amino acids eliminating either one or both of the two endodomain cysteine-rich motifs, respectively, inhibited cell fusion in comparison to the wild-type S. The 17 and 26 amino-acid deletions did not adversely affect S cell-surface expression, while the 39 amino-acid truncation inhibited S cell-surface expression suggesting that the membrane proximal cysteine-rich motif plays an essential role in S cell-surface expression. Mutagenesis of the acidic amino-acid cluster in the carboxyl terminus of the S glycoprotein as well as modification of a predicted phosphorylation site within the acidic cluster revealed that this amino-acid motif may play a functional role in the retention of S at cell surfaces. This genetic analysis reveals that the SARS-CoV S glycoprotein contains extracellular domains that regulate cell fusion as well as distinct endodomains that function in intracellular transport, cell-surface expression, and cell fusion

  1. Cell surface expression and function of the macromolecular C1 complex on the surface of human monocytes

    Directory of Open Access Journals (Sweden)

    Kinga K Hosszu

    2012-03-01

    Full Text Available The synthesis of the subunits of the C1 complex (C1q, C1s, C1r, and its regulator C1 inhibitor (C1-Inh by human monocytes has been previously established. However, surface expression of these molecules by monocytes has not been shown. Using flow cytometry and antigen-capture ELISA, we show here for the first time that, in addition to C1q, PB monocytes and the monocyte-derived U937 cells express C1s and C1r, as well as Factor B and C1-Inh on their surface. C1s and C1r immunoprecipitated with C1q, suggesting that at least some of the C1q on these cells is part of the C1 complex. Furthermore, the C1 complex on U937 cells was able to trigger complement activation via the classical pathway. The presence of C1-Inh may ensure that an unwarranted autoactivation of the C1 complex does not take place. Since C1-Inh closely monitors the activation of the C1 complex in a sterile or infectious inflammatory environment, further elucidation of the role of C1 complex is crucial to dissect its function in monocyte, DC and T cell activities, and its implications in host defense and tolerance.

  2. Differential Expression of Stem Cell Markers in Ocular Surface Squamous Neoplasia.

    Science.gov (United States)

    Mishra, Dilip Kumar; Veena, Uppala; Kaliki, Swathi; Kethiri, Abhinav Reddy; Sangwan, Virender S; Ali, Mohammed Hasnat; Naik, Milind N; Singh, Vivek

    2016-01-01

    Ocular Surface Squamous Neoplasm (OSSN) is the neoplasia arising from the conjunctiva, cornea and limbus. OSSN ranges from mild, moderate, severe dysplasia, carcinoma in situ (CIS) to squamous cell carcinoma (SCC). Recent findings on cancer stem cells theory indicate that population of stem-like cell as in neoplasia determines its heterogeneity and complexity leading to varying tumor development of metastatic behavior and recurrence. Cancer stem cell markers are not much explored in the cases of OSSN. In the present study, we aim to evaluate the expression of stem cells using stem cell markers mainly p63, ABCG2, c-KIT (CD117) and CD44 in OSSN tissue, which could have prognostic significance. The present study tries for the first time to explore expression of these stem markers in the cases of OSSN. These cases are subdivided into two groups. One group comprises of carcinoma in situ (n = 6) and the second group comprises of invasive carcinoma (n = 6). The mean age at presentation was 52 years; with 53 years for CIS group and 52 years for SCC group. From each group section from the paraffin block were taken for the IHC staining of p63, c-Kit, ABCG2 and CD44. Our experiments show high expression of P63 and CD44 in the cases of CIN and SCC. Both CIS and SCC displayed positive staining with p63, with more than 80% cells staining positive. However minimal expression of c-kit in both CIN and SCC. But surprisingly we got high expression of ABCG2 in cases of carcinoma in situ as compared to that of invasive squamous cell carcinoma. More than 50% of cells showed CD44 positivity in both CIS and SCC groups. Our results show for the first time that these four stem cells especially the limbal epithelium stem cells play a vital role in the genesis of OSSN but we need to explore more cases before establishing its clinical and biological significance. PMID:27584160

  3. Correlation between the Sensitivity to TRAIL and the Expression Level of DR5 on the Surface of Tumor Cells

    Institute of Scientific and Technical Information of China (English)

    Yuanfang Ma; Jun Zhang; Yueping Zhao

    2005-01-01

    OBJECTIVE To investigate the correlation between the sensitivity to the tumor necrosis factor- related apoptosis inducing ligand (TRAIL) and the level of expression of the death receptor 5 (DR5) on the surface of tumor cells.METHODS Anti-DR5 mAbs were used to directly detect the level of expression of DR5 on the surface of tumor cells. Using a TRAIL apoptosis kit and flow cytometry, the sensitivity of the tumor cells to TRAIL-induced apoptosis was determined and the correlation between DR5 expression and sensitivity to TRAIL analyzed.RESULTS The expression level of DR5 on the surface of different tumor cells was as follows: 97.9% in U937 cells, 95.1% in Jurkat cells, 93.8% in SW480 cells, 86.2% in HCT116 cells, 64.2% in HL-60 cells, 46.6% in Hela cells and 13.1% in K562 cells. The TRAIL-induced apoptotic rate was 72.6% in U937 cells, 85.2% in Jurkat cells, 78.6% in SW480 cells, 70.2% in HCT116 cells,60.1% in HL-60 cells, 45.4% in Hela cells and 12.3% in K562 cells. Statistical analysis showed there was a significant positive correlation (r=0.997, P<0.001) between DR5 expression and sensitivity to TRAIL.CONCLUSION The sensitivity of tumor cells to TRAIL is related to the level of expression of DR5 on the surface of tumor cells. These results confirm the importance of DR5 expression for induction of apoptosis by TRAIL.

  4. Campylobacter jejuni cocultured with epithelial cells reduces surface capsular polysaccharide expression.

    LENUS (Irish Health Repository)

    Corcionivoschi, N

    2012-02-01

    The host cell environment can alter bacterial pathogenicity. We employed a combination of cellular and molecular techniques to study the expression of Campylobacter jejuni polysaccharides cocultured with HCT-8 epithelial cells. After two passages, the amount of membrane-bound high-molecular-weight polysaccharide was considerably reduced. Microarray profiling confirmed significant downregulation of capsular polysaccharide (CPS) locus genes. Experiments using conditioned media showed that sugar depletion occurred only when the bacterial and epithelial cells were cocultured. CPS depletion occurred when C. jejuni organisms were exposed to conditioned media from a different C. jejuni strain but not when exposed to conditioned media from other bacterial species. Proteinase K or heat treatment of conditioned media under coculture conditions abrogated the effect on the sugars, as did formaldehyde fixation and cycloheximide treatment of host cells or chloramphenicol treatment of the bacteria. However, sugar depletion was not affected in flagellar export (fliQ) and quorum-sensing (luxS) gene mutants. Passaged C. jejuni showed reduced invasiveness and increased serum sensitivity in vitro. C. jejuni alters its surface polysaccharides when cocultured with epithelial cells, suggesting the existence of a cross talk mechanism that modulates CPS expression during infection.

  5. Proliferation, behavior, and cytokine gene expression of human umbilical vascular endothelial cells in response to different titanium surfaces.

    Science.gov (United States)

    An, Na; Schedle, Andreas; Wieland, Marco; Andrukhov, Oleh; Matejka, Michael; Rausch-Fan, Xiaohui

    2010-04-01

    Success of dental implantation is initially affected by wound healing of both, hard and soft tissues. Endothelial cells (ECs) are involved as crucial cells in the angiogenesis and inflammation process of wound healing. In the present study, proliferation, mobility, cluster formation, and gene expression of angiogenesis-related molecules of human umbilical vascular endothelial cells (HUVECs) were investigated on titanium surfaces with different roughnesses: acid-etched (A), coarse-grit-blasted and acid-etched (SLA) surfaces, as well as on hydrophilic modified modA and modSLA surfaces. Cell behaviors were analyzed by proliferation assay and time-lapse microscopy, gene expression was analyzed by real time PCR. Results showed that cell proliferation, mobility, and cluster formation were highest on modA surfaces compared with all other surfaces. HUVECs moved slowly and exhibited seldom cell aggregation on SLA and modSLA surfaces during the whole observing period of 120 h. The gene expressions of the angiogenesis-related factors von Willebrand factor, thrombomodulin, endothelial cell protein C receptor, and adhesion molecules intercellular adhesion molecule-1 and E-selectin were most enhanced on modSLA surfaces. These results suggest that modA surface is optimal for proliferation and angiogenic behavior of ECs. However, modSLA surface seems to promote ECs to express angiogenesis-related factor genes, which play essential roles in controlling inflammation and revascularization of wound healing. PMID:19569217

  6. Surface Expression of Precursor N-cadherin Promotes Tumor Cell Invasion

    Directory of Open Access Journals (Sweden)

    Deborah Maret

    2010-12-01

    Full Text Available The expression of N-cadherin (NCAD has been shown to correlate with increased tumor cell motility and metastasis. However, NCAD-mediated adhesion is a robust phenomenon and therefore seems to be inconsistent with the “release” from intercellular adhesion required for invasion. We show that in the most invasive melanoma and brain tumor cells, altered posttranslational processing results in abundant nonadhesive precursor N-cadherin (proNCAD at the cell surface, although total NCAD levels remain constant. We demonstrate that aberrantly processed proNCAD promotes cell migration and invasion in vitro. Furthermore, in human tumor specimens, we find high levels of proNCAD as well, supporting an overall conclusion that proNCAD and mature NCAD coexist on these tumor cell surfaces and that it is the ratio between these functionally antagonistic moieties that directly correlates with invasion potential. Our work provides insight into what may be a widespread mechanism for invasion and metastasis and challenges the current dogma of the functional roles played by classic cadherins in tumor progression.

  7. Relationship of CD86 surface marker expression and cytotoxicity on dendritic cells exposed to chemical allergen

    International Nuclear Information System (INIS)

    Human peripheral blood-derived dendritic cells (DC) respond to a variety of chemical allergens by up-regulating expression of the co-stimulatory molecule CD86. It has been postulated that this measure might provide the basis for an in vitro alternative approach for the identification of skin sensitizing chemicals. We recently reported that DC, exposed in culture to the highest non-cytotoxic concentrations of various chemical allergens, displayed marginal up-regulation of membrane CD86 expression; the interpretation being that such changes were insufficiently sensitive for the purposes of hazard identification. For the work presented here, immature DC were derived from human monocytes and treated with the chemical allergens 2,4-dinitrobenzenesulfonic acid (DNBS), nickel sulfate (NiSO4), p-phenylenediamine (PPD), Bandrowski's base (BB), hydroquinone (HQ) and propyl gallate (PG) for 48 h at concentrations which induced both no to slight to moderate cytotoxicity. For comparison, DC were treated with the irritants sodium dodecyl sulfate (SDS), benzoic acid (BA), and benzalkonium chloride (BZC) at concentrations resulting in comparable levels of cytotoxicity. CD86 expression, as measured by flow cytometry, was consistently up-regulated (ranging from 162 to 386% control) on DC treated with concentrations of chemical allergens that induced approximately 10-15% cytotoxicity. The irritants BA and BZC did not induce up-regulation of CD86 expression when tested at concentrations that induced similar levels of cytotoxicity. SDS, however, up-regulated CD86 expression to 125-138% of control in 2/4 preparations when tested at concentrations which induced similar toxicity. Our results confirm that chemical allergens up-regulate CD86 expression on blood-derived DC and illustrate further that up-regulation of CD86 surface marker expression is more robust when DC are treated with concentrations of chemical allergen that induce slight to moderate cytotoxicity

  8. Protein phosphatase 2A isotypes regulate cell surface expression of the T cell receptor

    DEFF Research Database (Denmark)

    Lauritsen, Jens Peter Holst; Menné, C; Kastrup, J;

    2001-01-01

    The mechanisms underlying T cell receptor (TCR) down-regulation have been extensively studied during the last decade. Whereas the importance of phosphorylation in this process has been established, it is less certain whether dephosphorylation plays a role in TCR down-regulation. In this study, we...... show that inhibition of the serine/threonine protein phosphatase PP2A family had a biphasic effect on TCR expression. Thus, low concentrations of PP2A inhibitors induced TCR down-regulation, whereas higher concentrations of PP2A inhibitors induced TCR up-regulation. The effect of PP2A inhibition was...... independent of phosphorylation of the CD3gamma endocytosis motif. Whereas TCR down-regulation was caused by a partial inhibition of exocytosis, TCR up-regulation was caused by an inhibition of endocytosis. The effects on exocytosis and endocytosis were not restricted to the TCR, indicating a more general...

  9. Expression of the human immunodeficiency virus envelope glycoprotein is restricted to basolateral surfaces of polarized epithelial cells

    International Nuclear Information System (INIS)

    Polarized epithelial cells exhibit apical (lumenal) and basolateral (serosal) membrane domains that are separated by circumferential tight junctions. In such cells, enveloped viruses that mature by budding at cell surfaces are released at particular membrane domains. The authors have used a vaccinia virus recombinant to investigate the site of surface expression of the human immunodeficiency virus type 1 envelope glycoprotein in Madin-Darby canine kidney cells. Cells were infected with the vaccinia virus recombinant, and surface expression of the glycoprotein was analyzed by indirect immunofluorescence, 125I-protein A binding, and immunoelectron microscopy. The glycoprotein appeared exclusively at the basolateral surface as early as 2 h postinfection and reached a maximum level at 8 h postinfection. The gp120 glycoprotein was found to be secreted efficiently into culture medium, and this secretion occurred exclusively at the basolateral surface

  10. Discovering aptamers by cell-SELEX against human soluble growth factors ectopically expressed on yeast cell surface.

    Directory of Open Access Journals (Sweden)

    Hsien-Wei Meng

    Full Text Available SELEX, the process of selecting aptamers, is often hampered by the difficulty of preparing target molecules in their native forms and by a lack of a simple yet quantitative assay for monitoring enrichment and affinity of reactive aptamers. In this study, we sought to discover DNA aptamers against human serum markers for potential therapeutic and diagnostic applications. To circumvent soluble expression and immobilization for performing SELEX, we ectopically expressed soluble growth factors on the surface of yeast cells to enable cell-SELEX and devised a flow cytometry-based method to quantitatively monitor progressive enrichment of specific aptamers. High-throughput sequencing of selected pools revealed that the emergence of highly enriched sequences concurred with the increase in the percentage of reactive aptamers shown by flow cytometry. Particularly, selected DNA aptamers against VEGF were specific and of high affinity (K(D  = ∼ 1 nM and demonstrated a potent inhibition of capillary tube formation of endothelial cells, comparable to the effect of a clinically approved anti-VEGF antibody drug, bevacizumab. Considering the fact that many mammalian secretory proteins have been functionally expressed in yeast, the strategy of implementing cell-SELEX and quantitative binding assay can be extended to discover aptamers against a broad array of soluble antigens.

  11. Signal peptide cleavage is essential for surface expression of a regulatory T cell surface protein, leucine rich repeat containing 32 (LRRC32

    Directory of Open Access Journals (Sweden)

    Sugiyama Hideaki

    2011-05-01

    Full Text Available Abstract Background Elevated numbers of regulatory T cells (Tregs have been implicated in certain cancers. Depletion of Tregs has been shown to increase anti-tumor immunity. Tregs also play a critical role in the suppression of autoimmune responses. The study of Tregs has been hampered by a lack of adequate surface markers. Leucine Rich Repeat Containing 32 (LRRC32, also known as Glycoprotein A Repetitions Predominant (GARP, has been postulated as a novel surface marker of activated Tregs. However, there is limited information regarding the processing of LRRC32 or the regulatory phenotype and functional activity of Tregs expressing LRRC32. Results Using naturally-occurring freshly isolated Tregs, we demonstrate that low levels of LRRC32 are present intracellularly prior to activation and that freshly isolated LRRC32+ Tregs are distinct from LRRC32- Tregs with respect to the expression of surface CD62L. Using LRRC32 transfectants of HEK cells, we demonstrate that the N-terminus of LRRC32 is cleaved prior to expression of the protein at the cell surface. Furthermore, we demonstrate using a construct containing a deleted putative signal peptide region that the presence of a signal peptide region is critical to cell surface expression of LRRC32. Finally, mixed lymphocyte assays demonstrate that LRRC32+ Tregs are more potent suppressors than LRRC32- Tregs. Conclusions A cleaved signal peptide site in LRRC32 is necessary for surface localization of native LRRC32 following activation of naturally-occurring freshly-isolated regulatory T cells. LRRC32 expression appears to alter the surface expression of activation markers of T cells such as CD62L. LRRC32 surface expression may be useful as a marker that selects for more potent Treg populations. In summary, understanding the processing and expression of LRRC32 may provide insight into the mechanism of action of Tregs and the refinement of immunotherapeutic strategies aimed at targeting these cells.

  12. Surface engineered magnetic nanoparticles for specific immunotargeting of cadherin expressing cells

    Science.gov (United States)

    Moros, Maria; Delhaes, Flavien; Puertas, Sara; Saez, Berta; de la Fuente, Jesús M.; Grazú, Valeria; Feracci, Helene

    2016-02-01

    In spite of historic advances in cancer biology and recent development of sophisticated chemotherapeutics, the outlook for patients with advanced cancer is still grim. In this sense nanoparticles (NPs), through their unique physical properties, enable the development of new approaches for cancer diagnosis and treatment. Thus far the most used active targeting scheme involves NPs functionalization with antibodies specific to molecules overexpressed on cancer cell’s surface. Therefore, such active targeting relies on differences in NPs uptake kinetics rates between tumor and healthy cells. Many cancers of epithelial origin are associated with the inappropriate expression of non-epithelial cadherins (e.g. N-, P-, -11) with concomitant loss of E-cadherin. Such phenomenon named cadherin switching favors tumor development and metastasis via interactions of tumor cells with stromal components. That is why we optimized the oriented functionalization of fluorescently labelled magnetic NPs with a novel antibody specific for the extracellular domain of cadherin-11. The obtained Ab-NPs exhibited high specificity when incubated with two cell lines used as models of tumor and healthy cells. Thus, cadherin switching offers a great opportunity for the development of active targeting strategies aimed to improve the early detection and treatment of cancer.

  13. Quantum dots affect expression of CD133 surface antigen in melanoma cells

    Directory of Open Access Journals (Sweden)

    Steponkiene S

    2011-10-01

    Full Text Available Simona Steponkiene1-3, Simona Kavaliauskiene1, Rasa Purviniene4, Ricardas Rotomskis3,5, Petras Juzenas11Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Radiumhospital, Oslo, Norway; 2Faculty of Natural Sciences, Vilnius University, Vilnius, Lithuania; 3Biomedical Physics Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 4Immunology Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 5Biophotonics Laboratory, Laser Research Center, Vilnius University, Vilnius, LithuaniaBackground: In novel treatment approaches, therapeutics should be designed to target cancer stem cells (CSCs. Quantum dots (QDs are a promising new tool in fighting against cancer. However, little is known about accumulation and cytotoxicity of QDs in CSCs.Methods: Accumulation and cytotoxicity of CdTe-MPA (mercaptopropionic acid QDs in CSCs were assessed using flow cytometry and fluorescence-activated cell sorting techniques as well as a colorimetric cell viability assay.Results: We investigated the expression of two cell surface-associated glycoproteins, CD44 and CD133, in four different cancer cell lines (glioblastoma, melanoma, pancreatic, and prostate adenocarcinoma. Only the melanoma cells were positive to both markers of CD44 and CD133, whereas the other cells were only CD44-positive. The QDs accumulated to a similar extent in all subpopulations of the melanoma cells. The phenotypical response after QD treatment was compared with the response after ionizing radiation treatment. The percentage of the CD44high-CD133high subpopulation decreased from 72% to 55%–58% for both treatments. The stem-like subpopulation CD44highCD133low/- increased from 26%–28% in the untreated melanoma cells to 36%–40% for both treatments.Conclusion: Treatment of melanoma cells with QDs results in an increase of stem-like cell subpopulations. The changes in phenotype distribution of the melanoma cells after

  14. Niemann Pick type C cells show cholesterol dependent decrease of APP expression at the cell surface its increased processing through the ?-secretase pathway

    OpenAIRE

    Malnar, Martina; KOŠIČEK, MARKO; Mitterreiter, Stefan; Omerbašić, Damir; Lichtenthaler, Stefan F.; Goate, Alison; Hećimović, Silva

    2010-01-01

    Abstract The link between cholesterol and Alzheimer's disease has recently been revealed in Niemann Pick type C disease. We found that NPC1-/- cells show decreased expression of APP at the cell surface and increased processing of APP through the ?-secretase pathway resulting in increased C99, sAPP? and intracellular A?40 levels. This effect is dependent on increased cholesterol levels, since cholesterol depletion reversed cell surface APP expression and lowered A?/C99 levels in NPC...

  15. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    International Nuclear Information System (INIS)

    Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA) were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL). TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4) expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3) on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells displayed very low levels of surface TRAIL-R4

  16. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Aydin Cigdem

    2005-05-01

    Full Text Available Abstract Background Tumor Necrosis Factor (TNF-Related Apoptosis-Inducing Ligand (TRAIL selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL. Methods TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. Results MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4 expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3 on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells

  17. Melanoma cell surface-expressed phosphatidylserine as a therapeutic target for cationic anticancer peptide, temporin-1CEa.

    Science.gov (United States)

    Wang, Che; Chen, Yin-Wang; Zhang, Liang; Gong, Xian-Ge; Zhou, Yang; Shang, De-Jing

    2016-07-01

    We have previously reported that temporin-1CEa, a cationic antimicrobial peptide, exerts preferential cytotoxicity toward cancer cells. However, the exact molecular mechanism for this cancer-selectivity is still largely unknown. Here, we found that the negatively charged phosphatidylserine (PS) expressed on cancer cell surface serves as a target for temporin-1CEa. Our results indicate that human A375 melanoma cells express 50-fold more PS than non-cancerous HaCaT cells. The expression of cell surface PS in various cancer cell lines closely correlated with their ability to be recognized, bound and killed by temporin-1CEa. Additionally, the cytotoxicity of temporin-1CEa against A375 cells can be ameliorated by annexin V, which binds to cell surface PS with high affinity. Moreover, the data of isothermal titration calorimetry assay further confirmed a direct binding of temporin-1CEa to PS, at a ratio of 1:5 (temporin-1CEa:PS). Interestingly, the circular dichroism spectra analysis using artificial biomembrane revealed that PS not only provides electrostatic attractive sites for temporin-1CEa but also confers the membrane-bound temporin-1CEa to form α-helical structure, therefore, enhances the affinity and membrane disrupting ability of temporin-1CEa. In summary, these findings suggested that the melanoma cells expressed PS may serve as a promising target for temporin-1CEa or other cationic anticancer peptides. PMID:26596643

  18. Small round blue cell tumours: diagnostic and prognostic usefulness of the expression of B7-H3 surface molecule

    OpenAIRE

    Gregorio, A.; Corrias, M V; R. Castriconi; Dondero, A; Mosconi, M.; Gambini, C; Moretta, A; Moretta, L; Bottino, C

    2008-01-01

    Aims: To assess whether the expression of B7-H3 surface molecule could improve differential diagnosis of small cell round tumours. Methods and results: One hundred and one well-characterized paraffin-embedded small round cell tumours, stored in the pathology archive of the Gaslini Institute, were immunohistochemically analysed with the 5B14 monoclonal antibody, which recognizes the surface molecule B7-H3. All lymphoblastic lymphomas and the blastematous component of Wilms’ tumours were comple...

  19. Pancreatic hormones are expressed on the surfaces of human and rat islet cells through exocytotic sites

    DEFF Research Database (Denmark)

    Larsson, L I; Hutton, J C; Madsen, O D;

    1989-01-01

    responsible for the staining. Human insulin cells were surface-labeled by monoclonal antibodies recognizing the mature secretory products, insulin and C-peptide but not with monoclonal antibodies specific for proinsulin. Thus, routing of unprocessed preproinsulin to the cell surface may not account for these...

  20. Characterization of surface interleukin-2 receptor expression on gated populations of peripheral blood mononuclear cells from manatees, Trichechus manatus latirostris.

    Science.gov (United States)

    Sweat, J M; Johnson, C M; Marikar, Y; Gibbs, E P

    2005-12-15

    An in vitro system to determine surface interleukin-2 receptor (IL-2R) expression on mitogen-stimulated peripheral blood mononuclear cells (PBMC) from free-ranging manatees, Trichechus manatus latirostris was developed. Human recombinant IL-2, conjugated with a fluorescein dye was used in conjunction with flow cytometric analysis to determine changes in surface expression of IL-2R at sequential times over a 48-h period of in vitro stimulation. Surface expression of IL-2R was detected on manatee PBMC, which also cross-reacted with an anti-feline pan T-cell marker. An expression index (EI) was calculated by comparing mitogen-activated and non-activated PBMC. Based on side- and forward-scatter properties, flow cytometric analysis showed an increase in the number of larger, more granular "lymphoblasts" following concanavalin A (Con A) stimulation. The appearance of lymphoblasts was correlated with an increase in their surface expression of IL-2 receptors. Surface IL-2R expression, in Con A-stimulated PBMC, was detected at 16 h, peaked at 24-36 h, and began to decrease by 48 h. Characterization of the IL-2R expression should provide additional information on the health status of manatees, and the effect of their sub lethal exposure to brevetoxin. PMID:16112745

  1. Regulation of NKG2D-ligand cell surface expression by intracellular calcium after HDAC-inhibitor treatment

    DEFF Research Database (Denmark)

    Jensen, Helle; Hagemann-Jensen, Michael Henrik; Lauridsen, Felicia Kathrine Bratt;

    2013-01-01

    In this study we demonstrate that histone deacetylase (HDAC)-inhibitor mediated cell surface expression of the structural different NKG2D-ligands MICA/B and ULBP2 is calcium-dependent. Treatment with the calcium chelator EGTA inhibited constitutive as well as HDAC-inhibitor induced MICA/B and ULBP2...... cell surface expression on melanoma cells and Jurkat T-cells. A NKG2D-dependent cytolytic assay and staining with a recombinant NKG2D-Fc fusion protein showed that calcium chelation impaired the functional ability of NKG2D-ligands induced by HDAC-inhibitor treatment. The HDAC-inhibitor induced cell...... surface expression of ULBP2, but not MICA/B, was sensitive to treatment calmidazolium and trifluoperazine, two agents known to block calcium signaling. siRNA-mediated knock-down of the calcium-regulated proteins calmodulin or calpain did however not affect NKG2D-ligand cell surface expression on Jurkat T...

  2. Vibrio cholerae expresses cell surface antigens during intestinal infection which are not expressed during in vitro culture.

    OpenAIRE

    Jonson, G.; Svennerholm, A M; Holmgren, J

    1989-01-01

    Vibrio cholerae O1 bacteria harvested directly from ligated or nonligated intestines of rabbits with experimental cholera expressed at least 7 to 8 novel, in vivo-specific cell envelope (env) proteins that were not found on vibrios after in vitro culture in various ordinary liquid media. At the same time, several of the env proteins ordinarily expressed in vitro had disappeared or become much reduced. The infection-induced novel env protein were immunogenic. In immunoblot analyses, antisera r...

  3. Oxidative Nanopatterning of Titanium Surface Influences mRNA and MicroRNA Expression in Human Alveolar Bone Osteoblastic Cells

    Science.gov (United States)

    Wimmers Ferreira, Maidy Rehder; Rodrigo Fernandes, Roger; Freire Assis, Amanda; Dernowsek, Janaína A.; Passos, Geraldo A.; Variola, Fabio; Fittipaldi Bombonato-Prado, Karina

    2016-01-01

    Titanium implants have been extensively used in orthopedic and dental applications. It is well known that micro- and nanoscale surface features of biomaterials affect cellular events that control implant-host tissue interactions. To improve our understanding of how multiscale surface features affect cell behavior, we used microarrays to evaluate the transcriptional profile of osteoblastic cells from human alveolar bone cultured on engineered titanium surfaces, exhibiting the following topographies: nanotexture (N), nano+submicrotexture (NS), and rough microtexture (MR), obtained by modulating experimental parameters (temperature and solution composition) of a simple yet efficient chemical treatment with a H2SO4/H2O2 solution. Biochemical assays showed that cell culture proliferation augmented after 10 days, and cell viability increased gradually over 14 days. Among the treated surfaces, we observed an increase of alkaline phosphatase activity as a function of the surface texture, with higher activity shown by cells adhering onto nanotextured surfaces. Nevertheless, the rough microtexture group showed higher amounts of calcium than nanotextured group. Microarray data showed differential expression of 716 mRNAs and 32 microRNAs with functions associated with osteogenesis. Results suggest that oxidative nanopatterning of titanium surfaces induces changes in the metabolism of osteoblastic cells and contribute to the explanation of the mechanisms that control cell responses to micro- and nanoengineered surfaces. PMID:27200092

  4. BRCA1 185delAG Mutation Enhances Interleukin-1β Expression in Ovarian Surface Epithelial Cells.

    Science.gov (United States)

    Woolery, Kamisha T; Mohamed, Mai; Linger, Rebecca J; Dobrinski, Kimberly P; Roman, Jesse; Kruk, Patricia A

    2015-01-01

    Familial history remains the strongest risk factor for developing ovarian cancer (OC) and is associated with germline BRCA1 mutations, such as the 185delAG founder mutation. We sought to determine whether normal human ovarian surface epithelial (OSE) cells expressing the BRCA1 185delAG mutant, BRAT, could promote an inflammatory phenotype by investigating its impact on expression of the proinflammatory cytokine, Interleukin-1β (IL-1β). Cultured OSE cells with and without BRAT were analyzed for differential target gene expression by real-time PCR, western blot, ELISA, luciferase reporter, and siRNA assays. We found that BRAT cells expressed increased cellular and secreted levels of active IL-1β. BRAT-expressing OSE cells exhibited 3-fold enhanced IL-1β mRNA expression, transcriptionally regulated, in part, through CREB sites within the (-1800) to (-900) region of its promoter. In addition to transcriptional regulation, BRAT-mediated IL-1β expression appears dualistic through enhanced inflammasome-mediated caspase-1 cleavage and activation of IL-1β. Further investigation is warranted to elucidate the molecular mechanism(s) of BRAT-mediated IL-1β expression since increased IL-1β expression may represent an early step contributing to OC. PMID:26357657

  5. BRCA1 185delAG Mutation Enhances Interleukin-1β Expression in Ovarian Surface Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Kamisha T. Woolery

    2015-01-01

    Full Text Available Familial history remains the strongest risk factor for developing ovarian cancer (OC and is associated with germline BRCA1 mutations, such as the 185delAG founder mutation. We sought to determine whether normal human ovarian surface epithelial (OSE cells expressing the BRCA1 185delAG mutant, BRAT, could promote an inflammatory phenotype by investigating its impact on expression of the proinflammatory cytokine, Interleukin-1β (IL-1β. Cultured OSE cells with and without BRAT were analyzed for differential target gene expression by real-time PCR, western blot, ELISA, luciferase reporter, and siRNA assays. We found that BRAT cells expressed increased cellular and secreted levels of active IL-1β. BRAT-expressing OSE cells exhibited 3-fold enhanced IL-1β mRNA expression, transcriptionally regulated, in part, through CREB sites within the (−1800 to (−900 region of its promoter. In addition to transcriptional regulation, BRAT-mediated IL-1β expression appears dualistic through enhanced inflammasome-mediated caspase-1 cleavage and activation of IL-1β. Further investigation is warranted to elucidate the molecular mechanism(s of BRAT-mediated IL-1β expression since increased IL-1β expression may represent an early step contributing to OC.

  6. Effects of 60Co γ-ray irradiation on expression of surface antigens in endothelial cells of human umbilical veins

    International Nuclear Information System (INIS)

    Culture of endothelial cells of human umbilical veins and avidin-biotin peroxidase complex (ABC) immunochemical technique were used in the experiment to detect the surface antigens in endothelial cells. Endothelial cells separated from five umbilical cords in original culture were divided into two groups, irradiated and non-irradiated. The cells were irradiated with 15 Gy of 60Co γ-rays at dose rates of 21.78 cGy/min. Then antigens RBC A, HLA-ABC, HLA-DR, CD4 and CD8 were assayed for both groups by the method of ABC. The results showed that the values of integrated optical density (IOD) for the surface antigens in the irradiated cells were lower than those in the non-irradiated cells with the difference in antigen expression in endothelial cells being significant (P<0.05) between the two groups

  7. EXPRESSION OF HLA-CLASS Ⅱ GENESOF IDDM PATIENTS ON THE SURFACE OF THE LTK- CELLS

    Institute of Scientific and Technical Information of China (English)

    王姮; 孙琦

    1994-01-01

    To investigate the function of HLA-class Ⅱ genes in the autoimmune response of insulin dependent diabetes mellitus(DDM),the HLA-class Ⅱ gene of IDDM patients was introd uced into Ltk-cells with pSV2-neo plas-mid,using the calcium phosphate precipitation technique.We obtained a stable cell line expressing the HLA-class Ⅱ gene from lymphocytes of IDDM patients.Expression was identified by direct ox erythocyte-CrCl3-HLA DR monoclonal antibody rosetting.

  8. Suppression of tumor growth and angiogenesis by a specific antagonist of the cell-surface expressed nucleolin.

    Directory of Open Access Journals (Sweden)

    Damien Destouches

    Full Text Available BACKGROUND: Emerging evidences suggest that nucleolin expressed on the cell surface is implicated in growth of tumor cells and angiogenesis. Nucleolin is one of the major proteins of the nucleolus, but it is also expressed on the cell surface where is serves as a binding protein for variety of ligands implicated in cell proliferation, differentiation, adhesion, mitogenesis and angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: By using a specific antagonist that binds the C-terminal tail of nucleolin, the HB-19 pseudopeptide, here we show that the growth of tumor cells and angiogenesis are suppressed in various in vitro and in vivo experimental models. HB-19 inhibited colony formation in soft agar of tumor cell lines, impaired migration of endothelial cells and formation of capillary-like structures in collagen gel, and reduced blood vessel branching in the chick embryo chorioallantoic membrane. In athymic nude mice, HB-19 treatment markedly suppressed the progression of established human breast tumor cell xenografts in nude mice, and in some cases eliminated measurable tumors while displaying no toxicity to normal tissue. This potent antitumoral effect is attributed to the direct inhibitory action of HB-19 on both tumor and endothelial cells by blocking and down regulating surface nucleolin, but without any apparent effect on nucleolar nucleolin. CONCLUSION/SIGNIFICANCE: Our results illustrate the dual inhibitory action of HB-19 on the tumor development and the neovascularization process, thus validating the cell-surface expressed nucleolin as a strategic target for an effective cancer drug. Consequently, the HB-19 pseudopeptide provides a unique candidate to consider for innovative cancer therapy.

  9. Elucidating the Kinetics of Expression and Immune Cell Infiltration Resulting from Plasmid Gene Delivery Enhanced by Surface Dermal Electroporation

    Directory of Open Access Journals (Sweden)

    Kate E. Broderick

    2013-08-01

    Full Text Available The skin is an attractive tissue for vaccination in a clinical setting due to the accessibility of the target, the ease of monitoring and most importantly the immune competent nature of the dermal tissue. While skin electroporation offers an exciting and novel future methodology for the delivery of DNA vaccines in the clinic, little is known about the actual mechanism of the approach and the elucidation of the resulting immune responses. To further understand the mechanism of this platform, the expression kinetics and localization of a reporter plasmid delivered via a surface dermal electroporation (SEP device as well as the effect that this treatment would have on the resident immune cells in that tissue was investigated. Initially a time course (day 0 to day 21 of enhanced gene delivery with electroporation (EP was performed to observe the localization of green fluorescent protein (GFP expression and the kinetics of its appearance as well as clearance. Using gross imaging, GFP expression was not detected on the surface of the skin until 8 h post treatment. However, histological analysis by fluorescent microscopy revealed GFP positive cells as early as 1 h after plasmid delivery and electroporation. Peak GFP expression was observed at 24 h and the expression was maintained in skin for up to seven days. Using an antibody specific for a keratinocyte cell surface marker, reporter gene positive keratinocytes in the epidermis were identified. H&E staining of treated skin sections demonstrated an influx of monocytes and granulocytes at the EP site starting at 4 h and persisting up to day 14 post treatment. Immunological staining revealed a significant migration of lymphocytic cells to the EP site, congregating around cells expressing the delivered antigen. In conclusion, this study provides insights into the expression kinetics following EP enhanced DNA delivery targeting the dermal space. These findings may have implications in the future to design

  10. Role of Site-Specific N-Glycans Expressed on GluA2 in the Regulation of Cell Surface Expression of AMPA-Type Glutamate Receptors.

    Directory of Open Access Journals (Sweden)

    Yusuke Takeuchi

    Full Text Available The AMPA-type glutamate receptor (AMPAR, which is a tetrameric complex composed of four subunits (GluA1-4 with several combinations, mediates the majority of rapid excitatory synaptic transmissions in the nervous system. Cell surface expression levels of AMPAR modulate synaptic plasticity, which is considered one of the molecular bases for learning and memory formation. To date, a unique trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc, human natural killer-1 (HNK-1 carbohydrate, was found expressed specifically on N-linked glycans of GluA2 and regulated the cell surface expression of AMPAR and the spine maturation process. However, evidence that the HNK-1 epitope on N-glycans of GluA2 directly affects these phenomena is lacking. Moreover, it is thought that other N-glycans on GluA2 also have potential roles in the regulation of AMPAR functions. In the present study, using a series of mutants lacking potential N-glycosylation sites (N256, N370, N406, and N413 within GluA2, we demonstrated that the mutant lacking the N-glycan at N370 strongly suppressed the intracellular trafficking of GluA2 from the endoplasmic reticulum (ER in HEK293 cells. Cell surface expression of GluA1, which is a major subunit of AMPAR in neurons, was also suppressed by co-expression of the GluA2 N370S mutant. The N370S mutant and wild-type GluA2 were co-immunoprecipitated with GluA1, suggesting that N370S was properly associated with GluA1. Moreover, we found that N413 was the main potential site of the HNK-1 epitope that promoted the interaction of GluA2 with N-cadherin, resulting in enhanced cell surface expression of GluA2. The HNK-1 epitope on N-glycan at the N413 of GluA2 was also involved in the cell surface expression of GluA1. Thus, our data suggested that site-specific N-glycans on GluA2 regulate the intracellular trafficking and cell surface expression of AMPAR.

  11. AMP-activated protein kinase downregulates Kv7.1 cell surface expression

    DEFF Research Database (Denmark)

    Andersen, Martin N; Krzystanek, Katarzyna; Jespersen, Thomas;

    2012-01-01

    downstream effector of AMPK is the E3 ubiquitin ligase Nedd4-2. Additionally, we show that AMPK activation results in a downregulation of Kv7.1 currents in Xenopus oocytes through a Nedd4-2-dependent mechanism. In summary, surface-expressed Kv7.1 channels are endocytosed and sent for degradation in lysosomes...

  12. Label-free and dynamic evaluation of cell-surface epidermal growth factor receptor expression via an electrochemiluminescence cytosensor.

    Science.gov (United States)

    Qiu, Youyi; Wen, Qingqing; Zhang, Lin; Yang, Peihui

    2016-04-01

    A label-free electrochemiluminescence (ECL) cytosensor was developed for dynamically evaluating of epidermal growth factor receptor (EGFR) expression on MCF-7 cancer cells based on the specific recognition of epidermal growth factor (EGF) with its receptor (EGFR). EGF-cytosensor was fabricated by in-situ electro-polymerization of polyaniline as substrate, using CdS quantum dots (CdS QDs) as ECL probe and gold nanoparticles (AuNPs) as a carrier for loading of EGF. AuNPs and CdS QDs were jointly attached on polyaniline surface to provide a sensitive and stable sensing interface, as well as a simple and label-free mode for ECL assay. Electron microscopy, atomic force microscopy (AFM) and electrochemical methods were employed to characterize the multilayer construction process of the sensing interface. The proposed EGF-cytosensor exhibited excellent analytical performance for MCF-7 cancer cells, ranging from 12 to 1.2 × 10(6) cells mL(-1), with a low detection limit of 12 cells mL(-1). Also, it was successfully applied in evaluating EGFR expression of cells surface, which was stimulated by some inhibitors or activator, and the results were confirmed by using flow cytometry and laser scanning confocal microscopy analysis. The proposed ECL cytosensor has potential applications in monitoring the dynamic variation of receptor molecules expression on cell surfaces in response to external stimulation by drugs and screening anti-cancer therapeutic agents. PMID:26838410

  13. Expression of Interleukin-15 and Its Receptor on the Surface of Stimulated Human Umbilical Vein Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    Xiuping LIU; Yumei ZUO; Weina ZHANG; Deguang YANG; Changyun XIONG; Xiaozhou ZHANG

    2009-01-01

    Human interleukin-15 (hlL-15) is an important cytokine to activate endothelial cells and can be regulated by many other cytokines. The aim of this study is to examine the ability of interferon-γ,(IFN-γ), and tumor necrosis factor-ct (TNF-α) to induce the production of human interleukin-15 (hlL-15)and IL-15 receptor (IL-15Rα) by human umbilical vein endothelial cells (HUVECs). The data are summarized as follows: 1. Northern blot revealed that IL-15 mRNA was up-regulated by IFN-γ and TNF-α. 2. lntracellular IL-15 protein was visualized by fluorescence microscopy, whereas the expres-sion of IL-15 on the surface of HUVECs was detected by fluorescence activated cell sorting (FACS),and no detectable IL-15 in the medium was verified by ELISA. 3. IL-15Rα was detected on the surface of HUVECs by FACS after IFN-γ and TNF-α stimulation, whereas Western blotting revealed that the elevated expression on surface IL-15Rα was not due to the increased protein expression. The conclusion demonstrated from our results is that IFN-γ and TNF-α play an important role in regulating the expres-sion of IL-15 and IL-15Rα on the surface of HUVECs.

  14. Gene expression of human osteoblasts cells on chemically treated surfaces of Ti–6Al–4V–ELI

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, D.P., E-mail: dpedreira@ufscar.br [Department of Materials Engineering, Federal University of São Carlos, São Carlos (Brazil); Palmieri, A.; Carinci, F. [Department of D.M.C.C.C., Section of Maxillofacial and Plastic Surgery, University of Ferrara, Ferrara (Italy); Bolfarini, C. [Department of Materials Engineering, Federal University of São Carlos, São Carlos (Brazil)

    2015-06-01

    Surface modifications of titanium alloys are useful methods to enhance the biological stability of intraosseous implants and to promote a well succeeded osseointegration in the early stages of implantation. This work aims to investigate the influence of chemically modified surfaces of Ti–6Al–4V–ELI (extra-low interstitial) on the gene expression of human osteoblastic (HOb) cells. The surface treatments by acid etching or acid etching plus alkaline treatment were carried out to modify the topography, effective area, contact angle and chemical composition of the samples. The surface morphology was investigated using: scanning electron microscopy (SEM) and confocal laser-scanning microscope (CLSM). Roughness measurements and effective surface area were obtained using the CLSM. Surface composition was analysed by energy dispersive X-ray spectroscopy (EDX) and by X-Ray Diffraction (XRD). The expression levels of some bone related genes (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analysed using real-time Reverse Transcription Polymerase Chain Reaction (real-time RT-PCR). The results showed that all the chemical modifications studied in this work influenced the surface morphology, wettability, roughness, effective area and gene expression of human osteoblasts. Acid phosphoric combined to alkaline treatment presented a more accelerated gene expression after 7 days while the only phosphoric etching or chloride etching combined to alkaline treatment presented more effective responses after 15 days. - Highlights: • Chemical treatments were effective for surface modification of Ti–6Al–4V. • Alkaline and phosphoric treatments induced osteopontin up-regulation. • Topographic formation on surface can induce RUNX2 up regulation. • Acid etch plus alkaline treatment accelerated the expression of some bone related genes.

  15. Gene expression of human osteoblasts cells on chemically treated surfaces of Ti–6Al–4V–ELI

    International Nuclear Information System (INIS)

    Surface modifications of titanium alloys are useful methods to enhance the biological stability of intraosseous implants and to promote a well succeeded osseointegration in the early stages of implantation. This work aims to investigate the influence of chemically modified surfaces of Ti–6Al–4V–ELI (extra-low interstitial) on the gene expression of human osteoblastic (HOb) cells. The surface treatments by acid etching or acid etching plus alkaline treatment were carried out to modify the topography, effective area, contact angle and chemical composition of the samples. The surface morphology was investigated using: scanning electron microscopy (SEM) and confocal laser-scanning microscope (CLSM). Roughness measurements and effective surface area were obtained using the CLSM. Surface composition was analysed by energy dispersive X-ray spectroscopy (EDX) and by X-Ray Diffraction (XRD). The expression levels of some bone related genes (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analysed using real-time Reverse Transcription Polymerase Chain Reaction (real-time RT-PCR). The results showed that all the chemical modifications studied in this work influenced the surface morphology, wettability, roughness, effective area and gene expression of human osteoblasts. Acid phosphoric combined to alkaline treatment presented a more accelerated gene expression after 7 days while the only phosphoric etching or chloride etching combined to alkaline treatment presented more effective responses after 15 days. - Highlights: • Chemical treatments were effective for surface modification of Ti–6Al–4V. • Alkaline and phosphoric treatments induced osteopontin up-regulation. • Topographic formation on surface can induce RUNX2 up regulation. • Acid etch plus alkaline treatment accelerated the expression of some bone related genes

  16. Differential Expression of Osteo-Modulatory Molecules in Periodontal Ligament Stem Cells in Response to Modified Titanium Surfaces

    Directory of Open Access Journals (Sweden)

    So Yeon Kim

    2014-01-01

    Full Text Available This study assessed differential gene expression of signaling molecules involved in osteogenic differentiation of periodontal ligament stem cells (PDLSCs subjected to different titanium (Ti surface types. PDLSCs were cultured on tissue culture polystyrene (TCPS, and four types of Ti discs (PT, SLA, hydrophilic PT (pmodPT, and hydrophilic SLA (modSLA with no osteoinductive factor and then osteogenic activity, including alkaline phosphatase (ALP activity, mRNA expression of runt-related gene 2, osterix, FOSB, FRA1, and protein levels of osteopontin and collagen type IA, were examined. The highest osteogenic activity appeared in PDLSCs cultured on SLA, compared with the TCPS and other Ti surfaces. The role of surface properties in affecting signaling molecules to modulate PDLSC behavior was determined by examining the regulation of Wnt pathways. mRNA expression of the canonical Wnt signaling molecules, Wnt3a and β-catenin, was higher on SLA and modSLA than on smooth surfaces, but gene expression of the calcium-dependent Wnt signaling molecules Wnt5a, calmodulin, and NFATc1 was increased significantly on PT and pmodPT. Moreover, integrin α2/β1, sonic hedgehog, and Notch signaling molecules were affected differently by each surface modification. In conclusion, surface roughness and hydrophilicity can affect differential Wnt pathways and signaling molecules, targeting the osteogenic differentiation of PDLSCs.

  17. Allelic imbalance modulates surface expression of the tolerance-inducing HLA-G molecule on primary trophoblast cells

    DEFF Research Database (Denmark)

    Djurisic, S; Teiblum, S; Tolstrup, Cæcilie Krogsgaard;

    2015-01-01

    The HLA-G molecule is expressed on trophoblast cells at the feto-maternal interface, where it interacts with local immune cells, and upholds tolerance against the semi-allogeneic fetus. Aberrant HLA-G expression in the placenta and reduced soluble HLA-G levels are observed in pregnancy...... complications, partly explained by HLA-G polymorphisms which are associated with differences in the alternative splicing pattern and of the stability of HLA-G mRNA. Of special importance is a 14 bp insertion/deletion polymorphism located in the 3'-untranslated region of the HLA-G gene. In the current study, we......RNA transcripts, which was further associated with low levels of HLA-G surface expression on primary trophoblast cells. Full gene sequencing of HLA-G allowed us to study correlations between HLA-G extended haplotypes and single-nucleotide polymorphisms and HLA-G surface expression. We found that a 1:1 expression...

  18. Surface membrane antigen expression changes induced in vitro by exogenous growth factors in chronic lymphocytic leukemia cells.

    Science.gov (United States)

    Vilpo, J; Hulkkonen, J; Hurme, M; Vilpo, L

    2002-09-01

    The factors determining the growth and survival of cells in B chronic lymphocytic leukemia (CLL) have remained poorly understood. We investigated the effects of optimal mitogen combinations (OMCs) on the expression of 26 surface membrane antigens among 33 CLL patients. The seven OMCs used were selected after pre-testing 14 combinations of (1) S. aureus Cowan I (SAC), (2) interleukin-2 (IL-2), (3) tumor necrosis factor alpha (TNF-alpha) and (4) 12-O-tetradecanoylphorbol 13-acetate (TPA; also known as phorbol 12-myristate 13-acetate or PMA). In flow cytometry we revealed that OMCs induced statistically highly significant upregulation of the expression of CD5, CD11c, CD19, CD22, CD23, CD25, CD38, CD40, CD45, CD45RO, CD95, CD126, CD130 and FMC7, and downregulation of CD20 and CD124 expression. Interestingly, the expression of CD27, CD45RA, CD79b, CD80, CD122 and that of the immunoglobulin gene superfamily members CD21, Ig-kappa, Ig-lambda, Ig-delta and Ig-micro were not significantly affected under similar conditions. The expression of several antigens was co-regulated, suggesting common regulatory pathways. These antigens include CD11c/CD5, CD11c/CD22, CD11c/CD126, CD11c/FMC7 as well as CD27/CD45, CD27/CD45RA and CD27/CD79b. Upregulation of surface antigen expression, induced by OMCs, should be applicable in antibody therapy in vitro and in vivo, and in negative stem cell selection for autotransplantation. Furthermore, the current strategy to enhance cell surface antigen expression may be a versatile tool to raise humoral and cell-mediated host defense against CLL cells. Upregulation of proteins mediating positive growth signals (eg CD25, CD40) and negative signals or apoptosis (eg CD95) may be used to sensitize cells to chemotherapy and programmed cell death. PMID:12200683

  19. EGCG decreases binding of calcium oxalate monohydrate crystals onto renal tubular cells via decreased surface expression of alpha-enolase.

    Science.gov (United States)

    Kanlaya, Rattiyaporn; Singhto, Nilubon; Thongboonkerd, Visith

    2016-06-01

    Crystal retention on tubular cell surface inside renal tubules is considered as the earliest and crucial step for kidney stone formation. Therapeutics targeting this step would cease the development of kidney stone. This study thus aimed to investigate the potential role of epigallocatechin-3-gallate (EGCG), a major antioxidant found in green tea leaves, in the reduction of calcium oxalate monohydrate (COM) crystal binding onto renal tubular cells. Pretreatment of the cells with EGCG for up to 6 h significantly diminished crystal-binding capability in a dose-dependent manner. Indirect immunofluorescence assay without and with cell permeabilization followed by laser-scanning confocal microscopy revealed that EGCG significantly reduced surface expression of alpha-enolase, whereas its intracellular level was increased. Western blot analysis confirmed such contradictory changes in membrane and cytosolic fractions of EGCG-treated cells, whereas the total level in whole cell lysate remained unchanged. Moreover, overexpression of surface alpha-enolase and enhancement of cell-crystal adhesion induced by 10 mM sodium oxalate were completely abolished by EGCG. Taken together, these data indicate that EGCG decreases binding of COM crystals onto renal tubular cells by decreasing the surface expression of alpha-enolase via re-localization or inhibition of alpha-enolase shuttling from the cytoplasm to the plasma membrane. These findings may also explain the effects of EGCG in reducing COM crystal deposition in previous animal models of kidney stone disease. Thus, EGCG may be useful for the prevention of new or recurrent stone formation. PMID:26898643

  20. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    OpenAIRE

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

  1. Separate developmental programs for HLA-A and -B cell surface expression during differentiation from embryonic stem cells to lymphocytes, adipocytes and osteoblasts.

    Directory of Open Access Journals (Sweden)

    Hardee J Sabir

    Full Text Available A major problem of allogeneic stem cell therapy is immunologically mediated graft rejection. HLA class I A, B, and Cw antigens are crucial factors, but little is known of their respective expression on stem cells and their progenies. We have recently shown that locus-specific expression (HLA-A, but not -B is seen on some multipotent stem cells, and this raises the question how this is in other stem cells and how it changes during differentiation. In this study, we have used flow cytometry to investigate the cell surface expression of HLA-A and -B on human embryonic stem cells (hESC, human hematopoietic stem cells (hHSC, human mesenchymal stem cells (hMSC and their fully-differentiated progenies such as lymphocytes, adipocytes and osteoblasts. hESC showed extremely low levels of HLA-A and no -B. In contrast, multipotent hMSC and hHSC generally expressed higher levels of HLA-A and clearly HLA-B though at lower levels. IFNγ induced HLA-A to very high levels on both hESC and hMSC and HLA-B on hMSC. Even on hESC, a low expression of HLA-B was achieved. Differentiation of hMSC to osteoblasts downregulated HLA-A expression (P = 0.017. Interestingly HLA class I on T lymphocytes differed between different compartments. Mature bone marrow CD4(+ and CD8(+ T cells expressed similar HLA-A and -B levels as hHSC, while in the peripheral blood they expressed significantly more HLA-B7 (P = 0.0007 and P = 0.004 for CD4(+ and CD8(+ T cells, respectively. Thus different HLA loci are differentially regulated during differentiation of stem cells.

  2. Effect of nitrogen-rich cell culture surfaces on type X collagen expression by bovine growth plate chondrocytes

    Directory of Open Access Journals (Sweden)

    Wertheimer Michael R

    2011-01-01

    Full Text Available Abstract Background Recent evidence indicates that osteoarthritis (OA may be a systemic disease since mesenchymal stem cells (MSCs from OA patients express type X collagen, a marker of late stage chondrocyte hypertrophy (associated with endochondral ossification. We recently showed that the expression of type X collagen was suppressed when MSCs from OA patients were cultured on nitrogen (N-rich plasma polymer layers, which we call "PPE:N" (N-doped plasma-polymerized ethylene, containing up to 36 atomic percentage (at.% of N. Methods In the present study, we examined the expression of type X collagen in fetal bovine growth plate chondrocytes (containing hypertrophic chondrocytes cultured on PPE:N. We also studied the effect of PPE:N on the expression of matrix molecules such as type II collagen and aggrecan, as well as on proteases (matrix metalloproteinase-13 (MMP-13 and molecules implicated in cell division (cyclin B2. Two other culture surfaces, "hydrophilic" polystyrene (PS, regular culture dishes and nitrogen-containing cation polystyrene (Primaria®, were also investigated for comparison. Results Results showed that type X collagen mRNA levels were suppressed when cultured for 4 days on PPE:N, suggesting that type X collagen is regulated similarly in hypertrophic chondrocytes and in human MSCs from OA patients. However, the levels of type X collagen mRNA almost returned to control value after 20 days in culture on these surfaces. Culture on the various surfaces had no significant effects on type II collagen, aggrecan, MMP-13, and cyclin B2 mRNA levels. Conclusion Hypertrophy is diminished by culturing growth plate chondrocytes on nitrogen-rich surfaces, a mechanism that is beneficial for MSC chondrogenesis. Furthermore, one major advantage of such "intelligent surfaces" over recombinant growth factors for tissue engineering and cartilage repair is potentially large cost-saving.

  3. Lactobacilli differentially modulate expression of cytokines and maturation surface markers in murine dendritic cells

    DEFF Research Database (Denmark)

    Christensen, Hanne Risager; Frøkiær, Hanne; Pestka, J.J.

    2002-01-01

    Dendritic cells (DC) play a pivotal immunoregulatory role in the Th1, Th2, and Th3 cell balance and are present throughout the gastrointestinal tract. Thus, DC may be targets for modulation by gut microbes, including ingested probiotics. In the present study, we tested the hypothesis that species...... among strains in the capacity to induce IL-12 and TNF-a production in the DC. Similar but less pronounced differences were observed among lactobacilli in the induction of IL-6 and IL-10. Although all strains up-regulated surface MHC class II and B7-2 (CD86), which is indicative of DC maturation, those...... lactobacilli with greatest capacity to induce IL-12 were most effective. Remarkably, Lactobacillus reuteri DSM12246, a poor IL-12 inducer, inhibited IL-12, IL-6, and TNF-alpha induction by the otherwise strong cytokine inducer L. casei CHCC3139, while IL-10 production remained unaltered. In analogous fashion...

  4. Separate Developmental Programs for HLA-A and -B Cell Surface Expression during Differentiation from Embryonic Stem Cells to Lymphocytes, Adipocytes and Osteoblasts

    DEFF Research Database (Denmark)

    Sabir, Hardee J; Nehlin, Jan O; Qanie, Diyako;

    2013-01-01

    A major problem of allogeneic stem cell therapy is immunologically mediated graft rejection. HLA class I A, B, and Cw antigens are crucial factors, but little is known of their respective expression on stem cells and their progenies. We have recently shown that locus-specific expression (HLA-A, but...... not -B) is seen on some multipotent stem cells, and this raises the question how this is in other stem cells and how it changes during differentiation. In this study, we have used flow cytometry to investigate the cell surface expression of HLA-A and -B on human embryonic stem cells (hESC), human...... hematopoietic stem cells (hHSC), human mesenchymal stem cells (hMSC) and their fully-differentiated progenies such as lymphocytes, adipocytes and osteoblasts. hESC showed extremely low levels of HLA-A and no -B. In contrast, multipotent hMSC and hHSC generally expressed higher levels of HLA-A and clearly HLA...

  5. Ric-3 chaperone-mediated stable cell-surface expression of the neuronal a7 nicotinic acetylcholine receptor in mammalian cells

    Institute of Scientific and Technical Information of China (English)

    Ana Sofia VALLfiS; Ana M ROCCAMO; Francisco J BARRANTES

    2009-01-01

    Aim: Studies of the a7-type neuronal nicotinic acetylcholine receptor (AChR), one of the receptor forms involved in many physiologically relevant processes in the central nervous system, have been hampered by the inability of this homomeric protein to assemble in most heterologous expression systems. In a recent study, it was shown that the chaperone Ric-3 is necessary for the maturation and functional expression of a7-type AChRs'11. The current work aims at obtaining and characterizing a cell line with high functional expression of the human a7 AChR.Methods: Ric-3 cDNA was incorporated into SHE-Pl-ha7 cells expressing the a7-type AChR. Functional studies were undertaken using single-channel patch-clamp recordings. Equilibrium and kinetic [125I]a-bungarotoxin binding assays, as well as fluorescence microscopy using fluorescent a-bungarotoxin, anti-a7 antibody, and GFP-a7 were performed on the new clone.Results: The human a7-type AChR was stably expressed in a new cell line, which we coined SHE-PI-ha7-Ric-3, by co-expression of the chaperone Ric-3. Cell-surface AChRs exhibited [125I]aBTX saturable binding with an apparent KD of about 55 nmol/L. Fluorescence microscopy revealed dispersed and micro-clustered AChR aggregates at the surface of SHE-PI-ha7-Ric-3 cells. Larger micron-sized clusters were observed in the absence of receptor-clustering proteins or upon aggregation with anti-a7 antibodies, hi contrast, chaperone-less SHE-PI-ha7 cells expressed only intracellular a.7 AChRs and failed to produce detectable single-channel currents.Conclusion: The production of a stable and functional cell line of neuroepithelial lineage with robust cell-surface expression of neuronal a7-type AChR, as reported here, constitutes an important advance in the study of homomeric receptors in mammalian cells.

  6. Cloning, protein expression and display of synthetic multi-epitope mycobacterial antigens on Salmonella typhi Ty21a cell surface.

    Science.gov (United States)

    Sarhan, Mohammed A A; Musa, Mustaffa; Zainuddin, Zainul F

    2011-09-01

    Expressing proteins of interest as fusion to proteins of bacterial envelope is a powerful technique for biotechnological and medical applications. The synthetic gene (VacII) encoding for T-cell epitopes of selected genes of Mycobacterium tuberculosis namely, ESAT6, MTP40, 38 kDa, and MPT64 was fused with N- terminus of Pseudomonas syringae ice nucleation protein (INP) outer membrane protein. The fused genes were cloned into a bacterial expression vector pKK223-3. The recombinant protein was purified by Ni-NAT column. VacII gene was displayed on the cell surface of Salmonella typhi Ty21a using N-terminal region of ice nucleation proteins (INP) as an anchoring motif. Glycine method confirmed that VacII was anchored on the cell surface. Western blot analysis further identified the synthesis of INP derivatives containing the N-terminal domain INP- VacII fusion protein of the expected size (52 kDa). PMID:21941936

  7. Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases.

    Science.gov (United States)

    Liu, Jin; Tan, Luming; Wang, Jing; Wang, Zhiyong; Ni, Hong; Li, Lin

    2016-08-01

    The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 °C) without the need for Cu(2+). Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice. PMID:27231878

  8. RANKL downregulates cell surface CXCR6 expression through JAK2/STAT3 signaling pathway during osteoclastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Changhong; Zhao, Jinxia; Sun, Lin; Yao, Zhongqiang; Liu, Rui [Department of Rheumatology and Immunology, Peking University Third Hospital, Beijing 100191 (China); Huang, Jiansheng [Department of Pediatrics, Washington University School of Medicine, St. Louis, MO (United States); Liu, Xiangyuan, E-mail: liu-xiangyuan@263.net [Department of Rheumatology and Immunology, Peking University Third Hospital, Beijing 100191 (China)

    2012-12-14

    Highlights: Black-Right-Pointing-Pointer CXCR6 is down-regulated during RANKL-induced osteoclastogenesis in RAW264.7 cells. Black-Right-Pointing-Pointer CXCR6 reduction was nearly reversed by inhibition of JAK2/STAT3 signaling pathway. Black-Right-Pointing-Pointer CXCL16 alone does not positively regulate osteoclastogenesis. -- Abstract: The receptor activator of nuclear factor-{kappa}B ligand (RANKL), as a member of the tumor necrosis factor (TNF) family, plays an essential role in osteoclast differentiation and function. Chemokines and their receptors have recently been shown to play critical roles in osteoclastogenesis, however, whether CXCL16-CXCR6 plays role in RANKL-mediated osteoclastogenesis is unknown. In this study, we first reported that RANKL decreased CXCR6 in a dose-dependent manner, which may be through deactivation of Akt and STAT3 signaling induced by CXCL16. Interestingly, RANKL-mediated CXCR6 reduction may be associated to the activation of STAT3 by phosphorylation. When STAT3 activation was blocked by JAK2/STAT3 inhibitor AG490, RANKL failed to shut down CXCR6 expression during osteoclastogenesis. However, CXCL16 alone did not augment RANKL-mediated osteoclast differentiation and did not alter RANKL-receptor RANK mRNA expression. These results demonstrate that reduction of CXCL16-CXCR6 is critical in RANKL-mediated osteoclastogenesis, which is mainly through the activation of JAK2/STAT3 signaling. CXCL16-CXCR6 axis may become a novel target for the therapeutic intervention of bone resorbing diseases such as rheumatoid arthritis and osteoporosis.

  9. Inefficient assembly limits transport and cell surface expression of HLA-Cw4 molecules in C1R.

    Science.gov (United States)

    Zemmour, J

    1996-12-01

    HLA-C antigens are expressed to the cell surface at roughly 10% the level of HLA-B or -A, and their serological definition remains persistently difficult. To characterize the factors limiting surface expression, the processes of assembly and intracellular transport of HLA-Cw4 molecules were investigated in the C1R cell line. When appropriate peptides were added to cultured cells or in cell lysates significant amounts of conformed HLA-C molecules that associate with beta 2-microglobulin (beta 2 m) are detected, but are indeed not sufficient to restore expression to the level observed for HLA-A or -B molecules. Furthermore, a precursor/product relationship exists between the free class I heavy chain and the mature conformation of HLA-Cw4 molecules. Thus, HLA-C assembly promotes the conversion of HC-10-reactive molecules (weakly-beta 2m-associated non-ligand associated free HC form) into the beta 2m-associated class I molecules recognized by W6/32. To further investigate the factors that regulate cell surface expression, intracellular transport of HLA-Cw4 was studied in pulse chase analysis. In contrast to some HLA-A and B, maturation of HLA-Cw4 heavy chains and their export to the medial and trans-Golgi compartments are quite inefficient. After 4 h of chase period, roughly half of the pulse-labeled HLA-Cw4 molecules have transited to the medial-Golgi and acquired complex oligosaccharides characteristic of mature form. In addition, treatment with gamma-interferon does not appear to improve maturation of HLA-Cw4 heavy chains, suggesting that increased supply of peptides does not influence intracellular transport. Moreover, only a small fraction in the pool of HLA-Cw4 molecules was subsequently transported through the trans-Golgi network, as indicated by their acquisition of sialic acids. Taken together these studies show that HLA-Cw4 molecules are inefficiently transported through the Golgi apparatus and presumably retained in the endoplasmic reticulum or cis

  10. Assembly, intracellular processing, and expression at the cell surface of the human alpha beta T cell receptor/CD3 complex. Function of the CD3-zeta chain

    DEFF Research Database (Denmark)

    Geisler, C; Kuhlmann, J; Rubin, B

    1989-01-01

    complex, the role of the CD3 chains for the TCR/CD3 expression have not been experimentally addressed in human T cells. In this study the function of the CD3-zeta chain for the assembly, intracellular processing, and expression of the TCR/CD3 complex in the human leukemic T cell line Jurkat was......The TCR/CD3 complex is a multimeric protein complex composed of a minimum of seven transmembrane chains (TCR alpha beta-CD3 gamma delta epsilon zeta 2). Whereas earlier studies have demonstrated that both the TCR-alpha and -beta chains are required for the cell surface expression of the TCR/CD3...... investigated. The results indicate that: 1) CD3-zeta is required for the cell surface expression of the TCR/CD3 complex; 2) the pentameric form (TCR alpha beta-CD3 gamma delta epsilon) of the TCR/CD3 complex and single TCR chains associated with CD3 (TCR alpha-CD3 gamma delta epsilon and TCR beta-CD3 gamma...

  11. Diurnal variation of tight junction integrity associates inversely with matrix metalloproteinase expression in Xenopus laevis corneal epithelium: implications for circadian regulation of homeostatic surface cell desquamation.

    Directory of Open Access Journals (Sweden)

    Allan F Wiechmann

    Full Text Available The corneal epithelium provides a protective barrier against pathogen entrance and abrasive forces, largely due to the intercellular junctional complexes between neighboring cells. After a prescribed duration at the corneal surface, tight junctions between squamous surface cells must be disrupted to enable them to desquamate as a component of the tissue homeostatic renewal. We hypothesize that matrix metalloproteinase (MMPs are secreted by corneal epithelial cells and cleave intercellular junctional proteins extracellularly at the epithelial surface. The purpose of this study was to examine the expression of specific MMPs and tight junction proteins during both the light and dark phases of the circadian cycle, and to assess their temporal and spatial relationships in the Xenopus laevis corneal epithelium.Expression of MMP-2, tissue inhibitor of MMP-2 (TIMP-2, membrane type 1-MMP (MT1-MMP and the tight junction proteins occludin and claudin-4 were examined by confocal double-label immunohistochemistry on corneas obtained from Xenopus frogs at different circadian times. Occludin and claudin-4 expression was generally uniformly intact on the surface corneal epithelial cell lateral membranes during the daytime, but was frequently disrupted in small clusters of cells at night. Concomitantly, MMP-2 expression was often elevated in a mosaic pattern at nighttime and associated with clusters of desquamating surface cells. The MMP-2 binding partners, TIMP-2 and MT1-MMP were also localized to surface corneal epithelial cells during both the light and dark phases, with TIMP-2 tending to be elevated during the daytime.MMP-2 protein expression is elevated in a mosaic pattern in surface corneal epithelial cells during the nighttime in Xenopus laevis, and may play a role in homeostatic surface cell desquamation by disrupting intercellular junctional proteins. The sequence of MMP secretion and activation, tight junction protein cleavage, and subsequent surface

  12. Method of rapid production of hybridomas expressing monoclonal antibodies on the cell surface

    Science.gov (United States)

    Meagher, Richard B.; Laterza, Vince

    2006-12-12

    The present invention relates to genetically altered hybridomas, myelomas and B cells. The invention also relates to utilizing genetically altered hybridomas, myelomas and B cells in methods of making monoclonal antibodies. The present invention also provides populations of hybridomas and B cells that can be utilized to make a monoclonal antibody of interest.

  13. Depletion of the surface CD4 molecule by the envelope protein of human immunodeficiency virus expressed in a human CD4+ monocytoid cell line

    International Nuclear Information System (INIS)

    A CD4+ human monocytoid cell line, U937, was transfected with a constructed plasmid which has the envelope gene of human immunodeficiency virus under the transcriptional control of the human metallothionein IIA promoter and was cloned thereafter. These cloned cell lines (EH and EL cells) expressed the viral gp160 in the cytoplasm. The expression of surface CD4 antigen examined by Leu3a and OKT4 monoclonal antibodies, however, disappeared completely in EH cells, which produce a larger amount of gp160, while diminishing only partly in EL cells, which produce a smaller amount of gp160. These results indicate that the level of expression of surface CD4 antigen correlates inversely with the amount of intracellular gp160. Moreover, immunoprecipitation studies using lysate from EH cells showed that OKT4 monoclonal antibody precipitated a significant number of CD4 molecules even after surface CD4 disappeared. However, Leu3a monoclonal antibody, which recognizes the binding site for envelope protein, could not precipitate any CD4 molecules in the same cell lysate. Taken together, these results suggested that CD4 molecules are still synthesized normally after the augmented production of gp160 in the cells but form a complex with the envelope protein in the cytoplasm and become unable to be transported to the cell surface, resulting in the observed depletion of surface CD4 antigen. This mechanism may explain the decrease or absence of surface CD4 antigens in human lymphocytes infected with human immunodeficiency virus

  14. Plasmodium falciparum parasites expressing pregnancy-specific variant surface antigens adhere strongly to the choriocarcinoma cell line BeWo

    DEFF Research Database (Denmark)

    Haase, Rikke N; Megnekou, Rosette; Lundquist, Maja; Ofori, Michael F; Hviid, Lars; Staalsoe, Trine

    2006-01-01

    Placenta-sequestering Plasmodium falciparum parasites causing pregnancy-associated malaria express pregnancy-specific variant surface antigens (VSA(PAM)). We report here that VSA(PAM)-expressing patient isolates adhere strongly to the choriocarcinoma cell line BeWo and that the BeWo line can be...

  15. Position 97 of HLA-B, a residue implicated in ankylosing spondylitis pathogenesis, plays a key role in cell surface free heavy chain expression

    OpenAIRE

    Chen, L.; Shi, H; Yuan, J; Bowness, P.

    2016-01-01

    Objective: Association of position 97 (P97) residue polymorphisms in human leukocyte antigen (HLA)-B, including HLA-B*27, with Ankylosing Spondylitis (AS) has recently been reported. We studied the effect of P97 variations on cell surface expression of the AS-associated HLA-B*27 and HLA-B*51, and the AS-protective HLA-B*7. Methods: Flow cytometry was used to measure surface expression of HLA-B*27 in C1R/HeLa cells expressing HLA-B*27 (N97) and six mutants at P97 (N97T, N9...

  16. Akt-mediated regulation of antidepressant-sensitive serotonin transporter function, cell-surface expression and phosphorylation

    DEFF Research Database (Denmark)

    Rajamanickam, Jeyaganesh; Annamalai, Balasubramaniam; Rahbek-Clemmensen, Troels; Sundaramurthy, Santhanalakshmi; Gether, Ulrik; Jayanthi, Lankupalle D; Ramamoorthy, Sammanda

    2015-01-01

    The serotonin [5-HT (5-hydroxytryptamine)] transporter (SERT) controls serotonergic neurotransmission in the brain by rapid clearance of 5-HT from the synaptic cleft into presynaptic neurons. SERTs are primary targets for antidepressants for therapeutic intervention of mood disorders. Our previous...... studies have identified the involvement of several signalling pathways and protein kinases in regulating SERT function, trafficking and phosphorylation. However, whether Akt/PKB (protein kinase) regulates SERT function is not known. In the present study, we made the novel observation that inhibition of...... basal phosphorylation. Our results provide evidence that Akt regulates SERT function and cell-surface expression by regulating the intracellular SERT distribution and plasma membrane availability, which perhaps may be linked to SERT phosphorylation state. Thus any changes in the activation of Akt and...

  17. Cloning and expression of the receptor for human urokinase plasminogen activator, a central molecule in cell surface, plasmin dependent proteolysis

    DEFF Research Database (Denmark)

    Roldan, A L; Cubellis, M V; Masucci, M T;

    1990-01-01

    The surface receptor for urokinase plasminogen activator (uPAR) has been recognized in recent years as a key molecule in regulating plasminogen mediated extracellular proteolysis. Surface plasminogen activation controls the connections between cells, basement membrane and extracellular matrix, an...

  18. Potential role of nuclear PD-L1 expression in cell-surface vimentin positive circulating tumor cells as a prognostic marker in cancer patients.

    Science.gov (United States)

    Satelli, Arun; Batth, Izhar Singh; Brownlee, Zachary; Rojas, Christina; Meng, Qing H; Kopetz, Scott; Li, Shulin

    2016-01-01

    Although circulating tumor cells (CTCs) have potential as diagnostic biomarkers for cancer, determining their prognostic role in cancer patients undergoing treatment is a challenge. We evaluated the prognostic value of programmed death-ligand 1 (PD-L1) expression in CTCs in colorectal and prostate cancer patients undergoing treatment. Peripheral blood samples were collected from 62 metastatic colorectal cancer patients and 30 metastatic prostate cancer patients. CTCs were isolated from the samples using magnetic separation with the cell-surface vimentin(CSV)-specific 84-1 monoclonal antibody that detects epithelial-mesenchymal transitioned (EMT) CTCs. CTCs were enumerated and analyzed for PD-L1 expression using confocal microscopy. PD-L1 expression was detectable in CTCs and was localized in the membrane and/or cytoplasm and nucleus. CTC detection alone was not associated with poor progression-free or overall survival in colorectal cancer or prostate cancer patients, but nuclear PD-L1 (nPD-L1) expression in these patients was significantly associated with short survival durations. These results demonstrated that nPD-L1 has potential as a clinically relevant prognostic biomarker for colorectal and prostate cancer. Our data thus suggested that use of CTC-based models of cancer for risk assessment can improve the standard cancer staging criteria and supported the incorporation of nPD-L1 expression detection in CTCs detection in such models. PMID:27363678

  19. Potential role of nuclear PD-L1 expression in cell-surface vimentin positive circulating tumor cells as a prognostic marker in cancer patients

    Science.gov (United States)

    Satelli, Arun; Batth, Izhar Singh; Brownlee, Zachary; Rojas, Christina; Meng, Qing H.; Kopetz, Scott; Li, Shulin

    2016-01-01

    Although circulating tumor cells (CTCs) have potential as diagnostic biomarkers for cancer, determining their prognostic role in cancer patients undergoing treatment is a challenge. We evaluated the prognostic value of programmed death-ligand 1 (PD-L1) expression in CTCs in colorectal and prostate cancer patients undergoing treatment. Peripheral blood samples were collected from 62 metastatic colorectal cancer patients and 30 metastatic prostate cancer patients. CTCs were isolated from the samples using magnetic separation with the cell-surface vimentin(CSV)-specific 84-1 monoclonal antibody that detects epithelial-mesenchymal transitioned (EMT) CTCs. CTCs were enumerated and analyzed for PD-L1 expression using confocal microscopy. PD-L1 expression was detectable in CTCs and was localized in the membrane and/or cytoplasm and nucleus. CTC detection alone was not associated with poor progression-free or overall survival in colorectal cancer or prostate cancer patients, but nuclear PD-L1 (nPD-L1) expression in these patients was significantly associated with short survival durations. These results demonstrated that nPD-L1 has potential as a clinically relevant prognostic biomarker for colorectal and prostate cancer. Our data thus suggested that use of CTC-based models of cancer for risk assessment can improve the standard cancer staging criteria and supported the incorporation of nPD-L1 expression detection in CTCs detection in such models. PMID:27363678

  20. Lactobacilli differentially modulate expression of cytokines and maturation surface markers in murine dendritic cells

    DEFF Research Database (Denmark)

    Christensen, Hanne Risager; Frøkiær, Hanne; Pestka, J.J.

    2002-01-01

    Dendritic cells (DC) play a pivotal immunoregulatory role in the Th1, Th2, and Th3 cell balance and are present throughout the gastrointestinal tract. Thus, DC may be targets for modulation by gut microbes, including ingested probiotics. In the present study, we tested the hypothesis that species...... of Lactobacillus, important members of the gut flora, differentially activate DC. Bone marrow-derived murine DC were exposed to various lethally irradiated Lactobacillus spp. and resultant culture supernatants were analyzed for IL-6, IL-10, IL-12, and TNF-alpha. Substantial differences were found...

  1. Gene expression profiling supports the hypothesis that human ovarian surface epithelia are multipotent and capable of serving as ovarian cancer initiating cells

    Directory of Open Access Journals (Sweden)

    Matyunina Lilya V

    2009-12-01

    Full Text Available Abstract Background Accumulating evidence suggests that somatic stem cells undergo mutagenic transformation into cancer initiating cells. The serous subtype of ovarian adenocarcinoma in humans has been hypothesized to arise from at least two possible classes of progenitor cells: the ovarian surface epithelia (OSE and/or an as yet undefined class of progenitor cells residing in the distal end of the fallopian tube. Methods Comparative gene expression profiling analyses were carried out on OSE removed from the surface of normal human ovaries and ovarian cancer epithelial cells (CEPI isolated by laser capture micro-dissection (LCM from human serous papillary ovarian adenocarcinomas. The results of the gene expression analyses were randomly confirmed in paraffin embedded tissues from ovarian adenocarcinoma of serous subtype and non-neoplastic ovarian tissues using immunohistochemistry. Differentially expressed genes were analyzed using gene ontology, molecular pathway, and gene set enrichment analysis algorithms. Results Consistent with multipotent capacity, genes in pathways previously associated with adult stem cell maintenance are highly expressed in ovarian surface epithelia and are not expressed or expressed at very low levels in serous ovarian adenocarcinoma. Among the over 2000 genes that are significantly differentially expressed, a number of pathways and novel pathway interactions are identified that may contribute to ovarian adenocarcinoma development. Conclusions Our results are consistent with the hypothesis that human ovarian surface epithelia are multipotent and capable of serving as the origin of ovarian adenocarcinoma. While our findings do not rule out the possibility that ovarian cancers may also arise from other sources, they are inconsistent with claims that ovarian surface epithelia cannot serve as the origin of ovarian cancer initiating cells.

  2. β1- and β3- voltage-gated sodium channel subunits modulate cell surface expression and glycosylation of Nav1.7 in HEK293 cells

    Directory of Open Access Journals (Sweden)

    Ninda Syam

    2013-08-01

    Full Text Available Voltage-gated sodium channels (Navs are glycoproteins composed of a pore-forming α-subunit and associated β-subunits that regulate Nav α-subunit plasma membrane density and biophysical properties. Glycosylation of the Nav α-subunit also directly affects Navs gating. β-subunits and glycosylation thus comodulate Nav α-subunit gating. We hypothesized that β-subunits could directly influence α-subunit glycosylation. Whole-cell patch clamp of HEK293 cells revealed that both β1- and β3-subunits coexpression shifted V1/2 of steady-state activation and inactivation and increased Nav1.7-mediated INa density. Biotinylation of cell surface proteins, combined with the use of deglycosydases, confirmed that Nav1.7 α-subunits exist in multiple glycosylated states. The α-subunit intracellular fraction was found in a core-glycosylated state, migrating at approximately 250 kDa. At the plasma membrane, in addition to the core-glycosylated form, a fully glycosylated form of Nav1.7 (~280 kDa was observed. This higher band shifted to an intermediate band (~260 kDa when β1-subunits were coexpressed, suggesting that the β1-subunit promotes an alternative glycosylated form of Nav1.7. Furthermore, the β1-subunit increased the expression of this alternative glycosylated form and the β3-subunit increased the expression of the core-glycosylated form of Nav1.7. This study describes a novel role for β1- and β3-subunits in the modulation of Nav1.7 α-subunit glycosylation and cell surface expression.

  3. Boronic acid recognition based-gold nanoparticle-labeling strategy for the assay of sialic acid expression on cancer cell surface by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Zhang, Xing; Chen, Beibei; He, Man; Zhang, Yuan; Peng, Lu; Hu, Bin

    2016-02-01

    Sialic acids are special sugars widely expressed at the termini of glycan chains on the cell surface, and their expression level on the cancer cell surface is much higher than on the normal cell surface. Herein, we reported an inductively coupled plasma mass spectrometry (ICP-MS) based method with elemental tags for the analysis of sialic acids on the cancer cell surface. The method is based on the selective recognition of sialic acids by biotinylated phenylboronic acid (biotin-APBA) at physiological pH and signal enhancement of gold nanoparticles (AuNPs) in ICP-MS when AuNPs were used as elemental tags labeled on biotin-APBA. A specificity test reveals that the proposed method has high specificity towards cancer cells. Taking HepG2 and MCF-7 cells as two model cancer cells, competitive experiments were performed to estimate the expression level of sialic acids on the cancer cell surface, and it was found that the average numbers of sialic acids expressed on the single MCF-7 and HepG2 cell surface were 7.0 × 10(9) and 5.4 × 10(9), respectively. With sialic acid as the biomarker for cancer cells, the method was further used for cell detection. The limits of detection in terms of cell number for HepG2 and MCF-7 cells were 120 and 64, respectively. And the relative standard deviations for nine replicate determinations of ca. 1000 HepG2 and MCF-7 cells were 9.6% and 8.9%, respectively. The linear ranges for HepG2 cells and MCF-7 cells were 300-10 000 and 170-11 000, respectively. The proposed approach is sensitive as well as selective for the analysis of sialic acids on the cancer cell surface, and is potentially applicable for the study of tumor malignancy and metastasis, which is helpful for biological research and clinical diagnostics. PMID:26811850

  4. Natural suppressor (NS) cells found in the spleen of neonatal mice and adult mice given total lymphoid irradiation (TLI) express the null surface phenotype

    International Nuclear Information System (INIS)

    The authors studied the surface markers of suppressor cells of the mixed leukocyte reaction (MLR) that are transiently present in the spleens of neonatal mice after birth and of adult mice after total lymphoid irradiation (TLI). Approximately 80% of the mononuclear cells in the spleen, within the first few days after birth or after TLI, express neither the Thy-1 antigen nor surface immunoglobulin (Ig). After 30 days, less than 20% of mononuclear cells bear this null phenotype. With the use of the panning technique, they showed that the suppressors of the MLR are confined to the null cell population. The null suppressor cells are not macrophages because they did not carry macrophage markers identified by the monoclonal antibodies anti-MAC-1 and F4/80. In addition, the suppressor cells did not stain for nonspecific esterase and did not adhere firmly to plastic or glass. Spleen cells from TLI-treated mice maintained their suppressive capacity after culture in vitro for 6 to 8 wk. The cultured suppressor cells did not develop mature T cell, B cell, or macrophage markers during this time interval. Thus, the suppressor cells did not appear to be precursors of the latter cells. The suppressor cells are similar to NK cells in that both are found in the absence of antigenic challenge, lack antigen specificity, and bear the null surface phenotype. Thus, they have termed the former cells natural suppressor (NS) cells

  5. Comparison of cell wall proteins of Saccharomyces cerevisiae as anchors for cell surface expression of heterologous proteins.

    OpenAIRE

    van der Vaart, J. M.; te Biesebeke, R; Chapman, J.W.; Toschka, H Y; Klis, F M; Verrips, C. T.

    1997-01-01

    The carboxyl-terminal regions of five cell wall proteins (Cwp1p, Cwp2p, Ag alpha 1p, Tip1p, and Flo1p) and three potential cell wall proteins (Sed1p, YCR89w, and Tir1p) all proved capable of immobilizing alpha-galactosidase in the cell wall of Saccharomyces cerevisiae. The fraction of the total amount of fusion protein that was localized to the cell wall varied depending on the anchor domain used. The highest proportion of cell wall incorporation was achieved with Cwp2p, Ag alpha 1p, or Sed1p...

  6. Discovering Aptamers by Cell-SELEX against Human Soluble Growth Factors Ectopically Expressed on Yeast Cell Surface

    OpenAIRE

    Hsien-Wei Meng; Pagano, John M.; White, Brian S.; Yoshiko Toyoda; Min, Irene M.; Craighead, Harold G; David Shalloway; Lis, John T.; Kai Xiao; Moonsoo M Jin

    2014-01-01

    SELEX, the process of selecting aptamers, is often hampered by the difficulty of preparing target molecules in their native forms and by a lack of a simple yet quantitative assay for monitoring enrichment and affinity of reactive aptamers. In this study, we sought to discover DNA aptamers against human serum markers for potential therapeutic and diagnostic applications. To circumvent soluble expression and immobilization for performing SELEX, we ectopically expressed soluble growth factors on...

  7. Upregulated baseline plasma CCL19 and CCR7 cell-surface expression on monocytes in early rheumatoid arthritis normalized during treatment and CCL19 correlated with radiographic progression

    DEFF Research Database (Denmark)

    Ellingsen, T; Hansen, I; Thorsen, J;

    2014-01-01

    OBJECTIVES: The aim of this study was to measure, in early rheumatoid arthritis (RA) patients, the concentration of CC-chemokine ligand 19 (CCL19) in plasma and the cell-surface expression of CC-chemokine receptor 7 (CCR7) on circulating monocytes and CD4+ T lymphocytes and to analyse correlations...... with disease activity and 5-year radiographic progression. METHOD: In disease-modifying anti-rheumatic drug (DMARD)-naïve RA patients (disease duration < 6 months), we measured plasma CCL19 by enzyme-linked immunosorbent assay (ELISA) (n = 160) and CCR7 cell-surface expression on monocytes and CD4+ T......-naïve RA patients, CCL19 plasma level and CCR7 surface expression on monocytes were upregulated and normalized after 1 year of treatment. Increased baseline plasma CCL19 level, anti-CCP antibody status, and TSS > 0 at baseline correlated independently with 5-year radiographic progression....

  8. An Innovative Method to Identify Autoantigens Expressed on the Endothelial Cell Surface: Serological Identification System for Autoantigens Using a Retroviral Vector and Flow Cytometry (SARF

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Shirai

    2013-01-01

    Full Text Available Autoantibodies against integral membrane proteins are usually pathogenic. Although anti-endothelial cell antibodies (AECAs are considered to be critical, especially for vascular lesions in collagen diseases, most molecules identified as autoantigens for AECAs are localized within the cell and not expressed on the cell surface. For identification of autoantigens, proteomics and expression library analyses have been performed for many years with some success. To specifically target cell-surface molecules in identification of autoantigens, we constructed a serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF. Here, we present an overview of recent research in AECAs and their target molecules and discuss the principle and the application of SARF. Using SARF, we successfully identified three different membrane proteins: fibronectin leucine-rich transmembrane protein 2 (FLRT2 from patients with systemic lupus erythematosus (SLE, intercellular adhesion molecule 1 (ICAM-1 from a patient with rheumatoid arthritis, and Pk (Gb3/CD77 from an SLE patient with hemolytic anemia, as targets for AECAs. SARF is useful for specific identification of autoantigens expressed on the cell surface, and identification of such interactions of the cell-surface autoantigens and pathogenic autoantibodies may enable the development of more specific intervention strategies in autoimmune diseases.

  9. Activation of human naïve Th cells increases surface expression of GD3 and induces neoexpression of GD2 that colocalize with TCR clusters.

    Science.gov (United States)

    Villanueva-Cabello, Tania M; Mollicone, Rosella; Cruz-Muñoz, Mario E; López-Guerrero, Delia V; Martínez-Duncker, Iván

    2015-12-01

    CD4+ T helper lymphocytes (Th) orchestrate the immune response after their activation by antigen-presenting cells. Activation of naïve Th cells is reported to generate the reduction in surface epitopes of sialic acid (Sia) in α2,3 and α2,6 linkages. In this work, we report that in spite of this glycophenotype, anti-CD3/anti-CD28-activated purified human naïve Th cells show a significant increase in surface Sia, as assessed by metabolic labeling, compared with resting naïve Th cells, suggesting an increased flux of Sia toward Siaα2,8 glycoconjugates. To understand this increase as a result of ganglioside up-regulation, we observed that very early after activation, human naïve Th cells show an increased expression in surface GD3 and neoexpression of surface GD2 gangliosides, the latter clustering with the T cell receptor (TCR). Also, we report that in contrast to GM2/GD2 synthase null mice, lentiviral vector-mediated silencing of the GM2/GD2 synthase in activated human naïve Th cells reduced efficient TCR clustering and downstream signaling, as assessed by proliferation assays and IL-2 and IL-2R expression, pointing to an important role of this enzyme in activation of human naive Th cells. PMID:26263924

  10. Quantification of differential ErbB1 and ErbB2 cell surface expression and spatial nanoclustering through plasmon coupling.

    Science.gov (United States)

    Wang, Jing; Yu, Xinwei; Boriskina, Svetlana V; Reinhard, Björn M

    2012-06-13

    Cell surface receptors play ubiquitous roles in cell signaling and communication and their expression levels are important biomarkers for many diseases. Expression levels are, however, only one factor that determines the physiological activity of a receptor. For some surface receptors, their distribution on the cell surface, especially their clustering, provides additional mechanisms for regulation. To access this spatial information robust assays are required that provide detailed insight into the organization of cell surface receptors on nanometer length scales. In this manuscript, we demonstrate through combination of scattering spectroscopy, electron microscopy, and generalized multiple particle Mie theory (GMT) simulations that the density- and morphology-dependent spectral response of Au nanoparticle (NP) immunolabels bound to the epidermal growth factor receptors ErbB1 and ErbB2 encodes quantitative information of both the cell surface expression and spatial clustering of the two receptors in different unliganded in vitro cancer cell lines (SKBR3, MCF7, A431). A systematic characterization of the collective spectral responses of NPs targeted at ErbB1 and ErbB2 at various NP concentrations indicates differences in the large-scale organization of ErbB1 and ErbB2 in cell lines that overexpress these receptors. Validation experiments in the scanning electron microscope (SEM) confirm that NPs targeted at ErbB1 on A431 are more strongly clustered than NPs bound to ErbB2 on SKBR3 or MCF7 at overall comparable NP surface densities. This finding is consistent with the existence of larger receptor clusters for ErbB1 than for ErbB2 in the plasma membranes of the respective cells. PMID:22587495

  11. Comparison of cell wall proteins of Saccharomyces cerevisiae as anchors for cell surface expression of heterologous proteins.

    Science.gov (United States)

    Van der Vaart, J M; te Biesebeke, R; Chapman, J W; Toschka, H Y; Klis, F M; Verrips, C T

    1997-01-01

    The carboxyl-terminal regions of five cell wall proteins (Cwp1p, Cwp2p, Ag alpha 1p, Tip1p, and Flo1p) and three potential cell wall proteins (Sed1p, YCR89w, and Tir1p) all proved capable of immobilizing alpha-galactosidase in the cell wall of Saccharomyces cerevisiae. The fraction of the total amount of fusion protein that was localized to the cell wall varied depending on the anchor domain used. The highest proportion of cell wall incorporation was achieved with Cwp2p, Ag alpha 1p, or Sed1p as an anchor. Although 80% of these fusion proteins were incorporated in the cell wall, the total production of alpha-galactosidase-Ag alpha 1p was sixfold lower than that of alpha-galactosidase-Cwp2p and eightfold lower than that of alpha-galactosidase-Sed1p. Differences in mRNA levels were not responsible for this discrepancy, nor was an intracellular accumulation of alpha-galactosidase-Ag alpha 1p detectable. A lower translation efficiency of the alpha-galactosidase-AG alpha 1 fusion construct is most likely to be responsible for the low level of protein production. alpha-Galactosidase immobilized by the carboxyl-terminal 67 amino acids of Cwp2p was most effective in the hydrolysis of the high-molecular-weight substrate guar gum from Cyamopsis tetragonoloba. This indicates that the use of a large anchoring domain does not necessarily result in a better exposure of the immobilized enzyme to the exterior of the yeast cell. PMID:9023939

  12. Impact of Concanavalin-A-Mediated Cytoskeleton Disruption on Low-Density Lipoprotein Receptor-Related Protein-1 Internalization and Cell Surface Expression in Glioblastomas

    Science.gov (United States)

    Nanni, Samuel Burke; Pratt, Jonathan; Beauchemin, David; Haidara, Khadidja; Annabi, Borhane

    2016-01-01

    The low-density lipoprotein receptor-related protein 1 (LRP-1) is a multiligand endocytic receptor, which plays a pivotal role in controlling cytoskeleton dynamics during cancer cell migration. Its rapid endocytosis further allows efficient clearance of extracellular ligands. Concanavalin-A (ConA) is a lectin used to trigger in vitro physiological cellular processes, including cytokines secretion, nitric oxide production, and T-lymphocytes activation. Given that ConA exerts part of its effects through cytoskeleton remodeling, we questioned whether it affected LRP-1 expression, intracellular trafficking, and cell surface function in grade IV U87 glioblastoma cells. Using flow cytometry and confocal microscopy, we found that loss of the cell surface 600-kDa mature form of LRP-1 occurs upon ConA treatment. Consequently, internalization of the physiological α2-macroglobulin and the synthetic angiopep-2 ligands of LRP-1 was also decreased. Silencing of known mediators of ConA, such as the membrane type-1 matrix metalloproteinase, and the Toll-like receptors (TLR)-2 and TLR-6 was unable to rescue ConA-mediated LRP-1 expression decrease, implying that the loss of LRP-1 was independent of cell surface relayed signaling. The ConA-mediated reduction in LRP-1 expression was emulated by the actin cytoskeleton-disrupting agent cytochalasin-D, but not by the microtubule inhibitor nocodazole, and required both lysosomal- and ubiquitin-proteasome system-mediated degradation. Our study implies that actin cytoskeleton integrity is required for proper LRP-1 cell surface functions and that impaired trafficking leads to specialized compartmentation and degradation. Our data also strengthen the biomarker role of cell surface LRP-1 functions in the vectorized transport of therapeutic angiopep bioconjugates into brain cancer cells.

  13. Distribution and levels of cell surface expression of CD33 and CD123 in acute myeloid leukemia

    International Nuclear Information System (INIS)

    Owing to the more recent positive results with the anti-CD33 immunotoxin gemtuzumab ozogamicin, therapy against acute myeloid leukemias (AMLs) targeting CD33 holds many promises. Here, CD33 and CD123 expression on AML blasts was studied by flow cytometry in a cohort of 319 patients with detailed information on French–American–British/World Health Organization (FAB/WHO) classification, cytogenetics and molecular aberrations. AMLs of 87.8% express CD33 and would therefore be targetable with anti-CD33 therapies. Additionally, 9.4% of AMLs express CD123 without concomitant CD33 expression. Thus, nearly all AMLs could be either targeted via CD33 or CD123. Simultaneous presence of both antigens was observed in 69.5% of patients. Most importantly, even AMLs with adverse cytogenetics express CD33 and CD123 levels comparable to those with favorable and intermediate subtypes. Some patient groups with unfavorable alterations, such as FMS-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations, high FLT3-ITD mutant/wild-type ratios and monosomy 5 are even characterized by high expression of CD33 and CD123. In addition, blasts of patients with mutant nucleophosmin (NPM1) revealed significantly higher CD33 and CD123 expression pointing toward the possibility of minimal residual disease-guided interventions in mutated NPM1-positive AMLs. These results stimulate the development of novel concepts to redirect immune effector cells toward CD33- and CD123-expressing blasts using bi-specific antibodies or engineered T cells expressing chimeric antigen receptors

  14. Effects of the nanotopographic surface structure of commercially pure titanium following anodization–hydrothermal treatment on gene expression and adhesion in gingival epithelial cells

    International Nuclear Information System (INIS)

    The long-term stability and maintenance of endosseous implants with anodized–hydrothermally treated commercially pure titanium surfaces and a nanotopographic structure (SA-treated c.p.Ti) depend on the barrier function provided by the interface between the transmucosal portion of the implant surface and the peri-implant epithelium. This study investigated the effects of extracellular and intracellular gene expression in adherent gingival epithelial cells cultured for 1–7 days on SA-treated c.p.Ti implant surfaces compared to anodic oxide (AO) c.p.Ti and c.p.Ti disks. Scanning electron microscopy (SEM) showed filopodium-like extensions bound closely to the nanotopographic structure of SA-treated c.p.Ti at day 7 of culture. Gene expressions of focal adhesion kinase, integrin-α6β4, and laminin-5 (α3, β3, γ2) were significantly higher on SA-treated c.p.Ti than on c.p.Ti or AO c.p.Ti after 7 days (P < 0.05). Our results confirmed that gingival epithelial cells adhere to SA-treated c.p.Ti as the transmucosal portion of an implant, and that this interaction markedly improves expression of focal adhesion molecules and enhances the epithelial cell phenotype. The cellular gene expression responses driving extracellular and intracellular molecular interactions thus play an important role in maintenance at the interface between SA-treated c.p.Ti implant surfaces and the gingival epithelial cells. - Highlights: • SA-treated Ti provides a nanotopographic structure for clinical oral implants. • This could regulate integrin-mediated epithelial cell adhesion and gene expression. • FAK mRNA was significantly higher on SA-treated Ti. • Integrin-α6β4 and laminin-5 mRNA were significantly higher on SA-treated Ti. • Extracellular/intracellular molecular interactions play a key role on SA-treated Ti

  15. Pneumococal Surface Protein A (PspA Regulates Programmed Death Ligand 1 Expression on Dendritic Cells in a Toll-Like Receptor 2 and Calcium Dependent Manner.

    Directory of Open Access Journals (Sweden)

    Mohit Vashishta

    Full Text Available Pneumonia leads to high mortality in children under the age of five years worldwide, resulting in close to 20 percent of all deaths in this age group. Therefore, investigations into host-pathogen interactions during Streptococcus pneumoniae infection are key in devising strategies towards the development of better vaccines and drugs. To that end, in this study we investigated the role of S. pneumoniae and its surface antigen Pneumococcal surface protein A (PspA in modulating the expression of co-stimulatory molecule Programmed Death Ligand 1 (PD-L1 expression on dendritic cells (DCs and the subsequent effects of increased PD-L1 on key defence responses. Our data indicate that stimulation of DCs with PspA increases the surface expression of PD-L1 in a time and dose dependent manner. Characterization of mechanisms involved in PspA induced expression of PD-L1 indicate the involvement of Toll-Like Receptor 2 (TLR2 and calcium homeostasis. While calcium release from intracellular stores positively regulated PD-L1 expression, calcium influx from external milieu negatively regulated PD-L1 expression. Increase in PD-L1 expression, when costimulated with PspA and through TLR2 was higher than when stimulated with PspA or through TLR2. Further, knockdown of TLR2 and the intermediates in the TLR signaling machinery pointed towards the involvement of a MyD88 dependent pathway in PspA induced PD-L1 expression. Incubation of DCs with S. pneumoniae resulted in the up-regulation of PD-L1 expression, while infection with a strain lacking surface PspA failed to do so. Our data also suggests the role of PspA in ROS generation. These results suggest a novel and specific role for PspA in modulating immune responses against S. pneumoniae by regulating PD-L1 expression.

  16. Whole-Genome Expression Analysis of Human Mesenchymal Stromal Cells Exposed to Ultrasmooth Tantalum vs. Titanium Oxide Surfaces

    DEFF Research Database (Denmark)

    Stiehler, C.; Bunger, C.; Overall, R. W.;

    2013-01-01

    Durable osseointegration of metallic bone implants requires that progenitor cells attach, proliferate and differentiate on the implant surface. Previously, we demonstrated superior biocompatibility of human mesenchymal stromal cells (MSCs) cultivated on ultrasmooth tantalum (Ta) as compared to...... MSCs cultivated on plain sputter-coated surfaces of Ta or Ti for 1, 2, 4, and 8 days were hybridized to n = 16 U133 Plus 2.0 arrays (Affymetrix(A (R))). Functional annotation, cluster and pathway analyses were performed. The vast majority of genes were differentially regulated after 4 days of...

  17. Differential expression of cell surface markers in response to 2,4-dinitrofluorobenzene in RAW 264.7 and primary immune cells

    Directory of Open Access Journals (Sweden)

    Dongbum Kim1, Min Chul Park1, Byoung Kwon Park1, Sanghoon Kwon2, Joon-Ho Choi3, Hyun-Jong Kim4, Soo-Young Choi5, Jinseu Park5, Younghee Lee6 & Hyung-Joo Kwon1,2,*

    2012-09-01

    Full Text Available We evaluated the expression of the costimulatory moleculesCD80 and CD83 and major histocompatibility (MHC class IIinduced by 2,4-dinitrofluorobenzene (DNFB in the RAW264.7 macrophage cell line. In contrast to the previously reportedeffect of DNFB on dendritic cells, CD86 expression didnot change. Furthermore, we observed that the CD83 expressionlevel transiently increased and then decreased.Induction of CD80 and MHC class II molecule expression anda decrease in CD83 expression by DNFB in vitro were alsoconfirmed in splenocytes of BALB/c and NC/Nga mice.However, DNFB did not influence CD83 expression in peritonealCD11b+ cells from BALB/c or NC/Nga mice. Detailedin vivo experiments and further studies on the possible contributionof CD11b+ cells to induce atopic dermatitis (ADwould be helpful to attain a better understanding of ADpathogenesis.

  18. Enhanced cell surface expression, immunogenicity and genetic stability resulting from a spontaneous truncation of HIV Env expressed by a recombinant MVA

    International Nuclear Information System (INIS)

    During propagation of modified vaccinia virus Ankara (MVA) encoding HIV 89.6 Env, a few viral foci stained very prominently. Virus cloned from such foci replicated to higher titers than the parent and displayed enhanced genetic stability on passage. Sequence analysis showed a single nucleotide deletion in the 89.6 env gene of the mutant that caused a frame shift and truncation of 115 amino acids from the cytoplasmic domain. The truncated Env was more highly expressed on the cell surface, induced higher antibody responses than the full-length Env, reacted with HIV neutralizing monoclonal antibodies and mediated CD4/co-receptor-dependent fusion. Intramuscular (IM), intradermal (ID) needleless, and intrarectal (IR) catheter inoculations gave comparable serum IgG responses. However, intraoral (IO) needleless injector route gave the highest IgA in lung washings and IR gave the highest IgA and IgG responses in fecal extracts. Induction of CTL responses in the spleens of individual mice as assayed by intracellular cytokine staining was similar with both the full-length and truncated Env constructs. Induction of acute and memory CTL in the spleens of mice immunized with the truncated Env construct by ID, IO, and IR routes was comparable and higher than by the IM route, but only the IR route induced CTL in the gut-associated lymphoid tissue. Thus, truncation of Env enhanced genetic stability as well as serum and mucosal antibody responses, suggesting the desirability of a similar modification in MVA-based candidate HIV vaccines

  19. New Strategies for Designing Inexpensive but Selective Bioadsorbants for Environmental Pollutants: Selection of specific Ligands and Their Cell Surface Expression

    Energy Technology Data Exchange (ETDEWEB)

    Brent L. Iverson; George Georgiou; Mohammad M. Ataai; Richard R. Koepsel

    2001-02-22

    The Broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in our laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules we will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal.

  20. Expression of Pneumocystis jirovecii Major Surface Glycoprotein in Saccharomyces cerevisiae

    OpenAIRE

    Kutty, Geetha; England, Katherine J.; Kovacs, Joseph A.

    2013-01-01

    The major surface glycoprotein (Msg), which is the most abundant protein expressed on the cell surface of Pneumocystis organisms, plays an important role in the attachment of this organism to epithelial cells and macrophages. In the present study, we expressed Pneumocystis jirovecii Msg in Saccharomyces cerevisiae, a phylogenetically related organism. Full-length P. jirovecii Msg was expressed with a DNA construct that used codons optimized for expression in yeast. Unlike in Pneumocystis orga...

  1. Expression of surface markers on peripheral CD4+CD25high T cells in patients with atopic asthma: role of inhaled corticosteroid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background CD4+CD25+ regulatory T cells (Tregs) mediate immune suppression through cell-cell contact with surface molecules,particularly cytotoxic T lymphocyte-associated antigen 4 (CTLA-4),glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR),and transforming growth factor β(TGF-β),but little is known about the exact role of Tregs in the pathogenesis of asthma.This study sought to characterize the expression of surface markers on peripheral blood mononuclear cells-derived Tregs in patients with atopic asthma and healthy subjects,and to investigate the effect of inhaled corticosteroid on them.Methods The expression of surface molecules on CD4+CD25hign Tregs was detected by flow cytometry.The effect of inhaled corticosteroid on expression of the surface molecules on Tregs was determined in vivo and in vitro.Total serum immunoglobulin E (IgE) and high-sensitivity C-reactive protein were measured by enzyme linked immunosorbent assay and latex enhanced immunoturbidimetric assay,respectively.Results Equivalent numbers of peripheral Tregs were found in patients with atopic asthma (stable and acute) and healthy subjects.Tregs preferentially expressed CTLA-4, GITR,toll-like receptor 4 (TLR4),latency-associated peptide (LAP/TGF-β1),and forkhead box P3 (FOXP3).Patients with acute asthma had decreased numbers of CD4+CD25high LAP+ T cells compared to healthy subjects and stable asthmatics.Inhaled corticosteroid enhanced the percentage of Tregs expressing LAP in vivo and in vitro dose-dependently.Furthermore,the percentages of Tregs expressing LAP were negatively correlated with total serum IgE levels and severity of asthma,but positively correlated with forced expiratory volume in one second percentage of the predicted value in patients with asthma.Concluslons The results suggest that membrane-bound TGF-β1 is a potential candidate for predicting the severity of asthma,and may contribute to the sustained remission of asthma,Strategies targeting

  2. Cell surface expression level variation between two common Human Leukocyte Antigen alleles, HLA-A2 and HLA-B8, is dependent on the structure of the C terminal part of the alpha 2 and the alpha 3 domains

    DEFF Research Database (Denmark)

    Dellgren, Christoffer; Nehlin, Jan O; Barington, Torben

    2015-01-01

    . Moreover, recent observations suggest that even minor differences in expression levels may influence the course of viral infections and the frequency of complications to stem cell transplantation. We have shown that some human multipotent stem cells have high expression of HLA-A while HLA-B is only weakly......Constitutive cell surface expression of Human Leukocyte Antigen (HLA) class I antigens vary extremely from tissue to tissue and individual antigens may differ widely in expression levels. Down-regulation of class I expression is a known immune evasive mechanism used by cancer cells and viruses...... expressed, and demonstrate here that this is also the case for the human embryonic kidney cell line HEK293T. Using quantitative flow cytometry and quantitative polymerase chain reaction we found expression levels of endogenous HLA-A3 (median 71,204 molecules per cell) 9.2-fold higher than the expression of...

  3. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-07-01

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and

  4. Stabilisation of an E3 ligase-E2-Ubiquitin complex increases cell surface MHC Class I expression

    OpenAIRE

    Duncan, Lidia M; Nathan, James A.; Lehner, Paul J.

    2010-01-01

    The Kaposi’s sarcoma-associated herpesvirus (KSHV) encoded ubiquitin E3 ligase, K3 ubiquitinates cell surface MHC class I molecules (MHC I), causing the internalisation and degradation of MHC I via the endolysosomal pathway. K3 recruits the cellular E2 ubiquitin conjugating enzyme, Ubc13 to generate lysine-63 linked polyubiquitin chains on MHC I leading to the clathrin-mediated endocytosis and lysosomal degradation of MHC I. Here we identify a ubiquitin Ile-44-Ala mutant (I44A) which inhibits...

  5. Endothelial progenitor cells, defined by the simultaneous surface expression of VEGFR2 and CD133, are not detectable in healthy peripheral and cord blood.

    Science.gov (United States)

    Lanuti, Paola; Rotta, Gianluca; Almici, Camillo; Avvisati, Giuseppe; Budillon, Alfredo; Doretto, Paolo; Malara, Natalia; Marini, Mirella; Neva, Arabella; Simeone, Pasquale; Di Gennaro, Elena; Leone, Alessandra; Falda, Alessandra; Tozzoli, Renato; Gregorj, Chiara; Di Cerbo, Melania; Trunzo, Valentina; Mollace, Vincenzo; Marchisio, Marco; Miscia, Sebastiano

    2016-03-01

    Circulating endothelial cells (CEC) and their progenitors (EPC) are restricted subpopulations of peripheral blood (PB), cord blood (CB), and bone marrow (BM) cells, involved in the endothelial homeostasis maintenance. Both CEC and EPC are thought to represent potential biomarkers in several clinical conditions involving endothelial turnover/remodeling. Although different flow cytometry methods for CEC and EPC characterization have been published so far, none of them have reached consistent conclusions, therefore consensus guidelines with respect to CEC and EPC identification and quantification need to be established. Here, we have carried out an in depth investigation of CEC and EPC phenotypes in healthy PB, CB and BM samples, by optimizing a reliable polychromatic flow cytometry (PFC) panel. Results showed that the brightness of CD34 expression on healthy PB and CB circulating cells represents a key benchmark for the identification of CEC (CD45neg/CD34bright/CD146pos) respect to the hematopoietic stem cell (HSC) compartment (CD45dim/CD34pos/CD146neg). This approach, combined with a dual-platform counting technique, allowed a sharp CEC enumeration in healthy PB (n = 38), and resulting in consistent CEC counts with previously reported data (median = 11.7 cells/ml). In parallel, by using rigorous PFC conditions, CD34pos/CD45dim/CD133pos/VEGFR2pos EPC were not found in any healthy PB or CB sample, since VEGFR2 expression was never detectable on the surface of CD34pos/CD45dim/CD133pos cells. Notably, the putative EPC phenotype was observed in all analyzed BM samples (n = 12), and the expression of CD146 and VEGFR2, on BM cells, was not restricted to the CD34bright compartment, but also appeared on the HSC surface. Altogether, our findings suggest that the previously reported EPC antigen profile, defined by the simultaneous expression of VEGFR2 and CD133 on the surface of CD45dim/CD34pos cells, should be carefully re-evaluated and further studies should be conducted to

  6. A dimeric peptide with erythropoiesis-stimulating activity uniquely affects erythropoietin receptor ligation and cell surface expression.

    Science.gov (United States)

    Verma, Rakesh; Green, Jennifer M; Schatz, Peter J; Wojchowski, Don M

    2016-08-01

    Erythropoiesis-stimulating agents (ESAs) that exert long-acting antianemia effects have been developed recently, but their mechanisms are poorly understood. Analyses reveal unique erythropoietin receptor (EPOR)-binding properties for one such ESA, the synthetic EPOR agonist peginesatide. Compared with recombinant human EPO and darbepoietin, peginesatide exhibited a slow on rate, but sustained EPOR residency and resistant displacement. In EPO-dependent human erythroid progenitor UT7epo cells, culture in peginesatide unexpectedly upmodulated endogenous cell surface EPOR levels with parallel increases in full-length EPOR-68K levels. These unique properties are suggested to contribute to the durable activity of this (and perhaps additional) dimeric peptide hematopoietic growth factor receptor agonist. PMID:27174804

  7. Quantification of cell surface receptor expression in live tissue culture media using a dual-tracer stain and rinse approach

    Science.gov (United States)

    Xu, Xiaochun; Sinha, Lagnojita; Singh, Aparna; Yang, Cynthia; Xiang, Jialing; Tichauer, Kenneth M.

    2015-03-01

    Immunofluorescence staining is a robust way to visualize the distribution of targeted biomolecules invasively in in fixed tissues and tissue culture. Despite the fact that these methods has been a well-established method in fixed tissue imaging for over 70 years, quantification of receptor concentration still simply assumes that the signal from the targeted fluorescent marker after incubation and sufficient rinsing is directly proportional to the concentration of targeted biomolecules, thus neglecting the experimental inconsistencies in incubation and rinsing procedures and assuming no, nonspecific binding of the fluorescent markers. This work presents the first imaging approach capable of quantifying the concentration of cell surface receptor on cancer cells grown in vitro based on compartment modeling in a nondestructive way. The approach utilizes a dual-tracer protocol where any non-specific retention or variability in incubation and rinsing of a receptor-targeted imaging agent is corrected by simultaneously imaging the retention of a chemically similar, "untargeted" imaging agent. Various different compartment models were used to analyze the data in order to find the optimal procedure for extracting estimates of epidermal growth factor receptor (EGFR) concentration (a receptor overexpressed in many cancers and a key target for emerging molecular therapies) in tissue cultures with varying concentrations of human glioma cells (U251). Preliminary results demonstrated a need to model nonspecific binding of both the targeted and untargeted imaging agents used. The approach could be used to carry out the first repeated measures of cell surface receptor dynamics during 3D tumor mass development, in addition to the receptor response to therapies.

  8. Expression of surface-associated 82kDa-proMMP-9 in primary acute leukemia blast cells inversely correlates with patients' risk.

    Science.gov (United States)

    Schmohl, Joerg; Santovito, Donato; Guenther, Thomas; Sutanto, Wishnu; Kroell, Tanja; Salih, Helmut; Pitsch, Thomas; Egea, Virginia; Weber, Christian; Schmetzer, Helga; Ries, Christian

    2016-05-01

    With its ability to degrade extracellular matrix proteins and activate growth factors and cytokines, matrix metalloproteinase (MMP)-9 is an important regulator of cell function. Previously, we reported that myeloid leukemic cells express a unique 82kDa-proMMP-9 variant on their cell surface that is not affected by its natural inhibitor. In this study, we generated monoclonal antibodies that specifically recognize 82kDa-proMMP-9. Flow cytometry analysis using these antibodies revealed significant surface expression of 82kDa-proMMP-9 in monocytes, but minimal amounts in T and B cells isolated from peripheral blood of nine healthy donors and 22 patients with acute myeloid leukemia (AML). In all AML patients, blasts expressed 82kDa-proMMP-9 at levels of 4%-46%, with significantly higher levels in patients with a better risk defined according to National Comprehensive Cancer Network (NCCN) guidelines (ρ = -0.748, p < 0.001) and favorable phenotype according to the French-American-British classification (p = 0.02) compared with patients with adverse prognoses. Receiver operating characteristic curve analysis confirmed the diagnostic accuracy of 82kDa-proMMP-9 measurement in AML blasts (area under the curve: 0.893 [0.739-1.000], p = 0.019). It led us to define a cutoff value of 11.5% for identifying patients with lower NCCN risk (p = 0.005) and with a tendency toward a higher probability of response to anthracycline-based therapy (p = 0.109) and increased event-free survival (p = 0.24). Thus, 82kDa-proMMP-9 expression on blasts may represent a novel independent marker of prognosis in patients with AML. PMID:26845021

  9. Maturation of dendritic cells by recombinant human CD40L-trimer leads to a homogeneous cell population with enhanced surface marker expression and increased cytokine production

    DEFF Research Database (Denmark)

    Würtzen, P A; Nissen, Mogens Holst; Claesson, M H

    2001-01-01

    -cell activating capacity of the DC. We studied DC phenotype and cytokine production as well as the T-cell proliferation and cytotoxic T lympocyte (CTL) activation induced by DC generated in vitro. In addition, the effect of exposure to recombinant human CD40L-trimer (huCD40LT) on these parameters was investigated....... Effective differentiation of monocytes derived from freshly isolated peripheral blood mononuclear cells (PBMC) was obtained with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4. The DC expression of human leucocyte antigen (HLA) molecules, CD80, CD83, and CD86 was markedly...

  10. Cloning, Expression, and Sequencing of a Cell Surface Antigen Containing a Leucine-Rich Repeat Motif from Bacteroides forsythus ATCC 43037

    Science.gov (United States)

    Sharma, Ashu; Sojar, Hakimuddin T.; Glurich, Ingrid; Honma, Kiyonobu; Kuramitsu, Howard K.; Genco, Robert J.

    1998-01-01

    Bacteroides forsythus is a recently recognized human periodontopathogen associated with advanced, as well as recurrent, periodontitis. However, very little is known about the mechanism of pathogenesis of this organism. The present study was undertaken to identify the surface molecules of this bacterium that may play roles in its adherence to oral tissues or triggering of a host immune response(s). The gene (bspA) encoding a cell surface-associated protein of B. forsythus with an apparent molecular mass of 98 kDa was isolated by immunoscreening of a B. forsythus gene library constructed in a lambda ZAP II vector. The encoded 98-kDa protein (BspA) contains 14 complete repeats of 23 amino acid residues that show partial homology to leucine-rich repeat motifs. A recombinant protein containing the repeat region was expressed in Escherichia coli, purified, and utilized for antibody production, as well as in vitro binding studies. The purified recombinant protein bound strongly to fibronectin and fibrinogen in a dose-dependent manner and further inhibited the binding of B. forsythus cells to these extracellular matrix (ECM) components. In addition, adult patients with B. forsythus-associated periodontitis expressed specific antibodies against the BspA protein. We report here the cloning and expression of an immunogenic cell surface-associated protein (BspA) of B. forsythus and speculate that it mediates the binding of bacteria to ECM components and clotting factors (fibronectin and fibrinogen, respectively), which may be important in the colonization of the oral cavity by this bacterium and is also a target for the host immune response. PMID:9826345

  11. Transient Surface CCR5 Expression by Naive CD8+ T Cells within Inflamed Lymph Nodes Is Dependent on High Endothelial Venule Interaction and Augments Th Cell-Dependent Memory Response.

    Science.gov (United States)

    Askew, David; Su, Charles A; Barkauskas, Deborah S; Dorand, R Dixon; Myers, Jay; Liou, Rachel; Nthale, Joseph; Huang, Alex Y

    2016-05-01

    In inflamed lymph nodes, Ag-specific CD4(+) and CD8(+) T cells encounter Ag-bearing dendritic cells and, together, this complex enhances the release of CCL3 and CCL4, which facilitate additional interaction with naive CD8(+) T cells. Although blocking CCL3 and CCL4 has no effect on primary CD8(+) T cell responses, it dramatically impairs the development of memory CD8(+) T cells upon Ag rechallenge. Despite the absence of detectable surface CCR5 expression on circulating native CD8(+) T cells, these data imply that naive CD8(+) T cells are capable of expressing surface CCR5 prior to cognate Ag-induced TCR signaling in inflamed lymph nodes; however, the molecular mechanisms have not been characterized to date. In this study, we show that CCR5, the receptor for CCL3 and CCL4, can be transiently upregulated on a subset of naive CD8(+) T cells and that this upregulation is dependent on direct contact with the high endothelial venule in inflamed lymph node. Binding of CD62L and CD11a on T cells to their ligands CD34 and CD54 on the high endothelial venule can be enhanced during inflammation. This enhanced binding and subsequent signaling promote the translocation of CCR5 molecules from intracellular vesicles to the surface of the CD8(+) T cell. The upregulation of CCR5 on the surface of the CD8(+) T cells increases the number of contacts with Ag-bearing dendritic cells, which ultimately results in increased CD8(+) T cell response to Ag rechallenge. PMID:26994221

  12. Effects of NKG2D haplotypes on the cell-surface expression of NKG2D protein on natural killer and CD8 T cells of peripheral blood among atomic-bomb survivors.

    Science.gov (United States)

    Imai, Kazue; Hayashi, Tomonori; Yamaoka, Mika; Kajimura, Junko; Yoshida, Kengo; Kusunoki, Yoichiro; Nakachi, Kei

    2012-06-01

    NKG2D is a primary activating receptor that triggers cell-mediated cytotoxicity in NK cells against tumor and virus-infected cells. We previously identified the NKG2D haplotypes in the natural killer gene complex region on chromosome 12p. Two major haplotype alleles, LNK1 and HNK1, were closely related to low and high natural cytotoxic activity phenotypes, respectively. Furthermore, the haplotype of HNK1/HNK1 has revealed a decreased risk of cancer compared with LNK1/LNK1. In the present study, using flow cytometry, we evaluated the functional effects of NKG2D haplotypes and five htSNPs in terms of the cell-surface expression of NKG2D protein on NK and CD8 T cells of peripheral blood among 732 atomic-bomb survivors. NKG2D expression on NK cells showed significant increases, in the order of LNK1/LNK1, LNK1/HNK1 and HNK1/HNK1 haplotypes (p for trend=0.003), or with major homozygous, heterozygous, and minor homozygous genotypes for individual htSNPs (p for trend=0.02-0.003). The same trend was observed for NKG2D expression on CD8 T cells. Our findings indicate that the NKG2D haplotypes are associated with the expression levels of NKG2D protein on NK and CD8 T cells, resulting in inter-individual variations in human cytotoxic response. PMID:22507622

  13. 2-deoxy D-glucose prevents cell surface expression of NKG2D ligands through inhibition of N-linked glycosylation

    DEFF Research Database (Denmark)

    Andresen, Lars; Skovbakke, Sarah Line; Persson, Gry; Hagemann-Jensen, Michael Henrik; Hansen, Karen Aagaard; Jensen, Helle; Skov, Søren

    2012-01-01

    -d-glucose (2DG), potently inhibited surface expression of MICA/B after histone deacetylase inhibitor treatment; the inhibition occurred posttranscriptionally without affecting MICA promoter activity. Transient overexpression of MICA surface expression was also inhibited by 2DG. 2DG blocks N......-linked glycosylation of MICA/B by a reversible mechanism that can be alleviated by addition of d-mannose; this does not, however, affect the inhibition of glycolysis. Addition of d-mannose restored MICA/B surface expression after 2DG treatment. In addition, specific pharmacological or small interfering RNA......-mediated targeting of glycolytic enzymes did not affect MICA/B surface expression, strongly suggesting that N-linked glycosylation, and not glycolysis, is essential for MICA/B surface expression. Corroborating this, tunicamycin, a selective inhibitor of N-linked glycosylation, abolished MICA/B surface expression...

  14. A PDZ-Like Motif in the Biliary Transporter ABCB4 Interacts with the Scaffold Protein EBP50 and Regulates ABCB4 Cell Surface Expression.

    Directory of Open Access Journals (Sweden)

    Quitterie Venot

    Full Text Available ABCB4/MDR3, a member of the ABC superfamily, is an ATP-dependent phosphatidylcholine translocator expressed at the canalicular membrane of hepatocytes. Defects in the ABCB4 gene are associated with rare biliary diseases. It is essential to understand the mechanisms of its canalicular membrane expression in particular for the development of new therapies. The stability of several ABC transporters is regulated through their binding to PDZ (PSD95/DglA/ZO-1 domain-containing proteins. ABCB4 protein ends by the sequence glutamine-asparagine-leucine (QNL, which shows some similarity to PDZ-binding motifs. The aim of our study was to assess the potential role of the QNL motif on the surface expression of ABCB4 and to determine if PDZ domain-containing proteins are involved. We found that truncation of the QNL motif decreased the stability of ABCB4 in HepG2-transfected cells. The deleted mutant ABCB4-ΔQNL also displayed accelerated endocytosis. EBP50, a PDZ protein highly expressed in the liver, strongly colocalized and coimmunoprecipitated with ABCB4, and this interaction required the QNL motif. Down-regulation of EBP50 by siRNA or by expression of an EBP50 dominant-negative mutant caused a significant decrease in the level of ABCB4 protein expression, and in the amount of ABCB4 localized at the canalicular membrane. Interaction of ABCB4 with EBP50 through its PDZ-like motif plays a critical role in the regulation of ABCB4 expression and stability at the canalicular plasma membrane.

  15. Chemokine receptor expression by mast cells.

    Science.gov (United States)

    Juremalm, Mikael; Nilsson, Gunnar

    2005-01-01

    There is a growing interest in the role of chemokines and their receptors in the determination of mast cell tissue localization and how chemokines regulate mast cell function. At least nine chemokine receptors (CXCR1, CXCR2, CXCR3, CXCR4, CX3CR1, CCR1, CCR3, CCR4 and CCR5) have been described to be expressed by human mast cells of different origins. Seven chemokines (CXCL1, CXCL5, CXCL8, CXCL14, CX3CL1, CCL5 and CCL11) have been shown to act on some of these receptors and to induce mast cell migration. Mast cells have a unique expression pattern of CCR3, CXCR1 and CXCR2. These receptors are mainly expressed intracellularly on cytoplasmic membranes. Upon an allergic activation, CCR3 expression is increased on the cell surface and the cell becomes vulnerable for CCL11 treatment. Chemokines do not induce mast cell degranulation but CXCL14 causes secretion of de novo synthesized CXCL8. Because of the expression of CCR3, CCR5 and CXCR4 on mast cell progenitors, these cells are susceptible to HIV infection and mast cells might therefore be a persistent HIV reservoir in AIDS. In this review, we summarize the knowledge about chemokine receptor expression and function on mast cells. PMID:16107768

  16. Surface expression of CXCR4 on circulating CD133+ progenitor cells is associated with plaque instability in subjects with carotid artery stenosis

    Directory of Open Access Journals (Sweden)

    Sadikovic Suwad

    2009-12-01

    Full Text Available Abstract Background Circulating progenitor cells (PCs are considered to contribute to the remodeling of atherosclerotic plaques. Their surface receptor CXCR4 plays an important role in the recruitment of PCs to their target. This study compares the mobilization of PCs and their functional characteristics in asymptomatic subjects with stable and with unstable carotid plaques. This could provide insight into plaque remodeling and help to develop biomarkers for plaque stability. Methods In 31 subjects with asymptomatic carotid artery stenosis we analyzed the number of CD133+ PCs, VEGFR2+CD34+ PCs and the surface expression of CXCR4 on CD133+ PCs by flow cytometry. Subjects underwent bilateral carotid MRI in a 1.5-T scanner in order to allow the categorization of plaques, following the modified criteria of the American Heart Association. Results The number of CD133+ PCs and VEGFR2+CD34+ PCs showed no significant difference between subjects with stable and unstable carotid plaques. The expression of CXCR4 on CD133+ PCs was higher in subjects with unstable plaques than in subjects with stable plaques (p = 0.009. Conclusions This study demonstrates an association between functional characteristics of circulating CD133+ PCs and plaque stability in subjects with asymptomatic carotid artery stenosis. The higher expression of CXCR4 on CD133+ PCs suggests a difference in the recruitment of PCs to the injured tissue in subjects with unstable plaques and subjects with stable plaques. As surface expression of CXCR4 on CD133+ PCs differs in subjects with unstable and with stable plaques, CXCR4 is a promising candidate for a serological biomarker for plaque stability.

  17. Cell-surface expression of a mutated Epstein–Barr virus glycoprotein B allows fusion independent of other viral proteins

    OpenAIRE

    McShane, Marisa P.; Longnecker, Richard

    2004-01-01

    Epstein–Barr virus (EBV) infects human B lymphocytes and epithelial cells. We have compared the requirements for EBV glycoprotein-induced cell fusion between Chinese hamster ovary effecter cells and human B lymphoblasts or epithelial cells by using a virus-free cell fusion assay. EBV-encoded gB, gH, gL, and gp42 glycoproteins were required for efficient B cell fusion, whereas EBV gB, gH, and gL glycoproteins were required for Chinese hamster ovary effecter cell fusion with epithelial cell lin...

  18. Generation of anti-TLR2 intrabody mediating inhibition of macrophage surface TLR2 expression and TLR2-driven cell activation

    Directory of Open Access Journals (Sweden)

    Lindenmaier Werner

    2010-04-01

    Full Text Available Abstract Background Toll-like receptor (TLR 2 is a component of the innate immune system and senses specific pathogen associated molecular patterns (PAMPs of both microbial and viral origin. Cell activation via TLR2 and other pattern recognition receptors (PRRs contributes to sepsis pathology and chronic inflammation both relying on overamplification of an immune response. Intracellular antibodies expressed and retained inside the endoplasmatic reticulum (ER-intrabodies are applied to block translocation of secreted and cell surface molecules from the ER to the cell surface resulting in functional inhibition of the target protein. Here we describe generation and application of a functional anti-TLR2 ER intrabody (αT2ib which was generated from an antagonistic monoclonal antibody (mAb towards human and murine TLR2 (T2.5 to inhibit the function of TLR2. αT2ib is a scFv fragment comprising the variable domain of the heavy chain and the variable domain of the light chain of mAb T2.5 linked together by a synthetic (Gly4Ser3 amino acid sequence. Results Coexpression of αT2ib and mouse TLR2 in HEK293 cells led to efficient retention and accumulation of TLR2 inside the ER compartment. Co-immunoprecipitation of human TLR2 with αT2ib indicated interaction of αT2ib with its cognate antigen within cells. αT2ib inhibited NF-κB driven reporter gene activation via TLR2 but not through TLR3, TLR4, or TLR9 if coexpressed in HEK293 cells. Co-transfection of human TLR2 with increasing amounts of the expression plasmid encoding αT2ib into HEK293 cells demonstrated high efficiency of the TLR2-αT2ib interaction. The αT2ib open reading frame was integrated into an adenoviral cosmid vector for production of recombinant adenovirus (AdV-αT2ib. Transduction with AdVαT2ib specifically inhibited TLR2 surface expression of murine RAW264.7 and primary macrophages derived from bone marrow (BMM. Furthermore, TLR2 activation dependent TNFα mRNA accumulation, as well

  19. Long-term T cell memory requires the surface expression of self-peptide/major histocompatibility complex molecules

    OpenAIRE

    Markiewicz, Mary A.; Girao, Cristina; Opferman, Joseph T.; Sun, Jiling; Hu, Qinghui; Agulnik, Alexander A.; Bishop, Colin E.; Thompson, Craig B.; Ashton-Rickardt, Philip G.

    1998-01-01

    How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo. Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-de...

  20. Cell surface engineering of renal cell carcinoma with glycosylphosphatidylinositol-anchored TIMP-1 blocks TGF- β 1 activation and reduces regulatory ID gene expression.

    Science.gov (United States)

    Notohamiprodjo, Susan; Djafarzadeh, Roghieh; Rieth, Nicole; Hofstetter, Monika; Jaeckel, Carsten; Nelson, Peter J

    2012-12-01

    Tissue inhibitor of metalloproteinase 1 (TIMP-1) controls matrix metalloproteinase activity through 1:1stoichiometric binding. Human TIMP-1 fused to a glycosylphosphatidylinositol(GPI) anchor (TIMP-1 - GPI) shifts the activity of TIMP-1 from the extracellular matrix to the cell surface. TIMP-1 - GPI treated renal cell carcinoma cells show increased apoptosis and reduced proliferation.Transcriptomic profiling and regulatory pathway mapping were used to identify the potential mechanisms driving these effects. Significant changes in the DNA binding inhibitors, TGF- β 1/SMAD and BMP pathways resulted from TIMP-1 - GPI treatment. These events were linked to reduced TGF- β 1 signaling mediated by inhibition of proteolytic processing of latent TGF- β 1 by TIMP-1 - GPI. PMID:23667903

  1. Adenovirus-mediated expression of pig α(1, 3) galactosyltransferase reconstructs Gal α(1, 3) Gal epitope on the surface of human tumor cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Gal α(1,3)Gal(gal epitope)is a carbohydrate epitope and synthesized in large amount by α(1,3)galactosyltransferase [α(1,3)GT] enzyme on the cells of lower mammalian animals such as pigs and mice.Human has no gal epitope due to the inactivation of α(1,3)GT gene but produces a large amount of antibodies(anti-Gal)which recognize Gal α(1,3)Gal structures specifically.In this study,a replicationdeficient recombinant adenoviral vector Ad5sGT containing pig α(1,3)GT cDNA was constructed and characterized.Adenoviral vector-mediated transfer of pig α(1,3)GT gene into human tumor cells such as malignant melanoma A375,stomach cancer SGC-7901,and lung cancer SPC-A-1 was reported for the first time.Results showed that Gal epitope did not increase the sensitivity of human tumor cells to human complement-mediated lysis,although human complement activation and the binding of human IgG and IgM natural antibodies to human tumor cells were enhanced significantly after Ad5sGT transduction.Appearance of gal epitope on the human tumor cells changed the expression of cell surface carbohydrates reacting with Ulex europaeus I(UEA I)lectins,Vicia villosa agglutinin(VVA),Arachis hypogaea agglutinin(PNA),and Glycine max agglutinin(SBA)to different degrees.In addition,no effect of gal epitope on the growth in vitro of human tumor cells was observed in MTT assay.

  2. Downregulation of cell-surface-expressed nucleolin inhibits the growth of hepatocellular carcinoma cells in vitro%细胞表面核仁素表达下调抑制肝癌细胞生长

    Institute of Scientific and Technical Information of China (English)

    蒙国照; 肖胜军; 曾思恩; 李运千

    2011-01-01

    目的 探讨核仁素在肝细胞癌(HCC)表面的表达及其表达下调对HCC细胞生长的影响.方法 用免疫荧光和流式细胞仪检测HCC细胞表面的核仁素表达;用RNA干扰技术将核仁素短发夹RNA(shRNA)质粒转染到HCC细胞,下调核仁素在HCC细胞中的表达;采用四甲基偶氮唑蓝(MTT)法检测细胞增殖,Transwell实验检测细胞的迁移能力,探讨细胞表面核仁素表达下调对HCC细胞生长和侵袭能力的影响.结果 核仁素不仅表达于HCC的细胞核,而且在细胞质和细胞膜也有表达.RNA干扰可下调细胞质和细胞膜内70.0%的核仁素表达(P<0.01),而细胞核内核仁素表达水平保持不变.HCC表面核仁素表达下调后,MTT实验显示,shRNA干扰组痛细胞体外增殖速度较对照组减慢(P<0.01);Transwell实验显示,shRNA干扰组癌细胞穿膜细胞数为(27.6±1.8)个,显著少于对照组[(37.5±2.1)个,P<0.01].结论 HCC细胞表面核仁素表达下调可抑制癌细胞生长.%Objective To detect the cell-surface-expressed nucleolin and investigate its tumor suppressing effect on the growth of hepatocellular carcinoma cells.Methods To detect cell-surfaceexpressed nucleolin in the hepatocellular carcinoma cells by immunofluorescence and flow cytometry.To down-regulate the nucleolin expression level in hepatocellular carcinoma cells by RNA interference.The tumor-suppressing effect of cell-surface nucleolin on hepatocellular carcinoma cells was assessed by MTT and transwell chamber assays.Results Nucleolin was expressed in the nuclei, cytoplasm and on the cell surface of hepatocellular carcinoma cells.ShRNA markedly decreased the nucleolin expression level in the cytoplasm and on the cell surface ( P <0.01 ), but the nuclear nucleolin remained unchanged.After downregulation of cell-surface nucleolin, MTT assays showed that the cell growth rate of hepatocellular carcinoma cells in the shRNA interference group was significantly inhibited as compared with that in

  3. Reconstruction of Cell Surface Densities of Ion Pumps, Exchangers, and Channels from mRNA Expression, Conductance Kinetics, Whole-Cell Calcium, and Current-Clamp Voltage Recordings, with an Application to Human Uterine Smooth Muscle Cells

    Science.gov (United States)

    Atia, Jolene; McCloskey, Conor; Shmygol, Anatoly S.; Rand, David A.; van den Berg, Hugo A.; Blanks, Andrew M.

    2016-01-01

    Uterine smooth muscle cells remain quiescent throughout most of gestation, only generating spontaneous action potentials immediately prior to, and during, labor. This study presents a method that combines transcriptomics with biophysical recordings to characterise the conductance repertoire of these cells, the ‘conductance repertoire’ being the total complement of ion channels and transporters expressed by an electrically active cell. Transcriptomic analysis provides a set of potential electrogenic entities, of which the conductance repertoire is a subset. Each entity within the conductance repertoire was modeled independently and its gating parameter values were fixed using the available biophysical data. The only remaining free parameters were the surface densities for each entity. We characterise the space of combinations of surface densities (density vectors) consistent with experimentally observed membrane potential and calcium waveforms. This yields insights on the functional redundancy of the system as well as its behavioral versatility. Our approach couples high-throughput transcriptomic data with physiological behaviors in health and disease, and provides a formal method to link genotype to phenotype in excitable systems. We accurately predict current densities and chart functional redundancy. For example, we find that to evoke the observed voltage waveform, the BK channel is functionally redundant whereas hERG is essential. Furthermore, our analysis suggests that activation of calcium-activated chloride conductances by intracellular calcium release is the key factor underlying spontaneous depolarisations. PMID:27105427

  4. Cells behaviors and genotoxicity on topological surface

    Energy Technology Data Exchange (ETDEWEB)

    Yang, N.; Yang, M.K.; Bi, S.X. [Tianjin Key Laboratory of Fiber Modification and Functional Fiber, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387 (China); Chen, L., E-mail: chenlis@tjpu.edu.cn [Tianjin Key Laboratory of Fiber Modification and Functional Fiber, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387 (China); Zhu, Z.Y.; Gao, Y.T.; Du, Z. [Tianjin Key Laboratory of Artificial Cell, Tianjin Third Central Hospital, Tianjin, 300170 (China)

    2013-08-01

    To investigate different cells behaviors and genotoxicity, which were driven by specific microenvironments, three patterned surfaces (pillars, wide grooves and narrow grooves) and one smooth surface were prepared by template-based technique. Vinculin is a membrane-cytoskeletal protein in focal adhesion plaques and associates with cell–cell and cell–matrix junctions, which can promote cell adhesion and spreading. The immunofluorescence staining of vinculin revealed that the narrow grooves patterned substrate was favorable for L929 cell adhesion. For cell multiplication, the narrow grooves surface was fitted for the proliferation of L929, L02 and MSC cells, the pillars surface was only in favor of L929 cells to proliferate during 7 days of cell cultivation. Cell genetic toxicity was evaluated by cellular micronuclei test (MNT). The results indicated that topological surfaces were more suitable for L929 cells to proliferate and maintain the stability of genome. On the contrary, the narrow grooves surface induced higher micronuclei ratio of L02 and MSC cells than other surfaces. With the comprehensive results of cell multiplication and MNT, it was concluded that the wide grooves surface was best fitted for L02 cells to proliferate and have less DNA damages, and the smooth surface was optimum for the research of MSC cells in vitro. - Highlights: • Different cells behaviors on microstructure surfaces were discussed in this paper. • The expression of cell protein of Vinculin was studied in this research. • Cellular micronuclei test was applied to evaluate cells' genotoxicity. • Cell genotoxicity was first studied in the research field of topological surfaces.

  5. Cells behaviors and genotoxicity on topological surface

    International Nuclear Information System (INIS)

    To investigate different cells behaviors and genotoxicity, which were driven by specific microenvironments, three patterned surfaces (pillars, wide grooves and narrow grooves) and one smooth surface were prepared by template-based technique. Vinculin is a membrane-cytoskeletal protein in focal adhesion plaques and associates with cell–cell and cell–matrix junctions, which can promote cell adhesion and spreading. The immunofluorescence staining of vinculin revealed that the narrow grooves patterned substrate was favorable for L929 cell adhesion. For cell multiplication, the narrow grooves surface was fitted for the proliferation of L929, L02 and MSC cells, the pillars surface was only in favor of L929 cells to proliferate during 7 days of cell cultivation. Cell genetic toxicity was evaluated by cellular micronuclei test (MNT). The results indicated that topological surfaces were more suitable for L929 cells to proliferate and maintain the stability of genome. On the contrary, the narrow grooves surface induced higher micronuclei ratio of L02 and MSC cells than other surfaces. With the comprehensive results of cell multiplication and MNT, it was concluded that the wide grooves surface was best fitted for L02 cells to proliferate and have less DNA damages, and the smooth surface was optimum for the research of MSC cells in vitro. - Highlights: • Different cells behaviors on microstructure surfaces were discussed in this paper. • The expression of cell protein of Vinculin was studied in this research. • Cellular micronuclei test was applied to evaluate cells' genotoxicity. • Cell genotoxicity was first studied in the research field of topological surfaces

  6. Effects of prebiotic oligosaccharides consumption on the growth and expression profile of cell surface-associated proteins of a potential probiotic Lactobacillus rhamnosus FSMM15.

    Science.gov (United States)

    Murtini, Devi; Aryantini, Ni Putu Desy; Sujaya, I Nengah; Urashima, Tadasu; Fukuda, Kenji

    2016-01-01

    To investigate carbohydrate preference of a potential probiotic, Lactobacillus rhamnosus FSMM15, six prebiotics, including two milk-derived prebiotics, galactooligosaccharides and lacto-N-biose I, and four plant-origin prebiotics, beet oligosaccharide syrup, difructose anhydride III, fructooligosaccharides, and raffinose, were examined. The strain utilized the milk-derived prebiotics at similar levels to glucose but did not utilize the plant-origin ones in the same manner, reflecting their genetic background, which allows them to adapt to dairy ecological niches. These prebiotics had little influence on the expression pattern of cell surface-associated proteins in the strain; however, an ATP-binding cassette transporter substrate-binding protein and a glyceraldehyde-3-phosphate dehydrogenase were suggested to be upregulated in response to carbon starvation stress. PMID:26858929

  7. Downregulation of transferrin receptor surface expression by intracellular antibody

    International Nuclear Information System (INIS)

    To deplete cellular iron uptake, and consequently inhibit the proliferation of tumor cells, we attempt to block surface expression of transferrin receptor (TfR) by intracellular antibody technology. We constructed two expression plasmids (scFv-HAK and scFv-HA) coding for intracellular single-chain antibody against TfR with or without endoplasmic reticulum (ER) retention signal, respectively. Then they were transfected tumor cells MCF-7 by liposome. Applying RT-PCR, Western blotting, immunofluorescence microscopy and immunoelectron microscope experiments, we insure that scFv-HAK intrabody was successfully expressed and retained in ER contrasted to the secreted expression of scFv-HA. Flow cytometric analysis confirmed that the TfR surface expression was markedly decreased approximately 83.4 ± 2.5% in scFv-HAK transfected cells, while there was not significantly decrease in scFv-HA transfected cells. Further cell growth and apoptosis characteristics were evaluated by cell cycle analysis, nuclei staining and MTT assay. Results indicated that expression of scFv-HAK can dramatically induce cell cycle G1 phase arrest and apoptosis of tumor cells, and consequently significantly suppress proliferation of tumor cells compared with other control groups. For First time this study demonstrates the potential usage of anti-TfR scFv-intrabody as a growth inhibitor of TfR overexpressing tumors

  8. Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.K. (Bristol Royal Infirmary (United Kingdom))

    1992-06-01

    Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus. (Author).

  9. Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions

    International Nuclear Information System (INIS)

    Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus. (Author)

  10. Modulation of ganglioside expression in human melanoma cell lines

    International Nuclear Information System (INIS)

    Cell surface gangliosides in human melanoma cell lines were modulated by pretreatment and adaptation to 6-thioguanine and 5-bromo-deoxyuridine. Chemo- and radiation sensitivities were compared in original cell lines and modulated cells by the human tumor colony-forming assay. Modulated cells showed decreased expression of cell surface GM2 and GD2 gangliosides. This reduction was correlated with increased resistance to bleomycin, vincristine, cisplatin and radiation treatment. These results suggest that cell surface GM2 and GD2 ganglioside expression in human melanoma cells is intimately associated with several cellular biological properties, such as drug or radiation sensitivity and cellular differentiation. (author)

  11. Expression of surface hydrophobic proteins by Candida albicans in vivo.

    OpenAIRE

    Glee, P M; Sundstrom, P; Hazen, K C

    1995-01-01

    Candida albicans modulates cell surface hydrophobicity during growth and morphogenesis in vitro. To determine if surface hydrophobicity is expressed during pathogenesis, we generated a polyclonal antiserum against yeast hydrophobic proteins. The antiserum was then used for indirect immunofluorescence analysis of tissues from mice colonized and chronically infected with C. albicans. Results demonstrated that yeast hydrophobic proteins are exposed on fungal cells present in host tissues. The po...

  12. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF, Adipose-derived Stem Cells (ASCs and those labeled by superparamagnetic iron oxide (SPIO nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT assay, proliferation by cell counting and bromodeoxyuridine (BrdU incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF, Insulin-like Growth Factor-1 (IGF-1, Transforming Growth Factor Beta 1 (TGF-β1, genetic markers comprising Stem Cell Antigen-1 (Sca1, Octamer-4 (Oct-4, ATP-binding Cassette Subfamily B Member 1 (ABCB1, adipogenic marker genes containing Lipoprotein Lipase (LPL, Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ, and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1 and Osterix (OSX. Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling.

  13. Generation of human scFvs antibodies recognizing a prion protein epitope expressed on the surface of human lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Imperiale Valentina

    2007-07-01

    Full Text Available Abstract Background A hallmark of prion disease is the transformation of normal cellular prion protein (PrPc into an infectious disease-associated isoform, (PrPsc. Anti-prion protein monoclonal antibodies are invaluable for structure-function studies of PrP molecules. Furthermore recent in vitro and in vivo studies indicate that anti-PrP monoclonal antibodies can prevent the incorporation of PrPc into propagating prions. In the present article, we show two new human phage antibodies, isolated on recombinant hamster prion protein (rHaPrP. Results We adopted an antibody phage display strategy to isolate specific human antibodies directed towards rHaPrP which has been used as a bait for panning the synthetic ETH-2 antibody phage library. Two phage antibodies clones named MA3.B4 and MA3.G3 were isolated and characterized under genetic biochemical and immunocytochemical aspects. The clones were found to recognize the prion protein in ELISA studies. In flow-cytometry studies, these human single chain Fragment variable (scFv phage-antibodies show a well defined pattern of reactivity on human lymphoblastoid and myeloid cells. Conclusion Sequence analysis of the gene encoding for the antibody fragments and antigen recognition patterns determined by flow-cytometry analysis indicate that the isolated scFvs recognize novel epitopes in the PrPc molecule. These new anti PrPc human antibodies are unique reagents for prion protein detection and may represent a biologic platform to develop new reagents to treat PrPsc associated disease.

  14. Endocytosis, oxidative stress and IL-8 expression in human lung epithelial cells upon treatment with fine and ultrafine TiO2: Role of the specific surface area and of surface methylation of the particles

    International Nuclear Information System (INIS)

    Inhaled ultrafine particles show considerably stronger pulmonary inflammatory effects when tested at equal mass dose with their fine counterparts. However, the responsible mechanisms are not yet fully understood. We investigated the role of particle size and surface chemistry in initiating pro-inflammatory effects in vitro in A549 human lung epithelial cells on treatment with different model TiO2 particles. Two samples of TiO2, i.e. fine (40-300 nm) and ultrafine (20-80 nm) were tested in their native forms as well as upon surface methylation, as was confirmed by Fourier transformed infrared spectroscopy. Radical generation during cell treatment was determined by electron paramagnetic resonance with 5,5-dimethyl-1-pyrroline-N-oxide or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl. Interleukin-8 mRNA expression/release was determined by RT-PCR and ELISA, whereas particle uptake was evaluated by transmission electron microscopy. TiO2 particles were rapidly taken up by the cells, generally as membrane bound aggregates and large intracellular aggregates in vesicles, vacuoles and lamellar bodies. Aggregate size tended to be smaller for the ultrafine samples and was also smaller for methylated fine TiO2 when compared to non-methylated fine TiO2. No particles were observed inside nuclei or any other vital organelle. Both ultrafine TiO2 samples but not their fine counterparts elicited significantly stronger oxidant generation and IL-8 release, despite their aggregation state and irrespective of their methylation. The present data indicate that ultrafine TiO2, even as aggregates/agglomerates, can trigger inflammatory responses that appear to be driven by their large surface area. Furthermore, our results indicate that these effects result from oxidants generated during particle-cell interactions through a yet to be elucidated mechanism(s)

  15. Two Domains of Vimentin Are Expressed on the Surface of Lymph Node, Bone and Brain Metastatic Prostate Cancer Lines along with the Putative Stem Cell Marker Proteins CD44 and CD133

    International Nuclear Information System (INIS)

    Vimentin was originally identified as an intermediate filament protein present only as an intracellular component in many cell types. However, this protein has now been detected on the surface of a number of different cancer cell types in a punctate distribution pattern. Increased vimentin expression has been indicated as an important step in epithelial-mesenchymal transition (EMT) required for the metastasis of prostate cancer. Here, using two vimentin-specific monoclonal antibodies (SC5 and V9 directed against the coil one rod domain and the C-terminus of the vimentin protein, respectively), we examined whether either of these domains would be displayed on the surface of three commonly studied prostate cancer cell lines isolated from different sites of metastases. Confocal analysis of LNCaP, PC3 and DU145 prostate cancer cell lines (derived from lymph node, bone or brain prostate metastases, respectively) demonstrated that both domains of vimentin are present on the surface of these metastatic cancer cell types. In addition, flow cytometric analysis revealed that vimentin expression was readily detected along with CD44 expression but only a small subpopulation of prostate cancer cells expressed vimentin and the putative stem cell marker CD133 along with CD44. Finally, Cowpea mosaic virus (CPMV) nanoparticles that target vimentin could bind and internalize into tested prostate cancer cell lines. These results demonstrate that at least two domains of vimentin are present on the surface of metastatic prostate cancer cells and suggest that vimentin could provide a useful target for nanoparticle- or antibody- cancer therapeutic agents directed against highly invasive cancer and/or stem cells

  16. Selective decrease in cell surface expression and mRNA level of the 55-kDa tumor necrosis factor receptor during differentiation of HL-60 cells into macrophage-like but not granulocyte-like cells

    DEFF Research Database (Denmark)

    Winzen, R; Wallach, D; Engelmann, H;

    1992-01-01

    Expression of the two known receptors for TNF was studied in the promyelocytic leukemia cell line HL-60 before and after differentiation of the cells along the granulocyte lineage (induced by incubation with retinoic acid), or along the macrophage lineage (induced by incubation with the phorbol...

  17. CD4(+) memory T cells with high CD26 surface expression are enriched for Th1 markers and correlate with clinical severity of multiple sclerosis

    DEFF Research Database (Denmark)

    Krakauer, M; Sorensen, P S; Sellebjerg, F

    An aberrant immune activation is believed to be important in the pathogenesis of multiple sclerosis (MS). Expression of CD4(+) T lymphocyte surface molecules indicative of immune activation and effector functions has been correlated with disease severity and activity. CD4(+) CD45R0(+) CD26(high) ...

  18. CD4(+) memory T cells with high CD26 surface expression are enriched for Th1 markers and correlate with clinical severity of multiple sclerosis

    DEFF Research Database (Denmark)

    Krakauer, M; Sorensen, P S; Sellebjerg, F

    2006-01-01

    ) memory T lymphocytes contained the high levels of markers of Th1, activation, and effector functions and cell counts of this subset correlated with MS disease severity. This subset had lower expression of PD-1, CCR4, and L-selectin in MS than in controls. These changes were only partially normalised by...

  19. Effects of space flight on surface marker expression

    Science.gov (United States)

    Sonnenfeld, G.

    1999-01-01

    Space flight has been shown to affect expression of several cell surface markers. These markers play important roles in regulation of immune responses, including CD4 and CD8. The studies have involved flight of experimental animals and humans followed by analysis of tissue samples (blood in humans, rats and monkeys, spleen, thymus, lymph nodes and bone marrow in rodents). The degree and direction of the changes induced by space flight have been determined by the conditions of the flight. Also, there may be compartmentalization of the response of surface markers to space flight, with differences in the response of cells isolated from blood and local immune tissue. The same type of compartmentalization was also observed with cell adhesion molecules (integrins). In this case, the expression of integrins from lymph node cells differed from that of splenocytes isolated from rats immediately after space flight. Cell culture studies have indicated that there may be an inhibition in conversion of a precursor cell line to cells exhibiting mature macrophage characteristics after space flight, however, these experiments were limited as a result of technical difficulties. In general, it is clear that space flight results in alterations of cell surface markers. The biological significance of these changes remains to be established.

  20. Cloning, Expression, and Sequencing of a Cell Surface Antigen Containing a Leucine-Rich Repeat Motif from Bacteroides forsythus ATCC 43037

    OpenAIRE

    Sharma, Ashu; Sojar, Hakimuddin T.; Glurich, Ingrid; Honma, Kiyonobu; Kuramitsu, Howard K.; Genco, Robert J.

    1998-01-01

    Bacteroides forsythus is a recently recognized human periodontopathogen associated with advanced, as well as recurrent, periodontitis. However, very little is known about the mechanism of pathogenesis of this organism. The present study was undertaken to identify the surface molecules of this bacterium that may play roles in its adherence to oral tissues or triggering of a host immune response(s). The gene (bspA) encoding a cell surface-associated protein of B. forsythus with an apparent mole...

  1. The cell-surface proteome of cultured adipose stromal cells.

    Science.gov (United States)

    Donnenberg, Albert D; Meyer, E Michael; Rubin, J Peter; Donnenberg, Vera S

    2015-07-01

    In this technical note we describe a method to evaluate the cell surface proteome of human primary cell cultures and cell lines. The method utilizes the BD Biosciences lyoplate, a system covering 242 surface proteins, glycoproteins, and glycosphingolipids plus relevant isotype controls, automated plate-based flow cytometry, conventional file-level analysis and unsupervised K-means clustering of markers on the basis of percent of positive events and mean fluorescence intensity of positive and total clean events. As an example, we determined the cell surface proteome of cultured adipose stromal cells (ASC) derived from 5 independent clinical isolates. Between-sample agreement of very strongly expressed (n = 32) and strongly expressed (n =16) markers was excellent, constituting a reliable profile for ASC identification and determination of functional properties. Known mesenchymal markers (CD29, CD44, CD73, CD90, CD105) were among the identified strongly expressed determinants. Among other strongly expressed markers are several that are potentially immunomodulatory including three proteins that protect from complement mediated effects (CD46, CD55, and CD59), two that regulate apoptosis (CD77 and CD95) and several with ectoenzymatic (CD10, CD26, CD13, CD73, and CD143) or receptor tyrosine kinase (CD140b (PDGFR), CD340 (Her-2), EGFR) activity, suggesting mechanisms for the anti-inflammatory and tissue remodeling properties of ASC. Because variables are standardized for K-means clustering, results generated using this methodology should be comparable between instrumentation platforms. It is widely generalizable to human primary explant cultures and cells lines and will prove useful to determine how cell passage, culture interventions, and gene expression and silencing affect the cell-surface proteome. PMID:25929697

  2. New Strategies for Designing Inexpensive but Selective Bioadsorbants for Environmental Pollutants: Selection of specific Ligands and Their Cell Surface Expression; FINAL

    International Nuclear Information System (INIS)

    The Broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in our laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules we will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal

  3. Cell Surface Markers in HTLV-1 Pathogenesis

    Directory of Open Access Journals (Sweden)

    Andrea K. Kress

    2011-08-01

    Full Text Available The phenotype of HTLV-1-transformed CD4+ T lymphocytes largely depends on defined viral effector molecules such as the viral oncoprotein Tax. In this review, we exemplify the expression pattern of characteristic lineage markers, costimulatory receptors and ligands of the tumor necrosis factor superfamily, cytokine receptors, and adhesion molecules on HTLV-1-transformed cells. These molecules may provide survival signals for the transformed cells. Expression of characteristic surface markers might therefore contribute to persistence of HTLV-1-transformed lymphocytes and to the development of HTLV-1-associated disease.

  4. Engineering novel cell surface chemistry for selective tumor cell targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, C.R. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1997-12-31

    A common feature of many different cancers is the high expression level of the two monosaccharides sialic acid and fucose within the context of cell-surface associated glycoconjugates. A correlation has been made between hypersialylation and/or hyperfucosylation and the highly metastatic phenotype. Thus, a targeting strategy based on sialic acid or fucose expression would be a powerful tool for the development of new cancer cell-selective therapies and diagnostic agents. We have discovered that ketone groups can be incorporated metabolically into cell-surface associated sialic acids. The ketone is can be covalently ligated with hydrazide functionalized proteins or small molecules under physiological conditions. Thus, we have discovered a mechanism to selectively target hydrazide conjugates to highly sialylated cells such as cancer cells. Applications of this technology to the generation of novel cancer cell-selective toxins and MRI contrast reagents will be discussed, in addition to progress towards the use of cell surface fucose residues as vehicles for ketone expression.

  5. Stable Surface Expression of a Gene for Helicobacter pylori Toxic Porin Protein with pBAD Expression System

    Institute of Scientific and Technical Information of China (English)

    Zhixiang PENG; Xi WEI; Zhengmei LIN

    2009-01-01

    successive passages could express Hope protein, while only 1 from 5 E. coli colonies that contained lac operon-regulated plasmid encoding hopE gene could express HopE. Indi-rect immunofluorescence confirmed the expression of HopE on E. coli cell surface.

  6. Effects of irradiation, glucocorticoid and FK506 on cell-surface antigen expression by rat thymocytes: a three-colour flow cytofluorometric analysis

    International Nuclear Information System (INIS)

    The expression of T-cell antigen receptor (TCR) αβ was investigated in rat CD4-CD8- thymocytes during thymic reconstitution after the exposure of animals to irradiation or glucocorticoid. The effect of the immunosuppressant FK506 on the expression of TCRαβ in rat CD4-CD8- thymocytes was also examined. The percentage of CD4-CD8- thymocytes constituted 2.6% of total thymocytes and that of CD4-CD8-TCRαβhigh cells constituted 12.6% of CD4-CD8-thymocytes in normal adult Lewis rats. The percentage of CD4-CD8- TCRαβhigh cells increased during thymic reconstitution after irradiation, and maximally constituted 28.6% of CD4-CD8- thymocytes on day 7. Similar results were obtained during thymic reconstitution after glucocorticoid treatment. In contrast, continuous treatment with FK506 for 7 days markedly decreased not only the percentages of CD4+CD8-TCRαβhigh and CD4-CD8+ TCRαβhigh thymocytes, but also that of CD4-CD8- TCRαβhigh thymocytes. These results indicate that rat CD4-CD8- thymocytes contain a subpopulation of mature (TCRαβhigh) cells. The possible implications of the existence of this subpopulation with regard to thymocyte differentiation and maturation are discussed. (author)

  7. The Plant Cell Surface

    Institute of Scientific and Technical Information of China (English)

    Anne-Mie C.Emons; Kurt V.Fagerstedt

    2010-01-01

    @@ Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. Since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it.

  8. Protein rib: a novel group B streptococcal cell surface protein that confers protective immunity and is expressed by most strains causing invasive infections

    OpenAIRE

    1993-01-01

    The group B Streptococcus, an important cause of invasive infections in the neonate, is classified into four major serotypes (Ia, Ib, II, and III) based on the structure of the polysaccharide capsule. Since the capsule is a known virulence factor, it has been extensively studied, in particular in type III strains, which cause the majority of invasive infections. Two cell surface proteins, alpha and beta, have also been studied in detail since they confer protective immunity, but these protein...

  9. Antigen expression on recurrent meningioma cells

    International Nuclear Information System (INIS)

    Meningiomas are intracranial brain tumours that frequently recur. Recurrence rates up to 20% in 20 years for benign meningiomas, up to 80% for atypical meningiomas and up to 100% for malignant meningiomas, have been reported. The most important prognostic factors for meningioma recurrence are meningioma grade, meningioma invasiveness and radicality of neurosurgical resection. The aim of our study was to evaluate the differences in antigenic expression on the surface of meningioma cells between recurrent and non-recurrent meningiomas. 19 recurrent meningiomas and 35 non-recurrent meningiomas were compared regarding the expression of MIB-1 antigen, progesterone receptors, cathepsin B and cathepsin L, using immunohistochemistry. MIB-1 antigen expression was higher in the recurrent meningioma group (p=0.001). No difference in progesterone receptor status between recurrent and non-recurrent meningiomas was confirmed. Immunohistochemical intensity scores for cathepsin B (p= 0.007) and cathepsin L (p<0.001) were both higher in the recurrent than in the non-recurrent meningioma group. MIB-1 antigen expression is higher in recurrent compared to non-recurrent meningiomas. There is no difference in expression of progesterone receptors between recurrent and non-recurrent meningiomas. Cathepsins B and L are expressed more in recurrent meningiomas

  10. New strategies for designing inexpensive but selective bioadsorbants for environmental pollutants: Selection of specific ligands and their cell surface expression. 1998 annual progress report

    International Nuclear Information System (INIS)

    'The broad, long term objective of the research plan is to develop exquisitely selective polypeptide metal chelators for the remediation of aqueous systems. A variety of polypeptide chelators will be developed and optimized ranging from antibodies to small peptides. Then, through unique molecular engineering approaches developed in the laboratories, the polypeptide chelators will be anchored directly on the surface of the cells that produce them. Thus, instead of using isolated biomolecules the authors will employ inexpensive genetically engineered whole cell adsorbents. Following a simple, easily scaleable treatment, the engineered cells can be used to manufacture an inexpensive, particulate adsorbent for metal removal. The authors are currently in year two of a three year program. Work has been focused on preparing the molecular biology constructs needed to carry out the optimization of a metal complex binding antibody, and on the isolation of a metal binding peptide.'

  11. Sodium arsenite accelerates TRAIL-mediated apoptosis in melanoma cells through upregulation of TRAIL-R1/R2 surface levels and downregulation of cFLIP expression

    OpenAIRE

    Ivanov, Vladimir N.; Hei, Tom K.

    2006-01-01

    AP-1/cJun, NF-κB and STAT3 transcription factors control expression of numerous genes, which regulate critical cell functions including proliferation, survival and apoptosis. Sodium arsenite is known to suppress both the IKK-NF-κB and JAK2-STAT3 signaling pathways and to activate the MAPK/JNK-cJun pathways, thereby committing some cancers to undergo apoptosis. Indeed, sodium arsenite is an effective drug for the treatment of acute promyelocytic leukemia with little nonspecific toxicity. Malig...

  12. Expression and secretion in Aspergillus nidulans and Aspergillus niger of a cell surface glycoprotein from the cattle tick, Boophilus microplus, by using the fungal amdS promoter system.

    OpenAIRE

    Turnbull, I F; Smith, D R; Sharp, P. J.; Cobon, G S; Hynes, M J

    1990-01-01

    A cell surface glycoprotein (Bm86) from cells of the digestive tract of the cattle tick Boophilus microplus, which has been shown to elicit a protective immunological response in vaccinated cattle, was expressed and secreted in the filamentous fungi Aspergillus nidulans and Aspergillus niger by using the fungal amdS promoter system. The cloned gene coded for the Bm86 secretory signal and all of the Bm86 mature polypeptide except for the hydrophobic carboxy-terminal segment. High levels of Bm8...

  13. The cell-surface interaction.

    Science.gov (United States)

    Hayes, J S; Czekanska, E M; Richards, R G

    2012-01-01

    The realm of surface-dependent cell and tissue responses is the foundation of orthopaedic-device-related research. However, to design materials that elicit specific responses from tissues is a complex proposition mainly because the vast majority of the biological principles controlling the interaction of cells with implants remain largely ambiguous. Nevertheless, many surface properties, such as chemistry and topography, can be manipulated in an effort to selectively control the cell-material interaction. On the basis of this information there has been much research in this area, including studies focusing on the structure and composition of the implant interface, optimization of biological and chemical coatings and elucidation of the mechanisms involved in the subsequent cell-material interactions. Although a wealth of information has emerged, it also advocates the complexity and dynamism of the cell-material interaction. Therefore, this chapter aims to provide the reader with an introduction to the basic concepts of the cell-material interaction and to provide an insight into the factors involved in determining the cell and tissue response to specific surface features, with specific emphasis on surface microtopography. PMID:21984613

  14. Anti-human CD73 monoclonal antibody inhibits metastasis formation in human breast cancer by inducing clustering and internalization of CD73 expressed on the surface of cancer cells

    DEFF Research Database (Denmark)

    Terp, Mikkel G; Olesen, Kristina A; Christensen, Eva Arnspang;

    2013-01-01

    -linking of CD73, because both whole IgG anti-CD73 AD2 mAb and Fab' fragments thereof exhibited this effect. Ex vivo treatment of different breast cancer cell lines with anti-CD73 AD2 mAb before i.v. injection into mice inhibited extravasation/colonization of circulating tumor cells and significantly reduced...... metastasis development. This effect was also observed when the cancer cell-surface expression of CD73 was significantly reduced by small interfering RNA knockdown. The antimetastatic activity is epitope specific, as another Ab that efficiently binds CD73-expressing live cancer cells did not lead to CD73...... internalization and metastasis inhibition. Furthermore, anti-CD73 AD2 mAb inhibited development of metastasis in a spontaneous animal model of human metastatic breast cancer. Our study shows that some anti-CD73 mAbs cause cell-surface clustering of CD73 followed by internalization, thus inhibiting the ability of...

  15. CD4+CD25- T cells that express latency-associated peptide on the surface suppress CD4+CD45RBhigh-induced colitis by a TGF-beta-dependent mechanism.

    Science.gov (United States)

    Oida, Takatoku; Zhang, Xingmin; Goto, Masao; Hachimura, Satoshi; Totsuka, Mamoru; Kaminogawa, Shuichi; Weiner, Howard L

    2003-03-01

    Murine CD4(+)CD25(+) regulatory cells have been reported to express latency-associated peptide (LAP) and TGF-beta on the surface after activation, and exert regulatory function by the membrane-bound TGF-beta in vitro. We have now found that a small population of CD4(+) T cells, both CD25(+) and CD25(-), can be stained with a goat anti-LAP polyclonal Ab without being stimulated. Virtually all these LAP(+) cells are also positive for thrombospondin, which has the ability to convert latent TGF-beta to the active form. In the CD4(+)CD45RB(high)-induced colitis model of SCID mice, regulatory activity was exhibited not only by CD25(+)LAP(+) and CD25(+)LAP(-) cells, but also by CD25(-)LAP(+) cells. CD4(+)CD25(-)LAP(+) T cells were part of the CD45RB(low) cell fraction. CD4(+)CD25(-)LAP(-)CD45RB(low) cells had minimal, if any, regulatory activity in the colitis model. The regulatory function of CD25(-)LAP(+) cells was abrogated in vivo by anti-TGF-beta mAb. These results identify a new TGF-beta-dependent regulatory CD4(+) T cell phenotype that is CD25(-) and LAP(+). PMID:12594277

  16. Surface expression of the Chicxulub crater

    Science.gov (United States)

    Pope, Kevin O.; Ocampo, Adriana C.; Kinsland, Gary L.; Smith, Randy

    1996-06-01

    Analyses of geomorphic, soil, and topographic data from the northern Yucatán Peninsula, México, confirm that the buried Chicxulub impact crater has a distinct surface expression and that carbonate sedimentation throughout the Cenozoic has been influenced by the crater. Late Tertiary sedimentation was mostly restricted to the region within the buried crater, and a semicircular moat existed until at least Pliocene time. The topographic expression of the crater is a series of features concentric with the crater. The most prominent is an ˜ 83-km-radius trough or moat containing sinkholes (the Cenote ring). Early Tertiary surfaces rise abruptly outside the moat and form a stepped topography with an outer trough and ridge crest at radii of ˜103 and ˜ 129 km, respectively. Two discontinuous troughs lie within the moat at radii of ˜ 41 and ˜ 62 km. The low ridge between the inner troughs corresponds to the buried peak ring. The moat corresponds to the outer edge of the crater floor demarcated by a major ring fault. The outer trough and the ˜ 62-km-radius inner trough also mark buried ring faults. The ridge crest corresponds to the topographic rim of the crater as modified by postimpact processes. These interpretations support previous findings that the principal impact basin has a diameter of ˜ 180 km, but concentric, low-relief slumping extends well beyond this diameter and the eroded crater rim may extend to a diameter of ˜ 260 km.

  17. Expression of the glycoprotein of viral haemorrhagic septicaemia virus (VHSV) on the surface of the fish cell line RTG-P1 induces type 1 interferon expression in neighbouring cells

    DEFF Research Database (Denmark)

    Acosta, F.; Collet, B.; Lorenzen, Niels;

    2006-01-01

    In the present study using a luciferase/Mx promoter reporter system, it was shown that the rainbow trout gonad cell line (RTG-P1), a fibroblastic cell line, produces IFN when transfected with a plasmid encoding the glycoprotein of VHSV but not with plasmid vector alone. Only a small percentage of...

  18. Advantages and Applications of CAR-Expressing Natural Killer Cells

    Directory of Open Access Journals (Sweden)

    Wolfgang eGlienke

    2015-02-01

    Full Text Available In contrast to donor T cells, natural killer (NK cells are known to mediate anti-cancer effects without the risk of inducing graft-versus-host disease (GvHD. In order to improve cytotoxicity against resistant cancer cells, auspicious efforts have been made with chimeric antigen receptor (CAR expressing T- and NK cells. These CAR-modified cells express antigen receptors against tumor-associated surface antigens, thus redirecting the effector cells and enhancing tumor-specific immunosurveillance. However, many cancer antigens are also expressed on healthy tissues, potentially leading to off tumor/ on target toxicity by CAR-engineered cells. In order to control such potentially severe side effects, the insertion of suicide genes into CAR-modified effectors can provide a means for efficient depletion of these cells. While CAR-expressing T cells have entered successfully clinical trials, experience with CAR-engineered NK cells is mainly restricted to pre-clinical investigations and predominantly to NK cell lines. In this review we summarize the data on CAR expressing NK cells focusing on the possible advantage using these short-lived effector cells and discuss the necessity of suicide switches. Furthermore, we address the compliance of such modified NK cells with regulatory requirements as a new field in cellular immunotherapy.

  19. Adrenomedullin Expression by Gastric Epithelial Cells in Response to Infection

    OpenAIRE

    Robert P. Allaker; Kapas, Supriya

    2003-01-01

    Many surface epithelial cells express adrenomedullin, a multifunctional peptide found in a wide number of body and cell systems. Recently, we and others have proposed that adrenomedullin has an important novel role in host defense. This peptide has many properties in common with other cationic antimicrobial peptides, including the human β-defensins. Upon exposure of human gastric epithelial cells to viable cells of invasive or noninvasive strains of Helicobacter pylori, Escherichia coli, Salm...

  20. Programmed cell death 1 ligand 1 expression in osteosarcoma

    OpenAIRE

    Shen, Jacson K.; Cote, Gregory M.; Choy, Edwin; Yang, Pei; Harmon, David; Schwab, Joseph; Nielsen, G. Petur; Chebib, Ivan; Ferrone, Soldano; Wang, Xinhui; Wang, Yangyang; Mankin, Henry; Francis J. Hornicek; Duan, Zhenfeng

    2014-01-01

    Programmed cell death 1 ligand 1 (PD-L1, B7H1) is a cell-surface protein that suppresses the cytotoxic CD8+ T cell-mediated immune response. PD-L1 expression and its clinical relevance in sarcomas are not well understood. Therefore, we sought to measure RNA expression levels for PD-L1 in 38 clinically annotated osteosarcoma tumor samples, and aimed to determine if PD-L1 expression correlates with clinical features and tumor-infiltrating T-lymphocytes (TILs). Quantitative real-time RT-PCR for ...

  1. Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells.

    Science.gov (United States)

    Xiong, Jimin; Menicanin, Danijela; Zilm, Peter S; Marino, Victor; Bartold, P Mark; Gronthos, Stan

    2016-01-01

    The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein "spots" were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

  2. gp140v-fms molecules expressed at the surface of cells transformed by the McDonough strain of feline sarcoma virus are phosphorylated in tyrosine and serine.

    OpenAIRE

    Tamura, T.; Simon, E.; Niemann, H.; Snoek, G T; Bauer, H.

    1986-01-01

    Cells transformed by the McDonough strain of feline sarcoma virus express at their surface a v-fms-specific transmembrane glycoprotein designated gp140v-fms. By labeling with 32Pi, gp140v-fms was shown to be phosphorylated 30-fold more in serine residues than were the cytosolic v-fms polypeptides gp180gag-fms and gp120v-fms. By using the phosphotyrosine phosphatase-specific inhibitor sodium orthovanadate, an additional tyrosine phosphorylation was observed in vivo, again involving predominant...

  3. Human retinal pigment epithelial cells inhibit proliferation and IL2R expression of activated T cells

    DEFF Research Database (Denmark)

    Kaestel, Charlotte G; Jørgensen, Annette; Nielsen, Mette;

    2002-01-01

    The purpose of this study was to characterize the effects of human retinal pigment epithelial (RPE) cells on activated T cells. Activated T cells were cocultured with adult and foetal human RPE cells whereafter apoptosis and proliferation were determined by flow cytometry and (3)H...... addition to use of TCR negative T cell lines. The expression of IL2R-alpha -beta and -gamma chains of activated T cells was analysed by flow cytometry after incubation of T cells alone or with RPE cells. Human RPE cells were found to inhibit the proliferation of activated T cells by a cell contact......-dependent mechanism. The RPE cells inhibitory abilities were not affected by blocking of any of the tested surface molecules. The inhibition of the T cells' proliferation correlates with a decreased expression of IL2R-beta and -gamma chains. The T cells regain their ability to proliferate and increase their IL2R...

  4. Soluble and cell surface receptors for tumor necrosis factor

    DEFF Research Database (Denmark)

    Wallach, D; Engelmann, H; Nophar, Y;

    1991-01-01

    Tumor necrosis factor (TNF) initiates its multiple effects on cell function by binding at a high affinity to specific cell surface receptors. Two different molecular species of these receptors, which are expressed differentially in different cells, have been identified. The cDNAs of both receptors...... certain pathological situations. Release of the soluble receptors from the cells seems to occur by proteolytic cleavage of the cell surface forms and appears to be a way of down-regulating the cell response to TNF. Because of their ability to bind TNF, the soluble receptors exert an inhibitory effect on...

  5. Whole genome expression profiling using DNA microarray for determining biocompatibility of polymeric surfaces

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Wang, Zhenyu; Kutter, Jörg Peter; Dufva, Hans Martin; Wolff, Anders

    2006-01-01

    There is an ever increasing need to find surfaces that are biocompatible for applications like medical implants and microfluidics-based cell culture systems. The biocompatibility of five different surfaces with different hydrophobicity was determined using gene expression profiling as well as more...... conventional methods to determine biocompatibility such as cellular growth rate, morphology and the hydrophobicity of the surfaces. HeLa cells grown on polymethylmethacrylate (PMMA) or a SU-8 surface treated with HNO3-ceric ammonium nitrate (HNO3-CAN) and ethanolamine showed no differences in growth rate......, morphology or gene expression profiles as compared to HeLa cells grown in cell culture flasks. Cells grown on SU-8 treated with only HNO3-CAN showed almost the same growth rate (36 ¡ 1 h) and similar morphology as cells grown in cell culture flasks (32 ¡ 1 h), indicating good biocompatibility. However, more...

  6. Human Neuroepithelial Cells Express NMDA Receptors

    Directory of Open Access Journals (Sweden)

    Cappell B

    2003-11-01

    Full Text Available Abstract L-glutamate, an excitatory neurotransmitter, binds to both ionotropic and metabotropic glutamate receptors. In certain parts of the brain the BBB contains two normally impermeable barriers: 1 cerebral endothelial barrier and 2 cerebral epithelial barrier. Human cerebral endothelial cells express NMDA receptors; however, to date, human cerebral epithelial cells (neuroepithelial cells have not been shown to express NMDA receptor message or protein. In this study, human hypothalamic sections were examined for NMDA receptors (NMDAR expression via immunohistochemistry and murine neuroepithelial cell line (V1 were examined for NMDAR via RT-PCR and Western analysis. We found that human cerebral epithelium express protein and cultured mouse neuroepithelial cells express both mRNA and protein for the NMDA receptor. These findings may have important consequences for neuroepithelial responses during excitotoxicity and in disease.

  7. Expression of CD44 in Cultured Human Trabecular Meshwork Cells

    Institute of Scientific and Technical Information of China (English)

    Zhongguo Li; Hong Zhang

    2004-01-01

    Purpose:To determine whether cultured human trabecular meshwork cells express CD44 and to discuss their possible relationship with primary open angle glaucoma.Methods:Human trabecular meshwork cells were cultured in DMEM/F12 media. Total RNAs from the cells were extracted with Trizol reagent. Messenger RNA expression of CD44 in human trabecular meshwork cells was examined by using reverse transcriptasepolymerase chain reaction ( RT-PCR ) analysis. Expression of CD44 was confirmed by Western-blotting and immunofiuorescent microscopy. Effect of CD44-specific antisense oligonucleotide on adhesion of trabecular meshwork cells to hyaluronate was determined by MTT assay.Results:A single RT-PCR product whose size was 471bp was obtained.A band about 80kD was stained by Western-blot. Immunofiuorescent examination of expression of CD44 on the cell surface was positive and reactions were mainly localized in cell membranes.Adhesion of trabecular meshwork cells to hyaluronate was inhibited by CD44-specific antisense oligonucleotide.Conclusions: Cultured human trabecular meshwork cells express CD44. CD44 may play a role in pathogenesis of primary open angle glaucoma. Eye Science 2004;20:52-56.

  8. Gene expressions changes in bronchial epithelial cells

    DEFF Research Database (Denmark)

    Remy, S.; Verstraelen, S.; Van Den Heuvel, R.;

    2014-01-01

    cells were exposed during 6, 10, and 24 h to 4 respiratory sensitizers and 6 non-respiratory sensitizers (3 skin sensitizers and 3 respiratory irritants) at a concentration inducing 20% cell viability loss after 24 h. Changes in gene expression were evaluated using Agilent Whole Human Genome 4 x 44 K...... differentially expressed compared to vehicle control for each chemical. The results show that the NRF2-mediated oxidative stress response is activated in the cell line after stimulation with all of the chemicals that were selected in our study, and that - at the level of gene expression - this pathway shows no...

  9. Foxp3 expression in human cancer cells

    Directory of Open Access Journals (Sweden)

    Gourgoulianis Konstantinos I

    2008-04-01

    Full Text Available Abstract Objective Transcription factor forkhead box protein 3 (Foxp3 specifically characterizes the thymically derived naturally occurring regulatory T cells (Tregs. Limited evidence indicates that it is also expressed, albeit to a lesser extent, in tissues other than thymus and spleen, while, very recently, it was shown that Foxp3 is expressed by pancreatic carcinoma. This study was scheduled to investigate whether expression of Foxp3 transcripts and mature protein occurs constitutively in various tumor types. Materials and methods Twenty five tumor cell lines of different tissue origins (lung cancer, colon cancer, breast cancer, melanoma, erythroid leukemia, acute T-cell leukemia were studied. Detection of Foxp3 mRNA was performed using both conventional RT-PCR and quantitative real-time PCR while protein expression was assessed by immunocytochemistry and flow cytometry, using different antibody clones. Results Foxp3 mRNA as well as Foxp3 protein was detected in all tumor cell lines, albeit in variable levels, not related to the tissue of origin. This expression correlated with the expression levels of IL-10 and TGFb1. Conclusion We offer evidence that Foxp3 expression, characterizes tumor cells of various tissue origins. The biological significance of these findings warrants further investigation in the context of tumor immune escape, and especially under the light of current anti-cancer efforts interfering with Foxp3 expression.

  10. Cell Surface Sensors: Lightning the Cellular Environment

    OpenAIRE

    Ali, Md Monsur; Kang, Dong-Ku; Tsang, Kyle; Fu, Moyu; Karp, Jeffrey M; Zhao, Weian

    2012-01-01

    Cell surface sensors are powerful tools to elucidate cell functions including cell signaling, metabolism and cell-to-cell communication. These sensors not only facilitate our understanding in basic biology but also advance the development of effective therapeutics and diagnostics. While genetically encoded fluorescent protein/peptide sensors have been most popular, emerging cell surface sensor systems including polymer-, nanoparticle-, and nucleic acid aptamer-based sensors have largely expan...

  11. Foxp3 expression in human cancer cells

    OpenAIRE

    Gourgoulianis Konstantinos I; Barda Angeliki K; Kerenidi Theodora; Loules Gedeon; Kalala Fani; Zamanakou Maria; Speletas Matthaios; Karanikas Vaios; Germenis Anastasios E

    2008-01-01

    Abstract Objective Transcription factor forkhead box protein 3 (Foxp3) specifically characterizes the thymically derived naturally occurring regulatory T cells (Tregs). Limited evidence indicates that it is also expressed, albeit to a lesser extent, in tissues other than thymus and spleen, while, very recently, it was shown that Foxp3 is expressed by pancreatic carcinoma. This study was scheduled to investigate whether expression of Foxp3 transcripts and mature protein occurs constitutively i...

  12. Interaction between Entamoeba histolytica and intestinal epithelial cells involves a CD44 cross-reactive protein expressed on the parasite surface.

    OpenAIRE

    Renesto, P; Sansonetti, P. J.; Guillén, N

    1997-01-01

    This study shows that Entamoeba histolytica binds hyaluronic acid. The binding molecule was identified as an 80-kDa membrane protein and was recognized by anti-CD44 monoclonal antibodies. These data indicate that a CD44 cross-reacting adherence molecule is expressed on E. histolytica.

  13. Fundamentals of Expression in Mammalian Cells.

    Science.gov (United States)

    Dyson, Michael R

    2016-01-01

    Expression of proteins in mammalian cells is a key technology important for many functional studies on human and higher eukaryotic genes. Studies include the mapping of protein interactions, solving protein structure by crystallization and X-ray diffraction or solution phase NMR and the generation of antibodies to enable a range of studies to be performed including protein detection in vivo. In addition the production of therapeutic proteins and antibodies, now a multi billion dollar industry, has driven major advances in cell line engineering for the production of grams per liter of active proteins and antibodies. Here the key factors that need to be considered for successful expression in HEK293 and CHO cells are reviewed including host cells, expression vector design, transient transfection methods, stable cell line generation and cultivation conditions. PMID:27165328

  14. Simvastatin Modulates Mesenchymal Stromal Cell Proliferation and Gene Expression

    OpenAIRE

    Zanette, Dalila Lucíola; Lorenzi, Julio Cesar Cetrulo; Panepucci, Rodrigo Alexandre; Palma, Patricia Vianna Bonini; dos Santos, Daiane Fernanda; Prata, Karen Lima; Silva, Wilson Araújo

    2015-01-01

    Statins are widely used hypocholesterolemic drugs that block the mevalonate pathway, responsible for the biosysnthesis of cholesterol. However, statins also have pleiotropic effects that interfere with several signaling pathways. Mesenchymal stromal cells (MSC) are a heterogeneous mixture of cells that can be isolated from a variety of tissues and are identified by the expression of a panel of surface markers and by their ability to differentiate in vitro into osteocytes, adipocytes and chond...

  15. Whole genome expression profiling using DNA microarray for determining biocompatibility of polymeric surfaces

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Wang, Zhenyu; Kutter, Jörg Peter;

    2006-01-01

    There is an ever increasing need to find surfaces that are biocompatible for applications like medical implants and microfluidics-based cell culture systems. The biocompatibility of five different surfaces with different hydrophobicity was determined using gene expression profiling as well as more...

  16. Fractalkine expression induces endothelial progenitor cell lysis by natural killer cells.

    Directory of Open Access Journals (Sweden)

    Dilyana Todorova

    Full Text Available BACKGROUND: Circulating CD34(+ cells, a population that includes endothelial progenitors, participate in the maintenance of endothelial integrity. Better understanding of the mechanisms that regulate their survival is crucial to improve their regenerative activity in cardiovascular and renal diseases. Chemokine-receptor cross talk is critical in regulating cell homeostasis. We hypothesized that cell surface expression of the chemokine fractalkine (FKN could target progenitor cell injury by Natural Killer (NK cells, thereby limiting their availability for vascular repair. METHODOLOGY/PRINCIPAL FINDINGS: We show that CD34(+-derived Endothelial Colony Forming Cells (ECFC can express FKN in response to TNF-α and IFN-γ inflammatory cytokines and that FKN expression by ECFC stimulates NK cell adhesion, NK cell-mediated ECFC lysis and microparticles release in vitro. The specific involvement of membrane FKN in these processes was demonstrated using FKN-transfected ECFC and anti-FKN blocking antibody. FKN expression was also evidenced on circulating CD34(+ progenitor cells and was detected at higher frequency in kidney transplant recipients, when compared to healthy controls. The proportion of CD34(+ cells expressing FKN was identified as an independent variable inversely correlated to CD34(+ progenitor cell count. We further showed that treatment of CD34(+ circulating cells isolated from adult blood donors with transplant serum or TNF-α/IFN-γ can induce FKN expression. CONCLUSIONS: Our data highlights a novel mechanism by which FKN expression on CD34(+ progenitor cells may target their NK cell mediated killing and participate to their immune depletion in transplant recipients. Considering the numerous diseased contexts shown to promote FKN expression, our data identify FKN as a hallmark of altered progenitor cell homeostasis with potential implications in better evaluation of vascular repair in patients.

  17. CNPase Expression in Olfactory Ensheathing Cells

    Directory of Open Access Journals (Sweden)

    Christine Radtke

    2011-01-01

    Full Text Available A large body of work supports the proposal that transplantation of olfactory ensheathing cells (OECs into nerve or spinal cord injuries can promote axonal regeneration and remyelination. Yet, some investigators have questioned whether the transplanted OECs associate with axons and form peripheral myelin, or if they recruit endogenous Schwann cells that form myelin. Olfactory bulbs from transgenic mice expressing the enhanced green fluorescent protein (eGFP under the control of the 2-3-cyclic nucleotide 3-phosphodiesterase (CNPase promoter were studied. CNPase is expressed in myelin-forming cells throughout their lineage. We examined CNPase expression in both in situ in the olfactory bulb and in vitro to determine if OECs express CNPase commensurate with their myelination potential. eGFP was observed in the outer nerve layer of the olfactory bulb. Dissociated OECs maintained in culture had both intense eGFP expression and CNPase immunostaining. Transplantation of OECs into transected peripheral nerve longitudinally associated with the regenerated axons. These data indicate that OECs in the outer nerve layer of the olfactory bulb of CNPase transgenic mice express CNPase. Thus, while OECs do not normally form myelin on olfactory nerve axons, their expression of CNPase is commensurate with their potential to form myelin when transplanted into injured peripheral nerve.

  18. Expression of Connexin43 in Rat Epithelial Cells and Fibroblasts

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To explore the role of connexin43 (Cx43) in gap junctional intercellular communication (GJIC) and propagated sensation along meridians, the expression of Cx43 in the rat epithelial cells and fibroblasts was studied both in vitro and in vivo. With the in vitro study, the rat epithelial cells and fibroblasts were cultured together, and the localization of Cx43 was detected by immunohistochemistry and indirect immunofluorescent cytochemistry and under confocal microscopy . And the expression of Cx43 on the surface of the cells was examined by flow cytometry. With the in vivo examination, 20 SD rats were randomized into control group (n = 10) and electrical acupuncture group (EAgroup, n=10). EA ( 0.5-1.5 V, 4-16 Hz , 30 min) was applied to"Zusanli"acupoint for 30 min at rat's hind paw, the localization of Cx43 was immunohistochemically detected.The immunohistochemical staining and indirect immunfluorescent cytochemistry showed that Cx43was localized on the surface of the cells and in the cytoplasm. The relative expression level of Cx43on the cellular membrane surfaces of the rat epithelial cells and fibroblasts, as determined by FACS, were 13.91 % and 29.53 % respectively. Our studied suggested that Cx43 might be involved in GJIC and propagated sensation along meridians.

  19. Patterns of expression of cell wall related genes in sugarcane

    Directory of Open Access Journals (Sweden)

    Lima D.U.

    2001-01-01

    Full Text Available Our search for genes related to cell wall metabolism in the sugarcane expressed sequence tag (SUCEST database (http://sucest.lbi.dcc.unicamp.br resulted in 3,283 reads (1% of the total reads which were grouped into 459 clusters (potential genes with an average of 7.1 reads per cluster. To more clearly display our correlation coefficients, we constructed surface maps which we used to investigate the relationship between cell wall genes and the sugarcane tissues libraries from which they came. The only significant correlations that we found between cell wall genes and/or their expression within particular libraries were neutral or synergetic. Genes related to cellulose biosynthesis were from the CesA family, and were found to be the most abundant cell wall related genes in the SUCEST database. We found that the highest number of CesA reads came from the root and stem libraries. The genes with the greatest number of reads were those involved in cell wall hydrolases (e.g. beta-1,3-glucanases, xyloglucan endo-beta-transglycosylase, beta-glucosidase and endo-beta-mannanase. Correlation analyses by surface mapping revealed that the expression of genes related to biosynthesis seems to be associated with the hydrolysis of hemicelluloses, pectin hydrolases being mainly associated with xyloglucan hydrolases. The patterns of cell wall related gene expression in sugarcane based on the number of reads per cluster reflected quite well the expected physiological characteristics of the tissues. This is the first work to provide a general view on plant cell wall metabolism through the expression of related genes in almost all the tissues of a plant at the same time. For example, developing flowers behaved similarly to both meristematic tissues and leaf-root transition zone tissues. Besides providing a basis for future research on the mechanisms of plant development which involve the cell wall, our findings will provide valuable tools for plant engineering in the

  20. Probe microscopy: Scanning below the cell surface

    Science.gov (United States)

    Sahin, Ozgur

    2008-08-01

    Conventional atomic force microscopy probes only the surface of specimens. A related technique called scanning near-field ultrasonic holography can now image nanoparticles buried below the surfaces of cells, which could prove useful in nanotoxicology.

  1. High epitope expression levels increase competition between T cells.

    Directory of Open Access Journals (Sweden)

    Almut Scherer

    2006-08-01

    Full Text Available Both theoretical predictions and experimental findings suggest that T cell populations can compete with each other. There is some debate on whether T cells compete for aspecific stimuli, such as access to the surface on antigen-presenting cells (APCs or for specific stimuli, such as their cognate epitope ligand. We have developed an individual-based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell competition is mainly for specific or aspecific stimuli. Under low epitope expression, competition is mainly for the specific epitope stimuli, and, hence, different epitope-specific T cell populations coexist readily. However, if epitope expression levels are high, aspecific competition becomes more important. Such between-specificity competition can lead to competitive exclusion between different epitope-specific T cell populations. Our model allows us to delineate the circumstances that facilitate coexistence of T cells of different epitope specificity. Understanding mechanisms of T cell coexistence has important practical implications for immune therapies that require a broad immune response.

  2. Fluid dynamics and noise in bacterial cell-cell and cell-surface scattering

    CERN Document Server

    Drescher, Knut; Cisneros, Luis H; Ganguly, Sujoy; Goldstein, Raymond E; 10.1073/pnas.1019079108

    2011-01-01

    Bacterial processes ranging from gene expression to motility and biofilm formation are constantly challenged by internal and external noise. While the importance of stochastic fluctuations has been appreciated for chemotaxis, it is currently believed that deterministic long-range fluid dynamical effects govern cell-cell and cell-surface scattering - the elementary events that lead to swarming and collective swimming in active suspensions and to the formation of biofilms. Here, we report the first direct measurements of the bacterial flow field generated by individual swimming Escherichia coli both far from and near to a solid surface. These experiments allowed us to examine the relative importance of fluid dynamics and rotational diffusion for bacteria. For cell-cell interactions it is shown that thermal and intrinsic stochasticity drown the effects of long-range fluid dynamics, implying that physical interactions between bacteria are determined by steric collisions and near-field lubrication forces. This dom...

  3. An expression profile analysis of ES cell-derived definitive endodermal cells and Pdx1-expressing cells

    Directory of Open Access Journals (Sweden)

    Kume Kazuhiko

    2011-03-01

    Full Text Available Abstract Background We developed an efficient in vitro method to differentiate mouse ES cells into the definitive endoderm (DE and then Pdx1-expressing pancreatic lineages using mesodermal-derived supporting cells, M15. Using this method, resulting ES cell-derived DE and Pdx1-expressing cells were isolated by cell sorting, and their gene expression profiles were investigated with DNA microarray. Genes that were specifically expressed in DE and/or in Pdx1-expressing cells were extracted and their expression patterns in normal embryonic development were studied. Results Genes whose expression increased in DE and Pdx1 positive cells compared to the undifferentiated ES cells were chosen and in situ hybridizations were performed. Out of 54 genes examined, 27 were expressed in the DE of E8.5 mouse embryos and 15 genes were expressed in distinct domains in the pancreatic buds of E14.5 embryos. Among those genes expressed were Foxq1, CpM, Foxp4, Pcdh1, and Zmiz1, which were previously reported in other endodermal tissues. Genes, such as Parm1, Tmem184a, Hipk2 and Sox4 were reported to be expressed during early pancreatic development. Nptx2, C2cd4b, Tcf7l2 and Kiss1r were reported to be associated with beta cell or pancreatic functions in the adult. Akr1c19, Aebp2, Pbxip1 and Creb3l1, were novel and have not been described as being expressed either in DE or the pancreas. Conclusions We identified 27 genes, including 4 novel genes expressed in DE and pancreatic progenitor cells during normal development using an ES cell in vitro differentiation system. These results showed that DE cells and Pdx1/GFP-expressing cells obtained from our M15 based differentiation method mimic cells during the normal developmental processes. Additionally, ES cells are an excellent model for studies of early developmental processes.

  4. The pancreatic beta cell surface proteome

    OpenAIRE

    Stützer, I.; Esterházy, D.; Stoffel, M.

    2012-01-01

    The pancreatic beta cell is responsible for maintaining normoglycaemia by secreting an appropriate amount of insulin according to blood glucose levels. The accurate sensing of the beta cell extracellular environment is therefore crucial to this endocrine function and is transmitted via its cell surface proteome. Various surface proteins that mediate or affect beta cell endocrine function have been identified, including growth factor and cytokine receptors, transporters, ion channels and prote...

  5. Involvement of cell surface phosphatidylinositol-anchored glycoproteins in cell-cell adhesion of chick embryo myoblasts

    OpenAIRE

    1989-01-01

    During myogenesis myoblasts fuse to form multinucleate cells that express muscle-specific proteins. A specific cell-cell adhesion process precedes lipid bilayer union during myoblast fusion (Knudsen, K. A., and A. F. Horwitz. 1977. Dev. Biol. 58:328-338) and is mediated by cell surface glycoproteins (Knudsen, K. A., 1985. J. Cell Biol. 101:891- 897). In this paper we show that myoblast adhesion and myotube formation are inhibited by treating fusion-competent myoblasts with phosphatidylinosito...

  6. Differential expression of cell adhesion genes

    DEFF Research Database (Denmark)

    Stein, Wilfred D; Litman, Thomas; Fojo, Tito;

    2005-01-01

    It is well known that tumors arising from tissues such as kidney, pancreas, liver and stomach are particularly refractory to treatment. Searching for new anticancer drugs using cells in culture has yielded some effective therapies, but these refractory tumors remain intractable. Studies that...... survival might, therefore, act through such a matrix-to-cell suppression of apoptosis. Indeed, correlative mining of gene expression and patient survival databases suggests that poor survival in patients with metastatic cancer correlates highly with tumor expression of a common theme: the genes involved in...

  7. Surface Functionalization for Protein and Cell Patterning

    Science.gov (United States)

    Colpo, Pascal; Ruiz, Ana; Ceriotti, Laura; Rossi, François

    The interaction of biological systems with synthetic material surfaces is an important issue for many biological applications such as implanted devices, tissue engineering, cell-based sensors and assays, and more generally biologic studies performed ex vivo. To ensure reliable outcomes, the main challenge resides in the ability to design and develop surfaces or artificial micro-environment that mimic 'natural environment' in interacting with biomolecules and cells without altering their function and phenotype. At this effect, microfabrication, surface chemistry and material science play a pivotal role in the design of advanced in-vitro systems for cell culture applications. In this chapter, we discuss and describe different techniques enabling the control of cell-surface interactions, including the description of some techniques for immobilization of ligands for controlling cell-surface interactions and some methodologies for the creation of well confined cell rich areas.

  8. Targeted Reduction in Expression of Trypanosoma cruzi Surface Glycoprotein gp90 Increases Parasite Infectivity

    OpenAIRE

    Málaga, Sergio; Yoshida, Nobuko

    2001-01-01

    A previous study had shown that the expression of gp90, a stage-specific surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes, is inversely correlated with the parasite's ability to invade mammalian cells. By using antisense oligonucleotides complementary to a region of the gp90 gene implicated in host cell adhesion, we investigated whether the selective inhibition of gp90 synthesis affected the capacity of metacyclic forms to enter target cells. Parasites were incubated for 2...

  9. Transitional cell carcinoma express vitamin D receptors

    DEFF Research Database (Denmark)

    Hermann, G G; Andersen, C B

    1997-01-01

    Recently, vitamin D analogues have shown antineoplastic effect in several diseases. Vitamin D analogues exert its effect by interacting with the vitamin D receptor (VDR). Studies of VDR in transitional cell carcinoma (TCC) have not been reported. The purpose of the present study was therefore.......05). Similarly, also tumor grade appeared to be related to the number of cells expressing the receptor. Normal urothlium also expressed VDR but only with low intensity. Our study shows that TCC cells possess the VDR receptor which may make them capable to respond to stimulation with vitamin D, but functional...... studies of vitamin D's effect on TCC cells in vitro are necessary before the efficacy of treatment with vitamin D analogues in TCC can be evaluated in patients....

  10. The cell surface of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Wanderley de Souza

    1984-01-01

    Full Text Available The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  11. The cell surface of Trypanosoma cruzi

    OpenAIRE

    Wanderley de Souza; Thais Souto-Padrón

    1984-01-01

    The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  12. Interaction of progenitor bone cells with different surface modifications of titanium implant

    International Nuclear Information System (INIS)

    Changes in the physical and chemical properties of Ti surfaces can be attributed to cell performance, which improves surface biocompatibility. The cell proliferation, mineralization ability, and gene expression of progenitor bone cells (D1 cell) were compared on five different Ti surfaces, namely, mechanical grinding (M), electrochemical modification through potentiostatic anodization (ECH), sandblasting and acid etching (SLA), sandblasting, hydrogen peroxide treatment, and heating (SAOH), and sandblasting, alkali heating, and etching (SMART). SAOH treatment produced the most hydrophilic surface, whereas SLA produced the most hydrophobic surface. Cell activity indicated that SLA and SMART produced significantly rougher surfaces and promoted D1 cell attachment within 1 day of culturing, whereas SAOH treatment produced moderate roughness (Ra = 1.26 μm) and accelerated the D1 cell proliferation up to 7 days after culturing. The ECH surface significantly promoted alkaline phosphatase (ALP) expression and osteocalcin (OCN) secretion in the D1 cells compared with the other surface groups. The ECH and SMART-treated Ti surfaces resulted in maximum ALP and OCN expressions during the D1 cell culture. SLA, SAOH, and SMART substrate surfaces were rougher and exhibited better cell metabolic responses during the early stage of cell attachment, proliferation, and morphologic expressions within 1 day of D1 cell culture. The D1 cells cultured on the ECH and SMART substrates exhibited higher differentiation, and higher ALP and OCN expressions after 10 days of culture. Thus, the ECH and SMART treatments promote better ability of cell mineralization in vitro, which demonstrate their great potential for clinical use. - Highlights: • Progenitor bone cells onto Ti with different modifications are characterized. • Surface roughness and hydrophilicity encourage early stage cell attachment. • Composition and surface treatments are more vital in bone cell mineralization.

  13. Interaction of progenitor bone cells with different surface modifications of titanium implant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Chen, Ya-Shun [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Yi; Kuo, Tzu-Huang; Kuo, Hsien-Nan [Medical Device Development Division, Metal Industries Research and Development Centre, Kaohsiung 82151, Taiwan (China)

    2014-04-01

    Changes in the physical and chemical properties of Ti surfaces can be attributed to cell performance, which improves surface biocompatibility. The cell proliferation, mineralization ability, and gene expression of progenitor bone cells (D1 cell) were compared on five different Ti surfaces, namely, mechanical grinding (M), electrochemical modification through potentiostatic anodization (ECH), sandblasting and acid etching (SLA), sandblasting, hydrogen peroxide treatment, and heating (SAOH), and sandblasting, alkali heating, and etching (SMART). SAOH treatment produced the most hydrophilic surface, whereas SLA produced the most hydrophobic surface. Cell activity indicated that SLA and SMART produced significantly rougher surfaces and promoted D1 cell attachment within 1 day of culturing, whereas SAOH treatment produced moderate roughness (Ra = 1.26 μm) and accelerated the D1 cell proliferation up to 7 days after culturing. The ECH surface significantly promoted alkaline phosphatase (ALP) expression and osteocalcin (OCN) secretion in the D1 cells compared with the other surface groups. The ECH and SMART-treated Ti surfaces resulted in maximum ALP and OCN expressions during the D1 cell culture. SLA, SAOH, and SMART substrate surfaces were rougher and exhibited better cell metabolic responses during the early stage of cell attachment, proliferation, and morphologic expressions within 1 day of D1 cell culture. The D1 cells cultured on the ECH and SMART substrates exhibited higher differentiation, and higher ALP and OCN expressions after 10 days of culture. Thus, the ECH and SMART treatments promote better ability of cell mineralization in vitro, which demonstrate their great potential for clinical use. - Highlights: • Progenitor bone cells onto Ti with different modifications are characterized. • Surface roughness and hydrophilicity encourage early stage cell attachment. • Composition and surface treatments are more vital in bone cell mineralization.

  14. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/106 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/106 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG

  15. Carbon Ion Irradiation Inhibits Glioma Cell Migration Through Downregulation of Integrin Expression

    International Nuclear Information System (INIS)

    Purpose: To investigate the effect of carbon ion irradiation on glioma cell migration. Methods and Materials: U87 and Ln229 glioma cells were irradiated with photons and carbon ions. Migration was analyzed 24 h after irradiation. Fluorescence-activated cell sorting analysis was performed in order to quantify surface expression of integrins. Results: Single photon doses of 2 Gy and 10 Gy enhanced ανβ3 and ανβ5 integrin expression and caused tumor cell hypermigration on both vitronectin (Vn) and fibronectin (Fn). Compared to integrin expression in unirradiated cells, carbon ion irradiation caused decreased integrin expression and inhibited cell migration on both Vn and Fn. Conclusion: Photon radiotherapy (RT) enhances the risk of tumor cell migration and subsequently promotes locoregional spread via photon induction of integrin expression. In contrast to photon RT, carbon ion RT causes decreased integrin expression and suppresses glioma cell migration on both Vn and Fn, thus promising improved local control.

  16. Study of surface cell Madelung constant and surface free energy of nanosized crystal grain

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei-Jia; Wang Tian-Min; Rong Ai-Lun; Cui Min

    2006-01-01

    Surface cell Madelung constant is firstly defined for calculating the surface free energy of nanosized crystal grains,which explains the physical performance of small crystals and may be greatly beneficial to the analysis of surface states and the study of the dynamics of crystal nucleation and growth.A new approximative expression of the surface energy and relevant thermodynamic data are used in this calculation.New formula and computing method for calculating the Madelung constant α of any complex crystals are proposed,and the surface free energies and surface electrostatic energies of nanosized crystal grains and the Madelung constant of some complex crystals are theoretically calculated in this paper.The surface free energy of nanosized-crystal-grain TiO2 and the surface electrostatic energy (absolute value) of nanosized-crystal-grain α-A12O3 are found to be the biggest among all the crystal grains including those of other species.

  17. Study of Surface Cell Madelung Constant and Surface Free Energy of Nanosized Crystal Grain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Jia; WANG Tian-Min; CUI Min

    2005-01-01

    Surface cell Madelung constant is firstly defined in calculating surface free energy of nanosized crystal grains, which explains the physical performance of small crystals and may be great benefit to make surface analysis and study dynamics of crystal nucleus growth. A new ap- proximative expression of surface energy and relevant thermodynamic data was used in this cal- culation. A new formula and computing method for calculating the Madelung constant α of any complex crystals is proposed, and surface free energies and surface electrostatic energies of nano- sized crystal grains as well as Madelung constant of some complex crystals are theoretically cal- culated in this paper. The surface free energy of nanosized crystal grain TiO2 and surface elec- trostatic energy(absolute value) of nanosized crystal grain α-Al2O3 are found to be the biggest among other crystal grains.

  18. Tissue factor expression by endothelial cells in sickle cell anemia.

    OpenAIRE

    Solovey, A; Gui, L; Key, N. S.; Hebbel, R.P.

    1998-01-01

    The role of the vascular endothelium in activation of the coagulation system, a fundamental homeostatic mechanism of mammalian biology, is uncertain because there is little evidence indicating that endothelial cells in vivo express tissue factor (TF), the system's triggering mechanism. As a surrogate for vessel wall endothelium, we examined circulating endothelial cells (CEC) from normals and patients with sickle cell anemia, a disease associated with activation of coagulation. We find that s...

  19. Inhibition of hepatitis B virus surface antigen expression by small hairpin RNA in vitro

    Institute of Scientific and Technical Information of China (English)

    Zheng-Gang Yang; Zhi Chen; Qin Ni; Ning Xu; Jun-Bin Shao; Hang-Ping Yao

    2005-01-01

    AIM: To explore the anti-hepatitis B virus effect of RNA interference (RNAi) using small hairpin RNA (shRNA)expression vector.METHODS: Hepatitis B virus surface antigen green fluorescent protein (HBs-GFP) fusion vector and shRNA expression vectors were constructed and cotransfected transiently into HepG2 cells. mRNAs extracted from HepG2 cells were detected by real-time PCR. Fluorescence of HBs-GFP protein was detected by fluorescence-activated cell sorting (FACS). The effective shRNA expression vector was transfected into HepG2.2.15 cells. HBsAg and HBeAg in HepG2.2.15 cells were analyzed by radioimmunoassay (RIA) method.RESULTS: FACS revealed that shRNA targeting at HBsAg reduced the GFP signal by 56% compared to the control.Real-time PCR showed that HBs-GFP mRNA extracted from HepG2 cells cotransfected with pAVU6+27 and HBs-GFP expression plasmids decreased by 90% compared to the empty vector control. The expressions of HBsAg and HBeAg were also inhibited by 43% and 64%, respectively.CONCLUSION: RNAi using shRNA expression vector can inhibit the expression of HBsAg, providing a fresh approach to screening the efficient small interfering RNAs (siRNAs).

  20. Cell Surface Human Airway Trypsin-Like Protease Is Lost During Squamous Cell Carcinogenesis.

    Science.gov (United States)

    Duhaime, Michael J; Page, Khaliph O; Varela, Fausto A; Murray, Andrew S; Silverman, Michael E; Zoratti, Gina L; List, Karin

    2016-07-01

    Cancer progression is accompanied by increased levels of extracellular proteases that are capable of remodeling the extracellular matrix, as well as cleaving and activating growth factors and receptors that are involved in pro-cancerous signaling pathways. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression, however, the expression or function of the TTSP Human Airway Trypsin-like protease (HAT) in carcinogenesis has not been examined. In the present study we aimed to determine the expression of HAT during squamous cell carcinogenesis. HAT transcript is present in several tissues containing stratified squamous epithelium and decreased expression is observed in carcinomas. We determined that HAT protein is consistently expressed on the cell surface in suprabasal/apical layers of squamous cells in healthy cervical and esophageal epithelia. To assess whether HAT protein is differentially expressed in normal tissue versus tissue in different stages of carcinogenesis, we performed a comprehensive immunohistochemical analysis of HAT protein expression levels and localization in arrays of paraffin embedded human cervical and esophageal carcinomas compared to the corresponding normal tissue. We found that HAT protein is expressed in the non-proliferating, differentiated cellular strata and is lost during the dedifferentiation of epithelial cells, a hallmark of squamous cell carcinogenesis. Thus, HAT expression may potentially be useful as a marker for clinical grading and assessment of patient prognosis in squamous cell carcinomas. J. Cell. Physiol. 231: 1476-1483, 2016. © 2015 Wiley Periodicals, Inc. PMID:26297835

  1. Nanostructuring of Solar Cell Surfaces

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    Solar energy is by far the most abundant renewable energy source available, but the levelized cost of solar energy is still not competitive with that of fossil fuels. Therefore there is a need to improve the power conversion effciency of solar cells without adding to the production cost. The main...... objective of this PhD thesis is to develop nanostructured silicon (Si) solar cells with higher power conversion efficiency using only scalable and cost-efficient production methods. The nanostructures, known as 'black silicon', are fabricated by single-step, maskless reactive ion etching and used as front...... and characterized for comparison. Power conversion eciency of 16.5% was obtained for this batch of RIE-textured Si solar cells. The eciency of the KOH-textured reference cell was 17.8%. Quantum Efficiency measurements and carrier loss analysis show that the lower eciency of the RIE-textured cells is primarily due...

  2. Characterization of cell subpopulations expressing progenitor cell markers in porcine cardiac valves.

    Directory of Open Access Journals (Sweden)

    Huan Wang

    Full Text Available Valvular interstitial cells (VICs are the main population of cells found in cardiac valves. These resident fibroblastic cells play important roles in maintaining proper valve function, and their dysregulation has been linked to disease progression in humans. Despite the critical functions of VICs, their cellular composition is still not well defined for humans and other mammals. Given the limited availability of healthy human valves and the similarity in valve structure and function between humans and pigs, we characterized porcine VICs (pVICs based on expression of cell surface proteins and sorted a specific subpopulation of pVICs to study its functions. We found that small percentages of pVICs express the progenitor cell markers ABCG2 (~5%, NG2 (~5% or SSEA-4 (~7%, whereas another subpopulation (~5% expresses OB-CDH, a type of cadherin expressed by myofibroblasts or osteo-progenitors. pVICs isolated from either aortic or pulmonary valves express most of these protein markers at similar levels. Interestingly, OB-CDH, NG2 and SSEA-4 all label distinct valvular subpopulations relative to each other; however, NG2 and ABCG2 are co-expressed in the same cells. ABCG2(+ cells were further characterized and found to deposit more calcified matrix than ABCG2(- cells upon osteogenic induction, suggesting that they may be involved in the development of osteogenic VICs during valve pathology. Cell profiling based on flow cytometry and functional studies with sorted primary cells provide not only new and quantitative information about the cellular composition of porcine cardiac valves, but also contribute to our understanding of how a subpopulation of valvular cells (ABCG2(+ cells may participate in tissue repair and disease progression.

  3. Cell behaviour on chemically microstructured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Magnani, Agnese; Priamo, Alfredo; Pasqui, Daniela; Barbucci, Rolando

    2003-03-03

    Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical topographies on the cell behaviour was then analysed. Human and 3T3 fibroblasts, bovine aortic and human (HGTFN line) endothelial cells were used and their behaviour on the micropatterned surfaces was analysed in terms of adhesion, proliferation, locomotion and orientation. Both chemical and topographical controls were found to be important for cell guidance. By decreasing the stripe dimensions, a more fusiform shape of cell was observed. At the same time, the cell locomotion and orientation parallel to the structure increased. However, differences in cell behaviour were detected according to both cell type and micropattern dimensions.

  4. MEMBRANE LEc EXPRESSION IN BREAST CANCER CELLS

    Directory of Open Access Journals (Sweden)

    Ya. A. Udalova

    2014-09-01

    Full Text Available Affine chromatography was used to isolate Lec antibodies from the sera of a healthy female donor with the high titers of these anti- bodies, which were labeled with biotin. The study enrolled 51 patients with primary breast cancer (BC. Antigen expression was found by immunohistochemistry and flow cytometry. With these two techniques being used, the detection rate of Lec expression in BC cells was 65% (33/51; the antigen was most frequently found by flow cytometry as compared with immunohistochemistry: 72 and 58% of cases, respectively.

  5. Regulation of gene expression in ovarian cancer cells by luteinizing hormone receptor expression and activation

    International Nuclear Information System (INIS)

    Since a substantial percentage of ovarian cancers express gonadotropin receptors and are responsive to the relatively high concentrations of pituitary gonadotropins during the postmenopausal years, it has been suggested that receptor activation may contribute to the etiology and/or progression of the neoplasm. The goal of the present study was to develop a cell model to determine the impact of luteinizing hormone (LH) receptor (LHR) expression and LH-mediated LHR activation on gene expression and thus obtain insights into the mechanism of gonadotropin action on ovarian surface epithelial (OSE) carcinoma cells. The human ovarian cancer cell line, SKOV-3, was stably transfected to express functional LHR and incubated with LH for various periods of time (0-20 hours). Transcriptomic profiling was performed on these cells to identify LHR expression/activation-dependent changes in gene expression levels and pathways by microarray and qRT-PCR analyses. Through comparative analysis on the LHR-transfected SKOV-3 cells exposed to LH, we observed the differential expression of 1,783 genes in response to LH treatment, among which five significant families were enriched, including those of growth factors, translation regulators, transporters, G-protein coupled receptors, and ligand-dependent nuclear receptors. The most highly induced early and intermediate responses were found to occupy a network impacting transcriptional regulation, cell growth, apoptosis, and multiple signaling transductions, giving indications of LH-induced apoptosis and cell growth inhibition through the significant changes in, for example, tumor necrosis factor, Jun and many others, supportive of the observed cell growth reduction in in vitro assays. However, other observations, e.g. the substantial up-regulation of the genes encoding the endothelin-1 subtype A receptor, stromal cell-derived factor 1, and insulin-like growth factor II, all of which are potential therapeutic targets, may reflect a positive

  6. Diverse mechanisms regulate the surface expression of immunotherapeutic target CTLA-4

    Directory of Open Access Journals (Sweden)

    Helga eSchneider

    2014-12-01

    Full Text Available T-cell co-receptor cytotoxic T-cell antigen 4 (CTLA-4 is a critical inhibitory regulator of T-cell immunity and antibody blockade of the co-receptor has been shown to be effective in tumor immunotherapy. Paradoxically, the majority of CTLA-4 is located in intracellular compartments from where it is transported to the cell surface and rapidly internalized. The intracellular trafficking pathways that control transport of the co-receptor to the cell surface will ensure the appropriate balance of negative and positive signaling for a productive immune response with minimal autoimmune disorders. It will also influence the degree of inhibition and the potency of antibody checkpoint blockade in cancer immunotherapy. Current evidence indicates that the mechanisms of CTLA-4 transport to the cell surface and its residency are multifactorial involving a combination of immune cell specific adaptors such as TRIM and LAX, the small GTPase Rab8 as well as generic components such as ARF-1, phospholipase D (PLD and the heterotetrameric AP1/2 complex. This review covers the recent developments in our understanding of the processes that control the expression of this important co-inhibitory receptor for the modulation of T-cell immunity. Interference with the processes that regulate CTLA-4 surface expression could be an alternate therapeutic approach in the treatment of cancer and autoimmunity.

  7. Naïve and memory B cells in the rhesus macaque can be differentiated by surface expression of CD27 and have differential responses to CD40 ligation

    OpenAIRE

    Kuhrt, David; Faith, Seth; Hattemer, Angela; Leone, Amanda; Sodora, Donald; Picker, Louis; Borghesi, Lisa; Cole, Kelly Stefano

    2010-01-01

    The rhesus macaque (RM) model has the potential to be an invaluable tool for studying B cell populations during pathogenic infections, however, to date, there has been no definitive delineation of naïve and memory B cell populations in the RM. This has precluded a rigorous analysis of the generation, persistence and resolution of a pathogen-specific memory B cell response. The present study utilized multiple analyses to demonstrate that CD27 expression on B cells is consistent with a memory p...

  8. Expression of TMPRSS4 in non-small cell lung cancer and its modulation by hypoxia

    OpenAIRE

    NGUYEN, TRI-HUNG; WEBER, WILLIAM; HAVARI, EVIS; CONNORS, TIMOTHY; BAGLEY, REBECCA G.; McLAREN, RAJASHREE; Nambiar, Prashant R; Madden, Stephen L.; Teicher, Beverly A.; Roberts, Bruce; Kaplan, Johanne; SHANKARA, SRINIVAS

    2012-01-01

    Overexpression of TMPRSS4, a cell surface-associated transmembrane serine protease, has been reported in pancreatic, colorectal and thyroid cancers, and has been implicated in tumor cell migration and metastasis. Few reports have investigated both TMPRSS4 gene expression levels and the protein products. In this study, quantitative RT-PCR and protein staining were used to assess TMPRSS4 expression in primary non-small cell lung carcinoma (NSCLC) tissues and in lung tumor cell lines. At the tra...

  9. Expression of bacterial luciferase in eukaryotic cells

    International Nuclear Information System (INIS)

    Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To evaluate gene expression, n-decanal and FMNH2 were supplemented to transfected HEK 293T cell lines which were measured by In Vivo Imaging System. The luxA gene was cloned into the MCS(A) of pIRESGFP via the 5' SalI and 3' EcoRI restriction sites to generate pIRESluxA. The luxB gene was cleaved via a 5' NcoI and 3' NotI site from luxB and cloned into the MCS(B) of pIRESluxA to generate pIRESluxAB. LuxA and B genes was cleaved by 5' EcoRI and 3' SpeI and cloned into the pcDNA3.1 mammalian expression vector to create pcDNALuxA and pcDNALuxB. We constructed bicistronic vector system which is composed of bacterial luciferase genes (lux A and B) on the single reading frame. These results hold a promise of an available development of an autonomous light generating lux reporter system in mammalian cells

  10. High vacuum cells for classical surface techniques

    International Nuclear Information System (INIS)

    Novel glass cells were designed and built to be able to perform surface potential and surface tension measurements in a contained environment. The cells can withstand pressures of approximately 1x10-6 Torr, providing a reasonable level of control in terms of the amounts of volatile contaminants during experimentation. The measurements can take several hours; thus the cells help maintain the integrity of the sample in the course of the experiment. To test for the feasibility of the cell design, calibration measurements were performed. For the surface potential cell, the modified TREK 6000B-7C probe exhibited performance comparable to its unmodified counterpart. The correlation measurements between applied potential on the test surface and the measured potential showed R-values very close to 1 as well as standard deviation values of less than 1. Results also demonstrate improved measurement values for experiments performed in vacuum. The surface tension cell, on the other hand, which was used to perform the pendant drop method, was tested on common liquids and showed percentage errors of 0.5% when compared to literature values. The fabricated cells redefine measurements using classical surface techniques, providing unique and novel methods of sample preparation, premeasurement preparation, and sample analysis at highly beneficial expenditure cost.

  11. Aberrant expression of metallothioneins in clear cell renal cell carcinomas

    Directory of Open Access Journals (Sweden)

    Rymar V. I.

    2015-12-01

    Full Text Available Aim. To find candidate tumor suppressor genes among metallothioneins for clear cell renal cell carcinoma. Methods. Analysis of the microarray data, quantitative PCR. Results. We found three genes encoding metallothioneines that showed reduced expression in different types of renal tumors, using protocol of the cross-platform meta-analysis of microarray data with normalization on several reference genes. Decreased expression of the MT1G, MT1F, and MT1H genes in clear cell renal cell carcinoma was confirmed by qPCR. Conclusions. The MT1G, MT1F and MT1H genes as well as may be considered as the candidate tumor suppressor genes for ccRCC.

  12. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.

    Directory of Open Access Journals (Sweden)

    Jacob M Laughery

    Full Text Available Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as

  13. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.

    Science.gov (United States)

    Laughery, Jacob M; Knowles, Donald P; Schneider, David A; Bastos, Reginaldo G; McElwain, Terry F; Suarez, Carlos E

    2014-01-01

    Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine

  14. Functional dynamics of cell surface membrane proteins

    Science.gov (United States)

    Nishida, Noritaka; Osawa, Masanori; Takeuchi, Koh; Imai, Shunsuke; Stampoulis, Pavlos; Kofuku, Yutaka; Ueda, Takumi; Shimada, Ichio

    2014-04-01

    Cell surface receptors are integral membrane proteins that receive external stimuli, and transmit signals across plasma membranes. In the conventional view of receptor activation, ligand binding to the extracellular side of the receptor induces conformational changes, which convert the structure of the receptor into an active conformation. However, recent NMR studies of cell surface membrane proteins have revealed that their structures are more dynamic than previously envisioned, and they fluctuate between multiple conformations in an equilibrium on various timescales. In addition, NMR analyses, along with biochemical and cell biological experiments indicated that such dynamical properties are critical for the proper functions of the receptors. In this review, we will describe several NMR studies that revealed direct linkage between the structural dynamics and the functions of the cell surface membrane proteins, such as G-protein coupled receptors (GPCRs), ion channels, membrane transporters, and cell adhesion molecules.

  15. Identification of Functional Human Splenic Memory B Cells by Expression of CD148 and CD27

    OpenAIRE

    Tangye, Stuart G.; Liu, Yong-Jun; Aversa, Gregorio; Phillips, Joseph H.; Vries, Jan E. de

    1998-01-01

    Memory B cells isolated from human tonsils are characterized by an activated cell surface phenotype, localization to mucosal epithelium, expression of somatically mutated immunoglobulin (Ig) variable (V) region genes, and a preferential differentiation into plasma cells in vitro. In spleens of both humans and rodents, a subset of memory B cells is believed to reside in the marginal zone of the white pulp. Similar to tonsil-derived memory B cells, splenic marginal zone B cells can be distingui...

  16. Adhesion of cells to polystyrene surfaces

    OpenAIRE

    1983-01-01

    The surface treatment of polystyrene, which is required to make polystyrene suitable for cell adhesion and spreading, was investigated. Examination of surfaces treated with sulfuric acid or various oxidizing agents using (a) x-ray photoelectron and attenuated total reflection spectroscopy and (b) measurement of surface carboxyl-, hydroxyl-, and sulfur-containing groups by various radiochemical methods showed that sulfuric acid produces an insignificant number of sulfonic acid groups on polyst...

  17. A cell cycle and nutritional checkpoint controlling bacterial surface adhesion.

    Directory of Open Access Journals (Sweden)

    Aretha Fiebig

    2014-01-01

    Full Text Available In natural environments, bacteria often adhere to surfaces where they form complex multicellular communities. Surface adherence is determined by the biochemical composition of the cell envelope. We describe a novel regulatory mechanism by which the bacterium, Caulobacter crescentus, integrates cell cycle and nutritional signals to control development of an adhesive envelope structure known as the holdfast. Specifically, we have discovered a 68-residue protein inhibitor of holdfast development (HfiA that directly targets a conserved glycolipid glycosyltransferase required for holdfast production (HfsJ. Multiple cell cycle regulators associate with the hfiA and hfsJ promoters and control their expression, temporally constraining holdfast development to the late stages of G1. HfiA further functions as part of a 'nutritional override' system that decouples holdfast development from the cell cycle in response to nutritional cues. This control mechanism can limit surface adhesion in nutritionally sub-optimal environments without affecting cell cycle progression. We conclude that post-translational regulation of cell envelope enzymes by small proteins like HfiA may provide a general means to modulate the surface properties of bacterial cells.

  18. Cholinergic regulation of VIP gene expression in human neuroblastoma cells

    DEFF Research Database (Denmark)

    Kristensen, Bo; Georg, Birgitte; Fahrenkrug, Jan

    Vasoactive intestinal polypeptide, muscarinic receptor, neuroblastoma cell, mRNA, gene expression, peptide processing......Vasoactive intestinal polypeptide, muscarinic receptor, neuroblastoma cell, mRNA, gene expression, peptide processing...

  19. Nanotomography of Cell Surfaces with Evanescent Fields

    Directory of Open Access Journals (Sweden)

    Michael Wagner

    2008-01-01

    Full Text Available The technique of variable-angle total internal reflection fluorescence microscopy (TIRFM and its application to nanotomography of cell surfaces are described. Present applications include (1 3D imaging of chromosomes in their metaphase to demonstrate axial resolution in the nanometre range, (2 measurements of cell-substrate topology, which upon cholesterol depletion shows some loosening of cell-substrate contacts, and (3 measurements of cell topology upon photodynamic therapy (PDT, which demonstrate cell swelling and maintenance of focal contacts. The potential of the method for in vitro diagnostics, but also some requirements and limitations are discussed.

  20. The topology of plasminogen binding and activation on the surface of human breast cancer cells

    OpenAIRE

    Andronicos, N M; Ranson, M.

    2001-01-01

    The urokinase-dependent activation of plasminogen by breast cancer cells plays an important role in metastasis. We have previously shown that the metastatic breast cancer cell line MDA-MB-231 over-expresses urokinase and binds and efficiently activates plasminogen at the cell surface compared to non-metastatic cells. The aim of this study was to further characterise plasminogen binding and determine the topology of cell surface-bound plasminogen in terms of its potential for activation. The l...

  1. Prion propagation in cells expressing PrP glycosylation mutants.

    Science.gov (United States)

    Salamat, Muhammad K; Dron, Michel; Chapuis, Jérôme; Langevin, Christelle; Laude, Hubert

    2011-04-01

    Infection by prions involves conversion of a host-encoded cell surface protein (PrP(C)) to a disease-related isoform (PrP(Sc)). PrP(C) carries two glycosylation sites variably occupied by complex N-glycans, which have been suggested by previous studies to influence the susceptibility to these diseases and to determine characteristics of prion strains. We used the Rov cell system, which is susceptible to sheep prions, to generate a series of PrP(C) glycosylation mutants with mutations at one or both attachment sites. We examined their subcellular trafficking and ability to convert into PrP(Sc) and to sustain stable prion propagation in the absence of wild-type PrP. The susceptibility to infection of mutants monoglycosylated at either site differed dramatically depending on the amino acid substitution. Aglycosylated double mutants showed overaccumulation in the Golgi compartment and failed to be infected. Introduction of an ectopic glycosylation site near the N terminus fully restored cell surface expression of PrP but not convertibility into PrP(Sc), while PrP(C) with three glycosylation sites conferred cell permissiveness to infection similarly to the wild type. In contrast, predominantly aglycosylated molecules with nonmutated N-glycosylation sequons, produced in cells expressing glycosylphosphatidylinositol-anchorless PrP(C), were able to form infectious PrP(Sc). Together our findings suggest that glycosylation is important for efficient trafficking of anchored PrP to the cell surface and sustained prion propagation. However, properly trafficked glycosylation mutants were not necessarily prone to conversion, thus making it difficult in such studies to discern whether the amino acid changes or glycan chain removal most influences the permissiveness to prion infection. PMID:21248032

  2. Cell Adhesion on Surface-Functionalized Magnesium.

    Science.gov (United States)

    Wagener, Victoria; Schilling, Achim; Mainka, Astrid; Hennig, Diana; Gerum, Richard; Kelch, Marie-Luise; Keim, Simon; Fabry, Ben; Virtanen, Sannakaisa

    2016-05-18

    The biocompatibility of commercially pure magnesium-based (cp Mg) biodegradable implants is compromised of strong hydrogen evolution and surface alkalization due to high initial corrosion rates of cp Mg in the physiological environment. To mitigate this problem, the addition of corrosion-retarding alloying elements or coating of implant surfaces has been suggested. In the following work, we explored the effect of organic coatings on long-term cell growth. cp Mg was coated with aminopropyltriehtoxysilane + vitamin C (AV), carbonyldiimidazole (CDI), or stearic acid (SA). All three coatings have been previously suggested to reduce initial corrosion and to enhance protein adsorption and hence cell adhesion on magnesium surfaces. Endothelial cells (DH1+/+) and osteosarcoma cells (MG63) were cultured on coated samples for up to 20 days. To quantify Mg corrosion, electrochemical impedance spectroscopy (EIS) was measured after 1, 3, and 5 days of cell culture. We also investigated the speed of initial cell spreading after seeding using fluorescently labeled fibroblasts (NIH/3T3). Hydrogen evolution after contact with cell culture medium was markedly decreased on AV- and SA-coated Mg compared to uncoated Mg. These coatings also showed improved cell adhesion and spreading after 24 h of culture comparable to tissue-treated plastic surfaces. On AV-coated cp Mg, a confluent layer of endothelial cells formed after 5 days and remained intact for up to 20 days. Together, these data demonstrate that surface coating with AV is a viable strategy for improving long-term biocompatibility of cp Mg-based implants. EIS measurements confirmed that the presence of a confluent cell layer increased the corrosion resistance. PMID:27089250

  3. Melanoma Cell Expression of CD200 Inhibits Tumor Formation and Lung Metastasis via Inhibition of Myeloid Cell Functions

    OpenAIRE

    Talebian, Fatemeh; Liu, Jin-Qing; Liu, Zhenzhen; Khattabi, Mazin; He, Yukai; Ganju, Ramesh; Bai, Xue-feng

    2012-01-01

    CD200 is a cell surface glycoprotein that functions through engaging CD200 receptor on cells of the myeloid lineage and inhibits their functions. Expression of CD200 has been implicated in a variety of human cancer cells including melanoma cells and has been thought to play a protumor role. To investigate the role of cancer cell expression of CD200 in tumor formation and metastasis, we generated CD200-positive and CD200-negative B16 melanoma cells. Subcutaneous injection of CD200-positive B16...

  4. Yeast cell surface display for lipase whole cell catalyst and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yun; Zhang, Rui; Lian, Zhongshuai; Wang, Shihui; Wright, Aaron T.

    2014-08-01

    The cell surface display technique allows for the expression of target proteins or peptides on the microbial cell surface by fusing an appropriate protein as an anchoring motif. Yeast display systems, such as Pichia pastoris, Yarowia lipolytica and Saccharomyces cerevisiae, are ideal, alternative and extensive display systems with the advantage of simple genetic manipulation and post-translational modification of expressed heterologous proteins. Engineered yeasts show high performance characteristics and variant utilizations. Herein, we comprehensively summarize the variant factors affecting lipase whole cell catalyst activity and display efficiency, including the structure and size of target proteins, screening anchor proteins, type and chain length of linkers, and the appropriate matching rules among the above-mentioned display units. Furthermore, we also address novel approaches to enhance stability and activity of recombinant lipases, such as VHb gene co-expression, multi-enzyme co-display technique, and the micro-environmental interference and self-assembly techniques. Finally, we represent the variety of applications of whole cell surface displayed lipases on yeast cells in non-aqueous phases, including synthesis of esters, PUFA enrichment, resolution of chiral drugs, organic synthesis and biofuels. We demonstrate that the lipase surface display technique is a powerful tool for functionalizing yeasts to serve as whole cell catalysts, and increasing interest is providing an impetus for broad application of this technique.

  5. Serotonin-induced down-regulation of cell surface serotonin transporter

    DEFF Research Database (Denmark)

    Jørgensen, Trine Nygaard; Christensen, Peter Møller; Gether, Ulrik

    2014-01-01

    The serotonin transporter (SERT) terminates serotonergic signaling and enables refilling of synaptic vesicles by mediating reuptake of serotonin (5-HT) released into the synaptic cleft. The molecular and cellular mechanisms controlling SERT activity and surface expression are not fully understood....... Here we demonstrate that the substrate 5-HT itself causes acute down-regulation of SERT cell surface expression. To assess surface SERT expression by ELISA, we used a SERT variant (TacSERT) where the N-terminus of SERT was fused to the intracellular tail of the extracellularly FLAG-tagged single...... neurons, indicting that endogenous cell-surface resident SERT likewise is down-regulated in the presence of substrate....

  6. Gene expression profiles in irradiated cancer cells

    International Nuclear Information System (INIS)

    Knowledge of the molecular and genetic mechanisms underlying cellular response to radiation may provide new avenues to develop innovative predictive tests of radiosensitivity of tumours and normal tissues and to improve individual therapy. Nowadays very few studies describe molecular changes induced by hadrontherapy treatments, therefore this field has to be explored and clarified. High-throughput methodologies, such as DNA microarray, allow us to analyse mRNA expression of thousands of genes simultaneously in order to discover new genes and pathways as targets of response to hadrontherapy. Our aim is to elucidate the molecular networks involved in the sensitivity/resistance of cancer cell lines subjected to hadrontherapy treatments with a genomewide approach by using cDNA microarray technology to identify gene expression profiles and candidate genes responsible of differential cellular responses

  7. Direct cell lysis for single-cell gene expression profiling

    Directory of Open Access Journals (Sweden)

    DavidSvec

    2013-11-01

    Full Text Available The interest to analyze single and few cell samples is rapidly increasing. Numerous extraction protocols to purify nucleic acids are available, but most of them compromise severely on yield to remove contaminants and are therefore not suitable for the analysis of samples containing small numbers of transcripts only. Here, we evaluate 17 direct cell lysis protocols for transcript yield and compatibility with downstream reverse transcription quantitative real-time PCR. Four endogenously expressed genes are assayed together with RNA and DNA spikes in the samples. We found bovine serum albumin (BSA to be the best lysis agent, resulting in efficient cell lysis, high RNA stability and enhanced reverse transcription efficiency. Furthermore, we found direct cell lysis with BSA superior to standard column based extraction methods, when analyzing from 1 up to 512 mammalian cells. In conclusion, direct cell lysis protocols based on BSA can be applied with most cell collection methods and are compatible with most analytical workflows to analyze single cells as well as samples composed of small numbers of cells.

  8. PD-L1 Expression Is Increased in a Subset of Basal Type Breast Cancer Cells

    OpenAIRE

    Soliman, Hatem; Khalil, Farah; Antonia, Scott

    2014-01-01

    Background Tumor cells express programmed death ligand 1 (PD-L1) and is a key immune evasion mechanism. PD-L1 expression in multiple breast cancer cell lines was evaluated to identify intrinsic differences that affect their potential for immune evasion. Methods PD-L1 expression was analyzed in six breast cancer cell lines: AU565&MCF7 (luminal), BT20&HCC1143 (basal A), MDA231&HCC38 (basal B). Surface and intracellular PD-L1 expression +/− interferon γ for 48 hours was measured by flow cytometr...

  9. Surface cell immobilization within perfluoroalkoxy microchannels

    Science.gov (United States)

    Stojkovič, Gorazd; Krivec, Matic; Vesel, Alenka; Marinšek, Marjan; Žnidaršič-Plazl, Polona

    2014-11-01

    Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor® and Topas®.

  10. Surface cell immobilization within perfluoroalkoxy microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Stojkovič, Gorazd; Krivec, Matic [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Vesel, Alenka [Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Marinšek, Marjan [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Žnidaršič-Plazl, Polona, E-mail: polona.znidarsic@fkkt.uni-lj.si [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia)

    2014-11-30

    Graphical abstract: - Highlights: • A very efficient approach for immobilization of cells into microreactors is presented. • It is applicable to various materials, including PFA and cyclic olefin (co)polymers. • It was used to immobilize different prokaryotic and eukaryotic microbes. • Cells were immobilized on the surface in high density and showed good stability. • Mechanisms of APTES interactions with target materials are proposed. - Abstract: Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor{sup ®} and Topas{sup ®}.

  11. Cell surface carbohydrates as prognostic markers in human carcinomas

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    1996-01-01

    cell types; within a given tissue, variation in expression may be related to cell maturation. Tumour-associated carbohydrate structures often reflect a certain stage of cellular development; most of these moieties are structures normally found in other adult or embryonic tissues. There is no unique......Tumour development is usually associated with changes in cell surface carbohydrates. These are often divided into changes related to terminal carbohydrate structures, which include incomplete synthesis and modification of normally existing carbohydrates, and changes in the carbohydrate core...... tumour carbohydrate structure, since certain structures which are tumour-related in one organ may be normal constituents of other tissues. Tumour-associated carbohydrate changes have been used in the diagnosis of human cancers. Recently, however, it has been demonstrated that the expression of some...

  12. Display of wasp venom allergens on the cell surface of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Poulsen Lars K

    2010-09-01

    Full Text Available Abstract Background Yeast surface display is a technique, where the proteins of interest are expressed as fusions with yeast surface proteins and thus remain attached to the yeast cell wall after expression. Our purpose was to study whether allergens expressed on the cell surface of baker's yeast Saccharomyces cerevisiae preserve their native allergenic properties and whether the yeast native surface glycoproteins interfere with IgE binding. We chose to use the major allergens from the common wasp Vespula vulgaris venom: phospholipase A1, hyaluronidase and antigen 5 as the model. Results The proteins were expressed on the surface as fusions with a-agglutinin complex protein AGA2. The expression was confirmed by fluorescent cytometry (FACS after staining the cells with antibody against a C-tag attached to the C-terminal end of the allergens. Phospholipase A1 and hyaluronidase retained their enzymatic activities. Phospholipase A1 severely inhibited the growth of the yeast cells. Antigen 5 - expressing yeast cells bound IgE antibodies from wasp venom allergic patient sera but not from control sera as demonstrated by FACS. Moreover, antigen 5 - expressing yeast cells were capable of mediating allergen-specific histamine release from human basophils. Conclusions All the three major wasp venom allergens were expressed on the yeast surface. A high-level expression, which was observed only for antigen 5, was needed for detection of IgE binding by FACS and for induction of histamine release. The non-modified S. cerevisiae cells did not cause any unspecific reaction in FACS or histamine release assay despite the expression of high-mannose oligosaccharides. In perspective the yeast surface display may be used for allergen discovery from cDNA libraries and possibly for sublingual immunotherapy as the cells can serve as good adjuvant and can be produced in large amounts at a low price.

  13. The ganglioside antigen GD2 is surface-expressed in Ewing sarcoma and allows for MHC-independent immune targeting

    Science.gov (United States)

    Kailayangiri, S; Altvater, B; Meltzer, J; Pscherer, S; Luecke, A; Dierkes, C; Titze, U; Leuchte, K; Landmeier, S; Hotfilder, M; Dirksen, U; Hardes, J; Gosheger, G; Juergens, H; Rossig, C

    2012-01-01

    Background: Novel treatment strategies are needed to cure disseminated Ewing sarcoma. Primitive neuroectodermal features and a mesenchymal stem cell origin are both compatible with aberrant expression of the ganglioside antigen GD2 and led us to explore GD2 immune targeting in this cancer. Methods: We investigated GD2 expression in Ewing sarcoma by immunofluorescence staining. We then assessed the antitumour activity of T cells expressing a chimeric antigen receptor specific for GD2 against Ewing sarcoma in vitro and in vivo. Results: Surface GD2 was detected in 10 out of 10 Ewing sarcoma cell lines and 3 out of 3 primary cell cultures. Moreover, diagnostic biopsies from 12 of 14 patients had uniform GD2 expression. T cells specifically modified to express the GD2-specific chimeric receptor 14. G2a-28ζ efficiently interacted with Ewing sarcoma cells, resulting in antigen-specific secretion of cytokines. Moreover, chimeric receptor gene-modified T cells from healthy donors and from a patient exerted potent, GD2-specific cytolytic responses to allogeneic and autologous Ewing sarcoma, including tumour cells grown as multicellular, anchorage-independent spheres. GD2-specific T cells further had activity against Ewing sarcoma xenografts. Conclusion: GD2 surface expression is a characteristic of Ewing sarcomas and provides a suitable target antigen for immunotherapeutic strategies to eradicate micrometastatic cells and prevent relapse in high-risk disease. PMID:22374462

  14. Overexpressed Ly-6A.2 mediates cell-cell adhesion by binding a ligand expressed on lymphoid cells.

    OpenAIRE

    Bamezai, A; Rock, K L

    1995-01-01

    The Ly-6 locus encodes several cell surface proteins whose functions are unknown. Although it is hypothesized that these proteins may be receptors, there is no direct evidence that they bind a ligand. Herein we present evidence that Ly-6A.2, a Ly-6 protein expressed on T lymphocytes, binds a ligand expressed on normal thymocytes and splenic B and T cells. We find that transgenic thymocytes that overexpress Ly-6A.2 spontaneously aggregate in culture. This homotypic adhesion requires the overex...

  15. Cloning and Expression of Hepatitis B Surface Antigen

    Directory of Open Access Journals (Sweden)

    Bahram Kazemi

    2008-02-01

    Full Text Available Background and Aims: Hepatitis B virus (HBV is a major cause of both acute and chronic liver disease. It is estimated that there are 350 million carriers of the virus in the world, and a high proportion will develop serious liver disease, including hepatocellular carcinoma. The aim of this study was cloning and expression hepatitis B surface antigen (HBsAg gene to design a DNA vaccine.Methods: In this study, we amplified the HBsAg gene from Iranian patients. The gene was cloned in pGEMEX-1 expression vector and recombinant plasmid was transformed in to JM109 E. coli strain and induced by IPTG.Results: We amplified, cloned and expressed hepatitis B virus surface antigen successfully and expressed protein was serologically assayed using gel diffusion and western blot analysis. Gene was sequenced and submitted to GenBank. Conclusions: The cloned HBsAg gene is ready for using in experimental DNA vaccine animal study. There are some mutations on this recombinant protein (T45D, Y206C and S207R which will affect on folding and function of recombinant protein.Keywords: Hepatitis B Virus, HBsAg, Recombinant Protein, Vaccine

  16. T cells stimulate catabolic gene expression by the stromal cells from giant cell tumor of bone

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Robert W. [Department of Pathology and Molecular Medicine, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L8 (Canada); Juravinski Cancer Centre, 699 Concession St., Hamilton, ON, Canada L8V 5C2 (Canada); Ghert, Michelle [Juravinski Cancer Centre, 699 Concession St., Hamilton, ON, Canada L8V 5C2 (Canada); Department of Surgery, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L8 (Canada); Singh, Gurmit, E-mail: gurmit.singh@jcc.hhsc.ca [Department of Pathology and Molecular Medicine, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L8 (Canada); Juravinski Cancer Centre, 699 Concession St., Hamilton, ON, Canada L8V 5C2 (Canada)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer Two T cell lines stimulate PTHrP, RANKL, MMP13 gene expression in GCT cell cultures. Black-Right-Pointing-Pointer CD40 expressed by stromal cells; CD40L detected in whole tumor but not cultures. Black-Right-Pointing-Pointer Effect of CD40L treatment on GCT cells increased PTHrP and MMP13 gene expression. Black-Right-Pointing-Pointer PTHrP treatment increased MMP13 expression, while inhibition decreased expression. Black-Right-Pointing-Pointer T cells may stimulate GCT stromal cells and promote the osteolysis of the tumor. -- Abstract: The factors that promote the localized bone resorption by giant cell tumor of bone (GCT) are not fully understood. We investigated whether T cells could contribute to bone resorption by stimulating expression of genes for parathyroid hormone-related protein (PTHrP), matrix metalloproteinase (MMP)-13, and the receptor activator of nuclear-factor {kappa}B ligand (RANKL). Two cell lines, Jurkat clone E6-1 and D1.1, were co-cultured with isolated GCT stromal cells. Real-time PCR analyses demonstrated a significant increase of all three genes following 48 h incubation, and PTHrP and MMP-13 gene expression was also increased at 24 h. Further, we examined the expression of CD40 ligand (CD40L), a protein expressed by activated T cells, and its receptor, CD40, in GCT. Immunohistochemistry results revealed expression of the CD40 receptor in both the stromal cells and giant cells of the tumor. RNA collected from whole GCT tissues showed expression of CD40LG, which was absent in cultured stromal cells, and suggests that CD40L is expressed within GCT. Stimulation of GCT stromal cells with CD40L significantly increased expression of the PTHrP and MMP-13 genes. Moreover, we show that inhibition of PTHrP with neutralizing antibodies significantly decreased MMP13 expression by the stromal cells compared to IgG-matched controls, whereas stimulation with PTHrP (1-34) increased MMP-13 gene expression. These

  17. Identification of astrocytoma associated genes including cell surface markers

    International Nuclear Information System (INIS)

    Despite intense effort the treatment options for the invasive astrocytic tumors are still limited to surgery and radiation therapy, with chemotherapy showing little or no increase in survival. The generation of Serial Analysis of Gene Expression (SAGE) profiles is expected to aid in the identification of astrocytoma-associated genes and highly expressed cell surface genes as molecular therapeutic targets. SAGE tag counts can be easily added to public expression databases and quickly disseminated to research efforts worldwide. We generated and analyzed the SAGE transcription profiles of 25 primary grade II, III and IV astrocytomas [1]. These profiles were produced as part of the Cancer Genome Anatomy Project's SAGE Genie [2], and were used in an in silico search for candidate therapeutic targets by comparing astrocytoma to normal brain transcription. Real-time PCR and immunohistochemistry were used for the validation of selected candidate target genes in 2 independent sets of primary tumors. A restricted set of tumor-associated genes was identified for each grade that included genes not previously associated with astrocytomas (e.g. VCAM1, SMOC1, and thymidylate synthetase), with a high percentage of cell surface genes. Two genes with available antibodies, Aquaporin 1 and Topoisomerase 2A, showed protein expression consistent with transcript level predictions. This survey of transcription in malignant and normal brain tissues reveals a small subset of human genes that are activated in malignant astrocytomas. In addition to providing insights into pathway biology, we have revealed and quantified expression for a significant portion of cell surface and extra-cellular astrocytoma genes

  18. Identification of astrocytoma associated genes including cell surface markers

    Directory of Open Access Journals (Sweden)

    Eberhart Charles G

    2004-07-01

    Full Text Available Abstract Background Despite intense effort the treatment options for the invasive astrocytic tumors are still limited to surgery and radiation therapy, with chemotherapy showing little or no increase in survival. The generation of Serial Analysis of Gene Expression (SAGE profiles is expected to aid in the identification of astrocytoma-associated genes and highly expressed cell surface genes as molecular therapeutic targets. SAGE tag counts can be easily added to public expression databases and quickly disseminated to research efforts worldwide. Methods We generated and analyzed the SAGE transcription profiles of 25 primary grade II, III and IV astrocytomas 1. These profiles were produced as part of the Cancer Genome Anatomy Project's SAGE Genie 2, and were used in an in silico search for candidate therapeutic targets by comparing astrocytoma to normal brain transcription. Real-time PCR and immunohistochemistry were used for the validation of selected candidate target genes in 2 independent sets of primary tumors. Results A restricted set of tumor-associated genes was identified for each grade that included genes not previously associated with astrocytomas (e.g. VCAM1, SMOC1, and thymidylate synthetase, with a high percentage of cell surface genes. Two genes with available antibodies, Aquaporin 1 and Topoisomerase 2A, showed protein expression consistent with transcript level predictions. Conclusions This survey of transcription in malignant and normal brain tissues reveals a small subset of human genes that are activated in malignant astrocytomas. In addition to providing insights into pathway biology, we have revealed and quantified expression for a significant portion of cell surface and extra-cellular astrocytoma genes.

  19. Expression of stem cell markers in the human fetal kidney.

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    Sally Metsuyanim

    Full Text Available In the human fetal kidney (HFK self-renewing stem cells residing in the metanephric mesenchyme (MM/blastema are induced to form all cell types of the nephron till 34(th week of gestation. Definition of useful markers is crucial for the identification of HFK stem cells. Because wilms' tumor, a pediatric renal cancer, initiates from retention of renal stem cells, we hypothesized that surface antigens previously up-regulated in microarrays of both HFK and blastema-enriched stem-like wilms' tumor xenografts (NCAM, ACVRIIB, DLK1/PREF, GPR39, FZD7, FZD2, NTRK2 are likely to be relevant markers. Comprehensive profiling of these putative and of additional stem cell markers (CD34, CD133, c-Kit, CD90, CD105, CD24 in mid-gestation HFK was performed using immunostaining and FACS in conjunction with EpCAM, an epithelial surface marker that is absent from the MM and increases along nephron differentiation and hence can be separated into negative, dim or bright fractions. No marker was specifically localized to the MM. Nevertheless, FZD7 and NTRK2 were preferentially localized to the MM and emerging tubules (50% of HFK cells and predominantly co-express EpCAM(bright, indicating they are mostly markers of differentiation. Furthermore, localization of NCAM exclusively in the MM and in its nephron progenitor derivatives but also in stroma and the expression pattern of significantly elevated renal stem/progenitor genes Six2, Wt1, Cited1, and Sall1 in NCAM(+EpCAM(- and to a lesser extent in NCAM(+EpCAM(+ fractions confirmed regional identity of cells and assisted us in pinpointing the presence of subpopulations that are putative MM-derived progenitor cells (NCAM(+EpCAM(+FZD7(+, MM stem cells (NCAM(+EpCAM(-FZD7(+ or both (NCAM(+FZD7(+. These results and concepts provide a framework for developing cell selection strategies for human renal cell-based therapies.

  20. Relationship between β-catenin expression and epithelial cell proliferation in gastric mucosa with intestinal metaplasia

    Institute of Scientific and Technical Information of China (English)

    Adriana Romiti; Pietro Mingazzini; Angelo Zullo; Francesco Borrini; Ida Sarcina; Cesare Hassan; Simon Winn; Silverio Tomao; Aldo Vecchione; Sergio Morini

    2005-01-01

    AIM: To investigate β-catenin expression in patients with intestinal metaplasia, and to look for a possible relationship between β-catenin expression and either epithelial proliferation values or Helicobacter pylori ( H pylori) infection.METHODS: Twenty patients with complete type intestinal metaplasia were studied. β-Catenin expression and epithelial cell proliferation in antral mucosa were assessed using an immunohistochemical analysis. Hpylori infectionwas detected by histology and a rapid urease test.RESULTS: Reduced β-catenin expression on the surface of metaplastic cells was detected in 13 (65%) out of 20 patients. Moreover, in eight (40%) patients intranuclear expression of β-catenin was found. When patients were analyzed according to Hpylori infection, the prevalence of both β-catenin reduction at the cell surface and its intranuclear localization did not significantly differ between infected and uninfected patients. Cell proliferation was higher in patients with intranudear β-catenin expression as compared to the remaining patients, although the difference failed to reach the statistical significance (36±8.9 vs 27.2±11.4, P = 0.06). On the contrary, a similar cell proliferation value was observed between patients with reduced expression of β-catenin on cell surface and those with a normal expression (28.1±11.8 vs26.1±8.8, P= 0.7).Hpyloriinfection significantly increased cell proliferation (33.3±10.2% vs 24.6±7.4%, respectively, P= 0.04).CONCLUSION: Both cell surface reduction and intranuclear accumulation of β-catenin were detected in intestinal metaplasia. The intranuclear localization of β-catenin increases cell proliferation. H pylori infection does not seem to play a direct role in β-catenin alterations, whilst it significantly increases cell proliferation.

  1. Alteration of cadherin isoform expression and inhibition of gap junctions in stomach carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To explore cell malignant phenotype correlated changes of cell surface adhesion molecules and cell-cell communication in carcinogenesis, human stomach transformed and cancer cell lines were investigated. Expressions of E-cadherin, N-cadherin, ?-catenin, ?-catenin as well as gap junction (GJ) protein Cx32 were studied by utilization of immunoblotting, immunocytochemical and fluorescent dye transfer methods. Mammalian normal stomach mucosal cells expressed E-cadherin but not N-cadherin. E-cadherin immunofluorescence was detected at cell membranous adherens junctions (AJ) where colocalization with immunofluorescent staining of inner surface adhesion plaque proteins ?- and ?-catenins was observed. The existence of E-cadherin/ catenin (?-, ?-) protein complexes as AJ was suggested. In transformed and stomach cancer cells E-cadherin was inhibited, instead, N-cadherin was expressed and localized at membranous AJ where co-staining with ?- and ?-catenin fluorescence was observed. Formation of N-cadherin/catenin (?-, ?-) protein complex at AJs of transformed and cancer cells was suggested. The above observations were further supported by immunoblotting results. Normal stomach muscosal and transformed cells expressed Cx32 at membranous GJ and were competent of gap junction communication (GJIC). In stomach cancer cells, Cx32 was inhibited and GJIC was defective. The results suggested that changes of signal pathways mediated by both cell adhesion and cell communication systems are associated intracellular events of stomach carcinogenesis. The alteration of cadherin isoform from E- to N-cadherin in transformed and stomach cancer cells is the first report.

  2. Gene expression profile of renal cell carcinoma clear cell type

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    Marcos F. Dall’Oglio

    2010-08-01

    Full Text Available PURPOSE: The determination of prognosis in patients with renal cell carcinoma (RCC is based, classically, on stage and histopathological aspects. The metastatic disease develops in one third of patients after surgery, even in localized tumors. There are few options for treating those patients, and even the new target designed drugs have shown low rates of success in controlling disease progression. Few studies used high throughput genomic analysis in renal cell carcinoma for determination of prognosis. This study is focused on the identification of gene expression signatures in tissues of low-risk, high-risk and metastatic RCC clear cell type (RCC-CCT. MATERIALS AND METHODS: We analyzed the expression of approximately 55,000 distinct transcripts using the Whole Genome microarray platform hybridized with RNA extracted from 19 patients submitted to surgery to treat RCC-CCT with different clinical outcomes. They were divided into three groups (1 low risk, characterized by pT1, Fuhrman grade 1 or 2, no microvascular invasion RCC; (2 high risk, pT2-3, Fuhrman grade 3 or 4 with, necrosis and microvascular invasion present and (3 metastatic RCC-CCT. Normal renal tissue was used as control. RESULTS: After comparison of differentially expressed genes among low-risk, high-risk and metastatic groups, we identified a group of common genes characterizing metastatic disease. Among them Interleukin-8 and Heat shock protein 70 were over-expressed in metastasis and validated by real-time polymerase chain reaction. CONCLUSION: These findings can be used as a starting point to generate molecular markers of RCC-CCT as well as a target for the development of innovative therapies.

  3. A dual tag system for facilitated detection of surface expressed proteins in Escherichia coli

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    Jarmander Johan

    2012-09-01

    Full Text Available Abstract Background The discovery of the autotransporter family has provided a mechanism for surface expression of proteins in laboratory strains of Escherichia coli. We have previously reported the use of the AIDA-I autotransport system to express the Salmonella enterica serovar Enteritidis proteins SefA and H:gm. The SefA protein was successfully exposed to the medium, but the orientation of H:gm in the outer membrane could not be determined due to proteolytic cleavage of the N-terminal detection-tag. The goal of the present work was therefore to construct a vector containing elements that facilitates analysis of surface expression, especially for proteins that are sensitive to proteolysis or otherwise difficult to express. Results The surface expression system pAIDA1 was created with two detection tags flanking the passenger protein. Successful expression of SefA and H:gm on the surface of E. coli was confirmed with fluorescently labeled antibodies specific for the N-terminal His6-tag and the C-terminal Myc-tag. While both tags were detected during SefA expression, only the Myc-tag could be detected for H:gm. The negative signal indicates a proteolytic cleavage of this protein that removes the His6-tag facing the medium. Conclusions Expression levels from pAIDA1 were comparable to or higher than those achieved with the formerly used vector. The presence of the Myc- but not of the His6-tag on the cell surface during H:gm expression allowed us to confirm the hypothesis that this fusion protein was present on the surface and oriented towards the cell exterior. Western blot analysis revealed degradation products of the same molecular weight for SefA and H:gm. The size of these fragments suggests that both fusion proteins have been cleaved at a specific site close to the C-terminal end of the passenger. This proteolysis was concluded to take place either in the outer membrane or in the periplasm. Since H:gm was cleaved to a much greater extent

  4. Tetracycline regulator expression alters the transcriptional program of mammalian cells

    OpenAIRE

    Hackl, Hubert; Rommer, Anna; Konrad, Torsten A; Nassimbeni, Christine; Wieser, Rotraud

    2010-01-01

    Tetracycline regulated ectopic gene expression is a widely used tool to study gene function. However, the tetracycline regulator (tetR) itself has been reported to cause certain phenotypic changes in mammalian cells. We, therefore, asked whether human myeloid U937 cells expressing the tetR in an autoregulated manner would exhibit alterations in gene expression upon removal of tetracycline.

  5. Simvastatin modulates mesenchymal stromal cell proliferation and gene expression.

    Science.gov (United States)

    Zanette, Dalila Lucíola; Lorenzi, Julio Cesar Cetrulo; Panepucci, Rodrigo Alexandre; Palma, Patricia Vianna Bonini; Dos Santos, Daiane Fernanda; Prata, Karen Lima; Silva, Wilson Araújo

    2015-01-01

    Statins are widely used hypocholesterolemic drugs that block the mevalonate pathway, responsible for the biosysnthesis of cholesterol. However, statins also have pleiotropic effects that interfere with several signaling pathways. Mesenchymal stromal cells (MSC) are a heterogeneous mixture of cells that can be isolated from a variety of tissues and are identified by the expression of a panel of surface markers and by their ability to differentiate in vitro into osteocytes, adipocytes and chondrocytes. MSC were isolated from amniotic membranes and bone marrows and characterized based on ISCT (International Society for Cell Therapy) minimal criteria. Simvastatin-treated cells and controls were directly assayed by CFSE (Carboxyfluorescein diacetate succinimidyl ester) staining to assess their cell proliferation and their RNA was used for microarray analyses and quantitative PCR (qPCR). These MSC were also evaluated for their ability to inhibit PBMC (peripheral blood mononuclear cells) proliferation. We show here that simvastatin negatively modulates MSC proliferation in a dose-dependent way and regulates the expression of proliferation-related genes. Importantly, we observed that simvastatin increased the percentage of a subset of smaller MSC, which also were actively proliferating. The association of MSC decreased size with increased pluripotency and the accumulating evidence that statins may prevent cellular senescence led us to hypothesize that simvastatin induces a smaller subpopulation that may have increased ability to maintain the entire pool of MSC and also to protect them from cellular senescence induced by long-term cultures/passages in vitro. These results may be important to better understand the pleiotropic effects of statins and its effects on the biology of cells with regenerative potential. PMID:25874574

  6. Simvastatin modulates mesenchymal stromal cell proliferation and gene expression.

    Directory of Open Access Journals (Sweden)

    Dalila Lucíola Zanette

    Full Text Available Statins are widely used hypocholesterolemic drugs that block the mevalonate pathway, responsible for the biosysnthesis of cholesterol. However, statins also have pleiotropic effects that interfere with several signaling pathways. Mesenchymal stromal cells (MSC are a heterogeneous mixture of cells that can be isolated from a variety of tissues and are identified by the expression of a panel of surface markers and by their ability to differentiate in vitro into osteocytes, adipocytes and chondrocytes. MSC were isolated from amniotic membranes and bone marrows and characterized based on ISCT (International Society for Cell Therapy minimal criteria. Simvastatin-treated cells and controls were directly assayed by CFSE (Carboxyfluorescein diacetate succinimidyl ester staining to assess their cell proliferation and their RNA was used for microarray analyses and quantitative PCR (qPCR. These MSC were also evaluated for their ability to inhibit PBMC (peripheral blood mononuclear cells proliferation. We show here that simvastatin negatively modulates MSC proliferation in a dose-dependent way and regulates the expression of proliferation-related genes. Importantly, we observed that simvastatin increased the percentage of a subset of smaller MSC, which also were actively proliferating. The association of MSC decreased size with increased pluripotency and the accumulating evidence that statins may prevent cellular senescence led us to hypothesize that simvastatin induces a smaller subpopulation that may have increased ability to maintain the entire pool of MSC and also to protect them from cellular senescence induced by long-term cultures/passages in vitro. These results may be important to better understand the pleiotropic effects of statins and its effects on the biology of cells with regenerative potential.

  7. Osteogenic differentiation of MC3T3-E1 cells on different titanium surfaces

    International Nuclear Information System (INIS)

    mRNA expressions related to osteogenic differentiation of MC3T3-E1 cells on electro-polished smooth (S), sandblasted small-grit (SSG) and sandblasted large-grit (SLG) surfaces of titanium alloys were investigated in vitro. Gene expression profiles of cells were evaluated using the RT2 Profiler PCR microarray on day 7. Mineralizing tissue-associated proteins, differentiation factors and extracellular matrix enzymes mRNA expressions were measured using Q-PCR. SLG surface upregulated 23 genes over twofolds and downregulated 3 genes when compared to the S surface. In comparison to the SSG surface, at least a twofold increase in 25 genes was observed in the SLG surface. BSP, OCN, OPN, COL I and ALP mRNA expressions increased in the SLG group when compared to the S and the SSG groups. BMP-2, BMP-6 and TGF-β mRNA expressions increased in both the SSG and the SLG surfaces. MMP-2 and MMP-9 mRNA expressions increased as the surface roughness increased. This study demonstrated that surface roughness of titanium implants has a significant effect on cellular behavior and SLG surface apparently increased gene expressions related to osteogenesis when compared to the S and the SSG surfaces. (paper)

  8. Uropathogenic Escherichia coli Express Type 1 Fimbriae Only in Surface Adherent Populations Under Physiological Growth Conditions

    DEFF Research Database (Denmark)

    Stærk, Kristian; Kolmos, Hans Jørn; Khandige, Surabhi;

    2015-01-01

    were correlated with the ability to adhere to and invade cultured human bladder cells. RESULTS:  Although inactive during planktonic growth in urine, T1F expression occurs when UPEC settles on and infects bladder epithelial cells or colonizes catheters. As a result, UPEC in these sessile populations...... enhances bladder cell adhesion and invasion potential. Only T1F-negative UPEC are subsequently released to the urine, thus limiting T1F expression to surface-associated UPEC alone. CONCLUSION:  Our results demonstrate that T1F expression is strictly regulated under physiological growth conditions with...

  9. Distribution of Prestin on Outer Hair Cell Basolateral Surface

    Institute of Scientific and Technical Information of China (English)

    YU Ning; ZHAI Suo-qiang; YANG Shi-ming; HAN Dong-yi; ZHAO Hong-bo

    2008-01-01

    Prestin has been identified as a motor protein responsible for outer hair cell (OHC) electromotility and is expressed on the OHC surface. Previous studies revealed that OHC eleetromotility and its associated nonlinear capacitance were mainly located at the OHC lateral wall and absent at the apical cutieular plate and the basal nucleus region. Immunofluorescent staining for prestin also failed to demonstrate prestin expression at the OHC basal ends in whole-mount preparation of the organ of Corti. However, there lacks a definitive demonstration of the pattern of prestin distribution. The OHC lateral wall has a trilaminate organization and is composed of the plasma membrane, cortical lattice, and subsurface cisternae. In this study, the location of prestin proteins in dissociated OHCs was examined using immunofluorescent staining and confocal microscopy. We found that prestin was uniformly expressed on the basolateral surface, including the basal pole. No staining was seen on the cuticular plate and stereocilia. When co-stained with a membrane marker di-8-ANEPPS, prestin-labeling was found to be in the outer layer of the OHC lateral wall. After separating the plasma membrane from the underlying subsurface eisternae using a hypotonic extracellular solution, prestin-labeling was found to be in the plasma membrane, not the subsurface cisternae. The data show that prestin is expressed in the plasma membrane on the entire OHC basolateral surface.

  10. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Huang, Xiaohua [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Biochemistry, College of Laboratory Medicine, Dalian Medical University, Dalian 116044 (China); An, Yue [Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Ren, Feng [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); He, Xiaowen; Schachner, Melitta [Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ (United States); Xiao, Zhicheng, E-mail: zhicheng.xiao@monash.edu [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); Ma, Keli, E-mail: makeli666@aliyun.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Li, Yali, E-mail: yalilipaper@gmail.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Anatomy, National University of Singapore, Singapore 119078 (Singapore)

    2013-10-25

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.

  11. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    International Nuclear Information System (INIS)

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression

  12. Surface-based mapping of gene expression and probabilistic expression maps in the mouse cortex.

    Science.gov (United States)

    Ng, Lydia; Lau, Chris; Sunkin, Susan M; Bernard, Amy; Chakravarty, M Mallar; Lein, Ed S; Jones, Allan R; Hawrylycz, Michael

    2010-02-01

    The Allen Brain Atlas (ABA, www.brain-map.org) is a genome wide, spatially registered collection of cellular resolution in situ hybridization gene expression image data of the C57Bl/6J mouse brain. Derived from the ABA, the Anatomic Gene Expression Atlas (AGEA, http://mouse.brain-map.org/agea) has demonstrated both laminar and areal spatial gene expression correlations in the mouse cortex. While the mouse cortex is lissencephalic, its curvature and substantial bending in boundary areas renders it difficult to visualize and analyze laminar versus areal effects in a rectilinear coordinate framework. In context of human and non-human primate cortex, surface-based representation has proven useful for understanding relative locations of laminar, columnar, and areal features. In this paper, we describe a methodology for constructing surface-based flatmaps of the mouse cortex that enables mapping of gene expression data from individual genes in the ABA, or probabilistic expression maps from the AGEA, to identify and visualize genetic relationships between layers and areas. PMID:19818854

  13. Characterization of cell-surface determinants important for baculovirus infection.

    Science.gov (United States)

    Tani, H; Nishijima, M; Ushijima, H; Miyamura, T; Matsuura, Y

    2001-01-01

    Baculovirus gp64 envelope glycoprotein is a major component of the envelope of the budded virus and is involved in virus entry into the host cells by endocytosis. To investigate the cell-surface molecules important for infection of baculovirus into mammalian cells, we constructed a recombinant baculovirus, Ac64-CAluc, which has gp64 and luciferase genes under the polyhedrin and the CAG promoter, respectively. For controls, we constructed recombinant viruses possessing vesicular stomatitis virus (VSV) G protein, mouse hepatitis virus (MHV) S protein, or green fluorescent protein (GFP) gene under the polyhedrin promoter and the luciferase gene under the CAG promoter (AcVSVG-CAluc, AcMHVS-CAluc, and AcGFP-CAluc). Treatment of HepG2 cells with phospholipase C markedly reduced the reporter gene expression by Ac64-CAluc or AcVSVG-CAluc in a dose-dependent manner, whereas AcMHVS-CAluc was shown to be resistant to the treatment. Inhibition with purified lipids and susceptibility to the mutant CHO hamster cell lines deficient in phospholipids synthesis suggest that the interaction of gp64 and phospholipids on the cell surface might play an important role in baculovirus infection into mammalian cells. PMID:11145915

  14. Morphology, proliferation, and gene expression of gingival fibroblasts on Laser-Lok, titanium, and zirconia surfaces.

    Science.gov (United States)

    Esfahanizadeh, Nasrin; Motalebi, Sara; Daneshparvar, Niloufar; Akhoundi, Nasrin; Bonakdar, Shahin

    2016-07-01

    Soft tissue seal plays a critical role in long-term success of dental implants, and the effects of implant surface treatments such as laser ablation have been a topic of particular interest in this respect. Considering the existing controversy regarding soft tissue behavior in contact with implant surfaces, this study sought to assess the morphology, proliferation, and gene expression of human gingival fibroblasts (HGFs) on different abutment surfaces. In this in vitro, experimental study, HGFs were cultured on 45 discs (Laser-Lok, titanium, and zirconia). Cell morphology, proliferation rate, and interleukin 10 (IL-10), tumor necrosis factor alpha (TNFα), fibronectin, and integrin gene expressions were assessed by electron microscopy, methyl thiazol tetrazolium (MTT) assay, and real-time polymerase chain reaction (PCR), respectively. Data were analyzed using ANOVA and the Kruskal-Wallis H test. Fibroblast attachment was noted in all the three groups. Spindle-shaped cells with pseudopod-like processes were more frequently seen in the Laser-Lok group. Cell proliferation was significantly higher in the Laser-Lok group compared to those in the other groups (P = 0.0002). Significant differences were found in the expression of IL-10, TNFα, fibronectin, and integrin genes among the groups (P dental implants. PMID:27025859

  15. Orf virus interferes with MHC class I surface expression by targeting vesicular transport and Golgi

    Directory of Open Access Journals (Sweden)

    Rohde Jörg

    2012-07-01

    Full Text Available Abstract Background The Orf virus (ORFV, a zoonotic Parapoxvirus, causes pustular skin lesions in small ruminants (goat and sheep. Intriguingly, ORFV can repeatedly infect its host, despite the induction of a specific immunity. These immune modulating and immune evading properties are still unexplained. Results Here, we describe that ORFV infection of permissive cells impairs the intracellular transport of MHC class I molecules (MHC I as a result of structural disruption and fragmentation of the Golgi apparatus. Depending on the duration of infection, we observed a pronounced co-localization of MHC I and COP-I vesicular structures as well as a reduction of MHC I surface expression of up to 50%. These subversion processes are associated with early ORFV gene expression and are accompanied by disturbed carbohydrate trimming of post-ER MHC I. The MHC I population remaining on the cell surface shows an extended half-life, an effect that might be partially controlled also by late ORFV genes. Conclusions The presented data demonstrate that ORFV down-regulates MHC I surface expression in infected cells by targeting the late vesicular export machinery and the structure and function of the Golgi apparatus, which might aid to escape cellular immune recognition.

  16. [Stable expression of recombinant human podoplanin in Chinese hamster ovary (CHO) cells].

    Science.gov (United States)

    Qu, Le; Zhao, Xingpeng; Fu, Jianxin; Xia, Lijun; Dai, Lan; Ruan, Changgeng; Zhao, Yiming

    2016-01-01

    Objective To construct podoplanin (PDPN) eukaryotic expression plasmid PDPN-pEGFP-N1, establish Chinese hamster ovary (CHO) cell line stably expressing recombinant human PDPN and investigate its biological activity. Methods PDPN cDNA was cloned from HEK293 cells by reverse transcription PCR and recombinant DNA technology and inserted into plasmid pEGFP-N1 labeled by enhanced green fluorescent protein (EGFP). The recombinant vector was identified by PCR, restriction enzyme digestion and DNA sequencing, and then transfected into CHO cells. Recombinant PDPN-EGFP was observed by fluorescent microscopy and CHO cell line with the high expression of PDPN-EGFP was selected by flow cytometry. Recombinant PDPN was detected by Western blotting and the biological activity of the cell line was determined by platelet aggregation assay. Results DNA sequencing and restriction enzyme digestion proved that the gene of PDPN was inserted successfully into pEGFP-N1 plasmid. After stable transfection of the recombinant plasmid into CHO cells, CHO with EGFP could be seen under a fluorescent microscope. The CHO cell line with the high expression of recombinant PDPN-EGFP was obtained after sorting by flow cytometry. Western blotting showed that the recombinant PDPN was expressed on the cell surface. The over-expressing PDPN-EGFP CHO cells were able to induce human platelet aggregation. Conclusion The CHO cell line with the stable and high expression of recombinant PDPN-EGFP has been constructed successfully, and it could induce platelet aggregation. PMID:26728373

  17. Molecular regulation of MICA expression after HDAC inhibitor treatment of cancer cells

    DEFF Research Database (Denmark)

    Jensen, Helle

    and NKG2D-ligands are upregulated on the surface of abnormal cells. We have previously shown that cancer cells can be stimulated to express the NKG2D-ligands MICA/B after exposure to HDAC-inhibitors (HDAC-i), an occurrence that is not observed in healthy cells. Here we characterize the molecular...... signal pathways that lead to MICA expression after HDAC-inhibitor treatment of cancer cells. Chelating Calcium with Bapta-AM or EGTA potently inhibited HDAC-inhibitor and CMV mediated MICA/B expression. It was further observed that ER Calcium stores were depleted after HDAC-inhibitor treatment. NF......The immune system is critically dependent on the ability to recognize or sense infected, stressed and transformed cells. One of these sensing systems rely on NKG2D/NKG2D-ligand interaction, where NKG2D is an activating receptor constitutively expressed by several effector cells of the immune system...

  18. Global gene expression analyses of hematopoietic stem cell-like cell lines with inducible Lhx2 expression

    Directory of Open Access Journals (Sweden)

    Lundeberg Joakim

    2006-04-01

    Full Text Available Abstract Background Expression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC-like cell lines. To address the molecular basis of Lhx2 function, we generated HSC-like cell lines where Lhx2 expression is regulated by a tet-on system and hence dependent on the presence of doxycyclin (dox. These cell lines efficiently down-regulate Lhx2 expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types. Results Global gene expression of these cell lines cultured in dox was compared to different time points after dox withdrawal using microarray technology. We identified 267 differentially expressed genes. The majority of the genes overlapping with HSC-specific databases were those down-regulated after turning off Lhx2 expression and a majority of the genes overlapping with those defined as late progenitor-specific genes were the up-regulated genes, suggesting that these cell lines represent a relevant model system for normal HSCs also at the level of global gene expression. Moreover, in situ hybridisations of several genes down-regulated after dox withdrawal showed overlapping expression patterns with Lhx2 in various tissues during embryonic development. Conclusion Global gene expression analysis of HSC-like cell lines with inducible Lhx2 expression has identified genes putatively linked to self-renewal / differentiation of HSCs, and function of Lhx2 in organ development and stem / progenitor cells of non-hematopoietic origin.

  19. Cloning and Expression of Hepatitis B Surface Antigen

    OpenAIRE

    Bahram Kazemi; Mahvash Khodabandeh; Mojgan Bandehpour

    2008-01-01

    Background and Aims: Hepatitis B virus (HBV) is a major cause of both acute and chronic liver disease. It is estimated that there are 350 million carriers of the virus in the world, and a high proportion will develop serious liver disease, including hepatocellular carcinoma. The aim of this study was cloning and expression hepatitis B surface antigen (HBsAg) gene to design a DNA vaccine.Methods: In this study, we amplified the HBsAg gene from Iranian patients. The gene was cloned in pGEMEX-1...

  20. Selective Lentiviral Gene Delivery to CD133-Expressing Human Glioblastoma Stem Cells

    OpenAIRE

    N Sumru Bayin; Aram S Modrek; August Dietrich; Jonathan Lebowitz; Tobias Abel; Hae-Ri Song; Markus Schober; David Zagzag; Christian J Buchholz; Chao, Moses V; Placantonakis, Dimitris G.

    2014-01-01

    Glioblastoma multiforme (GBM) is a deadly primary brain malignancy. Glioblastoma stem cells (GSC), which have the ability to self-renew and differentiate into tumor lineages, are believed to cause tumor recurrence due to their resistance to current therapies. A subset of GSCs is marked by cell surface expression of CD133, a glycosylated pentaspan transmembrane protein. The study of CD133-expressing GSCs has been limited by the relative paucity of genetic tools that specifically target them. H...

  1. Construction of Recombinant Modified Vaccinia Ankara (MVA) Expressing Hepatitis B Virus Surface Antigen

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The T lymphocyte response has been shown to be the determinant in the clearance of many viral infections.Hence, therapeutic vaccine candidates against HBV are designed to enhance this response of the immune system.Vaccinia virus vector-based vaccines have been proposed as excellent candidates to elicit long-term and strong T lymphocyte mediated immune responses. In this study, the recombinant MVA expressing HBV surface antigen has been constructed, which can elicit a potent T cell mediated response. The ELISA results for the surface protein in the medium of the recombinant MVA, strongly indicate that the recombinant virus has been successfully obtained.

  2. Metabolic behavior of cell surface biotinylated proteins

    International Nuclear Information System (INIS)

    The turnover of proteins on the surface of cultured mammalian cells was measured by a new approach. Reactive free amino or sulfhydryl groups on surface-accessible proteins were derivatized with biotinyl reagents and the proteins solubilized from culture dishes with detergent. Solubilized, biotinylated proteins were then adsorbed onto streptavidin-agarose, released with sodium dodecyl sulfate and mercaptoethanol, and separated on polyacrylamide gels. Biotin-epsilon-aminocaproic acid N-hydroxysuccinimide ester (BNHS) or N-biotinoyl-N'-(maleimidohexanoyl)hydrazine (BM) were the derivatizing agents. Only 10-12 bands were adsorbed onto streptavidin-agarose from undervatized cells or from derivatized cells treated with free avidin at 4 degrees C. Two-dimensional isoelectric focusing-sodium dodecyl sulfate gel electrophoresis resolved greater than 100 BNHS-derivatized proteins and greater than 40 BM-derivatized proteins. There appeared to be little overlap between the two groups of derivatized proteins. Short-term pulse-chase studies showed an accumulation of label into both groups of biotinylated proteins up until 1-2 h of chase and a rapid decrease over the next 1-5 h. Delayed appearance of labeled protein at the cell surface was attributed to transit time from site of synthesis. The unexpected and unexplained rapid disappearance of pulse-labeled proteins from the cell surface was invariant for all two-dimensionally resolved proteins and was sensitive to temperature reduction to 18 degrees C. Long-term pulse-chase experiments beginning 4-8 h after the initiation of chase showed the disappearance of derivatized proteins to be a simple first-order process having a half-life of 115 h in the case of BNHS-derivatized proteins and 30 h in the case of BM-derivatized proteins

  3. Expression of parafibromin in major renal cell tumors

    OpenAIRE

    Cui, C.; Lal, P; Master, S.; Ma, Y.; Baradet, T.; Bing, Z.

    2012-01-01

    Parafibromin, encoded by HRPT2 gene, is a recently identified tumor suppressor. Complete and partial loss of its expression have been observed in hyperparathyroidism-jaw tumor (HPT-JT), parathyroid carcinoma, breast carcinoma, lung carcinoma, gastric and colorectal carcinoma. However, little has been known about its expression in renal tumors. In order to study the expression of parafibromin in a series of the 4 major renal cell tumors - clear cell renal cell carcinoma (ccRCC), papillary ren...

  4. Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

    Directory of Open Access Journals (Sweden)

    Mamgain Hitesh

    2009-10-01

    Full Text Available Abstract Background Imaging tools such as scanning electron microscope (SEM and atomic force microscope (AFM can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK 293, human breast cancer (MCF-7 and mouse melanoma (B16F1 cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM and scanning electron microscopy (SEM. The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion Tumor suppressor

  5. Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

    International Nuclear Information System (INIS)

    Imaging tools such as scanning electron microscope (SEM) and atomic force microscope (AFM) can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK) 293, human breast cancer (MCF-7) and mouse melanoma (B16F1) cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Tumor suppressor protein SMAR1 might be used as a phenotypic differentiation

  6. Secretion of Interleukin-17 by CD8+ T Cells Expressing CD146 (MCAM)

    OpenAIRE

    Dagur, Pradeep K; Biancotto, Angélique; Stansky, Elena; Sen, H. Nida; Nussenblatt, Robert B.; McCoy, J. Philip

    2014-01-01

    Interleukin-17 (IL-17) has been associated with the pathogenesis of numerous autoimmune diseases. CD4+ T cells secreting IL-17 are termed Th17 cells. CD8+ T cells, designated Tc17 cells, are also capable of secreting IL-17. Here we describe a population of Tc17 cells characterized by the expression of surface CD146, an endothelial adhesion molecule. These cells display signatures of a human Tc17 genotype and phenotype. Circulating CD8+CD146+ T cells are present in low levels in healthy adults...

  7. Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide

    International Nuclear Information System (INIS)

    Recently it has been reported that, toll-like receptors (TLRs) are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS) via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line. Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis, respectively. Activation of nuclear factor (NF)-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP) kinase and interferon regulatory factor (IRF)-3 was detected by immunoblot analysis. Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS. Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3

  8. Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Mori Isamu

    2006-12-01

    Full Text Available Abstract Background Recently it has been reported that, toll-like receptors (TLRs are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line. Methods Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR and flow cytometric analysis, respectively. Activation of nuclear factor (NF-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP kinase and interferon regulatory factor (IRF-3 was detected by immunoblot analysis. Results Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS. Conclusion Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3.

  9. FOXP3, CBLB and ITCH gene expression and cytotoxic T lymphocyte antigen 4 expression on CD4(+) CD25(high) T cells in multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, F; Krakauer, M; Khademi, M; Olsson, T; Sørensen, P S

    2012-01-01

    phenotype of CD4(+) CD25(high) T cells in MS by flow cytometry and its relationship with expression of the FOXP3, ITCH and CBLB genes. We found that untreated MS patients had lower cell surface expression of cytotoxic T lymphocyte antigen 4 (CTLA-4) on CD4(+) CD25(high) T cells and higher intracellular CTLA......-4 expression than healthy controls. Cell surface expression of CTLA-4 on CD4(+) CD25(high) T cells correlated with expression of FOXP3 mRNA in untreated patients and increased significantly with time from most recent injection in patients treated with IFN-β. FOXP3 mRNA expression correlated with...... CBLB and ITCH and T helper type 2 cytokine mRNA expression in MS patients. These data link expression of FOXP3, CBLB and ITCH mRNA and CTLA-4 expression on the surface of CD4(+) CD25(high) T cell in MS. We hypothesize that this may reflect alterations in the inhibitory effect of CTLA-4 or in regulatory...

  10. Sox17 expression confers self-renewal potential and fetal stem cell characteristics upon adult hematopoietic progenitors

    OpenAIRE

    He, Shenghui; Kim, Injune; Lim, Megan S.; Morrison, Sean J

    2011-01-01

    A key question concerns the mechanisms that determine temporal identity in stem cells. Fetal hematopoietic stem cells (HSCs) differ from adult HSCs in terms of gene expression profile, surface marker expression, differentiation, and self-renewal capacity. We previously showed that the transcription factor SOX17 is expressed by fetal, but not adult, HSCs and is required for the maintenance of fetal and neonatal, but not adult, HSCs. In the current study, we show that ectopic expression of Sox1...

  11. Microarray Gene Expression Analysis to Evaluate Cell Type Specific Expression of Targets Relevant for Immunotherapy of Hematological Malignancies.

    Directory of Open Access Journals (Sweden)

    M J Pont

    Full Text Available Cellular immunotherapy has proven to be effective in the treatment of hematological cancers by donor lymphocyte infusion after allogeneic hematopoietic stem cell transplantation and more recently by targeted therapy with chimeric antigen or T-cell receptor-engineered T cells. However, dependent on the tissue distribution of the antigens that are targeted, anti-tumor responses can be accompanied by undesired side effects. Therefore, detailed tissue distribution analysis is essential to estimate potential efficacy and toxicity of candidate targets for immunotherapy of hematological malignancies. We performed microarray gene expression analysis of hematological malignancies of different origins, healthy hematopoietic cells and various non-hematopoietic cell types from organs that are often targeted in detrimental immune responses after allogeneic stem cell transplantation leading to graft-versus-host disease. Non-hematopoietic cells were also cultured in the presence of IFN-γ to analyze gene expression under inflammatory circumstances. Gene expression was investigated by Illumina HT12.0 microarrays and quality control analysis was performed to confirm the cell-type origin and exclude contamination of non-hematopoietic cell samples with peripheral blood cells. Microarray data were validated by quantitative RT-PCR showing strong correlations between both platforms. Detailed gene expression profiles were generated for various minor histocompatibility antigens and B-cell surface antigens to illustrate the value of the microarray dataset to estimate efficacy and toxicity of candidate targets for immunotherapy. In conclusion, our microarray database provides a relevant platform to analyze and select candidate antigens with hematopoietic (lineage-restricted expression as potential targets for immunotherapy of hematological cancers.

  12. Cell wall trapping of autocrine peptides for human G-protein-coupled receptors on the yeast cell surface.

    Directory of Open Access Journals (Sweden)

    Jun Ishii

    Full Text Available G-protein-coupled receptors (GPCRs regulate a wide variety of physiological processes and are important pharmaceutical targets for drug discovery. Here, we describe a unique concept based on yeast cell-surface display technology to selectively track eligible peptides with agonistic activity for human GPCRs (Cell Wall Trapping of Autocrine Peptides (CWTrAP strategy. In our strategy, individual recombinant yeast cells are able to report autocrine-positive activity for human GPCRs by expressing a candidate peptide fused to an anchoring motif. Following expression and activation, yeast cells trap autocrine peptides onto their cell walls. Because captured peptides are incapable of diffusion, they have no impact on surrounding yeast cells that express the target human GPCR and non-signaling peptides. Therefore, individual yeast cells can assemble the autonomous signaling complex and allow single-cell screening of a yeast population. Our strategy may be applied to identify eligible peptides with agonistic activity for target human GPCRs.

  13. Bioactive sugar surfaces for hepatocyte cell culture

    OpenAIRE

    Ambury, Rachael

    2010-01-01

    The primary objective of this study was to identify, develop and characterise a novel bioactive surface capable of binding hepatocytes and enabling the retention of hepatocyte-specific cell function during in-vitro culture. The materials were designed to exploit a unique characteristic of hepatocyte biology, with β-galactose moieties displayed to allow cellular adhesion via the specific asialoglycoprotein receptors (ASGP-R) found on hepatocytes. Hydrogels were created by modifying a commercia...

  14. Renalase's expression and distribution in renal tissue and cells.

    Directory of Open Access Journals (Sweden)

    Feng Wang

    Full Text Available To study renalase's expression and distribution in renal tissues and cells, renalase coded DNA vaccine was constructed, and anti-renalase monoclonal antibodies were produced using DNA immunization and hybridoma technique, followed by further investigation with immunological testing and western blotting to detect the expression and distribution of renalase among the renal tissue and cells. Anti-renalase monoclonal antibodies were successfully prepared by using DNA immunization technique. Further studies with anti-renalase monoclonal antibody showed that renalase expressed in glomeruli, tubule, mesangial cells, podocytes, renal tubule epithelial cells and its cells supernatant. Renalase is wildly expressed in kidney, including glomeruli, tubule, mesangial cells, podocytes and tubule epithelial cells, and may be secreted by tubule epithelial cells primarily.

  15. Establishment of cell surface engineering and its development.

    Science.gov (United States)

    Ueda, Mitsuyoshi

    2016-07-01

    Cell surface display of proteins/peptides has been established based on mechanisms of localizing proteins to the cell surface. In contrast to conventional intracellular and extracellular (secretion) expression systems, this method, generally called an arming technology, is particularly effective when using yeasts as a host, because the control of protein folding that is often required for the preparation of proteins can be natural. This technology can be employed for basic and applied research purposes. In this review, I describe various strategies for the construction of engineered yeasts and provide an outline of the diverse applications of this technology to industrial processes such as the production of biofuels and chemicals, as well as bioremediation and health-related processes. Furthermore, this technology is suitable for novel protein engineering and directed evolution through high-throughput screening, because proteins/peptides displayed on the cell surface can be directly analyzed using intact cells without concentration and purification. Functional proteins/peptides with improved or novel functions can be created using this beneficial, powerful, and promising technique. PMID:27305282

  16. A New Humanized HLA Transgenic Mouse Model of Multiple Sclerosis Expressing Class II on Mouse CD4 T Cells

    OpenAIRE

    Mangalam, Ashutosh; Rodriguez, Moses; David, Chella

    2007-01-01

    Among all the genetic factors associated with MS susceptibility, strongest association has been seen with expression of certain MHC class II molecules, although analysis of their exact function remains complicated. In general expression of class II is restricted to professional antigen presenting cells, however human but not mice CD4+ T cells express class II on their surface. Functional studies of classII+CD4+ T cells have been hampered due to lack of proper animal model. Here we describe de...

  17. Cell surface glycan alterations in epithelial mesenchymal transition process of Huh7 hepatocellular carcinoma cell.

    Directory of Open Access Journals (Sweden)

    Shan Li

    Full Text Available BACKGROUND AND OBJECTIVE: Due to recurrence and metastasis, the mortality of Hepatocellular carcinoma (HCC is high. It is well known that the epithelial mesenchymal transition (EMT and glycan of cell surface glycoproteins play pivotal roles in tumor metastasis. The goal of this study was to identify HCC metastasis related differential glycan pattern and their enzymatic basis using a HGF induced EMT model. METHODOLOGY: HGF was used to induce HCC EMT model. Lectin microarray was used to detect the expression of cell surface glycan and the difference was validated by lectin blot and fluorescence cell lectin-immunochemistry. The mRNA expression levels of glycotransferases were determined by qRT-PCR. RESULTS: After HGF treatment, the Huh7 cell lost epithelial characteristics and obtained mesenchymal markers. These changes demonstrated that HGF could induce a typical cell model of EMT. Lectin microarray analysis identified a decreased affinity in seven lectins ACL, BPL, JAC, MPL, PHA-E, SNA, and SBA to the glycan of cell surface glycoproteins. This implied that glycan containing T/Tn-antigen, NA2 and bisecting GlcNAc, Siaα2-6Gal/GalNAc, terminal α or βGalNAc structures were reduced. The binding ability of thirteen lectins, AAL, LCA, LTL, ConA, NML, NPL, DBA, HAL, PTL II, WFL, ECL, GSL II and PHA-L to glycan were elevated, and a definite indication that glycan containing terminal αFuc and ± Sia-Le, core fucose, α-man, gal-β(α GalNAc, β1,6 GlcNAc branching and tetraantennary complex oligosaccharides structures were increased. These results were further validated by lectin blot and fluorescence cell lectin-immunochemistry. Furthermore, the mRNA expression level of Mgat3 decreased while that of Mgat5, FucT8 and β3GalT5 increased. Therefore, cell surface glycan alterations in the EMT process may coincide with the expression of glycosyltransferase. CONCLUSIONS: The findings of this study systematically clarify the alterations of cell surface

  18. Hemoglobin is Expressed in Alveolar Epithelial Type II Cells

    OpenAIRE

    Bhaskaran, Manoj; Chen, Haifeng; Chen, Zhongmong; Liu, Lin

    2005-01-01

    Hemoglobin is the main oxygen carrying heme protein in erythrocytes. In an effort to study the differential gene expression of alveolar epithelial type I and type II cells using DNA microarray technique, we found that the mRNAs of hemoglobin α- and β-chains were expressed in type II cells, but not in type I cells. The microarray data were confirmed by RT-PCR. The mRNA expression of both chains decreased when type II cells trans-differentiated into type I-like cells. Immunocyto/histochemistry ...

  19. High Expression of NKG2A/CD94 and Low Expression of Granzyme B Are Associated with Reduced Cord Blood NK Cell Activity

    Institute of Scientific and Technical Information of China (English)

    Yanyan Wang; Han Xu; Xiaodong Zheng; Haiming Wei; Rui Sun; Zhigang Tian

    2007-01-01

    Human umbilical cord blood (CB) has recently been used as a source of stem cells in transplantation. NK cells derived from CB are the key effector cells involved in graft-versus-host disease (GVHD) and graft-versus-leukemia(GVL). It was reported that the activity of CB NK cells was lower than that of adult peripheral blood (PB) NK cells.In this study, we analyzed the expression of some NK cell receptors and cytotoxicity-related molecules in CB and PB NK cells. The expressions of activating NK receptors, CD16, NKG2D and NKp46, did not show significant difference between CB and PB NK cells. But the expression of inhibitory receptor NKG2A/CD94 was significantly higher on CB NK cells. As to the effector function molecules, granzyme B was expressed significantly lower in CB NK cells, but the expressions of intracellular perforin, IFN-γ, TNF-α and cell surface FasL and TRAIL did not show difference between CB and PB NK cells. The results indicated that the high expression of NKG2A/CD94 and low expression of granzyme B may be related with the reduced activity of CB NK cells.

  20. Pharmacologic suppression of target cell recognition by engineered T cells expressing chimeric T-cell receptors.

    Science.gov (United States)

    Alvarez-Vallina, L; Yañez, R; Blanco, B; Gil, M; Russell, S J

    2000-04-01

    Adoptive therapy with autologous T cells expressing chimeric T-cell receptors (chTCRs) is of potential interest for the treatment of malignancy. To limit possible T-cell-mediated damage to normal tissues that weakly express the targeted tumor antigen (Ag), we have tested a strategy for the suppression of target cell recognition by engineered T cells. Jurkat T cells were transduced with an anti-hapten chTCR tinder the control of a tetracycline-suppressible promoter and were shown to respond to Ag-positive (hapten-coated) but not to Ag-negative target cells. The engineered T cells were then reacted with hapten-coated target cells at different effector to target cell ratios before and after exposure to tetracycline. When the engineered T cells were treated with tetracycline, expression of the chTCR was greatly decreased and recognition of the hapten-coated target cells was completely suppressed. Tetracycline-mediated suppression of target cell recognition by engineered T cells may be a useful strategy to limit the toxicity of the approach to cancer gene therapy. PMID:10811469

  1. 7α-Hydroxycholesterol Elicits TLR6-Mediated Expression of IL-23 in Monocytic Cells

    OpenAIRE

    Seo, Hyun Chul; Kim, Sun-Mi; Eo, Seong-Kug; Rhim, Byung-Yong; KIM, Koanhoi

    2015-01-01

    We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. 7α-Hydroxycholesterol (7αOHChol) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with 7αOHChol resulted in enhanced production of IL-23...

  2. Impact of altered actin gene expression on vinculin, talin, cell spreading, and motility.

    Science.gov (United States)

    Schevzov, G; Lloyd, C; Gunning, P

    1995-08-01

    Previous studies have demonstrated a strong correlation between the expression of vinculin and the shape and motility of a cell (Rodriguez Fernandez et al., 1992a, b, 1993). This hypothesis was tested by comparing the expression of vinculin and talin with the motility of morphologically altered myoblasts. These mouse C2 myoblasts were previously generated by directly perturbing the cell cytoskeleton via the stable transfection of a mutant-form of the beta-actin gene (beta sm) and three different forms of the gamma-actin gene; gamma, gamma minus 3'UTR (gamma delta'UTR), and gamma minus intron III (gamma delta IVSIII) (Schevzov et al., 1992; Lloyd and Gunning, 1993). In the case of the beta sm and gamma-actin transfectants, a two-fold decrease in the cell surface area was coupled, as predicted, with a decrease in vinculin and talin expression. In contrast, the gamma delta IVSIII transfectants with a seven-fold decrease in the cell surface area showed an unpredicted slight increase in vinculin and talin expression and the gamma delta 3'-UTR transfectants with a slight increase in the cell surface area showed no changes in talin expression and a decrease in vinculin expression. We conclude that changes in actin gene expression alone can impact on the expression of vinculin and talin. Furthermore, we observed that these actin transfectants failed to show a consistent relationship between cell shape, motility, and the expression of vinculin. However, a relationship between talin and cell motility was found to exist, suggesting a role for talin in the establishment of focal contacts necessary for motility. PMID:7646816

  3. Interaction of KSHV with Host Cell Surface Receptors and Cell Entry

    Directory of Open Access Journals (Sweden)

    Mohanan Valiya Veettil

    2014-10-01

    Full Text Available Virus entry is a complex process characterized by a sequence of events. Since the discovery of KSHV in 1994, tremendous progress has been made in our understanding of KSHV entry into its in vitro target cells. KSHV entry is a complex multistep process involving viral envelope glycoproteins and several cell surface molecules that is utilized by KSHV for its attachment and entry. KSHV has a broad cell tropism and the attachment and receptor engagement on target cells have an important role in determining the cell type-specific mode of entry. KSHV utilizes heparan sulfate, integrins and EphrinA2 molecules as receptors which results in the activation of host cell pre-existing signal pathways that facilitate the subsequent cascade of events resulting in the rapid entry of virus particles, trafficking towards the nucleus followed by viral and host gene expression. KSHV enters human fibroblast cells by dynamin dependant clathrin mediated endocytosis and by dynamin independent macropinocytosis in dermal endothelial cells. Once internalized into endosomes, fusion of the viral envelope with the endosomal membranes in an acidification dependent manner results in the release of capsids which subsequently reaches the nuclear pore vicinity leading to the delivery of viral DNA into the nucleus. In this review, we discuss the principal mechanisms that enable KSHV to interact with the host cell surface receptors as well as the mechanisms that are required to modulate cell signaling machinery for a successful entry.

  4. Wettability influences cell behavior on superhydrophobic surfaces with different topographies

    OpenAIRE

    Lourenco, B.N.; Marchioli, G.; Song, W.; Reis, R.L.; Blitterswijk, van, C.A.; Karperien, H.B.J.; Apeldoorn, van, D.F.; Mano, J.F

    2012-01-01

    Surface wettability and topography are recognized as critical factors influencing cell behavior on biomaterials. So far only few works have reported cell responses on surfaces exhibiting extreme wettability in combination with surface topography. The goal of this work is to study whether cell behavior on superhydrophobic surfaces is influenced by surface topography and polymer type. Biomimetic superhydrophobic rough surfaces of polystyrene and poly(l-lactic acid) with different micro/nanotopo...

  5. Simian and Human Immunodeficiency Virus Nef Proteins Use Different Surfaces To Downregulate Class I Major Histocompatibility Complex Antigen Expression

    OpenAIRE

    Swigut, Tomek; Iafrate, A. John; Muench, Jan; Kirchhoff, Frank; Skowronski, Jacek

    2000-01-01

    Simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 (HIV-1) Nef proteins are related regulatory proteins that share several functions, including the ability to downregulate class I major histocompatibility complex (MHC) and CD4 expression on the cell surface and to alter T-cell-receptor-initiated signal transduction in T cells. We compared the mechanisms used by SIV mac239 Nef and HIV-1 Nef to downregulate class I MHC and found that the ability of SIV Nef to downregula...

  6. Nestin expression in osteosarcomas and derivation of nestin/CD133 positive osteosarcoma cell lines

    International Nuclear Information System (INIS)

    Nestin was originally identified as a class VI intermediate filament protein that is expressed in stem cells and progenitor cells in the mammalian CNS during development. This protein is replaced in the adult organism by other intermediate filament proteins; however, nestin may be re-expressed under certain pathological conditions such as ischemia, inflammation, brain injury, and neoplastic transformation. Nestin has been detected in many kinds of tumors, especially in tumors derived from the CNS. Co-expression of nestin and the CD133 surface molecule is considered to be a marker for cancer stem cells in neurogenic tumors. Our work was aimed at a detailed study of nestin expression in osteosarcomas and osteosarcoma-derived cell lines. Using immunodetection methods, we examined nestin in tumor tissue samples from 18 patients with osteosarcomas. We also successfully established permanent cell lines from the tumor tissue of 4 patients and immunodetection of nestin and CD133 was performed on these cell lines. Nestin-positive tumor cells were immunohistochemically detected in all of the examined osteosarcomas, but the proportion of these cells that were positively stained as well as the intensity of staining varied. Nestin-positive cells were rarely observed in 2 tumor samples, and the remaining 16 tumor samples showed various nestin expression patterns ranging from very sporadic occurrence to an overwhelming proportion of cells with strong positive staining. Three of the established osteosarcoma cell lines were demonstrated to be nestin-positive, and only one cell line showed no expression of nestin; this finding corresponds with the rare occurrence of nestin-positive cells in the respective tumor sample. Moreover, three of these osteosarcoma cell lines were undoubtedly proven to be Nes+/CD133+. Our results represent the first evidence of nestin expression in osteosarcomas and suggest the possible occurrence of cells with a stem-like phenotype in these tumors

  7. Notch signalling inhibits CD4 expression during initiation and differentiation of human T cell lineage.

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    Stephen M Carlin

    Full Text Available The Delta/Notch signal transduction pathway is central to T cell differentiation from haemopoietic stem cells (HSCs. Although T cell development is well characterized using expression of cell surface markers, the detailed mechanisms driving differentiation have not been established. This issue becomes central with observations that adult HSCs exhibit poor differentiation towards the T cell lineage relative to neonatal or embryonic precursors. This study investigates the contribution of Notch signalling and stromal support cells to differentiation of adult and Cord Blood (CB human HSCs, using the Notch signalling OP9Delta co-culture system. Co-cultured cells were assayed at weekly intervals during development for phenotype markers using flow cytometry. Cells were also assayed for mRNA expression at critical developmental stages. Expression of the central thymocyte marker CD4 was initiated independently of Notch signalling, while cells grown with Notch signalling had reduced expression of CD4 mRNA and protein. Interruption of Notch signalling in partially differentiated cells increased CD4 mRNA and protein expression, and promoted differentiation to CD4(+ CD8(+ T cells. We identified a set of genes related to T cell development that were initiated by Notch signalling, and also a set of genes subsequently altered by Notch signal interruption. These results demonstrate that while Notch signalling is essential for establishment of the T cell lineage, at later stages of differentiation, its removal late in differentiation promotes more efficient DP cell generation. Notch signalling adds to signals provided by stromal cells to allow HSCs to differentiate to T cells via initiation of transcription factors such as HES1, GATA3 and TCF7. We also identify gene expression profile differences that may account for low generation of T cells from adult HSCs.

  8. Optimization of Recombinant Expression of Synthetic Bacterial Phytase in Pichia pastoris Using Response Surface Methodology

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    Akbarzadeh

    2015-12-01

    Full Text Available Background Escherichia coli phytase is an acidic histidine phytase with great specific activity. Pichia pastoris is a powerful system for the heterologous expression of active and soluble proteins which can express recombinant proteins in high cell density fermenter without loss of product yield and efficiently secrete heterologous proteins into the media. Recombinant protein expression is influenced by expression conditions such as temperature, concentration of inducer, and pH. By optimization, the yield of expressed proteins can be increase. Response surface methodology (RSM has been widely used for the optimization and studying of different parameters in biotechnological processes. Objectives In this study, the expression of synthetic appA gene in P. pastoris was greatly improved by adjusting the expression condition. Materials and Methods The appA gene with 410 amino acids was synthesized by P. pastoris codon preference and cloned in expression vector pPinkα-HC, under the control of AOX1 promoter, and it was transformed into P. pastoris GS115 by electroporation. Recombinant phytase was expressed in buffered methanol-complex medium (BMMY and the expression was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE and enzymatic assay. To achieve the highest level of expression, methanol concentration, pH and temperature were optimized via RSM. Finally, the optimum pH and temperature for recombinant phytase activity was determined. Results Escherichia coli phytase was expressed in P. pastoris under different cultivation conditions (post-induction temperature, methanol concentration, and post-induction pH. The optimized conditions by RSM using face centered central composite design were 1% (v/v methanol, pH = 5.8, and 24.5°C. Under the optimized conditions, appA was successfully expressed in P. pastoris and the maximum phytase activity was 237.2 U/mL after 72 hours of expression. Conclusions By optimization of

  9. Systemic Sclerosis Patients Present Alterations in the Expression of Molecules Involved in B-Cell Regulation

    Science.gov (United States)

    Soto, Lilian; Ferrier, Ashley; Aravena, Octavio; Fonseca, Elianet; Berendsen, Jorge; Biere, Andrea; Bueno, Daniel; Ramos, Verónica; Aguillón, Juan Carlos; Catalán, Diego

    2015-01-01

    The activation threshold of B cells is tightly regulated by an array of inhibitory and activator receptors in such a way that disturbances in their expression can lead to the appearance of autoimmunity. The aim of this study was to evaluate the expression of activating and inhibitory molecules involved in the modulation of B cell functions in transitional, naive, and memory B-cell subpopulations from systemic sclerosis patients. To achieve this, blood samples were drawn from 31 systemic sclerosis patients and 53 healthy individuals. Surface expression of CD86, MHC II, CD19, CD21, CD40, CD22, Siglec 10, CD35, and FcγRIIB was determined by flow cytometry. IL-10 production was evaluated by intracellular flow cytometry from isolated B cells. Soluble IL-6 and IL-10 levels were measured by ELISA from supernatants of stimulated B cells. Systemic sclerosis patients exhibit an increased frequency of transitional and naive B cells related to memory B cells compared with healthy controls. Transitional and naive B cells from patients express higher levels of CD86 and FcγRIIB than healthy donors. Also, B cells from patients show high expression of CD19 and CD40, whereas memory cells from systemic sclerosis patients show reduced expression of CD35. CD19 and CD35 expression levels associate with different autoantibody profiles. IL-10+ B cells and secreted levels of IL-10 were markedly reduced in patients. In conclusion, systemic sclerosis patients show alterations in the expression of molecules involved in B-cell regulation. These abnormalities may be determinant in the B-cell hyperactivation observed in systemic sclerosis. PMID:26483788

  10. Robust Inference of Cell-to-Cell Expression Variations from Single- and K-Cell Profiling.

    Science.gov (United States)

    Narayanan, Manikandan; Martins, Andrew J; Tsang, John S

    2016-07-01

    Quantifying heterogeneity in gene expression among single cells can reveal information inaccessible to cell-population averaged measurements. However, the expression level of many genes in single cells fall below the detection limit of even the most sensitive technologies currently available. One proposed approach to overcome this challenge is to measure random pools of k cells (e.g., 10) to increase sensitivity, followed by computational "deconvolution" of cellular heterogeneity parameters (CHPs), such as the biological variance of single-cell expression levels. Existing approaches infer CHPs using either single-cell or k-cell data alone, and typically within a single population of cells. However, integrating both single- and k-cell data may reap additional benefits, and quantifying differences in CHPs across cell populations or conditions could reveal novel biological information. Here we present a Bayesian approach that can utilize single-cell, k-cell, or both simultaneously to infer CHPs within a single condition or their differences across two conditions. Using simulated as well as experimentally generated single- and k-cell data, we found situations where each data type would offer advantages, but using both together can improve precision and better reconcile CHP information contained in single- and k-cell data. We illustrate the utility of our approach by applying it to jointly generated single- and k-cell data to reveal CHP differences in several key inflammatory genes between resting and inflammatory cytokine-activated human macrophages, delineating differences in the distribution of 'ON' versus 'OFF' cells and in continuous variation of expression level among cells. Our approach thus offers a practical and robust framework to assess and compare cellular heterogeneity within and across biological conditions using modern multiplexed technologies. PMID:27438699

  11. Cdon, a cell surface protein, mediates oligodendrocyte differentiation and myelination.

    Science.gov (United States)

    Wang, Li-Chun; Almazan, Guillermina

    2016-06-01

    During central nervous system development, oligodendrocyte progenitors (OLPs) establish multiple branched processes and axonal contacts to initiate myelination. A complete understanding of the molecular signals implicated in cell surface interaction to initiate myelination/remyelination is currently lacking. The objective of our study was to assess whether Cdon, a cell surface protein that was shown to participate in muscle and neuron cell development, is involved in oligodendrocyte (OLG) differentiation and myelination. Here, we demonstrate that endogenous Cdon protein is expressed in OLPs, increasing in the early differentiation stages and decreasing in mature OLGs. Immunocytochemistry of endogenous Cdon showed localization on both OLG cell membranes and cellular processes exhibiting puncta- or varicosity-like structures. Cdon knockdown with siRNA decreased protein levels by 62% as well as two myelin-specific proteins, MBP and MAG. Conversely, overexpression of full-length rat Cdon increased myelin proteins in OLGs. The complexity of OLGs branching and contact point numbers with axons were also increased in Cdon overexpressing cells growing alone or in coculture with dorsal root ganglion neurons (DRGNs). Furthermore, myelination of DRGNs was decreased when OLPs were transfected with Cdon siRNA. Altogether, our results suggest that Cdon participates in OLG differentiation and myelination, most likely in the initial stages of development. GLIA 2016;64:1021-1033. PMID:26988125

  12. Chemistry and material science at the cell surface

    OpenAIRE

    Weian Zhao; Grace Sock Leng Teo; Namit Kumar; Karp, Jeffrey M.

    2010-01-01

    Cell surfaces are fertile ground for chemists and material scientists to manipulate or augment cell functions and phenotypes. This not only helps to answer basic biology questions but also has diagnostic and therapeutic applications. In this review, we summarize the most recent advances in the engineering of the cell surface. In particular, we focus on the potential applications of surface engineered cells for 1) targeting cells to desirable sites in cell therapy, 2) programming assembly of c...

  13. Expression of DP2 (CRTh2, a prostaglandin D₂ receptor, in human mast cells.

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    Tae Chul Moon

    Full Text Available PGD₂ has long been implicated in allergic diseases. Recent cloning of a second PGD₂ receptor, DP2 (also known as CRTh2, led to a greater understanding of the physiological and pathophysiological implications of PGD₂. PGD₂ signaling through DP1 and DP2 mediates different and often opposite effects in many cell types of the immune system. Although mast cells (MC are the largest source of PGD₂ in the body, there is little information about their potential expression of DP2 and its functional significance. In this study, we show that tissue MC in human nasal polyps express DP2 protein, and that human MC lines and primary cultured human MC express mRNA as well as protein of DP2. By immunohistochemistry, we detected that 34% of MC in human nasal polyps expressed DP2. In addition, flow cytometry showed that 87% of the LAD2 human MC line and 98% of primary cultured human MC contained intracellular DP2. However, we could not detect surface expression of DP2 on human MC by single cell analysis using imaging flow cytometry. Blocking of endogenous PGD2 production with aspirin did not induce surface expression of DP2 in human MC. Two DP2 selective agonists, DK-PGD₂ and 15R-15-methyl PGD₂ induced dose-dependent intracellular calcium mobilization that was abrogated by pertussis toxin, but not by three DP2 selective antagonists. MC mediator release including degranulation was not affected by DP2 selective agonists. Thus, human MC express DP2 intracellularly rather than on their surface, and the function of DP2 in human MC is different than in other immune cells such as Th2 cells, eosinophils and basophils where it is expressed on the cell surface and induces Th2 cytokine and/or granule associated mediator release. Further studies to elucidate the role of intracellular DP2 in human MC may expand our understanding of this molecule and provide novel therapeutic opportunities.

  14. Chemokine receptor expression by inflammatory T cells in EAE

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    Jyothi Thyagabhavan Mony

    2014-07-01

    Full Text Available Chemokines direct cellular infiltration to tissues, and their receptors and signaling pathways represent targets for therapy in diseases such as multiple sclerosis (MS. The chemokine CCL20 is expressed in choroid plexus, a site of entry of T cells to the central nervous system (CNS. The CCL20 receptor CCR6 has been reported to be selectively expressed by CD4+ T cells that produce the cytokine IL-17 (Th17 cells. Th17 cells and interferon-gamma (IFNγ-producing Th1 cells are implicated in induction of MS and its animal model experimental autoimmune encephalomyelitis (EAE. We have assessed whether CCR6 identifies specific inflammatory T cell subsets in EAE. Our approach was to induce EAE, and then examine chemokine receptor expression by cytokine-producing T cells sorted from CNS at peak disease. About 7% of CNS-infiltrating CD4+ T cells produced IFNγ in flow cytometric cytokine assays, whereas less than 1% produced IL-17. About 7.7% of CD4+ T cells produced both cytokines. CCR6 was expressed by Th1, Th1+17 and by Th17 cells, but not by CD8+ T cells. CD8+ T cells expressed CXCR3, which was also expressed by CD4+ T cells, with no correlation to cytokine profile. Messenger RNA for IFNγ, IL-17A, and the Th1 and Th17-associated transcription factors T-bet and RORγt was detected in both CCR6+ and CXCR3+ CD4+ T cells. IFNγ, but not IL-17A mRNA expression was detected in CD8+ T cells in CNS. CCR6 and CD4 were co-localized in spinal cord infiltrates by double immunofluorescence. Consistent with flow cytometry data some but not all CD4+ T cells expressed CCR6 within infiltrates. CD4-negative CCR6+ cells included macrophage/microglial cells. Thus we have for the first time directly studied CD4+ and CD8+ T cells in the CNS of mice with peak EAE, and determined IFNγ and IL17 expression by cells expressing CCR6 and CXCR3. We show that neither CCR6 or CXCR3 align with CD4 T cell subsets, and Th1 or mixed Th1+17 predominate in EAE.

  15. Surface expression, single-channel analysis and membrane topology of recombinant Chlamydia trachomatis Major Outer Membrane Protein

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    McClafferty Heather

    2005-01-01

    Full Text Available Abstract Background Chlamydial bacteria are obligate intracellular pathogens containing a cysteine-rich porin (Major Outer Membrane Protein, MOMP with important structural and, in many species, immunity-related roles. MOMP forms extensive disulphide bonds with other chlamydial proteins, and is difficult to purify. Leaderless, recombinant MOMPs expressed in E. coli have yet to be refolded from inclusion bodies, and although leadered MOMP can be expressed in E. coli cells, it often misfolds and aggregates. We aimed to improve the surface expression of correctly folded MOMP to investigate the membrane topology of the protein, and provide a system to display native and modified MOMP epitopes. Results C. trachomatis MOMP was expressed on the surface of E. coli cells (including "porin knockout" cells after optimizing leader sequence, temperature and medium composition, and the protein was functionally reconstituted at the single-channel level to confirm it was folded correctly. Recombinant MOMP formed oligomers even in the absence of its 9 cysteine residues, and the unmodified protein also formed inter- and intra-subunit disulphide bonds. Its topology was modeled as a (16-stranded β-barrel, and specific structural predictions were tested by removing each of the four putative surface-exposed loops corresponding to highly immunogenic variable sequence (VS domains, and one or two of the putative transmembrane strands. The deletion of predicted external loops did not prevent folding and incorporation of MOMP into the E. coli outer membrane, in contrast to the removal of predicted transmembrane strands. Conclusions C. trachomatis MOMP was functionally expressed on the surface of E. coli cells under newly optimized conditions. Tests of its predicted membrane topology were consistent with β-barrel oligomers in which major immunogenic regions are displayed on surface-exposed loops. Functional surface expression, coupled with improved understanding of MOMP

  16. Geometry of the Gene Expression Space of Individual Cells.

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    Yael Korem

    2015-07-01

    Full Text Available There is a revolution in the ability to analyze gene expression of single cells in a tissue. To understand this data we must comprehend how cells are distributed in a high-dimensional gene expression space. One open question is whether cell types form discrete clusters or whether gene expression forms a continuum of states. If such a continuum exists, what is its geometry? Recent theory on evolutionary trade-offs suggests that cells that need to perform multiple tasks are arranged in a polygon or polyhedron (line, triangle, tetrahedron and so on, generally called polytopes in gene expression space, whose vertices are the expression profiles optimal for each task. Here, we analyze single-cell data from human and mouse tissues profiled using a variety of single-cell technologies. We fit the data to shapes with different numbers of vertices, compute their statistical significance, and infer their tasks. We find cases in which single cells fill out a continuum of expression states within a polyhedron. This occurs in intestinal progenitor cells, which fill out a tetrahedron in gene expression space. The four vertices of this tetrahedron are each enriched with genes for a specific task related to stemness and early differentiation. A polyhedral continuum of states is also found in spleen dendritic cells, known to perform multiple immune tasks: cells fill out a tetrahedron whose vertices correspond to key tasks related to maturation, pathogen sensing and communication with lymphocytes. A mixture of continuum-like distributions and discrete clusters is found in other cell types, including bone marrow and differentiated intestinal crypt cells. This approach can be used to understand the geometry and biological tasks of a wide range of single-cell datasets. The present results suggest that the concept of cell type may be expanded. In addition to discreet clusters in gene-expression space, we suggest a new possibility: a continuum of states within a

  17. CZTSSe thin film solar cells: Surface treatments

    Science.gov (United States)

    Joglekar, Chinmay Sunil

    Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques. Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the thickness of sintered CZTSSe film. The etching treatment creates recombination centers which lead to poor device performance. Various after treatments were used to improve the performance of the devices. It was observed that the performance of the solar cell devices could not be improved by any of the after treatment steps. Other surface treatment processes are explored including KCN etching and gaseous H2S treatments. Hybrid solar cells which included use of CIGS nanoparticles at the interface between CZTSSe and CdS are also explored.

  18. Mechanisms of confluence-dependent expression of CD26 in colon cancer cell lines

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    Morimoto Chikao

    2011-02-01

    Full Text Available Abstract Background CD26 (dipeptidyl peptidase IV, DPPIV is a 110 kDa surface glycoprotein expressed in most normal tissues, and is a potential novel therapeutic target for selected cancers. Our work evaluates the mechanism involved in confluence-dependent CD26 expression in colon cancer. Methods Colon adenocarcinoma cells were grown to confluence, and expression of CD26 and transcription factors implicated in its regulation was confirmed by immunofluorescence and Western blotting. Real-time PCR was also performed to evaluate CD26 upregulation at the transcriptional level. The influence of c-Myc on CD26 expression during different growth conditions was further evaluated following transient transfection of a c-Myc-expressing plasmid and a c-Myc specific siRNA. Results We found that the colon cancer cell lines HCT-116 and HCT-15 exhibited a confluence-dependent increase in CD26 mRNA and protein, associated with decreased expression of c-Myc, increased USF-1 and Cdx 2 levels, and unchanged HNF-1α expression. Meanwhile, ectopic expression of c-Myc in both cell lines led to decreased CD26 expression. In contrast, transfection of a siRNA targeted to Cdx2 resulted in decreased CD26 level. Importantly, culturing of cells in serum-depleted media, but not acidic conditions, upregulated CD26. While HIF-1α level also increased when cells were cultured in serum-depleted media, its expression was required but not sufficient for CD26 upregulation. Conclusions CD26 mRNA and protein levels increase in a confluence-dependent manner in colon carcinoma cell lines, with c-Myc acting as a repressor and Cdx2 acting as an enhancer of CD26 expression. The enhanced expression of CD26 in serum-depleted media and a requirement for HIF-1α suggest a role for nutrients or growth factors in the regulation of CD26 protein expression.

  19. Mechanisms of confluence-dependent expression of CD26 in colon cancer cell lines

    International Nuclear Information System (INIS)

    CD26 (dipeptidyl peptidase IV, DPPIV) is a 110 kDa surface glycoprotein expressed in most normal tissues, and is a potential novel therapeutic target for selected cancers. Our work evaluates the mechanism involved in confluence-dependent CD26 expression in colon cancer. Colon adenocarcinoma cells were grown to confluence, and expression of CD26 and transcription factors implicated in its regulation was confirmed by immunofluorescence and Western blotting. Real-time PCR was also performed to evaluate CD26 upregulation at the transcriptional level. The influence of c-Myc on CD26 expression during different growth conditions was further evaluated following transient transfection of a c-Myc-expressing plasmid and a c-Myc specific siRNA. We found that the colon cancer cell lines HCT-116 and HCT-15 exhibited a confluence-dependent increase in CD26 mRNA and protein, associated with decreased expression of c-Myc, increased USF-1 and Cdx 2 levels, and unchanged HNF-1α expression. Meanwhile, ectopic expression of c-Myc in both cell lines led to decreased CD26 expression. In contrast, transfection of a siRNA targeted to Cdx2 resulted in decreased CD26 level. Importantly, culturing of cells in serum-depleted media, but not acidic conditions, upregulated CD26. While HIF-1α level also increased when cells were cultured in serum-depleted media, its expression was required but not sufficient for CD26 upregulation. CD26 mRNA and protein levels increase in a confluence-dependent manner in colon carcinoma cell lines, with c-Myc acting as a repressor and Cdx2 acting as an enhancer of CD26 expression. The enhanced expression of CD26 in serum-depleted media and a requirement for HIF-1α suggest a role for nutrients or growth factors in the regulation of CD26 protein expression

  20. Differential expression and function of CD27 in chronic lymphocytic leukemia cells expressing ZAP-70.

    Science.gov (United States)

    Lafarge, Sandrine T; Hou, Sen; Pauls, Samantha D; Johnston, James B; Gibson, Spencer B; Marshall, Aaron J

    2015-07-01

    Chronic lymphocytic leukemia is a malignancy driven by abberant B cell signaling and survival. Leukemic B cells accumulate in the peripheral blood and the lymphoid organs where contact with stromal cells and T cells provide critical survival signals. Clinical severity of CLL is associated with several prognostic markers including expression of the kinase ZAP-70. ZAP-70 expression enhances signaling via the B cell antigen receptor and is associated with increased cell adhesion and migration capacity. Here we report that ZAP-70-positive CLL patients display significantly higher expression of the TNF superfamily receptor and memory marker CD27 than do ZAP-70 negative patients. CD27 expression by CLL was acutely elevated upon BCR cross-linking, or upon ectopic expression of ZAP-70. CD27 expression correlated with functional capacity to adhere to stromal cells and antibody blockade of CD27 impaired CLL binding to stroma. These results provide the first evidence for differential expression of CD27 among CLL prognostic groups, suggest a role for ZAP-70 dependent signaling in CD27 induction and implicate CD27 in cell-cell interactions with the lymphoid tissue microenvironment. PMID:26002513

  1. Defining the expression of marker genes in equine mesenchymal stromal cells

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    Deborah J Guest

    2008-11-01

    Full Text Available Deborah J Guest1, Jennifer C Ousey1, Matthew RW Smith21Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU; 2Reynolds House Referrals, Greenwood Ellis and Partners, 166 High Street, Newmarket, Suffolk, CB8 9WS, UKAbstract: Mesenchymal stromal (MS cells have been derived from multiple sources in the horse including bone marrow, adipose tissue and umbilical cord blood. To date these cells have been investigated for their differentiation potential and are currently being used to treat damage to horse musculoskeletal tissues. However, no work has been done in horse MS cells to examine the expression profile of proteins and cell surface antigens that are expressed in human MS cells. The identification of such profiles in the horse will allow the comparison of putative MS cells isolated from different laboratories and different tissues. At present it is difficult to ascertain whether equivalent cells are being used in different reports. Here, we report on the expression of a range of markers used to define human MS cells. Using immunocytochemistry we show that horse MS cells homogenously express collagens, alkaline phosphatase activity, CD44, CD90 and CD29. In contrast, CD14, CD79α and the embryonic stem cell markers Oct-4, SSEA (stage specific embryonic antigen -1, -3, -4, TRA (tumor rejection antigen -1–60 and -1–81 are not expressed. The MS cells also express MHC class I antigens but do not express class II antigens, although they are inducible by treatment with interferon gamma (IFN-γ.Keywords: mesenchymal stem cells, equine, gene expression

  2. Cell surface galectin-3 defines a subset of chemoresistant gastrointestinal tumor-initiating cancer cells with heightened stem cell characteristics.

    Science.gov (United States)

    Ilmer, Matthias; Mazurek, Nachman; Byrd, James C; Ramirez, Karen; Hafley, Margarete; Alt, Eckhard; Vykoukal, Jody; Bresalier, Robert S

    2016-01-01

    Recurrence of gastrointestinal adenocarcinomas after surgery and chemotherapy may be attributed, in part, to the presence of a small population of tumor-initiating cancer stem cells (CSC). The expression of galectin-3 (Gal3), a multifunctional oncolectin, has been associated with biological behaviors associated with CSC. We examined the ability of Gal3 to characterize the CSC phenotype, and to identify a clinically important gastrointestinal cancer CSC population. Human colorectal and pancreatic cancer cell lines were sorted to identify subpopulations expressing commonly used CSC markers, and Gal3-positive CSC subpopulations. The association of Gal3 with the stem cell properties and alterations of these phenotypes by manipulation of Gal3 expression was examined. Gastrointestinal cancer cell lines contain both Gal3-positive and Gal3-negative subpopulations. Gal3-positive CSCs are characterized by high ALDH activity, enhanced self-renewal ability in vitro (sphere formation) and tumor forming ability in vivo, and resistance to chemotherapeutic agents and death-receptor-mediated apoptosis compared to Gal3-negative CSCs. Silencing Gal3 modifies this behavior. Cell surface Gal3 expression identifies a subset of CSCs in gastrointestinal cancers with high levels of stem cell characteristics, including chemoresistance. This may provide a platform for developing treatment strategies that target CSC. PMID:27512958

  3. Expression of recombinant myelin-associated glycoprotein in primary Schwann cells promotes the initial investment of axons by myelinating Schwann cells

    OpenAIRE

    1990-01-01

    Myelin-associated glycoprotein (MAG) is an integral membrane protein expressed by myelinating glial cells that occurs in two developmentally regulated forms with different carboxyterminal cytoplasmic domains (L- MAG and S-MAG). To investigate the role of MAG in myelination a recombinant retrovirus was used to introduce a MAG cDNA (L-MAG form) into primary Schwann cells in vitro. Stably infected populations of cells were obtained that constitutively expressed MAG at the cell surface without th...

  4. Frequency Selective Surfaces with Nanoparticles Unit Cell

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    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  5. Cell population-specific expression analysis of human cerebellum

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    Kuhn Alexandre

    2012-11-01

    Full Text Available Abstract Background Interpreting gene expression profiles obtained from heterogeneous samples can be difficult because bulk gene expression measures are not resolved to individual cell populations. We have recently devised Population-Specific Expression Analysis (PSEA, a statistical method that identifies individual cell types expressing genes of interest and achieves quantitative estimates of cell type-specific expression levels. This procedure makes use of marker gene expression and circumvents the need for additional experimental information like tissue composition. Results To systematically assess the performance of statistical deconvolution, we applied PSEA to gene expression profiles from cerebellum tissue samples and compared with parallel, experimental separation methods. Owing to the particular histological organization of the cerebellum, we could obtain cellular expression data from in situ hybridization and laser-capture microdissection experiments and successfully validated computational predictions made with PSEA. Upon statistical deconvolution of whole tissue samples, we identified a set of transcripts showing age-related expression changes in the astrocyte population. Conclusions PSEA can predict cell-type specific expression levels from tissues homogenates on a genome-wide scale. It thus represents a computational alternative to experimental separation methods and allowed us to identify age-related expression changes in the astrocytes of the cerebellum. These molecular changes might underlie important physiological modifications previously observed in the aging brain.

  6. Cell surface thiol isomerases may explain the platelet-selective action of S-nitrosoglutathione

    OpenAIRE

    Xiao, Fang; Gordge, Michael P

    2011-01-01

    S-nitrosoglutathione (GSNO) at low concentration inhibits platelet aggregation without causing vasodilation, suggesting platelet-selective nitric oxide delivery. The mechanism of this selectivity is unknown, but may involve cell surface thiol isomerases, in particular protein disulphide isomerase (csPDI) (EC 5.3.4.1). We have now compared csPDI expression and activity on platelets, endothelial cells and vascular smooth muscle cells, and the dependence on thiol reductase activity of these cell...

  7. Galectin-1-mediated cell adhesion, invasion and cell death in human anaplastic large cell lymphoma: regulatory roles of cell surface glycans.

    Science.gov (United States)

    Suzuki, Osamu; Abe, Masafumi

    2014-05-01

    Galectin-1 is known to be one of the extracellular matrix proteins. To elucidate the biological roles of galectin-1 in cell adhesion and invasion of human anaplastic large cell lymphoma, we performed cell adhesion and invasion assays using the anaplastic large cell lymphoma cell line H-ALCL, which was previously established in our laboratory. From the cell surface lectin array, treatment with neuraminidase from Arthrobacter ureafaciens which cleaves all linkage types of cell surface sialic acid enhanced Arachis hypogaea (PNA), Helix pomatia (HPA) and Phaseolus vulgaris-L (L-PHA) lectin binding reactivity to cell surface of lymphoma cells suggesting that neuraminidase removes cell surface sialic acid. In cell adhesion and invasion assays treatment with neuraminidase markedly enhanced cell adhesion to galectin-1 and decreased cell invasive capacity through galectin-1. α2,6-linked sialic acid may be involved in masking the effect of the interaction between galectin-1 and cell surface glycans. H-ALCL cells expressed the β-galactoside-α2,6-sialyltransferase ST6Gal1. On resialylation assay by recombinant ST6Gal1 with CMP-Neu5Ac, α2,6-resialylation of L-PHA reactive oligosaccharide by ST6Gal1 resulted in inhibition of H-ALCL cell adhesion to galectin-1 compared to the desialylated H-ALCL cells. On knockdown experiments, knockdown of ST6Gal1 dramatically enhanced cell adhesion to galectin-1. N-glycosylation inhibitor swainsonine treatment resulted in enhancement of cell adhesion to galectin-1. In glycomic analysis using the lectin blocking assay treatment with PNA, Artocarpus integrifolia (Jacalin), Glycine max (SBA), Helix pomatia (HPA), Vicia villosa (VVA), Ulex europaeus (UEA-1), Triticum vulgaris (WGA), Canavalia ensiformis (ConA), Phaseolus vulgaris-L (L-PHA), Phaseolus vulgaris-E4 (E-PHA), Datura stramonium (DSA) lectins resulted in modulation of lymphoma cell to galectin-1 suggesting that several types of glycans may regulate cell adhesion to galectin-1 by

  8. Intraclonal protein expression heterogeneity in recombinant CHO cells.

    Directory of Open Access Journals (Sweden)

    Warren Pilbrough

    Full Text Available Therapeutic glycoproteins have played a major role in the commercial success of biotechnology in the post-genomic era. But isolating recombinant mammalian cell lines for large-scale production remains costly and time-consuming, due to substantial variation and unpredictable stability of expression amongst transfected cells, requiring extensive clone screening to identify suitable high producers. Streamlining this process is of considerable interest to industry yet the underlying phenomena are still not well understood. Here we examine an antibody-expressing Chinese hamster ovary (CHO clone at single-cell resolution using flow cytometry and vectors, which couple light and heavy chain transcription to fluorescent markers. Expression variation has traditionally been attributed to genetic heterogeneity arising from random genomic integration of vector DNA. It follows that single cell cloning should yield a homogeneous cell population. We show, in fact, that expression in a clone can be surprisingly heterogeneous (standard deviation 50 to 70% of the mean, approaching the level of variation in mixed transfectant pools, and each antibody chain varies in tandem. Phenotypic variation is fully developed within just 18 days of cloning, yet is not entirely explained by measurement noise, cell size, or the cell cycle. By monitoring the dynamic response of subpopulations and subclones, we show that cells also undergo slow stochastic fluctuations in expression (half-life 2 to 11 generations. Non-genetic diversity may therefore play a greater role in clonal variation than previously thought. This also has unexpected implications for expression stability. Stochastic gene expression noise and selection bias lead to perturbations from steady state at the time of cloning. The resulting transient response as clones reestablish their expression distribution is not ordinarily accounted for but can contribute to declines in median expression over timescales of up to 50

  9. Purification and characterization of fetal hematopoietic cells that express the common acute lymphoblastic leukemia antigen (CALLA)

    DEFF Research Database (Denmark)

    Hokland, P; Rosenthal, P; Griffin, J D;

    1983-01-01

    Fetal hematopoietic cells that express the common acute lymphoblastic leukemia antigen (CALLA) were purified from both fetal liver and fetal bone marrow by immune rosetting with sheep erythrocytes coated with rabbit anti-mouse immunoglobulin and by fluorescence-activated cell sorting. Dual...... antigen. Furthermore, using methanol-fixed cells, it could be shown that approximately 20% contained intracytoplasmic mu chains (cyto-mu) and that approximately 15% were positive for the terminal transferase enzyme (TdT) marker. The CALLA+ fetal cells thus closely resemble the childhood acute...... lymphoblastic leukemia cell with respect to surface marker phenotype. A population of CALLA- cells devoid of mature erythroid and myeloid surface markers was found to contain higher numbers of TdT+ cells but lower numbers of cyto-mu, B1, and Ia+ cells than the CALLA+ subset. In vitro analysis of normal...

  10. Cell surface acetylcholinesterase molecules on multinucleated myotubes are clustered over the nucleus of origin

    OpenAIRE

    1992-01-01

    Multinucleated skeletal muscle fibers are compartmentalized with respect to the expression and organization of several intracellular and cell surface proteins including acetylcholinesterase (AChE). Mosaic muscle fibers formed from homozygous myoblasts expressing two allelic variants of AChE preferentially translate and assemble the polypeptides in the vicinity of the nucleus encoding the mRNA (Rotundo, R. L. 1990. J. Cell Biol. 110:715-719). To determine whether the locally synthesized AChE m...

  11. Surface antigen expression in chronic lymphocytic leukemia: clustering analysis, interrelationships and effects of chromosomal abnormalities.

    Science.gov (United States)

    Hulkkonen, J; Vilpo, L; Hurme, M; Vilpo, J

    2002-02-01

    Chronic lymphocytic leukemia (CLL) is a phenotypically distinguishable form of B-lymphoid leukemias. The regularity of surface membrane antigen expression patterns, their interrelationships as well as the effects of the three frequent chromosomal aberrations, ie 11q deletion, 13q deletion and trisomy 12, were investigated in 35 classic CLL cases by flow cytometry. The two-way cluster analysis of 31 individual antigens revealed three expression patterns: (1) most cells in most cases positive (CD5, CD19, CD20, CD23, CD27, CD40, CD45, CD45RA); (2) most cells in most cases negative (CD10, CD14, CD34, CD122, CD154, mIgG); and (3) a mixed pattern with a variable number of positive cases and a variable percentage of positive cells in individual cases (CD11c, CD21, CD22, CD25, CD38, CD45RO, CD79b, CD80, CD95, CD124, CD126, CD130, FMC7, mIgD, mIgkappa, mIglambda, mIgM). The expressions of several antigens were strongly interdependent, even when antigens belonged to entirely different gene families. Such antigen pairs were: CD11c/CD21; CD19/CD45; CD19/CD79b; CD22/CD45RA; CD23/Igkappa; CD25/mIgM; CD27/CD45; CD45/CD79b; CD45RA/Igkappa. In contrast, the expression of some antigens was mutually exclusive, the best examples being CD45RA/CD45RO, CD38/CD80 and CD45RA/CD80. Deletion of chromosome arm 11q attenuated expression of splicing variant CD45RA, but enhanced CD45RO expression. In contrast, cases of trisomy 12 were associated with enhanced CD45RA and attenuated CD45RO expression. Similarly, trisomy 12 was associated with enhanced CD27 and mIgkappa expression. The variable levels of signaling surface membrane antigens, their interactions and interference by genetic aberrations are likely to affect the clinical progression and drug response of CLL. PMID:11840283

  12. Wettability influences cell behavior on superhydrophobic surfaces with different topographies

    NARCIS (Netherlands)

    Lourenco, B.N.; Marchioli, G.; Song, W; Reis, R.L.; Blitterswijk, van C.A.; Karperien, H.B.J.; Apeldoorn, van A.A.; Mano, J.F.

    2012-01-01

    Surface wettability and topography are recognized as critical factors influencing cell behavior on biomaterials. So far only few works have reported cell responses on surfaces exhibiting extreme wettability in combination with surface topography. The goal of this work is to study whether cell behavi

  13. Expression and immunological characteristics of the surface-localized pyruvate kinase in Mycoplasma gallisepticum.

    Science.gov (United States)

    He, Suibin; Qi, Jingjing; Yu, Shengqing; Yin, Yuncong; Tan, Lei; Bao, Shijun; Qiu, Xvsheng; Wang, Xiaolan; Fei, Rongmei; Ding, Chan

    2015-12-01

    The widespread avian pathogen Mycoplasma gallisepticum is a causative agent of respiratory disease. The wall-less prokaryotes lack some tricarboxylic acid cycle enzymes, therefore, the glycolysis metabolic pathway is of great importance to these organisms. Pyruvate kinase (PK) is one of the key enzymes of the glycolytic pathway, and its immunological characteristics in Mycoplasma are not well known. In this study, the M. gallisepticum pyruvate kinase fusion protein (PykF) was expressed in a pET system. The full-length of the gene was subcloned into the expression vector pET28a(+) to construct the pET28a-rMGPykF plasmid, which was then transformed into Escherichia coli strain BL21 (DE3) cells. The expression of the 62 kDa recombinant protein of rMGPykF in E. coli strain BL21 (DE3) was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Coomassie blue staining. Purified rMGPykF exhibited PK catalytic activity, which could reflect the conversion of NADH to NAD(+). Mouse anti-PykF antibodies were generated by immunization of mice with rMGPykF. Immunoblot and immunoelectron microscopy assays identified PykF as an immunogenic protein expressed on the surface of M. gallisepticum cells. Bactericidal assay showed that anti-rMGPykF antiserum killed 70.55% of M. gallisepticum cells, suggesting the protective potential of PykF. Adherence inhibition assay on immortalized chicken fibroblasts (DF-1) cells revealed more than 39.31% inhibition of adhesion in the presence of anti-rMGPykF antiserum, suggesting that PykF of M. gallisepticum participates in bacterial adhesion to DF-1 cells. PMID:26456557

  14. Human thymic epithelial cells express functional HLA-DP molecules

    DEFF Research Database (Denmark)

    Jørgensen, A; Röpke, C; Nielsen, M;

    1996-01-01

    HLA-DP molecules function as restriction elements in the presentation of foreign antigens to T cells by antigen presenting cells and certain HLA-DP molecules confer susceptibility to autoimmune disease. Because HLA molecules play an essential role in thymic selection and elimination of autoreactive...... T lymphocytes, we examined whether human thymic epithelial cells (TEC) expressed HLA-DP molecules. We present evidence that TEC obtained from short time culture express low but significant levels of HLA-DP molecules. The expression of HLA-DP molecules was comparable to or higher than the expression...... of HLA-DQ but lower than that of HLA-DR. Upon IFN-gamma treatment, HLA-DP expression was strongly upregulated. Since HLA-DQ and DR expression was upregulated in parallel, the hierarchy between MHC class II isotypes remained unchanged following interferon treatment. TEC elicited significant...

  15. Ligand-affinity cloning and structure of a cell surface heparan sulfate proteoglycan that binds basic fibroblast growth factor.

    OpenAIRE

    Kiefer, M C; Stephans, J C; Crawford, K; Okino, K.; Barr, P.J.

    1990-01-01

    Expression cloning of cDNAs encoding a basic fibroblast growth factor (FGF) binding protein confirms previous hypotheses that this molecule is a cell-surface heparan sulfate proteoglycan. A cDNA library constructed from a hamster kidney cell line rich in FGF receptor activity was transfected into a human lymphoblastoid cell line. Clones expressing functional basic FGF binding proteins at their surfaces were enriched by panning on plastic dishes coated with human basic FGF. The amino acid sequ...

  16. TRPM5-expressing microvillous cells in the main olfactory epithelium

    Directory of Open Access Journals (Sweden)

    Liman Emily R

    2008-11-01

    Full Text Available Abstract Background The main olfactory epithelium (MOE in the nasal cavity detects a variety of air borne molecules that provide information regarding the presence of food, predators and other relevant social and environmental factors. Within the epithelium are ciliated sensory neurons, supporting cells, basal cells and microvillous cells, each of which is distinct in morphology and function. Arguably, the least understood, are the microvillous cells, a population of cells that are small in number and whose function is not known. We previously found that in a mouse strain in which the TRPM5 promoter drives expression of the green fluorescent protein (GFP, a population of ciliated olfactory sensory neurons (OSNs, as well as a population of cells displaying microvilli-like structures is labeled. Here we examined the morphology and immunocytochemical properties of these microvillous-like cells using immunocytochemical methods. Results We show that the GFP-positive microvillous cells were morphologically diversified and scattered throughout the entire MOE. These cells immunoreacted to an antibody against TRPM5, confirming the expression of this ion channel in these cells. In addition, they showed a Ca2+-activated non-selective cation current in electrophysiological recordings. They did not immunoreact to antibodies that label cell markers and elements of the transduction pathways from olfactory sensory neurons and solitary chemosensory cells of the nasal cavity. Further, the TRPM5-expressing cells did not display axon-like processes and were not labeled with a neuronal marker nor did trigeminal peptidergic nerve fibers innervate these cells. Conclusion We provide morphological and immunocytochemical characterization of the TRPM5-expressing microvillous cells in the main olfactory epithelium. Our data demonstrate that these cells are non-neuronal and in terms of chemosensory transduction do not resemble the TRPM5-expressing olfactory sensory neurons

  17. Pathogenic Leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily.

    Science.gov (United States)

    Matsunaga, James; Barocchi, Michele A; Croda, Julio; Young, Tracy A; Sanchez, Yolanda; Siqueira, Isadora; Bolin, Carole A; Reis, Mitermayer G; Riley, Lee W; Haake, David A; Ko, Albert I

    2003-08-01

    Proteins with bacterial immunoglobulin-like (Big) domains, such as the Yersinia pseudotuberculosis invasin and Escherichia coli intimin, are surface-expressed proteins that mediate host mammalian cell invasion or attachment. Here, we report the identification and characterization of a new family of Big domain proteins, referred to as Lig (leptospiral Ig-like) proteins, in pathogenic Leptospira. Screening of L. interrogans and L. kirschneri expression libraries with sera from leptospirosis patients identified 13 lambda phage clones that encode tandem repeats of the 90 amino acid Big domain. Two lig genes, designated ligA and ligB, and one pseudogene, ligC, were identified. The ligA and ligB genes encode amino-terminal lipoprotein signal peptides followed by 10 or 11 Big domain repeats and, in the case of ligB, a unique carboxy-terminal non-repeat domain. The organization of ligC is similar to that of ligB but contains mutations that disrupt the reading frame. The lig sequences are present in pathogenic but not saprophytic Leptospira species. LigA and LigB are expressed by a variety of virulent leptospiral strains. Loss of Lig protein and RNA transcript expression is correlated with the observed loss of virulence during culture attenuation of pathogenic strains. High-pressure freeze substitution followed by immunocytochemical electron microscopy confirmed that the Lig proteins were localized to the bacterial surface. Immunoblot studies with patient sera found that the Lig proteins are a major antigen recognized during the acute host infection. These observations demonstrate that the Lig proteins are a newly identified surface protein of pathogenic Leptospira, which by analogy to other bacterial immunoglobulin superfamily virulence factors, may play a role in host cell attachment and invasion during leptospiral pathogenesis. PMID:12890019

  18. Oral vaccination of mice with Tremella fuciformis yeast-like conidium cells expressing HBsAg.

    Science.gov (United States)

    Shin, Dong-Il; Song, Kyu-Seon; Park, Hee-Sung

    2015-03-01

    Tremella fuciformis yeast-like conidium (YLC) cells were transformed by co-cultivation with Agrobacterium cells harboring the hepatitis B surface antigen (HBsAg) gene construct under the control of the CaMV35S promoter. Integration of HBsAg DNA into the YLC genome was confirmed by PCR and dot-blot hybridization. Immunoblotting verified expression of the recombinant protein. Oral administration of YLC cells expressing HBsAg in mice significantly increased anti-HBsAg antibody titer levels using a double prime-boost strategy that combined parenteral and oral HBsAg boosters. PMID:25374008

  19. Endogenous Expression of Matriptase in Neural Progenitor Cells Promotes Cell Migration and Neuron Differentiation*

    OpenAIRE

    Fang, Jung-Da; Chou, Hsiao-Chin; Tung, Hsiu-Hui; Huang, Pao-Yi; Lee, Sheau-Ling

    2010-01-01

    Recent studies show that type II transmembrane serine proteases play important roles in diverse cellular activities and pathological processes. Their expression and functions in the central nervous system, however, are largely unexplored. In this study, we show that the expression of one such member, matriptase (MTP), was cell type-restricted and primarily expressed in neural progenitor (NP) cells and neurons. Blocking MTP expression or MTP activity prevented NP cell traverse of reconstituted...

  20. Mitogen-activated protein kinases mediate Mycobacterium tuberculosis–induced CD44 surface expression in monocytes

    Indian Academy of Sciences (India)

    Natarajan Palaniappan; S Anbalagan; Sujatha Narayanan

    2012-03-01

    CD44, an adhesion molecule, has been reported to be a binding site for Mycobacterium tuberculosis (M. tuberculosis) in macrophages and it also mediates mycobacterial phagocytosis, macrophage recruitment and protective immunity against pulmonary tuberculosis in vivo. However, the signalling pathways that are involved in M. tuberculosis–induced CD44 surface expression in monocytic cells are currently unknown. Exposure of THP-1 human monocytes to M. tuberculosis H37Rv and H37Ra induced distinct, time-dependent, phosphorylation of mitogen-activated protein kinase kinase-1, extracellular signal regulated kinase 1/2, mitogen-activated protein kinase kinase 3/6, p38 mitogen-activated protein kinase and c-jun N-terminal kinases. The strains also differed in their usage of CD14 and human leukocyte antigen-DR (HLA-DR) receptors in mediating mitogen-activated protein kinase activation. M. tuberculosis H37Rv strain induced lower CD44 surface expression and tumour necrosis factor-alpha levels, whereas H37Ra the reverse. Using highly specific inhibitors of mitogen-activated protein kinase kinase-1, p38 mitogen-activated protein kinase and c-jun N-terminal kinase, we report that inhibition of extracellular signal regulated kinase 1/2 and c-jun N-terminal kinases increases, but that inhibition of p38 mitogen-activated protein kinase decreases M. tuberculosis–induced CD44 surface expression in THP-1 human monocytes.

  1. Cyclin Dl expression in B-cell non Hodgkin lymphoma.

    Science.gov (United States)

    Aref, Salah; Mossad, Y; El-Khodary, T; Awad, M; El-Shahat, E

    2006-10-01

    Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over-expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the effect of its expression on clinical behavior and outcome in B-cell Non-Hodgkin lymphoma (NHL). In this study, we investigated the expression of cyclin Dl in group of patients with NHL and correlated the results with the clinical and laboratory data. The degree of expression of cyclin Dl protein was evaluated by flow cytometry in a group of NHL patients (n = 46) and in normal control group (n = 10). Cyclin Dl over expression was detected in 10 out of 46 (21.7%) patients; they were 5/5-mantle cell lymphoma (MCL) (100%) and 5/28 large B-cell lymphoma (17.8%). All other NHL subtypes showed normal cyclin D1 expression. The clinical signs (hepatomegaly, splenomegaly and B-symptoms, clinical staging) and laboratory data (hemoglobin, white cell count (WBCs), platelet count, and bone marrow infiltration) were not significantly different between NHL subgroup with cyclin Dl over expression and that with normal cyclin Dl expression. Serum lactic dehydrogenase (LDH) levels and lymphadenopathy were significantly higher in NHL group with cyclin D1 over expression as compared to those without. Also, cyclin D1 over expression is associated with poor outcome of NHL patients. Cyclin Dl over expression was evident among all cases of MCL and few cases of large B-cell lymphoma. Cyclin Dl over expression might be used as adjuvant tool for diagnosis of MCL; has role in NHL biology and is bad prognostic index in NHL. PMID:17607588

  2. The expression and modulation of CEACAM1 and tumor cell transformation

    Directory of Open Access Journals (Sweden)

    Valentina Fiori

    2012-06-01

    Full Text Available BACKGROUND: In this review, we focus our discussion on one class of carcinoembryonic antigen-related cell adhesion molecules, Carcinoembryonic antigen-related cell adhesion molecules 1 (CEACAM1. This has been observed in several malignant transformations to be subjected to complex mechanisms of modulation and dysregulation. AIMS: Restoration of CEACAM1 expression in tumor cell lines often abolishes their oncogenicity in vivo, and therefore, this adhesion molecule has been regarded as a tumor suppressor. In contrast, de novo expression of CEACAM1 is found with the progression of malignancy and metastatic spread in a large array of cancer tissues which include melanoma, Non Small cell Lung carcinoma (NSCLC as well as bladder, prostate, thyroid, breast, colon and gastric carcinomas. DISCUSSION: We report and discuss the most significant findings confirming at immunohistochemical and clinical level the correlation between poor prognosis and expression of CEACAM1 on the cell surface of tumors.

  3. Increased expression of PcG protein YY1 negatively regulates B cell development while allowing accumulation of myeloid cells and LT-HSC cells.

    Science.gov (United States)

    Pan, Xuan; Jones, Morgan; Jiang, Jie; Zaprazna, Kristina; Yu, Duonan; Pear, Warren; Maillard, Ivan; Atchison, Michael L

    2012-01-01

    Ying Yang 1 (YY1) is a multifunctional Polycomb Group (PcG) transcription factor that binds to multiple enhancer binding sites in the immunoglobulin (Ig) loci and plays vital roles in early B cell development. PcG proteins have important functions in hematopoietic stem cell renewal and YY1 is the only mammalian PcG protein with DNA binding specificity. Conditional knock-out of YY1 in the mouse B cell lineage results in arrest at the pro-B cell stage, and dosage effects have been observed at various YY1 expression levels. To investigate the impact of elevated YY1 expression on hematopoetic development, we utilized a mouse in vivo bone marrow reconstitution system. We found that mouse bone marrow cells expressing elevated levels of YY1 exhibited a selective disadvantage as they progressed from hematopoietic stem/progenitor cells to pro-B, pre-B, immature B and re-circulating B cell stages, but no disadvantage of YY1 over-expression was observed in myeloid lineage cells. Furthermore, mouse bone marrow cells expressing elevated levels of YY1 displayed enrichment for cells with surface markers characteristic of long-term hematopoietic stem cells (HSC). YY1 expression induced apoptosis in mouse B cell lines in vitro, and resulted in down-regulated expression of anti-apoptotic genes Bcl-xl and NFκB2, while no impact was observed in a mouse myeloid line. B cell apoptosis and LT-HSC enrichment induced by YY1 suggest that novel strategies to induce YY1 expression could have beneficial effects in the treatment of B lineage malignancies while preserving normal HSCs. PMID:22292011

  4. HCMV Infection Depress NGF Expression in Human Glioma Cells

    Institute of Scientific and Technical Information of China (English)

    Hai-tao WANG; Bin WANG; Zhi-jun LIU; Zhi-qiang BAI; Ling LI; Dong-meng QIAN; Zhi-yong YAN; Xu-xia SONG

    2009-01-01

    Human cytomegalovirus (HCMV) is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of endogenic nerve growth factor expression in neuroglia cells by HCMV infection. The results showed that basal, endogenous NGF expression in U251 was unchanged during early HCMV infection. NGF expression is strongly down-regulated during the latent phase of infection. These results suggest that HCMV can depress the NGF expression in U251 cells.

  5. Chemistry and material science at the cell surface

    Directory of Open Access Journals (Sweden)

    Weian Zhao

    2010-04-01

    Full Text Available Cell surfaces are fertile ground for chemists and material scientists to manipulate or augment cell functions and phenotypes. This not only helps to answer basic biology questions but also has diagnostic and therapeutic applications. In this review, we summarize the most recent advances in the engineering of the cell surface. In particular, we focus on the potential applications of surface engineered cells for 1 targeting cells to desirable sites in cell therapy, 2 programming assembly of cells for tissue engineering, 3 bioimaging and sensing, and ultimately 4 manipulating cell biology.

  6. Increase of CXCR4 Expression on Expanded Non-enriched Cord Blood CD34+ Cells Using MSCs

    Directory of Open Access Journals (Sweden)

    Masoud Soleimani

    2005-01-01

    Full Text Available Introduction: A number of potential cell adhesion molecules, which mediate essential cell-to-cell or cell-to-matrix interactions, are expressed on the surface of CD34+ hematopoietic progenitor cells (HPCs, including integrins, CD44, and CXCR4. These molecules are essential for homing process. In this study, we compared the changes of expression of CD44 and CXCR4 on the CD34+ hematopoietic progenitor cells expanded on MSCs in the presence of cytokines. Material and Methods: Cord blood CD34+ cells were expanded using human bone marrow mesenchymal stem cells and cytokines (TPO, SCF, FLt-3, IL-6, and IL-3, and then expression of CD44 and CXCR4 on CD34+ cells were evaluated by flow cytometric analysis. Results: After 2 weeks of serum free culture of CD34+ cells in the presence of cytokines, the expression of CXCR4 on CD34+ cells was decreased 3.4 fold (p<0.05. In contrast, the expression of CXCR4 on CD34+ cells expanded on hMSCs was increased (p<0.05. The expression of CD44 on expanded CD34+ cells in both methods did not differ significantly. Conclusions: Our results indicated that co-culture of cord blood stem cells on hMSCs significantly increased CXCR4 expression on cord blood CD34+ cells.

  7. Neurohypophysial Receptor Gene Expression by Thymic T Cell Subsets and Thymic T Cell Lymphoma Cell Lines

    Directory of Open Access Journals (Sweden)

    I. Hansenne

    2004-01-01

    transcribed in thymic epithelium, while immature T lymphocytes express functional neurohypophysial receptors. Neurohypophysial receptors belong to the G protein-linked seven-transmembrane receptor superfamily and are encoded by four distinct genes, OTR, V1R, V2R and V3R. The objective of this study was to identify the nature of neurohypophysial receptor in thymic T cell subsets purified by immunomagnetic selection, as well as in murine thymic lymphoma cell lines RL12-NP and BW5147. OTR is transcribed in all thymic T cell subsets and T cell lines, while V3R transcription is restricted to CD4+ CD8+ and CD8+ thymic cells. Neither V1R nor V2R transcripts are detected in any kind of T cells. The OTR protein was identified by immunocytochemistry on thymocytes freshly isolated from C57BL/6 mice. In murine fetal thymic organ cultures, a specific OTR antagonist does not modify the percentage of T cell subsets, but increases late T cell apoptosis further evidencing the involvement of OT/OTR signaling in the control of T cell proliferation and survival. According to these data, OTR and V3R are differentially expressed during T cell ontogeny. Moreover, the restriction of OTR transcription to T cell lines derived from thymic lymphomas may be important in the context of T cell leukemia pathogenesis and treatment.

  8. Hair cell damage recruited Lgr5-expressing cells are hair cell progenitors in neonatal mouse utricle

    Directory of Open Access Journals (Sweden)

    Jinchao Lin

    2015-04-01

    Full Text Available Damage-activated stem/progenitor cells play important roles in regenerating lost cells and in tissue repair. Previous studies reported that the mouse utricle has limited hair cell regeneration ability after hair cell ablation. However, the potential progenitor cell population regenerating new hair cells remains undiscovered. In this study, we first found that Lgr5, a Wnt target gene that is not usually expressed in the neonatal mouse utricle, can be activated by 24 hour neomycin treatment in a sub-population of supporting cells in the striolar region of the neonatal mouse utricle. Lineage tracing demonstrated that these Lgr5-positive supporting cells could regenerate new hair cells in explant culture. We isolated the damage-activated Lgr5-positive cells with flow cytometry and found that these Lgr5-positive supporting cells could regenerate hair cells in vitro, and self-renew to form spheres, which maintained the capacity to differentiate into hair cells over seven generations of passages. Our results suggest that damage-activated Lgr5-positive supporting cells act as hair cell progenitors in the neonatal mouse utricle, which may help to uncover a potential route to regenerate hair cell in mammals.

  9. Vesicular Stomatitis Virus Infection Promotes Immune Evasion by Preventing NKG2D-Ligand Surface Expression

    DEFF Research Database (Denmark)

    Jensen, Helle; Andresen, Lars; Nielsen, Jens; Christensen, Jan Pravsgaard; Skov, Søren

    2011-01-01

    leads to a robust induction of MICA mRNA expression, however the subsequent surface expression is potently hindered. Thus, VSV lines up with human cytomegalovirus (HCMV) and adenovirus, which actively subvert the immune system by negatively affecting NKG2D-ligand surface expression. VSV infection caused...

  10. Expression of NK cell and monocyte receptors in critically ill patients - potential biomarkers of sepsis

    DEFF Research Database (Denmark)

    Kjaergaard, A G; Nielsen, Jeppe Sylvest; Tønnesen, Else; Krog, Jan

    2015-01-01

    UNLABELLED: Sepsis is characterized by activation of both the innate and adaptive immune systems as a response to infection. During sepsis, the expression of surface receptors expressed on immune competent cells, such as NKG2D and NKp30 on NK cells and TLR4 and CD14 on monocytes, is partly......-septic patients (n = 15). Healthy volunteers (n = 15) served as controls. To elucidate variations over time, all patients were followed for 4 days. Cell surface expression of NKG2D, NKp30, TLR4 and CD14 and serum levels of IL-1β, IL-6, IFN-γ, TNF-α, IL-4 and IL-10 was estimated by flow cytometry. We found that NK...

  11. Tumorigenicity and adenovirus-transformed cells: Collagen interaction and cell surface laminin are controlled by the serotype origin of the E1A and E1B genes

    Energy Technology Data Exchange (ETDEWEB)

    Bober, F.J.; Birk, D.E.; Raska, K. Jr. (Princeton Univ., NJ (USA)); Shenk, T. (Univ. of Medicine and Dentistry of New Jersey, Piscataway (USA))

    1988-02-01

    A library of cells transformed with recombinant adenoviruses was used to study tumorigenicity and interaction with extracellular matrix. Cells expressing the complete E1 region of highly oncogenic adenovirus type 12 (Ad12) are tumorigenic, adhere preferentially to type IV collagen, and express cell surface laminin. Weakly tumorigenic cells, which express the E1A oncogene of Ad12 and the E1B genes of Ad5, also attach preferentially to type IV collagen but do not contain laminin on their surface. Cells which express the E1A oncogene of Ad5 and the E1B genes of Ad12 are nontumorigenic and do not preferentially attach to type IV versus type I collagen but have laminin on their surface. There is no significant difference in the amounts of laminin secreted into the culture medium among cells expressing the E1B genes of Ad5 or Ad12. In vitro assays show that cells which express the E1B genes of Ad12, irrespective of the origin of the E1A genes, can bind three times more exogenously added {sup 125}I-laminin than cells expressing the E1B genes of nononcogenic Ad5. The interaction of adenovirus-transformed cells with collagen is controlled by the serotype origin of the E1A oncogene, whereas cell surface laminin is controlled by the serotype origin of the E1B genes.

  12. Calculation of cell volumes and surface areas in MCNP

    International Nuclear Information System (INIS)

    MCNP is a general Monte Carlo neutron-photon particle transport code which treats an arbitrary three-dimensional configuration of materials in geometric cells bounded by first- and second-degree surfaces, and some special fourth-degree surfaces. It is necessary to calculate cell volumes and surface areas so that cell masses, fluxes, and other important information can be determined. The volume/area calculation in MCNP computes cell volumes and surface areas for cells and surfaces rotationally symmetric about any arbitrary axis. 5 figures, 1 table

  13. Estrogen regulation of TRPM8 expression in breast cancer cells

    International Nuclear Information System (INIS)

    The calcium-permeable cation channel TRPM8 (melastatin-related transient receptor potential member 8) is over-expressed in several cancers. The present study aimed at investigating the expression, function and potential regulation of TRPM8 channels by ER alpha (estrogen receptor alpha) in breast cancer. RT-PCR, Western blot, immuno-histochemical, and siRNA techniques were used to investigate TRPM8 expression, its regulation by estrogen receptors, and its expression in breast tissue. To investigate the channel activity in MCF-7 cells, we used the whole cell patch clamp and the calcium imaging techniques. TRPM8 channels are expressed at both mRNA and protein levels in the breast cancer cell line MCF-7. Bath application of the potent TRPM8 agonist Icilin (20 μM) induced a strong outwardly rectifying current at depolarizing potentials, which is associated with an elevation of cytosolic calcium concentration, consistent with established TRPM8 channel properties. RT-PCR experiments revealed a decrease in TRPM8 mRNA expression following steroid deprivation for 48 and 72 hours. In steroid deprived medium, addition of 17-beta-estradiol (E2, 10 nM) increased both TRPM8 mRNA expression and the number of cells which respond to Icilin, but failed to affect the Ca2+ entry amplitude. Moreover, silencing ERα mRNA expression with small interfering RNA reduced the expression of TRPM8. Immuno-histochemical examination of the expression of TRPM8 channels in human breast tissues revealed an over-expression of TRPM8 in breast adenocarcinomas, which is correlated with estrogen receptor positive (ER+) status of the tumours. Taken together, these results show that TRPM8 channels are expressed and functional in breast cancer and that their expression is regulated by ER alpha

  14. Estrogen regulation of TRPM8 expression in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Sevestre Henri

    2010-05-01

    Full Text Available Abstract Background The calcium-permeable cation channel TRPM8 (melastatin-related transient receptor potential member 8 is over-expressed in several cancers. The present study aimed at investigating the expression, function and potential regulation of TRPM8 channels by ER alpha (estrogen receptor alpha in breast cancer. Methods RT-PCR, Western blot, immuno-histochemical, and siRNA techniques were used to investigate TRPM8 expression, its regulation by estrogen receptors, and its expression in breast tissue. To investigate the channel activity in MCF-7 cells, we used the whole cell patch clamp and the calcium imaging techniques. Results TRPM8 channels are expressed at both mRNA and protein levels in the breast cancer cell line MCF-7. Bath application of the potent TRPM8 agonist Icilin (20 μM induced a strong outwardly rectifying current at depolarizing potentials, which is associated with an elevation of cytosolic calcium concentration, consistent with established TRPM8 channel properties. RT-PCR experiments revealed a decrease in TRPM8 mRNA expression following steroid deprivation for 48 and 72 hours. In steroid deprived medium, addition of 17-beta-estradiol (E2, 10 nM increased both TRPM8 mRNA expression and the number of cells which respond to Icilin, but failed to affect the Ca2+ entry amplitude. Moreover, silencing ERα mRNA expression with small interfering RNA reduced the expression of TRPM8. Immuno-histochemical examination of the expression of TRPM8 channels in human breast tissues revealed an over-expression of TRPM8 in breast adenocarcinomas, which is correlated with estrogen receptor positive (ER+ status of the tumours. Conclusion Taken together, these results show that TRPM8 channels are expressed and functional in breast cancer and that their expression is regulated by ER alpha.

  15. Spontaneous loss and alteration of antigen receptor expression in mature CD4+ T cells

    International Nuclear Information System (INIS)

    The T-cell receptor CD3 (TCR/CD3) complex plays a central role in antigen recognition and activation of mature T cells, and therefore abnormalities in the expression of the complex should induce unresponsiveness of T cells to antigen stimulus. Using flow cytometry, we detected and enumerated variant cells with loss or alteration of surface TCR/CD3 expression among human mature CD4+ T cells. The presence of variant CD4+ T cells was demonstrated by isolating and cloning them from peripheral blood, and their abnormalities can be accounted for by alterations in TCR expression such as defects of protein expression and partial protein deletion. The variant frequency in peripheral blood increased with aging in normal donors and was highly elevated in patients with ataxia telangiectasia, an autosomal recessive inherited disease with defective DNA repair and variable T-cell immunodeficiency. These findings suggest that such alterations in TCR expression are induced by somatic mutagenesis of TCR genes and can be important factors related to age-dependent and genetic disease-associated T-cell dysfunction. (author)

  16. Beta-Adrenergic Receptor Expression in Muscle Cells

    Science.gov (United States)

    Young, Ronald B.; Bridge, K.; Vaughn, J. R.

    1999-01-01

    beta-adrenergic receptor (bAR) agonists presumably exert their physiological action on skeletal muscle cells through the bAR. Since the signal generated by the bAR is cyclic AMP (cAMP), experiments were initiated in primary chicken muscle cell cultures to determine if artificial elevation of intracellular cAMP by treatment with forskolin would alter the population of bAR expressed on the surface of muscle cells. Chicken skeletal muscle cells after 7 days in culture were employed for the experiments because muscle cells have attained a steady state with respect to muscle protein metabolism at this stage. Cells were treated with 0-10 uM forskolin for a total of three days. At the end of the 1, 2, and 3 day treatment intervals, the concentration of cAMP and the bAR population were measured. Receptor population was measured in intact muscle cell cultures as the difference between total binding of [H-3]CGP-12177 and non-specific binding of [H-3]CGP-12177 in the presence of 1 uM propranolol. Intracellular cAMP concentration was measured by radioimmunoassay. The concentration of cAMP in forskolin-treated cells increased up to 10-fold in a dose dependent manner. Increasing concentrations of forskolin also led to an increase in (beta)AR population, with a maximum increase of approximately 50% at 10 uM. This increase in (beta)AR population was apparent after only 1 day of treatment, and the pattern of increase was maintained for all 3 days of the treatment period. Thus, increasing the intracellular concentration of cAMP leads to up-regulation of (beta)AR population. Clenbuterol and isoproterenol gave similar effects on bAR population. The effect of forskolin on the quantity and apparent synthesis rate of the heavy chain of myosin (mhc) were also investigated. A maximum increase of 50% in the quantity of mhc was observed at 0.2 UM forskolin, but higher concentrations of forskolin reduced the quantity of mhc back to control levels.

  17. Characterization of T cell receptor assembly and expression in a Ti gamma delta-positive cell line

    DEFF Research Database (Denmark)

    Kuhlmann, J; Caspar-Bauguil, S; Geisler, C; Rubin, B

    1993-01-01

    various components of this multimeric protein complex is still not fully understood. In this report, the human leukemic T cell line Lyon which expresses a Ti-gamma delta/CD3 complex, was characterized and compared to another human leukemic T cell line Jurkat (Ti-alpha beta/CD3). Membrane TCR-/CD3...... not associate with the Ti-gamma/CD3 gamma delta epsilon complex and (3) the Ti-delta chain was required for cell surface expression of the Ti-gamma delta/CD3 complex. Introduction of Jurkat wild-type Ti-alpha cDNA into Lyon T cells resulted in Ti-alpha beta/CD3 expression and abrogated Ti-gamma delta......T cell antigen receptor (TcR) heterodimers of both the Ti-alpha beta and Ti-gamma delta types are expressed at the surface of T cells noncovalently associated with the CD3 complex composed of the monomorphic chains gamma, delta, epsilon and zeta. The structural relationship and assembly of the...

  18. Chlamydia trachomatis Immune Evasion via Downregulation of MHC Class I Surface Expression Involves Direct and Indirect Mechanisms

    OpenAIRE

    Ibana, Joyce A.; Schust, Danny J.; Jun Sugimoto; Takeshi Nagamatsu; Greene, Sheila J.; Alison J. Quayle

    2011-01-01

    Genital C. trachomatis infections typically last for many months in women. This has been attributed to several strategies by which C. trachomatis evades immune detection, including well-described methods by which C. trachomatis decreases the cell surface expression of the antigen presenting molecules major histocompatibility complex (MHC) class I, MHC class II, and CD1d in infected genital epithelial cells. We have harnessed new methods that allow for separate evaluation of infected and uni...

  19. The effect of plasma-nitrided titanium surfaces on osteoblastic cell adhesion, proliferation, and differentiation.

    Science.gov (United States)

    Ferraz, Emanuela P; Sa, Juliana C; de Oliveira, Paulo T; Alves, Clodomiro; Beloti, Marcio M; Rosa, Adalberto L

    2014-04-01

    In this study, we evaluated the effect of new plasma-nitrided Ti surfaces on the progression of osteoblast cultures, including cell adhesion, proliferation and differentiation. Ti surfaces were treated using two plasma-nitriding protocols, hollow cathode for 3 h (HC 3 h) and 1 h (HC 1 h) and planar for 1 h. Untreated Ti surfaces were used as control. Cells derived from human alveolar and rat calvarial bones were cultured on Ti surfaces for periods of up to 14 days and the following parameters were evaluated: cell morphology, adhesion, spreading and proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization, and gene expression of key osteoblast markers. Plasma-nitriding treatments resulted in Ti surfaces with distinct physicochemical characteristics. The cell adhesion and ALP activity were higher on plasma-nitrided Ti surfaces compared with untreated one, whereas cell proliferation and extracellular matrix mineralization were not affected by the treatments. In addition, the plasma-nitrided Ti surfaces increased the ALP, reduced the osteocalcin and did not affect the Runx2 gene expression. We have shown that HC 3 h and planar Ti surfaces slightly favored the osteoblast differentiation process, and then these surfaces should be considered for further investigation using preclinical models. PMID:23625878

  20. Analysis of dysregulated long non-coding RNA expressions in glioblastoma cells.

    Science.gov (United States)

    Balci, Tugce; Yilmaz Susluer, Sunde; Kayabasi, Cagla; Ozmen Yelken, Besra; Biray Avci, Cigir; Gunduz, Cumhur

    2016-09-15

    Long non coding RNAs (lncRNAs) are associated with various biological roles such as embryogenesis, stem cell biology, cellular development and present specific tissue expression profiles. Aberrant expression of lncRNAs are thought to play a critical role in the progression and development of various cancer types, including gliomas. Glioblastomas (GBM) are common and malignant primary brain tumours. Brain cancer stem cells (BCSC) are isolated from both low and high-grade tumours in adults and children, by cell fraction which express neuronal stem cell surface marker CD133. The purpose of this study was to investigate the expression profiles of lncRNAs in brain tumour cells and determine its potential biological function. For this purpose, U118MG-U87MG; GBM stem cell series were used. Human parental brain cancer cells were included as the control group; the expressions of disease related human lncRNA profiles were studied by LightCycler 480 real-time PCR. Expression profiles of 83 lncRNA genes were analyzed for a significant dysregulation, compared to the control cells. Among lncRNAs, 51 lncRNA genes down-regulated, while 8 lncRNA genes were up-regulated. PCAT-1 (-2.36), MEG3 (-5.34), HOTAIR (-2.48) lncRNAs showed low expression in glioblastoma compared to the human (parental) brain cancer stem cells, indicating their role as tumour suppressor genes on gliomas. As a result, significant changes for anti-cancer gene expressions were detected with disease-related human lncRNA array plates. Identification of novel target genes may lead to promising developments in human brain cancer treatment. PMID:27306825

  1. Regulation and gene expression profiling of NKG2D positive human cytomegalovirus-primed CD4+ T-cells.

    Directory of Open Access Journals (Sweden)

    Helle Jensen

    Full Text Available NKG2D is a stimulatory receptor expressed by natural killer (NK cells, CD8(+ T-cells, and γδ T-cells. NKG2D expression is normally absent from CD4(+ T-cells, however recently a subset of NKG2D(+ CD4(+ T-cells has been found, which is specific for human cytomegalovirus (HCMV. This particular subset of HCMV-specific NKG2D(+ CD4(+ T-cells possesses effector-like functions, thus resembling the subsets of NKG2D(+ CD4(+ T-cells found in other chronic inflammations. However, the precise mechanism leading to NKG2D expression on HCMV-specific CD4(+ T-cells is currently not known. In this study we used genome-wide analysis of individual genes and gene set enrichment analysis (GSEA to investigate the gene expression profile of NKG2D(+ CD4(+ T-cells, generated from HCMV-primed CD4(+ T-cells. We show that the HCMV-primed NKG2D(+ CD4(+ T-cells possess a higher differentiated phenotype than the NKG2D(- CD4(+ T-cells, both at the gene expression profile and cytokine profile. The ability to express NKG2D at the cell surface was primarily determined by the activation or differentiation status of the CD4(+ T-cells and not by the antigen presenting cells. We observed a correlation between CD94 and NKG2D expression in the CD4(+ T-cells following HCMV stimulation. However, knock-down of CD94 did not affect NKG2D cell surface expression or signaling. In addition, we show that NKG2D is recycled at the cell surface of activated CD4(+ T-cells, whereas it is produced de novo in resting CD4(+ T-cells. These findings provide novel information about the gene expression profile of HCMV-primed NKG2D(+ CD4(+ T-cells, as well as the mechanisms regulating NKG2D cell surface expression.

  2. Expression of Bcl-2 in cells with different telomerase activities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both telomerase and Bcl-2 are important genes in controlling apoptosis. The activation of telomerase and the abnormal regulation of Bcl-2 are also closely related to carcinogenesis. However, little is known about the linkage between telomerase and Bcl-2. The effect of activated telomerase on the expression of Bcl-2 has been investigated. It is demonstrated that in tumor and transformed cells with higher telomerase activity, Bcl-2 expression is significantly lower than that in telomerase negative or less telomerose activity cells. Further study showed that in the telomerase gene-transformed 2BS-fibroblasts, Bcl-2 expression is inhibited significantly while the exogenous telomerase catalytic subunit gene is re-expressed in fibroblasts. Results indicated that there might be a certain linkage between the expression of telomerase and Bcl-2, and overexpression of exogenous telomerase gene might down regulate the expression of Bcl-2.

  3. Identification of Vulnerable Cell Types in Major Brain Disorders Using Single Cell Transcriptomes and Expression Weighted Cell Type Enrichment

    OpenAIRE

    Skene, Nathan G.; Grant, Seth G.N.

    2016-01-01

    The cell types that trigger the primary pathology in many brain diseases remain largely unknown. One route to understanding the primary pathological cell type for a particular disease is to identify the cells expressing susceptibility genes. Although this is straightforward for monogenic conditions where the causative mutation may alter expression of a cell type specific marker, methods are required for the common polygenic disorders. We developed the Expression Weighted Cell Type Enrichment ...

  4. Identification of vulnerable cell types in major brain disorders using single cell transcriptomes and expression weighted cell type enrichment

    OpenAIRE

    Skene, Nathan G.; Grant, Seth G.N.

    2016-01-01

    The cell types that trigger the primary pathology in many brain diseases remain largely unknown. One route to understanding the primary pathological cell type for a particular disease is to identify the cells expressing susceptibility genes. Although this is straightforward for monogenic conditions where the causative mutation may alter expression of a cell type specific marker, methods are required for the common polygenic disorders. We developed the Expression Weighted Cell Type Enrichment ...

  5. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    Science.gov (United States)

    Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

    2012-12-01

    A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface with HPDLCs. The Col-immobilized titanium surface could be used for forming ligament-like tissues around titanium dental implants.

  6. Automatic Control of Gene Expression in Mammalian Cells.

    Science.gov (United States)

    Fracassi, Chiara; Postiglione, Lorena; Fiore, Gianfranco; di Bernardo, Diego

    2016-04-15

    Automatic control of gene expression in living cells is paramount importance to characterize both endogenous gene regulatory networks and synthetic circuits. In addition, such a technology can be used to maintain the expression of synthetic circuit components in an optimal range in order to ensure reliable performance. Here we present a microfluidics-based method to automatically control gene expression from the tetracycline-inducible promoter in mammalian cells in real time. Our approach is based on the negative-feedback control engineering paradigm. We validated our method in a monoclonal population of cells constitutively expressing a fluorescent reporter protein (d2EYFP) downstream of a minimal CMV promoter with seven tet-responsive operator motifs (CMV-TET). These cells also constitutively express the tetracycline transactivator protein (tTA). In cells grown in standard growth medium, tTA is able to bind the CMV-TET promoter, causing d2EYFP to be maximally expressed. Upon addition of tetracycline to the culture medium, tTA detaches from the CMV-TET promoter, thus preventing d2EYFP expression. We tested two different model-independent control algorithms (relay and proportional-integral (PI)) to force a monoclonal population of cells to express an intermediate level of d2EYFP equal to 50% of its maximum expression level for up to 3500 min. The control input is either tetracycline-rich or standard growth medium. We demonstrated that both the relay and PI controllers can regulate gene expression at the desired level, despite oscillations (dampened in the case of the PI controller) around the chosen set point. PMID:26414746

  7. Hamster thecal cells express muscle characteristics

    International Nuclear Information System (INIS)

    Contraction of the follicular wall about the time of ovulation appears to be a coordinated event; however, the cells that mediate it remain poorly studied. We examined the theca externa cells in the wall of hamster follicles for the presence of a functional actomyosin system, both in developing follicles and in culture. We used a monoclonal antibody (HHF35) that recognizes the alpha and gamma isoelectric variants of actin normally found in muscle, but not the beta variant associated with non-muscle sources, to evaluate large preovulatory follicles for actin content and composition. Antibody staining of sectioned ovaries showed intense circumferential reactivity in the outermost wall of developing follicles. Immunoblots from two-dimensional gels of theca externa lysates demonstrated the presence of the two muscle-specific isozymes of actin. Immunofluorescence of cultured follicular cells pulse-labeled with [3H] thymidine (for autoradiographic detection of DNA replication) revealed the presence, in many dividing cells, of actin filaments aligned primarily along the longitudinal axis of the cells. In cultures exposed to the calcium ionophore A23187 (10(-4) M) for varying periods (5 min to 1 h), contraction of many individual muscle-actin-positive cells was observed. Immunofluorescence of these cells, fixed immediately after ionophore-induced contraction, revealed compaction of the actin filaments. Our findings demonstrate that the cells of the theca externa contain muscle actins from an early stage and that these cells are capable of contraction even while proliferating in subconfluent cultures. They suggest that follicular growth may include a naturally occurring developmental sequence in which a contractile cell type proliferates in the differentiated state

  8. Ectopic ERK Expression Induces Phenotypic Conversion of C10 Cells and Alters DNA Methyltransferase Expression

    Energy Technology Data Exchange (ETDEWEB)

    Sontag, Ryan L.; Weber, Thomas J.

    2012-05-04

    In some model systems constitutive extracellular signal regulated kinase (ERK) activation is sufficient to promote an oncogenic phenotype. Here we investigate whether constitutive ERK expression influences phenotypic conversion in murine C10 type II alveolar epithelial cells. C10 cells were stably transduced with an ERK1-green fluorescent protein (ERK1-GFP) chimera or empty vector and ectopic ERK expression was associated with the acquisition of soft agar focus-forming potential in late passage, but not early passage cells. Late passage ERK1-GFP cells exhibited a significant increase in the expression of DNA methyl transferases (DNMT1 and 3b) and a marked increase in sensitivity to 5-azacytidine (5-azaC)-mediated toxicity, relative to early passage ERK1-GFP cells and vector controls. The expression of xeroderma pigmentosum complementation group A (XPA) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) were significantly increased in late passage cells, suggesting enhanced DNA damage recognition and repair activity which we interpret as a reflection of genomic instability. Phospho-ERK levels were dramatically decreased in late passage ERK1-GFP cells, relative to early passage and vector controls, and phospho-ERK levels were restored by treatment with sodium orthovanadate, indicating a role for phosphatase activity in this response. Collectively these observations suggest that ectopic ERK expression promotes phenotypic conversion of C10 cells that is associated with latent effects on epigenetic programming and phosphatase activities.

  9. Expression of aquaporin-1 in SMMC-7221 liver carcinoma cells promotes cell migration

    Institute of Scientific and Technical Information of China (English)

    LI Yongming; FENG Xuechao; YANG Hong; MA Tonghui

    2006-01-01

    Migration of tumor cells is a crucial step in tumor invasion and metastasis. Here we provide evidence that aquaporin expression is involved in tumor cell migration. RT-PCR, immunofluorescence and Western blot analysis demonstrated the AQP1 protein expression on the plasma membrane of SMMC-7221 human hepatoma cells. SMMC-7221 cell clones with high (SMMC-7221hPf) and low (SMMC-7221/Pf) water permeability were identified by functional assays with corresponding high and low AQP1 expression. Cell migration rate was remarkably higher in SMMC-7221hPf cells than SMMC-7221/Pf cells, assessed by Boyden chamber and wound healing assays, whereas cell growth and adhesion were not different. Adenovirus-mediated AQP1 expression in SMMC-7221/Pf cells increased their water permeability and migration rate. These results provide the first evidence that aquaporin-mediated membrane water permeability enhances tumor cell migration and may be associated with tumor invasion and metastasis.

  10. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    International Nuclear Information System (INIS)

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  11. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Andreas, E-mail: andreas.tyler@medbio.umu.se [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden); Johansson, Anders [Department of Odontology, Umeå University, S-901 85 Umea (Sweden); Karlsson, Terese [Department of Radiation Sciences, Oncology, S-901 85 Umea (Sweden); Gudey, Shyam Kumar; Brännström, Thomas; Grankvist, Kjell; Behnam-Motlagh, Parviz [Department of Medical Biosciences, Umeå University, S-901 85 Umea (Sweden)

    2015-08-01

    Background: Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. Methods: Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72 h on expression and cisplatin cytotoxicity was tested. Results: The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. Conclusions: Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin

  12. Regulation of Thrombomodulin Expression and Release in Human Aortic Endothelial Cells by Cyclic Strain

    OpenAIRE

    Martin, Fiona A.; Alisha McLoughlin; Rochfort, Keith D.; Colin Davenport; Murphy, Ronan P.; Cummins, Philip M.

    2014-01-01

    Background and Objectives Thrombomodulin (TM), an integral membrane glycoprotein expressed on the lumenal surface of vascular endothelial cells, promotes anti-coagulant and anti-inflammatory properties. Release of functional TM from the endothelium surface into plasma has also been reported. Much is still unknown however about how endothelial TM is regulated by physiologic hemodynamic forces (and particularly cyclic strain) intrinsic to endothelial-mediated vascular homeostasis. Methods This ...

  13. Lipid rafts: cell surface platforms for T cell signaling

    Directory of Open Access Journals (Sweden)

    TONY MAGEE

    2002-01-01

    Full Text Available The Src family tyrosine kinase Lck is essential for T cell development and T cell receptor (TCR* signaling. Lck is post-translationally fatty acylated at its N-terminus conferring membrane targeting and concentration in plasma membrane lipid rafts, which are lipid-based organisational platforms. Confocal fluorescence microscopy shows that Lck colocalises in rafts with GPI-linked proteins, the adaptor protein LAT and Ras, but not with non-raft membrane proteins including the protein tyrosine phosphatase CD45. The TCR also associates with lipid rafts and its cross-linking causes coaggregation of raft-associated proteins including Lck, but not of CD45. Cross-linking of either the TCR or rafts strongly induces specific tyrosine phosphorylation of the TCR in the rafts. Remarkably, raft patching alone induces signalling events analogous to TCR stimulation, with the same dependence on expression of key TCR signalling molecules. Our results indicate a mechanism whereby TCR engagement promotes aggregation of lipid rafts, which facilitates colocalisation of signaling proteins including Lck, LAT, and the TCR, while excluding CD45, thereby potentiating protein tyrosine phosphorylation and downstream signaling. We are currently testing this hypothesis as well as using imaging techniques such as fluorescence resonance energy transfer (FRET microscopy to study the dynamics of proteins and lipids in lipid rafts in living cells undergoing signaling events. Recent data show that the key phosphoinositide PI(4,5P2 is concentrated in T cell lipid rafts and that on stimulation of the cells it is rapidly converted to PI(3,4,5P3 and diacylglycerol within rafts. Thus rafts are hotspots for both protein and lipid signalling pathways.

  14. Cytokine Expression in Homozygous Sickle Cell Anaemia

    Directory of Open Access Journals (Sweden)

    Nnodim Johnkennedy

    2015-01-01

    Full Text Available Background: Sickle cell anaemia is an inherited disease in which the red blood cells become rigid and sticky, and change from being disc-shaped to being crescent-shaped. The change in shape is due to the presence of an abnormal form of haemoglobin. This results in severe pain and damage to some organs. Aim and Objective: The study was carried out to determine the levels of cytokine in sickle cell anemia. Material and Methods: Thirty confirmed sickle cell patients in steady state (HbSS-SS and thirty persons with normal haemoglobin (HbAA as well as sixteen sickle cell disease in crises (HbSS-cr between the ages of 15 to 30 years were selected in this study. Cytokines including interleukin 1 beta (IL- 1β, interleukin 2 (IL- 2, interleukin (IL-6, tumour necrosis factor alpha (TNF-α, and interferon gamma (IFN- λ were measured by commercially available ELISA kits. Results: The results obtained showed that the levels of TNF-α and IL-6 in sickle cell anaemia patients in crisis were significantly elevated when compared with sickle cell in steady state (P<0.05. Similarly, the levels of IL-1β, IL-6, and IFN- λ were significantly increased in sickle cell anaemia stable state when compared to HbAA subjects (P<0.05. Conclusion: This may probably implies that cytokine imbalance is implicated in the pathogenesis of sickle cell crisis. Also, cytokines could be used as an inflammatory marker as well as related marker in disease severity and hence therapeutic intervention.

  15. Activation of cord T lymphocytes. IV. Analysis of surface expression and functional role of 1F7 (CD26) molecule.

    Science.gov (United States)

    Gerli, R; Agea, E; Muscat, C; Ercolani, R; Bistoni, O; Tognellini, R; Mariggió, M A; Spinozzi, F; Bertotto, A

    1994-04-15

    A role for CD26 surface antigen (Ag) in both CD3- and CD2-mediated T cell activation has been previously demonstrated. To analyze the functional role of CD26 in the CD3- and CD2-induced activation pathways of cord T cells, which represent the most reliable source of Ag-unprimed T cells, we employed a newly developed anti-CD26 monoclonal antibody, termed anti-1F7, anti-CD3 and anti-CD2 in activating T lymphocytes. The results showed that CD26 Ag is expressed on the surface of almost all resting cord T cells and that its fluorescence intensity is enhanced by activation. The binding of anti-1F7 induced a decrease in CD26 membrane expression, with no detectable effect on the surface expression of other cord T cell-related molecules. Moreover, the modulation of CD26 resulted in an increase in anti-CD3-mediated cord T cell activation through an enhancement in intracellular calcium levels, IL-2 receptor expression, and IL-2 synthesis, whereas it had no effect on cord T cell activation induced by anti-CD2 or anti-CD2 plus exogenous IL-2. The fact that the selective involvement of CD26 in the activation pathway triggered by anti-CD3, but not anti-CD2, could be reversed by prior stimulation of cord T cells with anti-CD3 suggests that this functional feature, which resembles that of mature thymocytes, may be linked to the Ag-unprimed cell phenotype of cord T lymphocytes. PMID:7909498

  16. ADHESION INDUCES MATRIX METALLOPROTEINASE-9 GENE EXPRESSION IN OVARIAN CANCER CELLS

    Institute of Scientific and Technical Information of China (English)

    田方; 颜春洪; 薛红; 肖凤君

    2002-01-01

    Objective: To investigate the expression of matrix metalloproteinase-9 (MMP-9) gene in cancer cells induced by adhesion with fibronectin and the underlying mechanism of cell invasion. Methods: Following adhesion of ovarian cancer cells A2780 to fibronectin, MMP mRNA expression was assayed by using reverse transcription-polymerase chain reaction (RT-PCR). MMP-9 promoter was cloned from genomic DNA of HT1080 cells with PCR. The MMP-9-pGL2 reporter gene vector was constructed and then transiently transfected into A2780 cells. Results: Adhesion could induce the expression of MMP-9 gene in A2780 cells, but did not affect longer theexpression of MMP-2 or TIMP-1 gene. The induction was enhanced with longer adhesion time. When the transfected cells were allowed to adhere and spread on FN-coated surface, the promoter activity of MMP-9 gene was also enhanced dramatically. Conclusion: adhesion of cells with ECM may stimulate the expression of MMP-9 gene through stimulating the promoter activity, thereby enhancing cancer cell invasion and metastasis.

  17. 'LungGENS': a web-based tool for mapping single-cell gene expression in the developing lung.

    Science.gov (United States)

    Du, Yina; Guo, Minzhe; Whitsett, Jeffrey A; Xu, Yan

    2015-11-01

    We developed LungGENS (Lung Gene Expression iN Single-cell), a web-based bioinformatics resource for querying single-cell gene expression databases by entering a gene symbol or a list of genes or selecting a cell type of their interest. Gene query provides quantitative RNA expression of the gene of interest in each lung cell type. Cell type query returns associated selective gene signatures and genes encoding cell surface markers and transcription factors in interactive heatmap and tables. LungGENS will be broadly applicable in respiratory research, providing a cell-specific RNA expression resource at single-cell resolution. LungGENS is freely available for non-commercial use at https://research.cchmc.org/pbge/lunggens/default.html. PMID:26130332

  18. Plet1 is an epigenetically regulated cell surface protein that provides essential cues to direct trophoblast stem cell differentiation

    Science.gov (United States)

    Murray, Alexander; Sienerth, Arnold R.; Hemberger, Myriam

    2016-01-01

    Gene loci that are hypermethylated and repressed in embryonic (ESCs) but hypomethylated and expressed in trophoblast (TSCs) stem cells are very rare and may have particularly important roles in early developmental cell fate decisions, as previously shown for Elf5. Here, we assessed another member of this small group of genes, Placenta Expressed Transcript 1 (Plet1), for its function in establishing trophoblast lineage identity and modulating trophoblast differentiation. We find that Plet1 is tightly repressed by DNA methylation in ESCs but expressed on the cell surface of TSCs and trophoblast giant cells. In hypomethylated ESCs that are prone to acquire some trophoblast characteristics, Plet1 is required to confer a trophoblast-specific gene expression pattern, including up-regulation of Elf5. Plet1 displays an unusual biphasic expression profile during TSC differentiation and thus may be pivotal in balancing trophoblast self-renewal and differentiation. Furthermore, overexpression and CRISPR/Cas9-mediated knockout in TSCs showed that high Plet1 levels favour differentiation towards the trophoblast giant cell lineage, whereas lack of Plet1 preferentially induces syncytiotrophoblast formation. Thus, the endogenous dynamics of Plet1 expression establish important patterning cues within the trophoblast compartment by promoting differentiation towards the syncytiotrophoblast or giant cell pathway in Plet1-low and Plet1-high cells, respectively. PMID:27121762

  19. Plet1 is an epigenetically regulated cell surface protein that provides essential cues to direct trophoblast stem cell differentiation.

    Science.gov (United States)

    Murray, Alexander; Sienerth, Arnold R; Hemberger, Myriam

    2016-01-01

    Gene loci that are hypermethylated and repressed in embryonic (ESCs) but hypomethylated and expressed in trophoblast (TSCs) stem cells are very rare and may have particularly important roles in early developmental cell fate decisions, as previously shown for Elf5. Here, we assessed another member of this small group of genes, Placenta Expressed Transcript 1 (Plet1), for its function in establishing trophoblast lineage identity and modulating trophoblast differentiation. We find that Plet1 is tightly repressed by DNA methylation in ESCs but expressed on the cell surface of TSCs and trophoblast giant cells. In hypomethylated ESCs that are prone to acquire some trophoblast characteristics, Plet1 is required to confer a trophoblast-specific gene expression pattern, including up-regulation of Elf5. Plet1 displays an unusual biphasic expression profile during TSC differentiation and thus may be pivotal in balancing trophoblast self-renewal and differentiation. Furthermore, overexpression and CRISPR/Cas9-mediated knockout in TSCs showed that high Plet1 levels favour differentiation towards the trophoblast giant cell lineage, whereas lack of Plet1 preferentially induces syncytiotrophoblast formation. Thus, the endogenous dynamics of Plet1 expression establish important patterning cues within the trophoblast compartment by promoting differentiation towards the syncytiotrophoblast or giant cell pathway in Plet1-low and Plet1-high cells, respectively. PMID:27121762

  20. Recombinant cells that highly express chromosomally-integrated heterologous gene

    Science.gov (United States)

    Ingram, Lonnie O.; Ohta, Kazuyoshi; Wood, Brent E.

    2007-03-20

    Recombinant host cells are obtained that comprise (A) a heterologous, polypeptide-encoding polynucleotide segment, stably integrated into a chromosome, which is under transcriptional control of an endogenous promoter and (B) a mutation that effects increased expression of the heterologous segment, resulting in enhanced production by the host cells of each polypeptide encoded by that segment, relative to production of each polypeptide by the host cells in the absence of the mutation. The increased expression thus achieved is retained in the absence of conditions that select for cells displaying such increased expression. When the integrated segment comprises, for example, ethanol-production genes from an efficient ethanol producer like Zymomonas mobilis, recombinant Escherichia coli and other enteric bacterial cells within the present invention are capable of converting a wide range of biomass-derived sugars efficiently to ethanol.

  1. Expression of Opacity Proteins Interferes with the Transmigration of Neisseria gonorrhoeae across Polarized Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Daniel C Stein

    Full Text Available Neisseria gonorrhoeae (GC establishes infection at the mucosal surface of the human genital tract, most of which is lined with polarized epithelial cells. GC can cause localized as well as disseminated infections, leading to various complications. GC constantly change their surface structures via phase and antigenic variation, which has been implicated as a means for GC to establish infection at various anatomic locations of male and female genital tracks. However, the exact contribution of each surface molecule to bacterial infectivity remains elusive due to their phase variation. Using a GC derivative that is genetically devoid of all opa genes (MS11∆Opa, this study shows that Opa expression interferes with GC transmigration across polarized human epithelial cells. MS11∆Opa transmigrates across polarized epithelial cells much faster and to a greater extent than MS11Opa+, while adhering at a similar level as MS11Opa+. When MS11Opa+, able to phase vary Opa expression, was inoculated, only those bacteria that turn off Opa expression transmigrate across the polarized epithelial monolayer. Similar to bacteria alone or co-cultured with non-polarized epithelial cells, MS11∆Opa fails to form large microcolonies at the apical surface of polarized epithelial cells. Apical inoculation of MS11Opa+, but not MS11∆Opa, induces the recruitment of the Opa host-cell receptor carcinoembryonic antigen-related cell adhesion molecules (CEACAMs to the apical junction and the vicinity of bacterial adherent sites. Our results suggest that Opa expression limits gonococcal ability to invade into subepithelial tissues by forming tight interactions with neighboring bacteria and by inducing CEACAM redistribution to cell junctions.

  2. Flavonoids inhibit cytokine-induced endothelial cell adhesion protein gene expression.

    OpenAIRE

    Gerritsen, M. E.; Carley, W. W.; Ranges, G. E.; Shen, C. P.; Phan, S. A.; Ligon, G. F.; Perry, C. A.

    1995-01-01

    Treatment of human endothelial cells with cytokines such as interleukin-1, tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma induces the expression of specific leukocyte adhesion molecules on the endothelial cell surface. Interfering with either leukocyte adhesion or adhesion protein upregulation is an important therapeutic target as evidenced by the potent anti-inflammatory actions of neutralizing antibodies to these ligands in various animal models and in patients. In the present ...

  3. Altered expression of the urokinase receptor homologue, C4.4A, in invasive areas of human esophageal squamous cell carcinoma

    DEFF Research Database (Denmark)

    Hansen, L.V.; Laerum, O.D.; Illemann, M.;

    2008-01-01

    present study, we have therefore analyzed the expression of C4.4A in 14 esophageal squamous cell carcinomas (ESCC). Normal squamous esophageal epithelium shows a strong cell surface associated C4.4A expression in the suprabasal layers, whereas basal cells are negative. Upon transition to dysplasia and...... carcinoma in situ the expression of C4.4A is abruptly and coordinately weakened. Double immunofluorescence staining of normal and dysplastic tissue showed that C4.4A colocalizes with the epithelial cell surface marker E-cadherin in the suprabasal cells and has a complementary expression pattern compared to...

  4. MYC Expression Promotes the Proliferation of Neural Progenitor Cells in Culture and In Vivo

    Directory of Open Access Journals (Sweden)

    Dan Fults

    2002-01-01

    Full Text Available Primitive neuroectodermal tumors. (20PNETs are pediatric brain tumors that result from defects in signaling molecules governing the growth and differentiation of neural progenitor cells. We used the RCAS-TVA system to study the growth effects of three genetic alterations implicated in human PNETs on a subset of neural progenitor cells that express the intermediate filament protein, nestin. The genetic alterations tested were: 1 overexpression of the cellular oncoprotein, MYC; 2 activation of transcription factor, β-catenin; and 3 haploinsufficiency of Ptc, the hedgehog receptor gene. The RCAS-TVA system uses an avian retroviral vector, RCAS, to target gene expression to specific cell types in transgenic mice. To express exogenous genes in neural progenitor cells, we used Ntv-a mice. In these mice, the Nestin gene promoter drives expression of TVA, the cell surface receptor for the virus. Ectopic expression of MYC, but not activated β-catenin, promoted the proliferation of neural progenitor cells in culture and in the cerebral leptomeninges in vivo. These effects were equally penetrant in mice with Ptc+/− and Ptc+/+ genetic backgrounds. Although overexpression of MYC is not sufficient to cause intraparenchymal tumors, it may facilitate PNET formation by sustaining the growth of undifferentiated progenitor cells.

  5. Different titanium surfaces modulate the bone phenotype of SaOS-2 osteoblast-like cells

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    L Postiglione

    2009-06-01

    Full Text Available Commercially pure titanium implants presenting a relatively smooth, machined surface or a roughened endosseous surface show a large percentage of clinical success. Surface properties of dental implants seem to affect bone cells response. Implant topography appears to modulate cell growth and differentiation of osteoblasts affecting the bone healing around the titanium implant. The aim of the present study was to examine the effects of 1cm diameter and 1mm thick titanium disks on cellular morphology, adhesion and bone phenotypic expression of human osteoblast-like cells, SaOS-2. SaOS-2 cells were cultured on commercially 1 cm pure titanium disks with three different surface roughness: smooth (S, sandblasted (SB and titanium plasma sprayed (TPS. Differences in the cellular morphology were found when they were grown on the three different surfaces. An uniform monolayer of cells recovered the S surface, while clusters of multilayered irregularly shaped cells were distributed on the rough SB and TPS surfaces. The adhesion of SaOS-2 cells, as measured after 3h of culture, was not affected by surface roughness. ECM components such as Collagen I (CoI, Fibronectin (FN, Vitronectin (VN and Tenascin (TN were secreted and organized only on the SB and TPS surfaces while they remained into the cytoplasm on the S surfaces. Osteopontin and BSP-II were largely detected on the SB and TPS surfaces, while only minimal production was observed on the S ones. These data show that titanium surface roughness affects bone differentiation of osteoblast like-cells, SaOS-2, indicating that surface properties may be able to modulate the osteoblast phenotype. These observations also suggest that the bone healing response around dental implants can be affected by surface topography.

  6. Titanium Surface Coating with a Laminin-Derived Functional Peptide Promotes Bone Cell Adhesion

    Directory of Open Access Journals (Sweden)

    Seung-Ki Min

    2013-01-01

    Full Text Available Laminin-derived peptide coatings can enhance epithelial cell adhesion to implants, and the positive effect of these peptides on bone cell adhesion has been anticipated. The purpose of this study was to evaluate the improvement in bone cell attachment to and activity on titanium (Ti scaffolds coated with a laminin-derived functional peptide, Ln2-P3 (the DLTIDDSYWYRI motif. Four Ti disc surfaces were prepared, and a human osteosarcoma (HOS cell attachment test was performed to select two candidate surfaces for peptide coating. These two candidates were then coated with Ln2-P3 peptide, a scrambled peptide, or left uncoated to measure cell attachment to each surface, following which one surface was chosen to assess alkaline phosphatase (ALP activity and osteogenic marker gene expression with quantitative real-time PCR. On the commercially pure Ti surface, the Ln2-P3 coating significantly increased cellular ALP activity and the expression levels of ALP and bone sialoprotein mRNA as compared with the scrambled peptide-coated and uncoated surfaces. In conclusion, although further in vivo studies are needed, the findings of this in vitro study indicate that the Ln2-P3-coated implant surface promotes bone cell adhesion, which has clinical implications for reducing the overall treatment time of dental implant therapy.

  7. UV-induced changes in cell cycle and gene expression within rabbit lens epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Sidjanin, D. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Biological Sciences; Grdina, D. [Argonne National Lab., IL (United States); Woloschak, G.E. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Biological Sciences

    1994-11-01

    Damage to lens epithelial cells is a probable initiation process in cataract formation induced by ultraviolet radiation. These experiments investigated the ability of 254 nm radiation on cell cycle progression and gene expression in rabbit lens epithelial cell line N/N1003A. No changes in expression of c-fos, c-jun, alpha- tubulin, or vimentin was observed following UV exposure. Using flow cytometry, an accumulation of cells in G1/S phase of the cell cycle 1 hr following exposure. The observed changes in gene expression, especially the decreased histone transcripts reported here may play a role in UV induced inhibition of cell cycle progression.

  8. Expression and function of nicotinic acetylcholine receptors in stem cells

    Directory of Open Access Journals (Sweden)

    Carlos M. Carballosa

    2016-07-01

    Full Text Available Nicotinic acetylcholine receptors are prototypical ligand gated ion channels typically found in muscular and neuronal tissues. Functional nicotinic acetylcholine receptors, however, have also recently been identified on other cell types, including stem cells. Activation of these receptors by the binding of agonists like choline, acetylcholine, or nicotine has been implicated in many cellular changes. In regards to stem cell function, nicotinic acetylcholine receptor activation leads to changes in stem cell proliferation, migration and differentiation potential. In this review we summarize the expression and function of known nicotinic acetylcholine receptors in different classes of stem cells including: pluripotent stem cells, mesenchymal stem cells, periodontal ligament derived stem cells, and neural progenitor cells and discuss the potential downstream effects of receptor activation on stem cell function.

  9. Functional expression of CD137 (4-1BB) on T helper follicular cells

    Science.gov (United States)

    Alfaro, Carlos; Echeveste, Jose I; Rodriguez-Ruiz, Maria E; Solorzano, Jose L; Perez-Gracia, Jose L; Idoate, Miguel A; Lopez-Picazo, Jose M; Sanchez-Paulete, Alfonso R; Labiano, Sara; Rouzaut, Ana; Oñate, Carmen; Aznar, Angela; Lozano, Maria D; Melero, Ignacio

    2015-01-01

    CD137 (4-1BB) is a surface protein initially discovered to mark activated T lymphocytes. However, its broader expression pattern also encompasses activated NK cells, B cells and myeloid cells, including mature dendritic cells. In this study, we have immunostained for CD137 on paraffin-embedded lymphoid tissues including tonsils, lymph nodes, ectopic tertiary lymphoid tissue in Hashimoto thyroiditis and cancer. Surprisingly, immunostaining mainly decorated intrafollicular lymphocytes in the tissues analyzed, with only scattered staining in interfollicular areas. Moreover, pathologic lymphoid follicles in follicular lymphoma and tertiary lymphoid tissue associated with non-small cell lung cancer showed a similar pattern of immunostaining. Multispectral fluorescence cytometry demonstrated that CD137 expression was restricted to CD4+ CXCR5+ follicular T helper lymphocytes (TFH cells) in tonsils and lymph nodes. Short-term culture of lymph node cell suspensions in the presence of either an agonistic anti-CD137 monoclonal antibody (mAb) or CD137-ligand stimulated the functional upregulation of TFH cells in 3 out of 6 cases, as indicated by CD40L surface expression and cytokine production. As a consequence, immunostimulatory monoclonal antibodies targeting CD137 (such as urelumab and PF-05082566) should be expected to primarily act on this lymphocyte subset, thus modifying ongoing humoral immune responses in patients with autoimmune disease and cancer. PMID:26587331

  10. Rho-associated kinase (ROCK) inhibition reverses low cell activity on hydrophobic surfaces

    International Nuclear Information System (INIS)

    Hydrophobic polymers do not offer an adequate scaffold surface for cells to attach, migrate, proliferate, and differentiate. Thus, hydrophobic scaffolds for tissue engineering have traditionally been physicochemically modified to enhance cellular activity. However, modifying the surface by chemical or physical treatment requires supplementary engineering procedures. In the present study, regulation of a cell signal transduction pathway reversed the low cellular activity on a hydrophobic surface without surface modification. Inhibition of Rho-associated kinase (ROCK) by Y-27632 markedly enhanced adhesion, migration, and proliferation of osteoblastic cells cultured on a hydrophobic polystyrene surface. ROCK inhibition regulated cell-cycle-related molecules on the hydrophobic surface. This inhibition also decreased expression of the inhibitors of cyclin-dependent kinases such as p21cip1 and p27kip1 and increased expression of cyclin A and D. These results indicate that defective cellular activity on the hydrophobic surface can be reversed by the control of a cell signal transduction pathway without physicochemical surface modification.

  11. Basic surface properties of mononuclear cells from Didelphis marsupialis.

    Science.gov (United States)

    Nacife, V P; de Meirelles, M de N; Silva Filho, F C

    1998-01-01

    The electrostatic surface charge and surface tension of mononuclear cells/monocytes obtained from young and adult marsupials (Didelphis marsupialis) were investigated by using cationized ferritin and colloidal iron hydroxyde, whole cell electrophoresis, and measurements of contact angles. Anionic sites were found distributed throughout the entire investigated cell surfaces. The results revealed that the anionic character of the cells is given by electrostatic charges corresponding to -18.8 mV (cells from young animals) and -29.3 mV (cells from adult animals). The surface electrostatic charge decreased from 10 to 65.2% after treatment of the cells with each one of trypsin, neuraminidase and phospholipase C. The hydrophobic nature of the mononuclear cell surfaces studied by using the contact angle method revealed that both young and adult cells possess cell surfaces of high hidrofilicity since the angles formed with drops of saline water were 42.5 degrees and 40.8 degrees, respectively. Treatment of the cells with trypsin or neuraminidase rendered their surfaces more hydrophobic, suggesting that sialic acid-containing glycoproteins are responsible for most of the hydrophilicity observed in the mononuclear cell surfaces from D. marsupialis. PMID:9921307

  12. Basic Surface Properties of Mononuclear Cells from Didelphis marsupialis

    Directory of Open Access Journals (Sweden)

    Nacife Valéria Pereira

    1998-01-01

    Full Text Available The electrostatic surface charge and surface tension of mononuclear cells/monocytes obtained from young and adult marsupials (Didelphis marsupialis were investigated by using cationized ferritin and colloidal iron hydroxyde, whole cell electrophoresis, and measurements of contact angles. Anionic sites were found distributed throughout the entire investigated cell surfaces. The results revealed that the anionic character of the cells is given by electrostatic charges corresponding to -18.8 mV (cells from young animals and -29.3 mV (cells from adult animals. The surface electrostatic charge decreased from 10 to 65.2% after treatment of the cells with each one of trypsin, neuraminidase and phospholipase C. The hydrophobic nature of the mononuclear cell surfaces studied by using the contact angle method revealed that both young and adult cells possess cell surfaces of high hidrofilicity since the angles formed with drops of saline water were 42.5°and 40.8°, respectively. Treatment of the cells with trypsin or neuraminidase rendered their surfaces more hydrophobic, suggesting that sialic acid-containing glycoproteins are responsible for most of the hydrophilicity observed in the mononuclear cell surfaces from D. marsupialis.

  13. Neuropilin 1 is expressed on thymus-derived natural regulatory T cells, but not mucosa-generated induced Foxp3+ T reg cells

    OpenAIRE

    Weiss, Jonathan M.; Bilate, Angelina M.; Gobert, Michael; Ding, Yi; Curotto de Lafaille, Maria A; Parkhurst, Christopher N.; Xiong, Huizhong; Dolpady, Jayashree; Frey, Alan B.; Ruocco, Maria Grazia; Yi YANG; Floess, Stefan; Huehn, Jochen; Oh, Soyoung; Li, Ming O.

    2012-01-01

    Foxp3 activity is essential for the normal function of the immune system. Two types of regulatory T (T reg) cells express Foxp3, thymus-generated natural T reg (nT reg) cells, and peripherally generated adaptive T reg (iT reg) cells. These cell types have complementary functions. Until now, it has not been possible to distinguish iT reg from nT reg cells in vivo based solely on surface markers. We report here that Neuropilin 1 (Nrp1) is expressed at high levels by most nT reg cells; in contra...

  14. Microarray gene expression profiling and analysis in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Sadhukhan Provash

    2004-06-01

    Full Text Available Abstract Background Renal cell carcinoma (RCC is the most common cancer in adult kidney. The accuracy of current diagnosis and prognosis of the disease and the effectiveness of the treatment for the disease are limited by the poor understanding of the disease at the molecular level. To better understand the genetics and biology of RCC, we profiled the expression of 7,129 genes in both clear cell RCC tissue and cell lines using oligonucleotide arrays. Methods Total RNAs isolated from renal cell tumors, adjacent normal tissue and metastatic RCC cell lines were hybridized to affymatrix HuFL oligonucleotide arrays. Genes were categorized into different functional groups based on the description of the Gene Ontology Consortium and analyzed based on the gene expression levels. Gene expression profiles of the tissue and cell line samples were visualized and classified by singular value decomposition. Reverse transcription polymerase chain reaction was performed to confirm the expression alterations of selected genes in RCC. Results Selected genes were annotated based on biological processes and clustered into functional groups. The expression levels of genes in each group were also analyzed. Seventy-four commonly differentially expressed genes with more than five-fold changes in RCC tissues were identified. The expression alterations of selected genes from these seventy-four genes were further verified using reverse transcription polymerase chain reaction (RT-PCR. Detailed comparison of gene expression patterns in RCC tissue and RCC cell lines shows significant differences between the two types of samples, but many important expression patterns were preserved. Conclusions This is one of the initial studies that examine the functional ontology of a large number of genes in RCC. Extensive annotation, clustering and analysis of a large number of genes based on the gene functional ontology revealed many interesting gene expression patterns in RCC. Most

  15. CellCODE: a robust latent variable approach to differential expression analysis for heterogeneous cell populations

    OpenAIRE

    Chikina, Maria; Zaslavsky, Elena; Sealfon, Stuart C.

    2015-01-01

    Motivation: Identifying alterations in gene expression associated with different clinical states is important for the study of human biology. However, clinical samples used in gene expression studies are often derived from heterogeneous mixtures with variable cell-type composition, complicating statistical analysis. Considerable effort has been devoted to modeling sample heterogeneity, and presently, there are many methods that can estimate cell proportions or pure cell-type expression from m...

  16. Expression of GABAergic receptors in mouse taste receptor cells.

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    Margaret R Starostik

    Full Text Available BACKGROUND: Multiple excitatory neurotransmitters have been identified in the mammalian taste transduction, with few studies focused on inhibitory neurotransmitters. Since the synthetic enzyme glutamate decarboxylase (GAD for gamma-aminobutyric acid (GABA is expressed in a subset of mouse taste cells, we hypothesized that other components of the GABA signaling pathway are likely expressed in this system. GABA signaling is initiated by the activation of either ionotropic receptors (GABA(A and GABA(C or metabotropic receptors (GABA(B while it is terminated by the re-uptake of GABA through transporters (GATs. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcriptase-PCR (RT-PCR analysis, we investigated the expression of different GABA signaling molecules in the mouse taste system. Taste receptor cells (TRCs in the circumvallate papillae express multiple subunits of the GABA(A and GABA(B receptors as well as multiple GATs. Immunocytochemical analyses examined the distribution of the GABA machinery in the circumvallate papillae. Both GABA(A-and GABA(B- immunoreactivity were detected in the peripheral taste receptor cells. We also used transgenic mice that express green fluorescent protein (GFP in either the Type II taste cells, which can respond to bitter, sweet or umami taste stimuli, or in the Type III GAD67 expressing taste cells. Thus, we were able to identify that GABAergic receptors are expressed in some Type II and Type III taste cells. Mouse GAT4 labeling was concentrated in the cells surrounding the taste buds with a few positively labeled TRCs at the margins of the taste buds. CONCLUSIONS/SIGNIFICANCE: The presence of GABAergic receptors localized on Type II and Type III taste cells suggests that GABA is likely modulating evoked taste responses in the mouse taste bud.

  17. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

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    Tam Yew

    2012-10-01

    Full Text Available Abstract Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg from Pichia pastoris expression cells were optimized using response surface methodology (RSM based on the central composite design (CCD. The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

  18. Nanofabrication of Nonfouling Surfaces for Micropatterning of Cell and Microtissue

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    Hidenori Otsuka

    2010-08-01

    Full Text Available Surface engineering techniques for cellular micropatterning are emerging as important tools to clarify the effects of the microenvironment on cellular behavior, as cells usually integrate and respond the microscale environment, such as chemical and mechanical properties of the surrounding fluid and extracellular matrix, soluble protein factors, small signal molecules, and contacts with neighboring cells. Furthermore, recent progress in cellular micropatterning has contributed to the development of cell-based biosensors for the functional characterization and detection of drugs, pathogens, toxicants, and odorants. In this regards, the ability to control shape and spreading of attached cells and cell-cell contacts through the form and dimension of the cell-adhesive patches with high precision is important. Commitment of stem cells to different specific lineages depends strongly on cell shape, implying that controlled microenvironments through engineered surfaces may not only be a valuable approach towards fundamental cell-biological studies, but also of great importance for the design of cell culture substrates for tissue engineering. To develop this kind of cellular microarray composed of a cell-resistant surface and cell attachment region, micropatterning a protein-repellent surface is important because cellular adhesion and proliferation are regulated by protein adsorption. The focus of this review is on the surface engineering aspects of biologically motivated micropatterning of two-dimensional surfaces with the aim to provide an introductory overview described in the literature. In particular, the importance of non-fouling surface chemistries is discussed.

  19. Tff3 is Expressed in Neurons and Microglial Cells

    Directory of Open Access Journals (Sweden)

    Ting Fu

    2014-11-01

    Full Text Available Background/Aims: The trefoil factor family (TFF peptide TFF3 is typically secreted by mucous epithelia, but is also expressed in the immune system and the brain. It was the aim of this study to determine the cerebral cell types which express Tff3. Methods: Primary cultures from rat embryonic or neonatal cerebral cortex and hippocampus, respectively, were studied by means of RT-PCR and immunofluorescence. Moreover, Tff3 expression was localized by immunocytochemistry in sections of adult rat cerebellum. Results: Tff3 transcripts were detectable in neural cultures of both the cortex and the hippocampus as well as in glial cell-enriched cultures. Tff3 peptide co-localized with Map2 indicating an expression in neurons in vitro. The neuronal expression was confirmed by immunofluorescence studies of adult rat cerebellum. Furthermore, Tff3 peptide showed also a clear co-localization with Iba-1 in vitro typical of activated microglial cells. Conclusion: The neuronal expression of Tff3 is in line with a function of a typical neuropeptide influencing, e.g., fear, memory, depression and motoric skills. The expression in activated microglial cells, which is demonstrated here for the first time, points towards a possible function for Tff3 in immune reactions in the CNS. This opens a plethora of additional possible functions for Tff3 including synaptic plasticity and cognition as well as during neuroinflammatory diseases and psychiatric disorders.

  20. Osteoblast cell response to surface-modified carbon nanotubes

    International Nuclear Information System (INIS)

    In order to investigate the interaction of cells with modified multi-walled carbon nanotubes (MWCNTs) for their potential biomedical applications, the MWCNTs were chemically modified with carboxylic acid groups (–COOH), polyvinyl alcohol (PVA) polymer and biomimetic apatite on their surfaces. Additionally, human osteoblast MG-63 cells were cultured in the presence of the surface-modified MWCNTs. The metabolic activities of osteoblastic cells, cell proliferation properties, as well as cell morphology were studied. The surface modification of MWCNTs with biomimetic apatite exhibited a significant increase in the cell viability of osteoblasts, up to 67.23%. In the proliferation phases, there were many more cells in the biomimetic apatite-modified MWCNT samples than in the MWCNTs–COOH. There were no obvious changes in cell morphology in osteoblastic MG-63 cells cultured in the presence of these chemically-modified MWCNTs. The surface modification of MWCNTs with apatite achieves an effective enhancement of their biocompatibility.

  1. Surface cell differentiation controls tissue surface tension and tissue positioning during zebrafish gastrulation

    Science.gov (United States)

    Krens, S. F. G.

    2011-03-01

    Differences in tissue surface tension (TST) between different tissue types are thought to guide tissue organization and cell sorting in development. Measurements of TST have been useful to predict the outcome of in vitro cell sorting and envelopment experiments. However, the outcome of cell sorting experiments in vitro often substantially differs from tissue positioning in vivo, raising questions as to the actual contribution of TST to tissue positioning within the developing embryo. Here, we show that surface tension of germ layer tissues during zebrafish gastrulation critically relies on the differentiation of their surface cells. We also show that surface differentiation of the different germ layer tissues varies and is considerably different between the situation in vitro and in vivo, explaining the apparent dissimilar outcome of cell segregation between these two situations. To analyze germ layer TST as a function of surface cell differentiation, we interfere with surface cell properties of germ layer aggregates by misexpressing genes involved in surface cell differentiation specifically within surface cells using the GAL4-UAS system, and measure tissue surface tension using both parallel plate compression and micropipette aspiration techniques. Our data provides evidence in favor of a critical function of surface cell differentiation in modulating TST and subsequently tissue positioning within the developing embryo.

  2. Dental enamel cells express functional SOCE channels

    OpenAIRE

    Nurbaeva, Meerim K.; Miriam Eckstein; Concepcion, Axel R.; Smith, Charles E.; Sonal Srikanth; Paine, Michael L.; Yousang Gwack; HUBBARD, MICHAEL J.; Stefan Feske; LACRUZ, Rodrigo S.

    2015-01-01

    Dental enamel formation requires large quantities of Ca2+ yet the mechanisms mediating Ca2+ dynamics in enamel cells are unclear. Store-operated Ca2+ entry (SOCE) channels are important Ca2+ influx mechanisms in many cells. SOCE involves release of Ca2+ from intracellular pools followed by Ca2+ entry. The best-characterized SOCE channels are the Ca2+ release-activated Ca2+ (CRAC) channels. As patients with mutations in the CRAC channel genes STIM1 and ORAI1 show abnormal enamel mineralization...

  3. The expression of ADAMTS13 in human microvascular endothelial cells.

    Science.gov (United States)

    Wang, Anyou; Duan, Qiaohong; Wu, Jingsheng; Liu, Xin; Sun, Zimin

    2016-06-01

    ADAMTS13, as a specific von Willebrand factor (VWF)-cleaving protease, prevents microvascular thrombosis of VWF/platelet thrombi. It has been reported that human vascular endothelial cells could also synthesize and secrete ADAMTS13, and these reports were focused in human umbilical vascular endothelial cells. Considering the particularity of its huge quantity and structure of human microvascular endothelial cells (HMECs) in the body, whether ADAMTS13 is expressed in HMECs also needs to be confirmed. To investigate whether ADAMTS13 is expressed in HMECs. Real-time PCR (RT-PCR) amplification detected ADAMTS13 mRNA in HMEC-1 cell line. The expression and distribution of ADAMTS13 protein and VWF were detected by fluorescence immunoassay and western blot. We observed the expression and distribution of ADAMTS13 in HMECs. We confirmed the expression of ADAMTS13 mRNA in HMEC-1, and found that there were some partly common distributions of ADAMTS13 protein and VWF. This study provides the evidence that HMECs also express ADAMTS13. HMECs might also be a primary source for human plasma ADAMTS13. The overlap region for the distribution of ADAMTS13 and VWF suggests that ADAMTS13 might have a potential regulation role for VWF inside cells. PMID:26366828

  4. Suppression of MHC gene expression in cancer cells

    OpenAIRE

    Bernards, R.A.

    1987-01-01

    The class I antigens of the major histocompatibility complex play a crucial part in the recognition of foreign antigens by cytotoxic T lymphocytes. Some cancer cells exhibit a reduced expression of these antigens and this may help these cells to escape immune surveillance.

  5. Protein profile of basal prostate epithelial progenitor cells-stage-specific embryonal antigen 4 expressing cells have enhanced regenerative potential in vivo.

    Science.gov (United States)

    Höfner, Thomas; Klein, Corinna; Eisen, Christian; Rigo-Watermeier, Teresa; Haferkamp, Axel; Sprick, Martin R

    2016-04-01

    The long-term propagation of basal prostate progenitor cells ex vivo has been very difficult in the past. The development of novel methods to expand prostate progenitor cells in vitro allows determining their cell surface phenotype in greater detail. Mouse (Lin(-) Sca-1(+) CD49f(+) Trop2(high) -phenotype) and human (Lin(-) CD49f(+) TROP2(high) ) basal prostate progenitor cells were expanded in vitro. Human and mouse cells were screened using 242 anti-human or 176 antimouse monoclonal antibodies recognizing the cell surface protein profile. Quantitative expression was evaluated at the single-cell level using flow cytometry. Differentially expressed cell surface proteins were evaluated in conjunction with the known CD49f(+) /TROP2(high) phenotype of basal prostate progenitor cells and characterized by in vivo sandwich-transplantation experiments using nude mice. The phenotype of basal prostate progenitor cells was determined as CD9(+) /CD24(+) /CD29(+) /CD44(+) /CD47(+) /CD49f(+) /CD104(+) /CD147(+) /CD326(+) /Trop2(high) of mouse as well as human origin. Our analysis revealed several proteins, such as CD13, Syndecan-1 and stage-specific embryonal antigens (SSEAs), as being differentially expressed on murine and human CD49f(+) TROP2(+) basal prostate progenitor cells. Transplantation experiments suggest that CD49f(+) TROP2(high) SSEA-4(high) human prostate basal progenitor cells to be more potent to regenerate prostate tubules in vivo as compared with CD49f(+) TROP2(high) or CD49f(+) TROP2(high) SSEA-4(low) cells. Determination of the cell surface protein profile of functionally defined murine and human basal prostate progenitor cells reveals differentially expressed proteins that may change the potency and regenerative function of epithelial progenitor cells within the prostate. SSEA-4 is a candidate cell surface marker that putatively enables a more accurate identification of the basal PESC lineage. PMID:26849468

  6. Inhibition of macrophage migration inhibitory factor decreases proliferation and cytokine expression in bladder cancer cells

    International Nuclear Information System (INIS)

    The importance of various inflammatory cytokines in maintaining tumor cell growth and viability is well established. Increased expression of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) has previously been associated with various types of adenocarcinoma. MIF IHC was used to localize MIF in human bladder tissue. ELISA and Western blot analysis determined the synthesis and secretion of MIF by human bladder transitional cell carcinoma cells. The effects of MIF inhibitors (high molecular weight hyaluronate (HA), anti-MIF antibody or MIF anti-sense) on cell growth and cytokine expression were analyzed. Human bladder cancer cells (HT-1376) secrete detectable amounts of MIF protein. Treatment with HA, anti-MIF antibody and MIF anti-sense reduced HT-1376 cell proliferation, MIF protein secretion, MIF gene expression and secreted inflammatory cytokines. Our evidence suggests MIF interacts with the invariant chain, CD74 and the major cell surface receptor for HA, CD44. This study is the first to report MIF expression in the human bladder and these findings support a role for MIF in tumor cell proliferation. Since MIF participates in the inflammatory response and bladder cancer is associated with chronic inflammatory conditions, these new findings suggest that neutralizing bladder tumor MIF may serve as a novel therapeutic treatment for bladder carcinoma

  7. Estrogen induces Vav1 expression in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Ming-juan Du

    Full Text Available Vav1, a guanine nucleotide exchange factor (GEF for Rho family GTPases, is a hematopoietic protein involved in a variety of cellular events. In recent years, aberrant expression of Vav1 has been reported in non-hematopoietic cancers including human breast cancer. It remains to be answered how Vav1 is expressed and what Vav1 does in its non-resident tissues. In this study, we aimed to explore the mechanism for Vav1 expression in breast cancer cells in correlation with estrogen-ER pathway. We not only verified the ectopic expression of Vav1 in human breast cancer cell lines, but also observed that Vav1 expression was induced by 17β-estradiol (E2, a typical estrogen receptor (ER ligand, in ER-positive cell lines. On the other hand, Tamoxifen, a selective estrogen receptor modulator (SERM, and ICI 182,780, an ER antagonist, suppressed the expression of Vav1. The estrogen receptor modulating Vav1 expression was identified to be α form, not β. Furthermore, treatment of E2 increased the transcription of vav1 gene by enhancing the promoter activity, though there was no recognizable estrogen response element (ERE. Nevertheless, two regions at the vav1 gene promoter were defined to be responsible for E2-induced activation of vav1 promoter. Chromatin immunoprecipitation (ChIP and co-immunoprecipitation (Co-IP analyses suggested that ERα might access to the vav1 promoter via interacting with transcription factors, c-Myb and ELF-1. Consequently, the enhanced expression of Vav1 led to the elevation of Cyclin D1 and the progression of cell cycle. The present study implies that estrogen-ER modulates the transcription and expression of Vav1, which may contribute to the proliferation of cancerous cells.

  8. Protein Expression Profiling in the Spectrum of Renal Cell Carcinomas

    Directory of Open Access Journals (Sweden)

    Vladimir A Valera, Elsa Li-Ning-T, Beatriz A Walter, David D. Roberts, W M Linehan, Maria J Merino

    2010-01-01

    Full Text Available In this study, we aimed to evaluate the protein expression profile of a spectrum of renal cell carcinomas (RCC to find potential biomarkers for disease onset and progression and therefore, prospective therapeutic targets. A 2D-gel based proteomic analysis was used to outline differences in protein levels among different subtypes of renal cell carcinomas, including clear cell carcinomas, papillary lesions, chromophobe tumors and renal oncocytomas. Spot pattern was compared to the corresponding normal kidney from the same patients and distinctive, differentially expressed proteins were characterized by mass spectrometry. Twenty-one protein spots were found differentially expressed between clear cell RCC and normal tissue and 38 spots were found expressed in chromophobe tumors. Eleven proteins were identified, with most differentially expressed -by fold change- between clear cell tumors and the corresponding normal tissue. Two of the identified proteins, Triosephosphate isomerase 1 (TPI-1 and Heat Shock protein 27 (Hsp27, were further validated in a separate set of tumors by immunohistochemistry and expression levels were correlated with clinicopathologic features of the patients. Hsp27 was highly expressed in 82% of the tumors used for validation, and all cases showed strong immunoreactivity for TPI-1. In both Hsp27 and TPI-1, protein expression positively correlated with histologic features of the disease. Our results suggest that the subjacent cytogenetic abnormalities seen in different histological types of RCC are followed by specific changes in protein expression. From these changes, Hsp27 and TPI-1 emerged as potential candidates for the differentiation and prognosis in RCC.

  9. Toward Cell Selective Surfaces: Cell Adhesion and Proliferation on Breath Figures with Antifouling Surface Chemistry.

    Science.gov (United States)

    Martínez-Campos, Enrique; Elzein, Tamara; Bejjani, Alice; García-Granda, Maria Jesús; Santos-Coquillat, Ana; Ramos, Viviana; Muñoz-Bonilla, Alexandra; Rodríguez-Hernández, Juan

    2016-03-16

    We report the preparation of microporous functional polymer surfaces that have been proven to be selective surfaces toward eukaryotic cells while maintaining antifouling properties against bacteria. The fabrication of functional porous films has been carried out by the breath figures approach that allowed us to create porous interfaces with either poly(ethylene glycol) methyl ether methacrylate (PEGMA) or 2,3,4,5,6-pentafluorostyrene (5FS). For this purpose, blends of block copolymers in a polystyrene homopolymer matrix have been employed. In contrast to the case of single functional polymer, using blends enables us to vary the chemical distribution of the functional groups inside and outside the formed pores. In particular, fluorinated groups were positioned at the edges while the hydrophilic PEGMA groups were selectively located inside the pores, as demonstrated by TOF-SIMS. More interestingly, studies of cell adhesion, growth, and proliferation on these surfaces confirmed that PEGMA functionalized interfaces are excellent candidates to selectively allow cell growth and proliferation while maintaining antifouling properties. PMID:26909529

  10. PRL-3 suppresses c-Fos and integrin α2 expression in ovarian cancer cells

    International Nuclear Information System (INIS)

    Phosphatase of regenerating liver-3 (PRL-3), a protein tyrosine phosphatase, is highly expressed in multiple human cancers and strongly implicated in tumor progression and cancer metastasis. However, the mechanisms by which PRL-3 promotes cancer cell migration, invasion, and metastasis are not very well understood. In this study, we investigated the contribution and molecular mechanisms of PRL-3 in ovarian cancer progression. PRL-3 protein expression was detected on ovarian cancer tissue microarrays using immunohistochemistry. Stable PRL-3 depleted cell lines were generated using short hairpin RNA (shRNA) constructs. The migration and invasion potential of these cells were analyzed using Transwell and Matrigel assays, respectively. Immunoblotting and immunofluorescence were used to detect protein levels and distribution in PRL-3-ablated cells and the control cells. Cell morphology was observed with hematoxylin-eosin staining and transmission electron microscopy. Finally, PRL-3-ablated and control cells were injected into nude mice for xenograft tumorigenicity assays. Elevated PRL-3 expression was detected in 19% (26 out of 135) of human ovarian cancer patient samples, but not in normal ovary tissues (0 out of 14). Stable depletion of PRL-3 in A2780 ovarian cancer cells resulted in decreased migration ability and invasion activity compared with control parental A2780 cells. In addition, PRL-3-ablated cells also exhibited flattened morphology and extended lamellipodia. To address the possible molecular basis for the altered phenotypes associated with PRL-3 down-regulation, we assessed the expression profiles of various proteins involved in cell-matrix adhesion. Depletion of PRL-3 dramatically enhanced both RNA and protein levels of the cell surface receptor integrin α2, but not its heterologous binding partner integrin β1. Inhibition of PRL-3 also correlated with elevated expression and phosphorylation of paxillin. A pronounced increase in the expression and

  11. SPARC expression induces cell cycle arrest via STAT3 signaling pathway in medulloblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Chetty, Chandramu [Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Dontula, Ranadheer [Section of Hematology/Oncology, Department of Medicine, University of Illinois College of Medicine at Chicago, 840 South Wood Street, Suite 820-E, Chicago, IL-60612 (United States); Ganji, Purnachandra Nagaraju [Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Gujrati, Meena [Department of Pathology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL-61605 (United States); Lakka, Sajani S., E-mail: slakka@uic.edu [Section of Hematology/Oncology, Department of Medicine, University of Illinois College of Medicine at Chicago, 840 South Wood Street, Suite 820-E, Chicago, IL-60612 (United States)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Ectopic expression of SPARC impaired cell proliferation in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression induces STAT3 mediated cell cycle arrest in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression significantly inhibited pre-established tumor growth in nude-mice. -- Abstract: Dynamic cell interaction with ECM components has profound influence in cancer progression. SPARC is a component of the ECM, impairs the proliferation of different cell types and modulates tumor cell aggressive features. We previously reported that SPARC expression significantly impairs medulloblastoma tumor growth in vivo. In this study, we demonstrate that expression of SPARC inhibits medulloblastoma cell proliferation. MTT assay indicated a dose-dependent reduction in tumor cell proliferation in adenoviral mediated expression of SPARC full length cDNA (Ad-DsRed-SP) in D425 and UW228 cells. Flow cytometric analysis showed that Ad-DsRed-SP-infected cells accumulate in the G2/M phase of cell cycle. Further, immunoblot and immunoprecipitation analyses revealed that SPARC induced G2/M cell cycle arrest was mediated through inhibition of the Cyclin-B-regulated signaling pathway involving p21 and Cdc2 expression. Additionally, expression of SPARC decreased STAT3 phosphorylation at Tyr-705; constitutively active STAT3 expression reversed SPARC induced G2/M arrest. Ad-DsRed-SP significantly inhibited the pre-established orthotopic tumor growth and tumor volume in nude-mice. Immunohistochemical analysis of tumor sections from mice treated with Ad-DsRed-SP showed decreased immunoreactivity for pSTAT3 and increased immunoreactivity for p21 compared to tumor section from mice treated with mock and Ad-DsRed. Taken together our studies further reveal that STAT3 plays a key role in SPARC induced G2/M arrest in medulloblastoma cells. These new findings provide a molecular basis for the mechanistic understanding of the

  12. Adipose tissue-derived stromal cells express neuronal phenotypes

    Institute of Scientific and Technical Information of China (English)

    杨立业; 刘相名; 孙兵; 惠国桢; 费俭; 郭礼和

    2004-01-01

    Background Adipose tissue-derived stromal cells (ADSCs) can be greatly expanded in vitro, and induced to differentiate into multiple mesenchymal cell types, including osteogenic, chondrogenic, myogenic, and adipogenic cells. This study was designed to investigate the possibility of ADSCs differentiating into neurons.Methods Adipose tissue from rats was digested with collagenase, and adherent stromal cells were cultured. A medium containing a low concentration of fetal bovine serum was adopted to induce the cells to differentiate. ADSCs were identified by immunocytochemistry, and semi-quantitative RT-PCR was applied to detect mRNA expression of neurofilament 1 (NF1), nestin, and neuron-specific enolase (NSE).Results Nestin-positive cells were found occasionally among ADSCs. ADSCs were found to express NSE mRNA and nestin mRNA, but not NF1 mRNA. ADSCs could differentiate into neuron-like cells in a medium composed of a low concentration of fetal bovine serum, and these differentiated cells displayed complicated neuron-like morphologies.Conclusions The data support the hypothesis that adipose tissue contains stem cells capable of differentiating into neurons. These stem cells can overcome their mesenchymal commitment, and may represent an alternative autologous stem cell source for CNS cell transplantation.

  13. Melittin interaction with sulfated cell surface sugars.

    Science.gov (United States)

    Klocek, Gabriela; Seelig, Joachim

    2008-03-01

    Melittin is a 26-residue cationic peptide with cytolytic and antimicrobial properties. Studies on the action mechanism of melittin have focused almost exclusively on the membrane-perturbing properties of this peptide, investigating in detail the melittin-lipid interaction. Here, we report physical-chemical studies on an alternative mechanism by which melittin could interact with the cell membrane. As the outer surface of many cells is decorated with anionic (sulfated) glycosaminoglycans (GAGs), a strong Coulombic interaction between the two oppositely charged molecules can be envisaged. Indeed, the present study using isothermal titration calorimetry reveals a high affinity of melittin for several GAGs, that is, heparan sulfate (HS), dermatan sulfate, and heparin. The microscopic binding constant of melittin for HS is 2.4 x 10 (5) M (-1), the reaction enthalpy is Delta H melittin (0) = -1.50 kcal/mol, and the peptide-to-HS stoichiometry is approximately 11 at 10 mM Tris, 100 mM NaCl at pH 7.4 and 28 degrees C. Delta H melittin (0) is characterized by a molar heat capacity of Delta C P (0) = -227 cal mol (-1) K (-1). The large negative heat capacity change indicates that hydrophobic interactions must also be involved in the binding of melittin to HS. Circular dichroism spectroscopy demonstrates that the binding of the peptide to HS induces a conformational change to a predominantly alpha-helical structure. A model for the melittin-HS complex is presented. Melittin binding was compared with that of magainin 2 and nisin Z to HS. Magainin 2 is known for its antimicrobial properties, but it does not cause lysis of the eukaryotic cells. Nisin Z shows activity against various Gram-positive bacteria. Isothermal titration calorimetry demonstrates that magainin 2 and nisin Z do not bind to HS (5-50 degrees C, 10 mM Tris, and 100 mM NaCl at pH 7.4). PMID:18220363

  14. Studies of cell biomechanics with surface micro-/nano-technology

    International Nuclear Information System (INIS)

    We report the recent progress in our studies of cell biology using micro-/nano-technology. Cells have a size of several to tens of microns, which makes them easily manipulated by micro-/nano-technology. The shape of the cell influences the alignment of the actin cytoskeleton, which bears the main forces of the cell, maintains the shape,and mediates a series of biochemical reactions. We invented a stretching device and studied the real-time actin filament dynamics under stretch. We found that one stretch cycle shortened the actin filaments and promoted their reassemble process. Cell migration is a complex mechanical process. We found that cell geometry determines the cell polarity and migration direction. We fabricated three-dimensional surfaces to mimic the topography in vivo, and further built a cell culture model by integrating the three-dimensional surface, microfluidics, cell patterning,and coculturing of multiple cell types. We also investigated the neuronal guidance by surface patterning. (authors)

  15. Dendritic Cell Responses to Surface Properties of Clinical Titanium Surfaces

    OpenAIRE

    Kou, Peng Meng; Schwartz, Zvi; Boyan, Barbara D; Babensee, Julia E.

    2010-01-01

    Dendritic cells (DCs) play pivotal roles in responding to foreign entities during an innate immune response and initiating effective adaptive immunity as well as maintaining immune tolerance. The sensitivity of DCs to foreign stimuli also makes them useful cells to assess the inflammatory response to biomaterials. Elucidating the material property-DC phenotype relationships using a well-defined biomaterial system is expected to provide criteria for immuno-modulatory biomaterial design. Clinic...

  16. Cardiomyocyte expression and cell-specific processing of procholecystokinin

    DEFF Research Database (Denmark)

    Gøtze, Jens P.; Johnsen, Anders H.; Kistorp, Caroline;

    2015-01-01

    Heart muscle cells produce peptide hormones such as natriuretic peptides. Developing hearts also express the gene for the classic intestinal hormone cholecystokinin (CCK) in amounts similar to those in the intestine and brain. However, cardiac expression of peptides other than natriuretic peptides...... has only been suggested using transcriptional measures or methods, with the post-translational phase of gene expression unaddressed. In this study, we examined the cardiac expression of the CCK gene in adult mammals and its expression at the protein level. Using quantitative PCR, a library of sequence......-specific pro-CCK assays, peptide purification, and mass spectrometry, we demonstrate that the mammalian heart expresses pro-CCK in amounts comparable to natriuretic prohormones and processes it to a unique, triple-sulfated, and N-terminally truncated product distinct from intestinal and cerebral CCK peptides...

  17. Changes of TIZ expression in epithelial ovarian cancer cells

    Institute of Scientific and Technical Information of China (English)

    Huan-Yu Zheng; Hong-Yu Zheng; Yun-Tao Zhou; En-Ling Liu; Jie Li; Yan-Mei Zhang

    2015-01-01

    Objective:To study the change ofTIZ expression in epithelial ovarian cancer cells.Methods:HO8910 cells were transinfected with siRNA to inhibit the expression ofTIZ. pcDNA3.1-TIZ vectors were combined to increase theTIZ expression level.The cell viability, colony forming efficiency and cycle distribution ofHO8910,HO8910/NC,HO8910/pcDNA3.1-NC,HO8910/TIZ-573 andHO8910/pcDNA3.1-TIZ were compared, and the invasion rate, migration rate and adhesion rate between5 groups of cells were compared.Results:Compared with those ofHO8910,HO8910/NC andHO8910/pcDNA3.1-NC, the cell viability, colony forming efficiency and cell cycle distribution ofHO8910/TIZ-573 were increased, while the indexes ofHO8910/pcDNA3.1-NC were decreased with statistical significant difference(P0.05). Conclusions:The expression ofTIZ can inhibit the proliferation of epithelial ovarian cancer cells.

  18. A Novel Protein Is Lower Expressed in Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Ruili Guan

    2014-04-01

    Full Text Available Engrailed-2 (EN2 has been identified as a candidate oncogene in breast cancer and prostate cancer. It is usually recognized as a mainly nuclear staining in the cells. However, recent studies showed a cytoplasmic staining occurred in prostate cancer, bladder cancer and clear cell renal cell carcinoma. The inconsistency makes us confused. To clarify the localization and expression of EN2 in renal cell carcinoma, anti-EN2 antibody (ab28731 and anti-EN2 antibody (MAB2600 were used for immunohistochemistry (IHC respectively. Interestingly, we found that EN2 detected by ab28731 was mainly presented in cytoplasm while EN2 detected by MAB2600 was mainly presented in nucleus. To further investigate the different patterns observed above, lysates from full-length EN2 over expression in HEK293T cells were used to identify which antibody the EN2 molecule bound by western blot. Results showed ab28731 did not react with the lysates. For this reason, the novel specific protein detected by ab28731 was not the EN2 molecule and was named nonEN2. Then using the renal carcinoma tissue microarray and renal tissues, we found that the protein expression levels of nonEN2 in kidney tumor tissues was significantly lower than that in kidney normal tissues (p < 0.05, so was in renal cell lines. Taken together, nonEN2 is lower expressed and may play an important role in renal cell carcinoma.

  19. Cell surface estrogen receptor alpha is upregulated during subchronic metabolic stress and inhibits neuronal cell degeneration.

    Directory of Open Access Journals (Sweden)

    Cristiana Barbati

    Full Text Available In addition to the classical nuclear estrogen receptor, the expression of non-nuclear estrogen receptors localized to the cell surface membrane (mER has recently been demonstrated. Estrogen and its receptors have been implicated in the development or progression of numerous neurodegenerative disorders. Furthermore, the pathogenesis of these diseases has been associated with disturbances of two key cellular programs: apoptosis and autophagy. An excess of apoptosis or a defect in autophagy has been implicated in neurodegeneration. The aim of this study was to clarify the role of ER in determining neuronal cell fate and the possible implication of these receptors in regulating either apoptosis or autophagy. The human neuronal cell line SH-SY5Y and mouse neuronal cells in primary culture were thus exposed to chronic minimal peroxide treatment (CMP, a form of subcytotoxic minimal chronic stress previously that mimics multiple aspects of long-term cell stress and represents a limited molecular proxy for neurodegenerative processes. We actually found that either E2 or E2-bovine serum albumin construct (E2BSA, i.e. a non-permeant form of E2 was capable of modulating intracellular cell signals and regulating cell survival and death. In particular, under CMP, the up-regulation of mERα, but not mERβ, was associated with functional signals (ERK phosphorylation and p38 dephosphorylation compatible with autophagic cytoprotection triggering and leading to cell survival. The mERα trafficking appeared to be independent of the microfilament system cytoskeletal network but was seemingly associated with microtubular apparatus network, i.e., to MAP2 molecular chaperone. Importantly, antioxidant treatments, administration of siRNA to ERα, or the presence of antagonist of ERα hindered these events. These results support that the surface expression of mERα plays a pivotal role in determining cell fate, and that ligand-induced activation of mER signalling exerts a

  20. Surface expression of protein A on magnetosomes and capture of pathogenic bacteria by magnetosome/ antibody complexes

    Directory of Open Access Journals (Sweden)

    JieshengTian

    2014-04-01

    Full Text Available Magnetosomes are membrane-enclosed magnetite nanocrystals synthesized by magnetotactic bacteria (MTB. They display chemical purity, narrow size ranges, and species-specific crystal morphologies. Specific transmembrane proteins are sorted to the magnetosome membrane (MM. MamC is the most abundant MM protein of Magnetospirillum gryphiswaldense strain MSR-1. MamF is the second most abundant MM protein of MSR-1 and forms stable oligomers. We expressed staphylococcal protein A (SPA, an immunoglobulin-binding protein from the cell wall of Staphylococcus aureus, on MSR-1 magnetosomes by fusion with MamC or MamF. The resulting recombinant magnetosomes were capable of self-assembly with the Fc region of mammalian antibodies (Abs and were therefore useful for functionalization of magnetosomes. Recombinant plasmids pBBR-mamC-spa and pBBR-mamF-spa were constructed by fusing spa (the gene that encodes SPA with mamC and mamF, respectively. Recombinant magnetosomes with surface expression of SPA were generated by introduction of these fusion genes into wild-type MSR-1 or a mamF mutant strain. Studies with a Zeta Potential Analyzer showed that the recombinant magnetosomes had hydrated radii significantly smaller than those of WT magnetosomes and zeta potentials less than -30 mV, indicating that the magnetosome colloids were relatively stable. Observed conjugation efficiencies were as high as 71.24 µg Ab per mg recombinant magnetosomes, and the conjugated Abs retained most of their activity. Numbers of Vibrio parahaemolyticus (a common pathogenic bacterium in seafood captured by recombinant magnetosome/ Ab complexes were measured by real-time fluorescence-based quantitative PCR. One mg of complex was capable of capturing as many as 1.74×107 Vibrio cells. The surface expression system described here will be useful for design of functionalized magnetosomes from MSR-1 and other MTB.

  1. Suppressed proliferation of mouse osteoblast-like cells by a rough-surfaced substrate leads to low differentiation and mineralization

    International Nuclear Information System (INIS)

    The cellular responses of mouse osteoblast-like MC3T3-E1 cells to the surface roughness were examined in the sequential events of cell adhesion, proliferation, differentiation, and mineralization. The cells were plated and cultured on sandblasted borosilicate glass slideslips with different surface roughnesses. DNA synthesis at day 1 after plating and the cell number at day 5 significantly decreased as the surface roughness increased. The suppressed cell proliferation on the rough-surfaced substrates, closely related to the round cell morphology, caused underdeveloped intercellular contacts via the gap junction due to the low population of neighboring cells. Expressions of the representative osteoblastic genes at day 14, alkaline phosphatase activity at day 21, and mineralization at day 28 were markedly reduced on the rough-surfaced substrates. These results clearly indicated that the reduced cell differentiation and mineralization resulted from the early cellular responses of the suppressed cell proliferation depending on the surface roughness and the consequent poor intercellular communication. The specific changes in the early gene expression profiles at day 1, depending on the surface roughness, were examined by a large-scale analysis of the gene expression using a mouse DNA chip. The ribosomal protein S6 kinase polypeptide 1 gene, which is a cell growth-related gene involved in the PI3-kinase/Akt pathway, was found to be the most down-regulated among the 4277 screened genes.

  2. Expression of transcobalamin II receptors by human leukemia K562 and HL-60 cells

    International Nuclear Information System (INIS)

    Plasma membrane receptors for the serum cobalamin-binding protein transcobalamin II (TCII) were identified on human leukemia K562 and HL-60 cells using immunoaffinity-purified human TCII labeled with [57Co]cyanocobalamin. The Bmax values for TCII receptors on proliferating K562 and HL-60 cells were 4,500 and 2,700 per cell, respectively. Corresponding dissociation constants (kd) were 8.0 x 10(-11) mol/L and 9.0 x 10(-11) mol/L. Rabbit TCII also bound to K562 and HL-60 cells but with slightly reduced affinities. Calcium was required for the binding of transcobalamin II to K562 cells. Brief treatment of these cells with trypsin resulted in almost total loss of surface binding activity. After removal of trypsin, surface receptors for TCII slowly reappeared, reaching pretrypsin treatment densities only after 24 hours. Reappearance of receptors was blocked by cycloheximide. TCII receptor densities on K562 and HL-60 cells correlated inversely with the concentration of cobalamin in the culture medium. This suggests that intracellular stores of cobalamin may affect the expression of transcobalamin receptors. Nonproliferating stationary-phase K562 cells had low TCII receptor densities. However, the density of TCII receptors increased substantially when cells were subcultured in fresh medium. Up-regulation of receptor expression coincided with increased 3H-thymidine incorporation, which preceded the resumption of cellular proliferation as measured by cell density. In the presence of cytosine arabinoside, which induces erythroid differentiation, K562 cells down-regulated expression of TCII receptors. When HL-60 cells were subcultured in fresh medium containing dimethysulfoxide to induce granulocytic differentiation, the up-regulation of TCII receptors was suppressed. This event occurred well before a diminution of 3H-thymidine incorporation and cessation of proliferation

  3. Pax4 Expression does not Transduce Pancreatic Alpha Cells to Beta Cells

    Directory of Open Access Journals (Sweden)

    Ling Chen

    2015-07-01

    Full Text Available Background/Aims: The lack of available beta cells greatly limits the use of beta cell transplantation as a therapy for diabetes. Thus, generation of beta cells from other sources is substantially required. Pax4 has been shown to induce reprograming of alpha cells into beta cells during embryogenesis. Nevertheless, whether expression of Pax4 in adult alpha cells could trigger this alpha-to-beta cell reprogramming is unknown. Methods: Here we generated an adeno-associated virus carrying Pax4 and GFP under a CMV promoter (AAV-Pax4. We used AAV-Pax4 to transduce a mouse alpha cell line in vitro, and to transduce primary alpha cells in diabetic mice. Reprogramming was examined by double immunostaining and by changes in beta cell number. The effects on blood glucose were evaluated by fasting blood glucose and glucose response. Results: In vitro, Pax4 overexpression neither induced insulin expression, nor suppressed glucagon expression in alpha cells. In vivo, Pax4 overexpression failed to increase beta cell number, and did not alter hyperglycemia and glucose response in diabetic mice. Conclusion: Pax4 expression is not sufficient to transduce pancreatic alpha cells into beta cells. Overexpression of Pax4 in alpha cells may not increase functional beta cell number in diabetic patients.

  4. Targeting Negative Surface Charges of Cancer Cells by Multifunctional Nanoprobes.

    Science.gov (United States)

    Chen, Bingdi; Le, Wenjun; Wang, Yilong; Li, Zhuoquan; Wang, Dong; Ren, Lei; Lin, Ling; Cui, Shaobin; Hu, Jennifer J; Hu, Yihui; Yang, Pengyuan; Ewing, Rodney C; Shi, Donglu; Cui, Zheng

    2016-01-01

    A set of electrostatically charged, fluorescent, and superparamagnetic nanoprobes was developed for targeting cancer cells without using any molecular biomarkers. The surface electrostatic properties of the established cancer cell lines and primary normal cells were characterized by using these nanoprobes with various electrostatic signs and amplitudes. All twenty two randomly selected cancer cell lines of different organs, but not normal control cells, bound specifically to the positively charged nanoprobes. The relative surface charges of cancer cells could be quantified by the percentage of cells captured magnetically. The activities of glucose metabolism had a profound impact on the surface charge level of cancer cells. The data indicate that an elevated glycolysis in the cancer cells led to a higher level secretion of lactate. The secreted lactate anions are known to remove the positive ions, leaving behind the negative changes on the cell surfaces. This unique metabolic behavior is responsible for generating negative cancer surface charges in a perpetuating fashion. The metabolically active cancer cells are shown to a unique surface electrostatic pattern that can be used for recovering cancer cells from the circulating blood and other solutions. PMID:27570558

  5. Targeting Negative Surface Charges of Cancer Cells by Multifunctional Nanoprobes

    Science.gov (United States)

    Chen, Bingdi; Le, Wenjun; Wang, Yilong; Li, Zhuoquan; Wang, Dong; Ren, Lei; Lin, Ling; Cui, Shaobin; Hu, Jennifer J.; Hu, Yihui; Yang, Pengyuan; Ewing, Rodney C.; Shi, Donglu; Cui, Zheng

    2016-01-01

    A set of electrostatically charged, fluorescent, and superparamagnetic nanoprobes was developed for targeting cancer cells without using any molecular biomarkers. The surface electrostatic properties of the established cancer cell lines and primary normal cells were characterized by using these nanoprobes with various electrostatic signs and amplitudes. All twenty two randomly selected cancer cell lines of different organs, but not normal control cells, bound specifically to the positively charged nanoprobes. The relative surface charges of cancer cells could be quantified by the percentage of cells captured magnetically. The activities of glucose metabolism had a profound impact on the surface charge level of cancer cells. The data indicate that an elevated glycolysis in the cancer cells led to a higher level secretion of lactate. The secreted lactate anions are known to remove the positive ions, leaving behind the negative changes on the cell surfaces. This unique metabolic behavior is responsible for generating negative cancer surface charges in a perpetuating fashion. The metabolically active cancer cells are shown to a unique surface electrostatic pattern that can be used for recovering cancer cells from the circulating blood and other solutions. PMID:27570558

  6. Interaction of herpes simplex virus glycoprotein gC with mammalian cell surface molecules.

    OpenAIRE

    Tal-Singer, R; Peng, C.; Ponce de Leon, M; Abrams, W R; Banfield, B W; Tufaro, F; Cohen, G H; Eisenberg, R J

    1995-01-01

    The entry of herpes simplex virus (HSV) into mammalian cells is a multistep process beginning with an attachment step involving glycoproteins gC and gB. A second step requires the interaction of glycoprotein gD with a cell surface molecule. We explored the interaction between gC and the cell surface by using purified proteins in the absence of detergent. Truncated forms of gC and gD, gC1(457t), gC2(426t), and gD1(306t), lacking the transmembrane and carboxyl regions were expressed in the bacu...

  7. Surface localization of the nuclear receptor CAR in influenza A virus-infected cells

    International Nuclear Information System (INIS)

    Constitutive active/androstane receptor CAR is a member of the nuclear receptors which regulate transcription of xenobiotic metabolism enzymes. CAR is usually localized in the cytosol and nucleus. Here, we found that CAR was localized at the cell surface of influenza A virus (IAV)-infected cells. Additionally, we demonstrated that expression of a viral envelope glycoprotein, either hemagglutinin (HA) or neuraminidase (NA), but not viral nucleoprotein (NP), was responsible for this localization. This report is the first demonstration of CAR at the surface of tissue culture cells, and suggests that CAR may exert the IAV infection mechanism

  8. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Wang Bin

    2008-03-01

    Full Text Available Abstract Background The efficacy of highly active antiretroviral therapy (HAART determined by simultaneous monitoring over 100 cell-surface antigens overtime has not been attempted. We used an antibody microarray to analyze changes in the expression of 135 different cell-surface antigens overtime on PBMC from HIV+ patients on HAART. Two groups were chosen, one (n = 6 achieved sustainable response by maintaining below detectable plasma viremia and the other (n = 6 responded intermittently. Blood samples were collected over an average of 3 years and 5–8 time points were selected for microarray assay and statistical analysis. Results Significant trends over time were observed for the expression of 7 cell surface antigens (CD2, CD3epsilon, CD5, CD95, CD36, CD27 and CD28 for combined patient groups. Between groups, expression levels of 10 cell surface antigens (CD11a, CD29, CD38, CD45RO, CD52, CD56, CD57, CD62E, CD64 and CD33 were found to be differential. Expression levels of CD9, CD11a, CD27, CD28 and CD52, CD44, CD49d, CD49e, CD11c strongly correlated with CD4+ and CD8+ T cell counts, respectively. Conclusion Our findings not only detected markers that may have potential prognostic/diagnostic values in evaluating HAART efficacy, but also showed how density of cell surface antigens could be efficiently exploited in an array-like manner in relation to HAART and HIV-infection. The antigens identified in this study should be further investigated by other methods such as flow cytometry for confirmation as biological analysis of these antigens may help further clarify their role during HAART and HIV infection.

  9. Proteomic analysis and identification of cell surface-associated proteins of Clostridium chauvoei.

    Science.gov (United States)

    Jayaramaiah, Usharani; Singh, Neetu; Thankappan, Sabarinath; Mohanty, Ashok Kumar; Chaudhuri, Pallab; Singh, Vijendra Pal; Nagaleekar, Viswas Konasagara

    2016-06-01

    Blackleg is a highly fatal disease of cattle and sheep, caused by Clostridium chauvoei, a Gram positive, anaerobic, spore forming bacteria. Cell surface-associated proteins play a major role in inducing the protective immunity. However, the identity of a majority of cell surface-associated proteins of C. chauvoei is not known. In the present investigation, we have used SDS-PAGE, 2D-gel electrophoresis and Western blotting followed by mass spectrometry to identify cell surface-associated proteins of C. chauvoei. Among the identified proteins, which have shown to offer protective antigencity in other bacteria, Enolase, Chaperonin, Ribosomal protein L10, Glycosyl Hydrolase and Flavoprotein were characterized by sequencing and their overexpression in Escherichia coli. In conclusion, cell surface-associated proteins were identified using proteomic approach and the genes for the immunoreactive proteins were expressed, which may prove to be potential diagnostic or vaccine candidates. PMID:26971466

  10. Induction and Selection of Sox17-Expressing Endoderm Cells Generated from Murine Embryonic Stem Cells

    OpenAIRE

    Schroeder, I.; Sulzbacher, S.; T. Nolden; Fuchs, J.; Czarnota, J.; Meisterfeld, R.; Himmelbauer, H.; Wobus, A

    2014-01-01

    Embryonic stem (ES) cells offer a valuable source for generating insulin-producing cells. However, current differentiation protocols often result in heterogeneous cell populations of various developmental stages. Here we show the activin A-induced differentiation of mouse ES cells carrying a homologous dsRed-IRES-puromycin knock-in within the Sox17 locus into the endoderm lineage. Sox17-expressing cells were selected by fluorescence-assisted cell sorting (FACS) and characterized at the transc...

  11. The anticancer activity of lytic peptides is inhibited by heparan sulfate on the surface of the tumor cells

    Directory of Open Access Journals (Sweden)

    Rekdal Øystein

    2009-06-01

    Full Text Available Abstract Background Cationic antimicrobial peptides (CAPs with antitumor activity constitute a promising group of novel anticancer agents. These peptides induce lysis of cancer cells through interactions with the plasma membrane. It is not known which cancer cell membrane components influence their susceptibility to CAPs. We have previously shown that CAPs interact with the two glycosaminoglycans (GAGs, heparan sulfate (HS and chondroitin sulfate (CS, which are present on the surface of most cells. The purpose of this study was to investigate the role of the two GAGs in the cytotoxic activity of CAPs. Methods Various cell lines, expressing different levels of cell surface GAGs, were exposed to bovine lactoferricin (LfcinB and the designer peptide, KW5. The cytotoxic effect of the peptides was investigated by use of the colorimetric MTT viability assay. The cytotoxic effect on wild type CHO cells, expressing normal amounts of GAGs on the cell surface, and the mutant pgsA-745, that has no expression of GAGs on the cell surface, was also investigated. Results We show that cells not expressing HS were more susceptible to CAPs than cells expressing HS at the cell surface. Further, exogenously added heparin inhibited the cytotoxic effect of the peptides. Chondroitin sulfate had no effect on the cytotoxic activity of KW5 and only minor effects on LfcinB cytotoxicity. Conclusion Our results show for the first time that negatively charged molecules at the surface of cancer cells inhibit the cytotoxic activity of CAPs. Our results indicate that HS at the surface of cancer cells sequesters CAPs away from the phospholipid bilayer and thereby impede their ability to induce cytolysis.

  12. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    Energy Technology Data Exchange (ETDEWEB)

    Kado, T.; Hidaka, T. [Division of Periodontology and Endodontology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Aita, H. [Division of Occlusion and Removable Prosthodontics, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Endo, K. [Division of Biomaterials and Bioengineering, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Furuichi, Y., E-mail: furuichi@hoku-iryo-u.ac.jp [Division of Periodontology and Endodontology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Cell-adhesive molecules were covalently immobilized on a Ti surface. Black-Right-Pointing-Pointer Immobilized cell-adhesive molecules maintained native function on the Ti surface. Black-Right-Pointing-Pointer Immobilized collagen enhanced adhesion of periodontal ligament cells to the Ti. - Abstract: A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully

  13. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    International Nuclear Information System (INIS)

    Highlights: ► Cell-adhesive molecules were covalently immobilized on a Ti surface. ► Immobilized cell-adhesive molecules maintained native function on the Ti surface. ► Immobilized collagen enhanced adhesion of periodontal ligament cells to the Ti. - Abstract: A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface

  14. Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression

    OpenAIRE

    Deaglio, Silvia; Dwyer, Karen M.; GAO, WENDA; Friedman, David; Usheva, Anny; Erat, Anna; Chen, Jiang-Fan; Enjyoji, Keiichii; Linden, Joel; Oukka, Mohamed; Kuchroo, Vijay K.; Strom, Terry B.; Robson, Simon C.

    2007-01-01

    The study of T regulatory cells (T reg cells) has been limited by the lack of specific surface markers and an inability to define mechanisms of suppression. We show that the expression of CD39/ENTPD1 in concert with CD73/ecto-5′-nucleotidase distinguishes CD4+/CD25+/Foxp3+ T reg cells from other T cells. These ectoenzymes generate pericellular adenosine from extracellular nucleotides. The coordinated expression of CD39/CD73 on T reg cells and the adenosine A2A receptor on activated T effector...

  15. Dynamic distribution and stem cell characteristics of Sox1-expressing cells in the cerebellar cortex

    Institute of Scientific and Technical Information of China (English)

    Joelle Alcock; Virginie Sottile

    2009-01-01

    Bergmann glia cells are a discrete radial glia population surrounding Purkinje cells in the cerebellar cortex. Al-though Bergmann glia are essential for the development and correct arborization of Purkinje cells, little is known about the regulation of this cell population after the developmental phase. In an effort to characterize this population at the molecular level, we have analyzed marker expression and established that adult Bergmann glia express Soxl, Sox2 and Sox9, a feature otherwise associated with neural stem cells (NSCs). In the present study, we have further analyzed the developmental pattern of Soxl-expressing cells in the developing cerebellum. We report that before be-coming restricted to the Purkinje cell layer, Soxl-positive cells are present throughout the immature tissue, and that these cells show characteristics of Bergmann glia progenitors. Our study shows that these progenitors express Soxl, Sox2 and Sox9, a signature maintained throughout cerebellar maturation into adulthood. When isolated in culture, the Soxl-expressing cerebellar population exhibited neurosphere-forming ability, NSC-marker characteristics, and demonstrated multipotency at the clonal level. Our results show that the Bergmann glia population expresses Soxl during cerebellar development, and that these cells can be isolated and show stem cell characteristics in vitro, sug-gesting that they could hold a broader potential than previously thought.

  16. Regulation of cell-to-cell variability in divergent gene expression

    Science.gov (United States)

    Yan, Chao; Wu, Shuyang; Pocetti, Christopher; Bai, Lu

    2016-03-01

    Cell-to-cell variability (noise) is an important feature of gene expression that impacts cell fitness and development. The regulatory mechanism of this variability is not fully understood. Here we investigate the effect on gene expression noise in divergent gene pairs (DGPs). We generated reporters driven by divergent promoters, rearranged their gene order, and probed their expressions using time-lapse fluorescence microscopy and single-molecule fluorescence in situ hybridization (smFISH). We show that two genes in a co-regulated DGP have higher expression covariance compared with the separate, tandem and convergent configurations, and this higher covariance is caused by more synchronized firing of the divergent transcriptions. For differentially regulated DGPs, the regulatory signal of one gene can stochastically `leak' to the other, causing increased gene expression noise. We propose that the DGPs' function in limiting or promoting gene expression noise may enhance or compromise cell fitness, providing an explanation for the conservation pattern of DGPs.

  17. Glucocorticoids Suppress Renal Cell Carcinoma Progression by Enhancing Na,K-ATPase Beta-1 Subunit Expression

    Science.gov (United States)

    Huynh, Thu P.; Barwe, Sonali P.; Lee, Seung J.; McSpadden, Ryan; Franco, Omar E.; Hayward, Simon W.; Damoiseaux, Robert; Grubbs, Stephen S.; Petrelli, Nicholas J.; Rajasekaran, Ayyappan K.

    2015-01-01

    Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-β1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-β1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-β1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function. PMID:25836370

  18. How cells tiptoe on adhesive surfaces before sticking

    CERN Document Server

    Pierres, Anne; Touchard, Dominique; Bongrand, Pierre

    2008-01-01

    Cell membranes are studded with protrusions that were thoroughly analyzed with electron microscopy. However, the nanometer-scale three-dimensional motions generated by cell membranes to fit the topography of foreign surfaces and initiate adhesion remain poorly understood. Here, we describe the dynamics of surface deformations displayed by monocytic cells bumping against fibronectin-coated surfaces. We observed membrane undulations with typically 5 nm amplitude and 5-10 second lifetime. Cell membranes behaved as independent units of micrometer size. Cells detected the presence of foreign surfaces at 50 nm separation, resulting in time-dependent amplification of membrane undulations. Molecular contact then ensued with apparent cell-membrane separation of 30-40 nm, and this distance steadily decreased during the following tens of seconds. Contact maturation was associated with in-plane egress of bulky molecules and robust membrane fluctuations. Thus, membrane undulations may be the major determinant of cell sens...

  19. Roles for Cell Wall Glycopeptidolipid in Surface Adherence and Planktonic Dispersal of Mycobacterium avium

    Science.gov (United States)

    The opportunistic pathogen Mycobacterium avium is a significant inhabitant of biofilms in drinking water distribution systems. M. avium expresses on its cell surface serovar-specific glycopeptidolipids (ssGPLs). Studies have implicated the core GPL in biofilm formation by M. aviu...

  20. Connexin expression and gap-junctional intercellular communication in ES cells and iPS cells

    Directory of Open Access Journals (Sweden)

    Masahito eOyamada

    2013-07-01

    Full Text Available Pluripotent stem cells, i.e., embryonic stem (ES and induced pluripotent stem (iPS cells, can indefinitely proliferate without commitment and differentiate into all cell lineages. ES cells are derived from the inner cell mass of the preimplantation blastocyst, whereas iPS cells are generated from somatic cells by overexpression of a few transcription factors. Many studies have demonstrated that mouse and human iPS cells are highly similar but not identical to their respective ES cell counterparts. The potential to generate basically any differentiated cell types from these cells offers the possibility to establish new models of mammalian development and to create new sources of cells for regenerative medicine. ES cells and iPS cells also provide useful models to study connexin expression and gap-junctional intercellular communication (GJIC during cell differentiation and reprogramming. In 1996, we reported connexin expression and GJIC in mouse ES cells. Because a substantial number of papers on these subjects have been published since our report, this Mini Review summarizes currently available data on connexin expression and GJIC in ES cells and iPS cells during undifferentiated state, differentiation, and reprogramming.

  1. Human Neural Cells Transiently Express Reelin during Olfactory Placode Development

    Science.gov (United States)

    Antal, M. Cristina; Samama, Brigitte; Ghandour, M. Said; Boehm, Nelly

    2015-01-01

    Reelin, an extracellular glycoprotein is essential for migration and correct positioning of neurons during development. Since the olfactory system is known as a source of various migrating neuronal cells, we studied Reelin expression in the two chemosensory olfactory systems, main and accessory, during early developmental stages of human foetuses/embryos from Carnegie Stage (CS) 15 to gestational week (GW) 14. From CS 15 to CS 18, but not at later stages, a transient expression of Reelin was detected first in the presumptive olfactory and then in the presumptive vomeronasal epithelium. During the same period, Reelin-positive cells detach from the olfactory/vomeronasal epithelium and migrate through the mesenchyme beneath the telencephalon. Dab 1, an adaptor protein of the Reelin pathway, was simultaneously expressed in the migratory mass from CS16 to CS17 and, at later stages, in the presumptive olfactory ensheathing cells. Possible involvements of Reelin and Dab 1 in the peripheral migrating stream are discussed. PMID:26270645

  2. Protein expression analyses at the single cell level.

    Science.gov (United States)

    Ohno, Masae; Karagiannis, Peter; Taniguchi, Yuichi

    2014-01-01

    The central dogma of molecular biology explains how genetic information is converted into its end product, proteins, which are responsible for the phenotypic state of the cell. Along with the protein type, the phenotypic state depends on the protein copy number. Therefore, quantification of the protein expression in a single cell is critical for quantitative characterization of the phenotypic states. Protein expression is typically a dynamic and stochastic phenomenon that cannot be well described by standard experimental methods. As an alternative, fluorescence imaging is being explored for the study of protein expression, because of its high sensitivity and high throughput. Here we review key recent progresses in fluorescence imaging-based methods and discuss their application to proteome analysis at the single cell level. PMID:25197931

  3. Protein Expression Analyses at the Single Cell Level

    Directory of Open Access Journals (Sweden)

    Masae Ohno

    2014-09-01

    Full Text Available The central dogma of molecular biology explains how genetic information is converted into its end product, proteins, which are responsible for the phenotypic state of the cell. Along with the protein type, the phenotypic state depends on the protein copy number. Therefore, quantification of the protein expression in a single cell is critical for quantitative characterization of the phenotypic states. Protein expression is typically a dynamic and stochastic phenomenon that cannot be well described by standard experimental methods. As an alternative, fluorescence imaging is being explored for the study of protein expression, because of its high sensitivity and high throughput. Here we review key recent progresses in fluorescence imaging-based methods and discuss their application to proteome analysis at the single cell level.

  4. Detection of an Immunogenic HERV-E Envelope with Selective Expression in Clear Cell Kidney Cancer.

    Science.gov (United States)

    Cherkasova, Elena; Scrivani, Claire; Doh, Susan; Weisman, Quinn; Takahashi, Yoshiyuki; Harashima, Nanae; Yokoyama, Hisayuki; Srinivasan, Ramaprasad; Linehan, W Marston; Lerman, Michael I; Childs, Richard W

    2016-04-15

    VHL-deficient clear cell renal cell carcinomas (ccRCC), the most common form of kidney cancer, express transcripts derived from the novel human endogenous retrovirus HERV-E (named CT-RCC HERV-E). In this study, we define a transcript encoding the entire envelope gene of HERV-E as expressed selectively in ccRCC tumors, as distinct from normal kidney tissues or other tumor types. Sequence analysis of this envelope transcript revealed long open reading frames encoding putative surface and transmembrane envelope proteins. Retroviral envelopes are known to be capable of eliciting immunity in humans. Accordingly, we found that HLA-A*0201-restricted peptides predicted to be products of the CT-RCC HERV-E envelope transcript-stimulated CD8(+) T cells, which could recognize HLA-A*0201-positive HERV-E-expressing kidney tumor cells. Overall, our results offer evidence of unique HERV-E envelope peptides presented on the surface of ccRCC cells, offering potentially useful tumor-restricted targets for T-cell-based immunotherapy of kidney cancer. Cancer Res; 76(8); 2177-85. ©2016 AACR. PMID:26862115

  5. Epidermal growth factor receptor expression in canine transitional cell carcinoma

    OpenAIRE

    HANAZONO, Kiwamu; Fukumoto, Shinya; KAWAMURA, Yoshio; ENDO, Yoshifumi; Kadosawa, Tsuyoshi; IWANO, Hidetomo; UCHIDE, Tsuyoshi

    2014-01-01

    Transitional cell carcinoma (TCC), a urinary bladder tumor with high mortality, is encountered commonly in dogs. Whereas overexpression of epidermal growth factor receptor (EGFR) is associated with development of human urinary bladder cancer, information on EGFR expression in canine TCC is lacking. In this study, EGFR protein and mRNA expression in canine normal bladder (n=5), polypoid cystitis (n=5) and TCC (n=25) were examined by immunohistochemistry and real-time polymerase chain reaction....

  6. CD1d expression and invariant NKT cell responses in herpesvirus infections

    Directory of Open Access Journals (Sweden)

    Rusung eTan

    2015-06-01

    Full Text Available Invariant natural killer T (iNKT cells are a highly conserved subset of unconventional T lymphocytes that express a canonical, semi-invariant T cell receptor (TCR and surface markers shared with the natural killer cell lineage. iNKT cells recognize exogenous and endogenous glycolipid antigens restricted by non-polymorphic CD1d molecules, and are highly responsive to the prototypical agonist, α-galactosylceramide. Upon activation, iNKT cells rapidly coordinate signaling between innate and adaptive immune cells through the secretion of proinflammatory cytokines, leading to the maturation of antigen-presenting cells and expansion of antigen-specific CD4+ and CD8+ T cells. Because of their potent immunoregulatory properties, iNKT cells have been extensively studied and are known to play a pivotal role in mediating immune responses against microbial pathogens including viruses. Here, we review evidence that herpesviruses manipulate CD1d expression to escape iNKT cell surveillance and establish lifelong latency in humans. Collectively, published findings suggest that iNKT cells play critical roles in anti-herpesvirus immune responses and could be harnessed therapeutically to limit viral infection and viral-associated disease.

  7. Cloning and expression of human colon mast cell carboxypeptidase

    Institute of Scientific and Technical Information of China (English)

    Zhang-Quan Chen; Shao-Heng He

    2004-01-01

    AIM: To clone and express the human colon mast cell METHODS: Total RNA was extracted from colon tissue, and the cDNA encoding human colon mast cell carboxypeptidase was amplified by reverse-transcription PCR (RT-PCR). The product cDNA was subcloned into the prokaryotic expression vector pMAL-c2x and eukaryotic expression vector pPIC9K to conrtruct prokaryotic expression vector pMAL/human MC-CP (hMC-CP) and eukaryotic pPIC9K/hMC-CP. The recombinant fusion protein expressed in E.coli was induced with IPTG and purified by amylose affinity chromatography. After digestion with factor Xa, recombinant hMC-CP was purified by heparin agarose chromatography. The recombinant hMC-CP expressed in Pichia pastoris (P.pastoris) was induced with methanol and analyzed by SDS-PAGE, Western blot, N-terminal amino acid RESULTS: The cDNA encoding the human colon mast cell carboxypeptidase was cloned, which had five nucleotide variations compared with skin MC-CP cDNA. The recombinant hMC-CP protein expressed in E.coli was purified with amylose affinity chromatography and heparin agarose chromatogphy.SDS-PAGE and Western blot analysis showed that the recombinant protein expressed by E. coli had a molecular weight of 36 kDa and reacted to the anti-native hMC-CP monoclonal antibody (CA5). The N-terminal amino acid sequence confirmed further the product was hMC-CP. E. coli generated hMC-CP showed a very low level of enzymatic activity, but P. pastoris produced hMC-CP had a relatively high enzymatic activity towards a synthetic substrate hippuryl-L-phenylalanine.carboxypeptidase can be successfully cloned and expressed in E.coli and P. pastoris, which will contribute greatly to the fonctional study on hMC-CP.

  8. A Novel Protein Is Lower Expressed in Renal Cell Carcinoma

    OpenAIRE

    Ruili Guan; Yongde Xu; Hongen Lei; Zhezhu Gao; Zhongcheng Xin; Yinglu Guo

    2014-01-01

    Engrailed-2 (EN2) has been identified as a candidate oncogene in breast cancer and prostate cancer. It is usually recognized as a mainly nuclear staining in the cells. However, recent studies showed a cytoplasmic staining occurred in prostate cancer, bladder cancer and clear cell renal cell carcinoma. The inconsistency makes us confused. To clarify the localization and expression of EN2 in renal cell carcinoma, anti-EN2 antibody (ab28731) and anti-EN2 antibody (MAB2600) were used for immunohi...

  9. Single step generation of protein arrays from DNA by cell-free expression and in situ immobilisation (PISA method)

    OpenAIRE

    He, Mingyue; Michael J. Taussig

    2001-01-01

    We describe a format for production of protein arrays termed ‘protein in situ array’ (PISA). A PISA is rapidly generated in one step directly from PCR-generated DNA fragments by cell-free protein expression and in situ immobilisation at a surface. The template for expression is DNA encoding individual proteins or domains, which is produced by PCR using primers designed from information in DNA databases. Coupled transcription and translation is carried out on a surface ...

  10. Cell-specific information processing in segregating populations of Eph receptor ephrin-expressing cells

    DEFF Research Database (Denmark)

    Jørgensen, Claus; Sherman, Andrew; Chen, Ginny I; Pasculescu, Adrian; Poliakov, Alexei; Hsiung, Marilyn; Larsen, Brett; Wilkinson, David G; Linding, Rune; Pawson, Tony

    2009-01-01

    Cells have self-organizing properties that control their behavior in complex tissues. Contact between cells expressing either B-type Eph receptors or their transmembrane ephrin ligands initiates bidirectional signals that regulate cell positioning. However, simultaneously investigating how...... information is processed in two interacting cell types remains a challenge. We implemented a proteomic strategy to systematically determine cell-specific signaling networks underlying EphB2- and ephrin-B1-controlled cell sorting. Quantitative mass spectrometric analysis of mixed populations of EphB2- and...... revealed that signaling between mixed EphB2- and ephrin-B1-expressing cells is asymmetric and that the distinct cell types use different tyrosine kinases and targets to process signals induced by cell-cell contact. We provide systems- and cell-specific network models of contact-initiated signaling between...

  11. Nestin expression in the cell lines derived from glioblastoma multiforme

    International Nuclear Information System (INIS)

    Nestin is a protein belonging to class VI of intermediate filaments that is produced in stem/progenitor cells in the mammalian CNS during development and is consecutively replaced by other intermediate filament proteins (neurofilaments, GFAP). Down-regulated nestin may be re-expressed in the adult organism under certain pathological conditions (brain injury, ischemia, inflammation, neoplastic transformation). Our work focused on a detailed study of the nestin cytoskeleton in cell lines derived from glioblastoma multiforme, because re-expression of nestin together with down-regulation of GFAP has been previously reported in this type of brain tumor. Two cell lines were derived from the tumor tissue of patients treated for glioblastoma multiforme. Nestin and other cytoskeletal proteins were visualized using imunocytochemical methods: indirect immunofluorescence and immunogold-labelling. Using epifluorescence and confocal microscopy, we described the morphology of nestin-positive intermediate filaments in glioblastoma cells of both primary cultures and the derived cell lines, as well as the reorganization of nestin during mitosis. Our most important result came through transmission electron microscopy and provided clear evidence that nestin is present in the cell nucleus. Detailed information concerning the pattern of the nestin cytoskeleton in glioblastoma cell lines and especially the demonstration of nestin in the nucleus represent an important background for further studies of nestin re-expression in relationship to tumor malignancy and invasive potential

  12. Immunglobulin Expression and Its Biological Significance in Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Duosha Hu; Hui Zheng; Haidan Liu; Ming Li; Wei Ren; Wei Liao; Zhi Duan; Lili Li; Ya Cao

    2008-01-01

    It is generally believed that the expression of a gene iS restricted "within the right place and at the right time".This principle has long been considered applicable as well to the expression of immunoglobulin(Ig)lymphocytes of B cell lineage.However,increasing evidence has shown Ig "paradoxically" expressed in malignant tumors of epitheliaI origin.We reviewed the recent progress in the study of cancer-derived Ig,and also discussed its mechanisms and possible functions,trying to arouse interest and attention to those working in the field of immunology and oncology.

  13. Expression of myeloid differentiation antigens on normal and malignant myeloid cells.

    OpenAIRE

    Griffin, J D; Ritz, J; Nadler, L M; Schlossman, S F

    1981-01-01

    A series of monoclonal antibodies have been characterized that define four surface antigens (MY3, MY4, MY7, and MY8) of human myeloid cells. They were derived from a fusion of the NS-1 plasmacytoma cell line with splenocytes from a mouse immunized with human acute myelomonocytic leukemia cells. MY3 and MY4 are expressed by normal monocytes and by greater than 90% of patients with acute monocytic leukemia or acute myelomonocytic leukemia, but are detected much less often on other types of myel...

  14. Melanoma cell expression of CD200 inhibits tumor formation and lung metastasis via inhibition of myeloid cell functions.

    Directory of Open Access Journals (Sweden)

    Fatemeh Talebian

    Full Text Available CD200 is a cell surface glycoprotein that functions through engaging CD200 receptor on cells of the myeloid lineage and inhibits their functions. Expression of CD200 has been implicated in a variety of human cancer cells including melanoma cells and has been thought to play a protumor role. To investigate the role of cancer cell expression of CD200 in tumor formation and metastasis, we generated CD200-positive and CD200-negative B16 melanoma cells. Subcutaneous injection of CD200-positive B16 melanoma cells inhibited tumor formation and growth in C57BL/6 mice but not in Rag1⁻/⁻C57BL/6 mice. However, i.v. injection of CD200-positive B16 melanoma cells dramatically inhibited tumor foci formation in the lungs of both C57BL/6 and Rag1⁻/⁻C57BL6 mice. Flow cytometry analysis revealed higher expression of CD200R in Gr1⁺ myeloid cells in the lung than in peripheral myeloid cells. Depletion of Gr1⁺ cells or stimulation of CD200R with an agonistic antibody in vivo dramatically inhibited tumor foci formation in the lungs. In addition, treatment with tumor antigen specific CD4 or CD8 T cells or their combination yielded a survival advantage for CD200 positive tumor bearing mice over mice bearing CD200-negative tumors. Taken together, we have revealed a novel role for CD200-CD200R interaction in inhibiting tumor formation and metastasis. Targeting CD200R may represent a novel approach for cancer immunotherapy.

  15. Growth hormone action in rat insulinoma cells expressing truncated growth hormone receptors

    DEFF Research Database (Denmark)

    Møldrup, Annette; Allevato, G; Dyrberg, Thomas;

    1991-01-01

    Transfection of the insulin-producing rat islet tumor cell line RIN-5AH with a full length cDNA of the rat hepatic growth hormone (GH) receptor (GH-R1-638) augments the GH-responsive insulin synthesis in these cells. Using this functional system we analyzed the effect of COOH-terminal truncation of...... the GH receptor. Two mutated cDNAs encoding truncated GH receptors, GH-R1-294 and GH-R1-454, respectively, were generated by site-directed mutagenesis and transfected into the RIN cells. Both receptor mutants were expressed on the cell surface and displayed normal GH binding affinity. Whereas GH-R1......-638 had a molecular mass of about 110 kDa, GH-R1-294 and GH-R1-454 showed molecular masses of 49 and 80 kDa, respectively. Cells expressing GH-R1-454 internalized GH to a similar extent as cells transfected with the full length receptor and the parent cell line, but GH-R1-294-expressing cells showed a...

  16. Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces

    International Nuclear Information System (INIS)

    This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants

  17. Sarcosine induces increase in HER2/neu expression in androgen-dependent prostate cancer cells

    DEFF Research Database (Denmark)

    Dahl, Malin; Bouchelouche, Pierre; Kramer-Marek, Gabriela; Capala, Jacek; Nordling, Jørgen; Bouchelouche, Kirsten

    2011-01-01

    epithelial cells. The aim of this work was to investigate the effect of sarcosine on HER2/neu expression in prostate cancer cell lines LNCaP (androgen dependent), PC-3 and DU145 (both androgen independent). Relative amounts of HER2/neu and androgen receptor (AR) transcripts were determined using RT......Increasing evidence suggests that Human epidermal growth factor receptor 2 (HER2/neu) is involved in progression of prostate cancer. Recently, sarcosine was reported to be highly increased during prostate cancer progression, and exogenous sarcosine induces an invasive phenotype in benign prostate......-qPCR. Total expression of HER2/neu was confirmed by Western blot (WB). HER2/neu protein on the surface of living LNCaP cells was visualized by confocal microscopy using a HER2/neu-specific fluorescent probe. Exposure of LNCaP cells to 50 μM sarcosine for 24 h resulted in a 58% increase of the HER2/neu m...

  18. Investigation of back surface fields effect on bifacial solar cells

    Science.gov (United States)

    Sepeai, Suhaila; Sulaiman, M. Y.; Sopian, Kamaruzzaman; Zaidi, Saleem H.

    2012-11-01

    A bifacial solar cell, in contrast with a conventional monofacial solar cell, produces photo-generated current from both front and back sides. Bifacial solar cell is an attractive candidate for enhancing photovoltaic (PV) market competitiveness as well as supporting the current efforts to increase efficiency and lower material costs. This paper reports on the fabrication of bifacial solar cells using phosphorus-oxytrichloride (POCl3) emitter formation on p-type, nanotextured silicon (Si) wafer. Backside surface field was formed through Al-diffusion using conventional screen-printing process. Bifacial solar cells with a structure of n+pp+ with and without back surface field (BSF) were fabricated in which silicon nitride (SiN) anti reflection and passivation films were coated on both sides, followed by screen printing of Argentum (Ag) and Argentum/Aluminum (Ag/Al) on front and back contacts, respectively. Bifacial solar cells without BSF exhibited open circuit voltage (VOC) of 535 mV for front and 480 mV for back surface. With Al-alloyed BSF bifacial solar cells, the VOC improved to 580 mV for the front surface and 560 mV for the back surface. Simulation of bifacial solar cells