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Sample records for cell antigen downregulation

  1. Rational antigen modification as a strategy to upregulate or downregulate antigen recognition.

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    Abrams, S I; Schlom, J

    2000-02-01

    Recent and rapid advances in our understanding of the cellular and molecular mechanisms of antigen recognition by CD8(+) and CD4(+) T lymphocytes have led to the birth of possibilities for site-directed, rational modification of cognate antigenic determinants. This immunologic concept has vast biomedical implications for regulation of host immunity against the pathogenesis of diverse disease processes. The upregulation of antigen-specific T-cell responses by 'agonistic' peptides would be most desirable in response to invasive pathogenic challenges, such as infectious and neoplastic disease, while the downregulation of antigen-specific T-cell responses by 'antagonistic' peptides would be most efficacious during inappropriate pathologic consequences, such as autoimmunity. The capacity to experimentally manipulate intrinsic properties of cognate peptide ligands to appropriately alter the nature, course and potency of cellular immune interactions has important potential in both preventive and therapeutic clinical paradigms.

  2. Down-regulation of human leukocyte antigens class I on peripheral T lymphocytes and NK cells from subjects in region of high-incidence gastrointestinal tumor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-mian; LI Ying-jie; GUAN Xiao; YANG Xiao-yun; GAO Xi-mei; YANG Xiao-jing; WANG Li-shui; ZOU Xiong

    2011-01-01

    Background Many types of human tumors can suppress the immune system to enhance their survival. Loss or down-regulation of human leukocyte antigens (HLA) class I on tumors is considered to be a major mechanism of tumor immune escape. Our previous studies found that HLA class I on peripheral-blood mononuclear cells was significantly lower in gastric cancer patients. The present study made an analysis of HLA class I expression on peripheral-blood T lymphocytes and NK cells from subjects of Lijiadian village, a village with high-incidence gastrointestinal tumor. Methods A total of 181 villagers from Lijiadian village and 153 normal controls from the Department of Health Examination Center were enrolled in this study. Using a multi-tumor markers detection system, these villagers were divided into two groups: high-risk group (tumor markers positive group) and low-risk group (tumor markers negative group). The percentage of T lymphocytes and NK cells and levels of HLA class I on their surface were determined in these subjects by flow cytometry.Results Percentages of T lymphocytes and NK cells in peripheral-blood mononuclear cells did not vary with age. The expression level of HLA class I on peripheral T lymphocytes and NK cells was not affected by age or gender, but was significantly down-regulated in Lijiadian villagers (P<0.05), especially on the surface of NK cells (P<0.01). Compared with the low-risk group, there was a significant reduction of HLA class I on peripheral T lymphocytes (P <0.05) and NK cells (P <0.05) in the high-risk group.Conclusions HLA class I on peripheral T lymphocytes and NK cells may be involved in tumorigenesis and development of gastrointestinal tumor, and understanding their changes in expression may provide new insights into the mechanism of tumor immunity.

  3. Trypanosoma cruzi down-regulates lipopolysaccharide-induced MHC class I on human dendritic cells and impairs antigen presentation to specific CD8(+) T lymphocytes.

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    Van Overtvelt, Laurence; Andrieu, Muriel; Verhasselt, Valérie; Connan, Francine; Choppin, Jeannine; Vercruysse, Vincent; Goldman, Michel; Hosmalin, Anne; Vray, Bernard

    2002-10-01

    Trypanosoma cruzi, the etiological agent of Chagas' disease, may persist for many years in its mammalian host. This suggests escape from the immune response and particularly a suboptimal CD8(+) T cell response, since these cells are involved in infection control. In this report, we show that T. cruzi inhibits the lipopolysaccharide (LPS)-induced up-regulation of MHC class I molecules at the surface of human dendritic cells (DC). To further investigate the functional consequences of this inhibition, a trypomastigote surface antigen-derived peptide (TSA-1(514-522) peptide) was selected for its stable binding to HLA-A*0201 molecules and used to generate a primary T. cruzi-specific human CD8(+) T cell line in vitro. We observed that DC infected with T. cruzi or treated with T. cruzi-conditioned medium (TCM) had a weaker capacity to present this peptide to the specific CD8(+) T cell line as shown in an IFN-gamma ELISPOT assay. Interestingly, T. cruzi or TCM also reduced the antigen presentation capacity of DC to CD8(+) T cell lines specific for the influenza virus M(58-66) or HIV RT(476-484) epitopes. This dysfunction appears to be linked essentially to reduced MHC class I molecule expression since the stimulation of the RT(476-484) peptide-specific CD8(+) T cell line was shown to depend mainly on the MHC class I-TCR interaction and not on the co-stimulatory signals which, however, were also inhibited by T. cruzi. This impairment of DC function may represent a novel mechanism reducing in vivo the host's ability to combat efficiently T. cruzi infection.

  4. Effect of BSA Antigen Sensitization during the Acute Phase of Influenza A Viral Infection on CD11c+ Pulmonary Antigen Presenting Cells

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    Fumitaka Sato

    2009-01-01

    Conclusions: BSA antigen sensitization during the acute phase of influenza A viral infection enhanced IL-10 production from naive CD4+ T cell interaction with CD11c+ pulmonary APCs. The IL-10 secretion evoked Th2 responses in the lungs with downregulation of Th1 responses and was important for the eosinophil recruitment into the lungs after BSA antigen challenge.

  5. Antigen-specific memory B cell development.

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    McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

    2005-01-01

    Helper T (Th) cell-regulated B cell immunity progresses in an ordered cascade of cellular development that culminates in the production of antigen-specific memory B cells. The recognition of peptide MHC class II complexes on activated antigen-presenting cells is critical for effective Th cell selection, clonal expansion, and effector Th cell function development (Phase I). Cognate effector Th cell-B cell interactions then promote the development of either short-lived plasma cells (PCs) or germinal centers (GCs) (Phase II). These GCs expand, diversify, and select high-affinity variants of antigen-specific B cells for entry into the long-lived memory B cell compartment (Phase III). Upon antigen rechallenge, memory B cells rapidly expand and differentiate into PCs under the cognate control of memory Th cells (Phase IV). We review the cellular and molecular regulators of this dynamic process with emphasis on the multiple memory B cell fates that develop in vivo.

  6. Downregulated stromal antigen 2 expression in de novo acute myeloid leukemia patients

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    Han, Qiaoyan; He, Xuefeng; Wu, Lili; Gao, Feng; Ye, Jinsong; Wu, Lingyu; Chen, Lu; Jiang, Xin; Sun, Miao; Chen, Suning

    2017-01-01

    The stromal antigen 2 (STAG2) gene encodes a component of the cohesin complex that participates in the regulation of sister chromatid separation during mitosis. When activated, STAG2 may act as a ‘caretaker’ tumor suppressor gene. As it is unknown whether STAG2 gene is responsible for the occurrence and associated with the prognosis of acute myeloid leukemia (AML), the present study analyzed the relative expression levels of STAG2 in 127 de novo AML patients and 17 healthy volunteers using reverse transcription-quantitative polymerase chain reaction. In addition, AML patients were divided into three risk groups using cytogenetic and molecular genetic abnormalities to define their risk status. STAG2 gene expression was found to be significantly downregulated in de novo AML patients, when compared with the healthy controls; however, the expression was not significantly different in the various gender and age subgroups. Furthermore, no significant difference between risk groups was detected in AML patients. Thus, the STAG2 gene may serve an important role in AML development, but is not associated with prognosis in AML.

  7. The anaphylatoxin C3a downregulates the Th2 response to epicutaneously introduced antigen.

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    Kawamoto, Seiji; Yalcindag, Ali; Laouini, Dhafer; Brodeur, Scott; Bryce, Paul; Lu, Bao; Humbles, Alison A; Oettgen, Hans; Gerard, Craig; Geha, Raif S

    2004-08-01

    Mechanical injury to the skin results in activation of the complement component C3 and release of the anaphylatoxin C3a. C3a binds to a seven-transmembrane G protein-coupled receptor, C3aR. We used C3aR(-/-) mice to examine the role of C3a in a mouse model of allergic inflammation induced by epicutaneous sensitization with OVA. C3aR(-/-) mice exhibited an exaggerated Th2 response to epicutaneous but not to intraperitoneal sensitization with OVA, as evidenced by significantly elevated levels of serum OVA-specific IgG1 and significantly increased secretion of the Th2 cytokines IL-4, IL-5, and IL-10 by antigen-stimulated splenocytes. Presentation of OVA peptide by C3aR(-/-) APCs caused significantly more IL-4 and IL-5 secretion by T cells from OVA-T cell receptor (OVA-TCR) transgenic mice compared with presentation by WT APCs. C3a inhibited the ability of splenocytes, but not of highly purified T cells, to secrete Th2 cytokines in response to TCR ligation. This inhibition was mediated by IL-12 secreted by APCs in response to C3a. These results suggest that C3a-C3aR interactions inhibit the ability of APCs to drive Th2 cell differentiation in response to epicutaneously introduced antigen and may have important implications for allergic skin diseases.

  8. Presentation of antigen by B cells subsets. Pt. 2. The role of CD5 B cells in the presentation of antigen to antigen-specific T cells

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    Zimecki, Michal [Polish Academy of Sciences, Wroclaw (Poland). Institute of Immunology and Experimental Therapy; Kapp, Judith A. [Emory Univ., Atlanta, GA (United States). School of Medicine

    1994-12-31

    We demonstrate that peritoneal B cells have a much higher ability to present antigen to antigen-specific T cell lines splenic B cells. Presentation of antigen by B cells is abrogated or drastically reduced after removal of Lyb-5{sup +} cells from the population of splenic or peritoneal B cells. Peritoneal B cells, precultured for 7 days prior to the antigen presentation assay, retain their antigen presenting cell (APC) function. Enrichment for CD5{sup +} cells in the peritoneal B cell population results in a more effective antigen presentation. Lastly, stimulation of B cells via CD5 antigen, by treatment of cells with anti-CD5 antibodies or cross-linking of CD5 receptors, enhances APC function of these cells. The results indicate, both indirectly and directly, that CD5{sup +} B cells play a predominant role in the presentation of conventional antigens to antigen-specific T cells. (author). 30 refs, 6 tabs.

  9. Antigen Export Reduces Antigen Presentation and Limits T Cell Control of M. tuberculosis.

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    Srivastava, Smita; Grace, Patricia S; Ernst, Joel D

    2016-01-13

    Persistence of Mycobacterium tuberculosis results from bacterial strategies that manipulate host adaptive immune responses. Infected dendritic cells (DCs) transport M. tuberculosis to local lymph nodes but activate CD4 T cells poorly, suggesting bacterial manipulation of antigen presentation. However, M. tuberculosis antigens are also exported from infected DCs and taken up and presented by uninfected DCs, possibly overcoming this blockade of antigen presentation by infected cells. Here we show that the first stage of this antigen transfer, antigen export, benefits M. tuberculosis by diverting bacterial proteins from the antigen presentation pathway. Kinesin-2 is required for antigen export and depletion of this microtubule-based motor increases activation of antigen-specific CD4 T cells by infected cells and improves control of intracellular infection. Thus, although antigen transfer enables presentation by bystander cells, it does not compensate for reduced antigen presentation by infected cells and represents a bacterial strategy for CD4 T cell evasion.

  10. Antigen presentation by MHC-dressed cells

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    Masafumi eNakayama

    2015-01-01

    Full Text Available Professional antigen presenting cells (APCs such as conventional dendritic cells (DCs process protein antigens to MHC-bound peptides and then present the peptide-MHC complexes to T cells. In addition to this canonical antigen presentation pathway, recent studies have revealed that DCs and non-APCs can acquire MHC class I (MHCI and/or MHC class II (MHCII from neighboring cells through a process of cell-cell contact-dependent membrane transfer called trogocytosis. These MHC-dressed cells subsequently activate or regulate T cells via the preformed antigen peptide-MHC complexes without requiring any further processing. In addition to trogocytosis, intercellular transfer of MHCI and MHCII can be mediated by secretion of membrane vesicles such as exosomes from APCs, generating MHC-dressed cells. This review focuses on the physiological role of antigen presentation by MHCI- or MHCII-dressed cells, and also discusses differences and similarities between trogocytosis and exosome-mediated transfer of MHC.

  11. 前列腺癌抗原1蛋白表达下调对前列腺癌LNCaP细胞恶性生物学行为的影响%Effect of downregulation of prostate cancer antigen-1 expression on malignant biological behavior of prostate cancer LNCaP cells

    Institute of Scientific and Technical Information of China (English)

    刘秉乾; 王义昆; 武玉东; 魏金星; 李鑫

    2013-01-01

    Objective To detect the expression of prostate cancer antigen-1 (PCA-1) in prostate cancer,and to analyze the effects of downregulation of PCA-1 expression on malignant biological behavior of prostate cancer LNCaP cells,and to explore their possible molecular mechanisms.Methods PCA-1-siRNA and control siRNA were transfected into LNCaP cells with lipofectamine 2000.The cell cycle,proliferation and migration were determined by methyl thiazolyl tetrazolium (MTT) assay,flow cytometry and Transwell chambers,respectively.Western blotting was used to detect the expression of cyclin E,matrix metallopeptidase 9 (MMP-9)and p21.Immunohistochemistry was used to detect the expression of PCA-1 protein in 126 cases of prostate cancer and 88 cases of benign prostatic hyperplasia (BPH).Results The positive rate of PCA-1 expression was 77.8% (98/126) in prostate cancer,and 10.2% (9/88)in BPH,and its expression was not significantly related to age,prostate specific antigen (PSA),Eastern Cooperative Oncology Group (ECOG) score (P > 0.05),and was associated with Gleason score,TNM staging and bone metastasis (P < 0.05).Downregulation of PCA-1 expression inhibited cell proliferation,arrested cell cycle at S phase and decreased cell migration of LNCaP cells.The downregulation of PCA-1 expression decreased the expression of Bcl-xl,cyclin E and MMP-9 proteins,but increased the expression of p21 proteins.Conclusions PCA-1 may play an important role in the development of prostate cancer.The downregulation of PCA-1 expression can lead to changes in the proliferation,cell cycle and migration of prostate cancer LNCaP cells,and these effects may be associated with the decrease of Bcl-xl,cyclin E and MMP-9 proteins and increase of p21 protein.%目的 探讨前列腺癌抗原1(PCA-1)蛋白表达下调对前列腺癌LNCaP细胞增殖、细胞周期分布和细胞侵袭能力的影响,及其可能的分子机制.方法 将PCA-1-siRNA和对照siRNA转染前列腺癌LNCaP细胞,采用四甲基

  12. Harnessing Dendritic Cells for Tumor Antigen Presentation

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    Nierkens, Stefan [Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, Nijmegen 6525 GA (Netherlands); Janssen, Edith M., E-mail: edith.janssen@cchmc.org [Division of Molecular Immunology, Cincinnati Children' s Hospital Research Foundation, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States)

    2011-04-26

    Dendritic cells (DC) are professional antigen presenting cells that are crucial for the induction of anti-tumor T cell responses. As a consequence, research has focused on the harnessing of DCs for therapeutic interventions. Although current strategies employing ex vivo-generated and tumor-antigen loaded DCs have been proven feasible, there are still many obstacles to overcome in order to improve clinical trial successes and offset the cost and complexity of customized cell therapy. This review focuses on one of these obstacles and a pivotal step for the priming of tumor-specific CD8{sup +} and CD4{sup +} T cells; the in vitro loading of DCs with tumor antigens.

  13. HIPK2 downregulates vimentin and inhibits breast cancer cell invasion.

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    Nodale, Cristina; Sheffer, Michal; Jacob-Hirsch, Jasmine; Folgiero, Valentina; Falcioni, Rita; Aiello, Aurora; Garufi, Alessia; Rechavi, Gideon; Givol, David; D'Orazi, Gabriella

    2012-02-15

    Vimentin, a mesenchymal marker, is frequently overexpressed in epithelial carcinomas undergoing epithelial to mesenchymal transition (EMT), a condition correlated with invasiveness and poor prognosis. Therefore, vimentin is a potential molecular target for anticancer therapy. Emerging studies in experimental models underscore the functions of homeodomain-interacting protein kinase 2 (HIPK2) as potential oncosuppressor by acting as transcriptional corepressor or catalytic activator of molecules involved in apoptosis and response to antitumor drugs. However, an involvement of HIPK2 in limiting tumor invasion remains to be elucidated. This study, by starting with a microarray analysis, demonstrates that HIPK2 downregulates vimentin expression in invasive, vimentin-positive, MDA-MB-231 breast cancer cells and in the non-invasive MCF7 breast cancer cells subjected to chemical hypoxia, a drive for mesenchymal shift and tumor invasion. At functional level, vimentin downregulation by HIPK2 correlates with inhibition of breast tumor cell invasion. Together, these data show that vimentin is a novel target for HIPK2 repressor function and that HIPK2-mediated vimentin downregulation can contribute to inhibition of breast cancer cells invasion that might be applied in clinical therapy.

  14. Chemokine programming dendritic cell antigen response: part I - select chemokine programming of antigen uptake even after maturation.

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    Park, Jaehyung; Wu, Cindy T; Bryers, James D

    2013-05-01

    Here, we report on the successful programming of dendritic cells (DCs) using selectively applied mixtures of chemokines as a novel protocol for engineering vaccine efficiency. Antigen internalization by DCs is a pivotal step in antigen uptake/presentation for bridging innate and adaptive immunity and in exogenous gene delivery used in vaccine strategies. Contrary to most approaches to improve vaccine efficiency, active enhancement of antigen internalization by DCs as a vaccine strategy has been less studied because DCs naturally down-regulate antigen internalization upon maturation. Whereas chemokines are mainly known as signal proteins that induce leucocyte chemotaxis, very little research has been carried out to identify any additional effects of chemokines on DCs following maturation. Here, immature DCs are pre-treated with select chemokines before intentional maturation using lipopolysaccharide (LPS). When pre-treated with a mixture of CCL3 and CCL19 in a 7 : 3 ratio, then matured with LPS, chemokine pre-treated DCs exhibited 36% higher antigen uptake capacity than immature DCs and 27% higher antigen-processing capacity than immature DCs treated only with LPS. Further, CCL3 : CCL19 (7 : 3) pre-treatment of DCs modulated MHC molecule expression and secretion of various cytokines of DCs. Collectively, DC programming was feasible using a specific chemokine combination and these results provide a novel strategy for enhancing DC-based vaccine efficiency. In Part II, we report on the phenotype changes and antigen presentation capacity of chemokine pre-treated murine bone marrow-derived DCs examined in long-term co-culture with antigen-specific CD4(+) T cells.

  15. The Antigen Presenting Cells Instruct Plasma Cell Differentiation

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    Wei eXu

    2014-01-01

    Full Text Available The professional antigen presenting cells (APCs, including many subsets of dendritic cells and macrophages, not only mediate prompt but nonspecific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells, which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only signal 1 (the antigen, but also signal 2 to directly instruct the differentiation process of plasma cells in a T cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  16. ARSENIC TRIOXIDE DOWNREGULATES TELOMERASE ACTIVITY IN HL-60 CELLS

    Institute of Scientific and Technical Information of China (English)

    何冬梅; 张洹

    2002-01-01

    Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: Apoptosis was detected by morphological observation and flow cytomertric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label, respectively. Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Results: Treatment of 2 μmol/L at As2O3 could induce apoptosis of HL-60 cells. hTERT was decreased at both mRNA and protein levels during apoptosis of HL-60 cells. Telomerase activity of HL-60 cells was significantly inhibited. Conclusion:It is suggested that telomerase activity of HL-60 cells might be specifically inhibited by AS2O3 through the downregulation of hTERT gene expression.

  17. Antisense downregulation of mutant huntingtin in a cell model

    DEFF Research Database (Denmark)

    Hasholt, L.; Abell, K.; Norremolle, A.;

    2003-01-01

    of specific neurons in the brains of HD patients correlate with the expression of mutant huntingtin. Therefore, we have studied whether mutant huntingtin expression can be downregulated by antisense technique. Methods NT2 precursor cells and differentiated postmitotic NT2-N neurons, respectively, were...... transfected with plasmid constructs containing exon 1 of the HD gene with expanded CAG repeats in frame with the reporter protein EGFP. The transfected cell cultures were treated with a phosphorothioated antisense oligonucleotide (PS-ASHD/20+) or a control oligonucleotide either by cotransfection...... or by addition to the culture medium. Results Expression of the fusion protein containing the mutant huntingtin fragment resulted in diffuse green fluorescence in the cytoplasm and formation of aggregates in some of the NT2 cells and NT2-N neurons. We obtained antisense sequence-specific inhibition of expression...

  18. TCR down-regulation controls T cell homeostasis

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    Boding, Lasse; Bonefeld, Charlotte Menné; Nielsen, Bodil L

    2009-01-01

    TCR and cytokine receptor signaling play key roles in the complex homeostatic mechanisms that maintain a relative stable number of T cells throughout life. Despite the homeostatic mechanisms, a slow decline in naive T cells is typically observed with age. The CD3gamma di-leucine-based motif...... controls TCR down-regulation and plays a central role in fine-tuning TCR expression and signaling in T cells. In this study, we show that the age-associated decline of naive T cells is strongly accelerated in CD3gammaLLAA knock-in mice homozygous for a double leucine to alanine mutation in the CD3gamma di......-leucine-based motif, whereas the number of memory T cells is unaffected by the mutation. This results in premature T cell population senescence with a severe dominance of memory T cells and very few naive T cells in middle-aged to old CD3gamma mutant mice. The reduced number of naive T cells in CD3gamma mutant mice...

  19. Endothelial cells downregulate apolipoprotein D expression in mural cells through paracrine secretion and Notch signaling.

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    Pajaniappan, Mohanasundari; Glober, Nancy K; Kennard, Simone; Liu, Hua; Zhao, Ning; Lilly, Brenda

    2011-09-01

    Endothelial and mural cell interactions are vitally important for proper formation and function of blood vessels. These two cell types communicate to regulate multiple aspects of vessel function. In studying genes regulated by this interaction, we identified apolipoprotein D (APOD) as one gene that is downregulated in mural cells by coculture with endothelial cells. APOD is a secreted glycoprotein that has been implicated in governing stress response, lipid metabolism, and aging. Moreover, APOD is known to regulate smooth muscle cells and is found in abundance within atherosclerotic lesions. Our data show that the regulation of APOD in mural cells is bimodal. Paracrine secretion by endothelial cells causes partial downregulation of APOD expression. Additionally, cell contact-dependent Notch signaling plays a role. NOTCH3 on mural cells promotes the downregulation of APOD, possibly through interaction with the JAGGED-1 ligand on endothelial cells. Our results show that NOTCH3 contributes to the downregulation of APOD and by itself is sufficient to attenuate APOD transcript expression. In examining the consequence of decreased APOD expression in mural cells, we show that APOD negatively regulates cell adhesion. APOD attenuates adhesion by reducing focal contacts; however, it has no effect on stress fiber formation. These data reveal a novel mechanism in which endothelial cells control neighboring mural cells through the downregulation of APOD, which, in turn, influences mural cell function by modulating adhesion.

  20. Monocyte human leukocyte antigen-DR transcriptional downregulation by cortisol during septic shock.

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    Le Tulzo, Yves; Pangault, Celine; Amiot, Laurence; Guilloux, Valérie; Tribut, Olivier; Arvieux, Cédric; Camus, Christophe; Fauchet, Renée; Thomas, Rémi; Drénou, Bernard

    2004-05-15

    Monocyte deactivation has been identified as a major factor of immunosuppression in sepsis and is associated with a loss of surface human leukocyte antigen-DR (HLA-DR) expression on circulating monocytes. Using flow cytometry, quantitative reverse transcription-polymerase chain reaction, we investigated this phenomenon in septic patients. We confirmed the early loss of monocyte HLA-DR expression in all infected patients and demonstrated that this persistent lowered expression at Day 6 correlated with severity scores, secondary infection, and death. This phenomenon occurred at a transcriptional level via a decrease in the class II transactivator A (CIITA) transcription. Furthermore, these abnormalities correlated with the high cortisol levels observed in sepsis and not with those of other putative factors such as catecholamines or interleukin-10. Finally, in vitro studies evidenced that glucocorticoids decrease HLA-DR expression at a transcriptional level via a decrease in CIITA mRNA levels, mainly by down modulating its isoforms I and III. We conclude that in human sepsis, the loss of HLA-DR expression on circulating monocytes is associated with a poor outcome. We suggest that the high endogenous cortisol level observed in septic shock may be a possible new factor involved in the loss of HLA-DR expression on monocytes via its effect on HLA-DR and CIITA transcription.

  1. Antigen presentation for priming T cells in central system.

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    Dasgupta, Shaoni; Dasgupta, Subhajit

    2017-01-01

    Generation of myelin antigen-specific T cells is a major event in neuroimmune responses that causes demyelination. The antigen-priming of T cells and its location is important in chronic and acute inflammation. In autoimmune multiple sclerosis, the effector T cells are considered to generate in periphery. However, the reasons for chronic relapsing-remitting events are obscure. Considering mechanisms, a feasible aim of research is to investigate the role of antigen-primed T cells in lupus cerebritis. Last thirty years of investigations emphasize the relevance of microglia and infiltrated dendritic cells/macrophages as antigen presenting cells in the central nervous system. The recent approach towards circulating B-lymphocytes is an important area in the context. Here, we analyze the existing findings on antigen presentation in the central nervous system. The aim is to visualize signaling events of myelin antigen presentation to T cells and lead to the strategy of future goals on immunotherapy research.

  2. IL-10 downregulates CXCR3 expression on Th1 cells and interferes with their migration to intestinal inflammatory sites.

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    Wadwa, M; Klopfleisch, R; Adamczyk, A; Frede, A; Pastille, E; Mahnke, K; Hansen, W; Geffers, R; Lang, K S; Buer, J; Büning, J; Westendorf, A M

    2016-09-01

    Inflammatory bowel disease (IBD) is characterized by chronic, uncontrolled inflammation in the intestinal mucosa. Although the etiology is poorly understood, it is widely accepted that loss of tolerance is involved in the development of IBD. Therefore, re-establishing tolerance or gut homeostasis is one of the key features in the development of new therapeutic strategies. Here we show that antigen targeting to DEC-205 on dendritic cells leads to an interleukin (IL)-10-dependent downregulation of C-X-C chemokine receptor 3 (CXCR3) expression on differentiated antigen-specific T helper type 1 (Th1) cells in vivo. This downregulation interferes with the migration of Th1 cells into the gut and protects mice against severe acute and relapsing intestinal inflammation. Moreover, CD4(+)CXCR3(+) T cells are highly enriched in the inflamed mucosa of IBD patients. Interference with this pathway may therefore be a promising approach for the treatment of IBD. In conclusion, we propose a hitherto undescribed mechanism by which IL-10 can act on effector T cells and orchestrate intestinal immune responses.

  3. Neural Crest Cells Isolated from the Bone Marrow of Transgenic Mice Express JCV T-Antigen.

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    Jennifer Gordon

    Full Text Available JC virus (JCV, a common human polyomavirus, is the etiological agent of the demyelinating disease, progressive multifocal leukoencephalopathy (PML. In addition to its role in PML, studies have demonstrated the transforming ability of the JCV early protein, T-antigen, and its association with some human cancers. JCV infection occurs in childhood and latent virus is thought to be maintained within the bone marrow, which harbors cells of hematopoietic and non-hematopoietic lineages. Here we show that non-hematopoietic mesenchymal stem cells (MSCs isolated from the bone marrow of JCV T-antigen transgenic mice give rise to JCV T-antigen positive cells when cultured under neural conditions. JCV T-antigen positive cells exhibited neural crest characteristics and demonstrated p75, SOX-10 and nestin positivity. When cultured in conditions typical for mesenchymal cells, a population of T-antigen negative cells, which did not express neural crest markers arose from the MSCs. JCV T-antigen positive cells could be cultured long-term while maintaining their neural crest characteristics. When these cells were induced to differentiate into neural crest derivatives, JCV T-antigen was downregulated in cells differentiating into bone and maintained in glial cells expressing GFAP and S100. We conclude that JCV T-antigen can be stably expressed within a fraction of bone marrow cells differentiating along the neural crest/glial lineage when cultured in vitro. These findings identify a cell population within the bone marrow permissible for JCV early gene expression suggesting the possibility that these cells could support persistent viral infection and thus provide clues toward understanding the role of the bone marrow in JCV latency and reactivation. Further, our data provides an excellent experimental model system for studying the cell-type specificity of JCV T-antigen expression, the role of bone marrow-derived stem cells in the pathogenesis of JCV-related diseases

  4. Interleukin 10 (IL-10)-mediated Immunosuppression: MARCH-I INDUCTION REGULATES ANTIGEN PRESENTATION BY MACROPHAGES BUT NOT DENDRITIC CELLS.

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    Mittal, Sharad K; Cho, Kyung-Jin; Ishido, Satoshi; Roche, Paul A

    2015-11-06

    Efficient immune responses require regulated antigen presentation to CD4 T cells. IL-10 inhibits the ability of dendritic cells (DCs) and macrophages to stimulate antigen-specific CD4 T cells; however, the mechanisms by which IL-10 suppresses antigen presentation remain poorly understood. We now report that IL-10 stimulates expression of the E3 ubiquitin ligase March-I in activated macrophages, thereby down-regulating MHC-II, CD86, and antigen presentation to CD4 T cells. By contrast, IL-10 does not stimulate March-I expression in DCs, does not suppress MHC-II or CD86 expression on either resting or activated DCs, and does not affect antigen presentation by activated DCs. IL-10 does, however, inhibit the process of DC activation itself, thereby reducing the efficiency of antigen presentation in a March-I-independent manner. Thus, IL-10 suppression of antigen presenting cell function in macrophages is March-I-dependent, whereas in DCs, suppression is March- I-independent.

  5. Antigen specificity of invariant natural killer T-cells

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    Alysia M. Birkholz

    2015-12-01

    Full Text Available Natural killer T-cells, with an invariant T-cell antigen receptor α-chain (iNKT cells, are unique and conserved subset of lymphocytes capable of altering the immune system through their rapid and potent cytokine responses. They are reactive to lipid antigens presented by the CD1d molecule, an antigen-presenting molecule that is not highly polymorphic. iNKT cell responses frequently involve mixtures of cytokines that work against each other, and therefore attempts are underway to develop synthetic antigens that elicit only strong interferon-gamma (IFNγ or only strong interleukin-4 responses but not both. Strong IFNγ responses may correlate with tighter binding to CD1d and prolonged stimulation of iNKT cells, and this may be useful for vaccine adjuvants and for stimulating anti-tumor responses. iNKT cells are self-reactive although the structure of the endogenous antigen is controversial. By contrast, bacterial and fungal lipids that engage the T-cell receptor and activate IFNγ from iNKT cells have been identified from both pathogenic and commensal organisms and the responses are in some cases highly protective from pathogens in mice. It is possible that the expanding knowledge of iNKT cell antigens and iNKT cell activation will provide the basis for therapies for patients suffering from infectious and immune diseases and cancer.

  6. Antigen specificity of invariant natural killer T-cells.

    Science.gov (United States)

    Birkholz, Alysia M; Kronenberg, Mitchell

    2015-12-01

    Natural killer T-cells, with an invariant T-cell antigen receptor α-chain (iNKT cells), are unique and conserved subset of lymphocytes capable of altering the immune system through their rapid and potent cytokine responses. They are reactive to lipid antigens presented by the CD1d molecule, an antigen-presenting molecule that is not highly polymorphic. iNKT cell responses frequently involve mixtures of cytokines that work against each other, and therefore attempts are underway to develop synthetic antigens that elicit only strong interferon-gamma (IFNγ) or only strong interleukin-4 responses but not both. Strong IFNγ responses may correlate with tighter binding to CD1d and prolonged stimulation of iNKT cells, and this may be useful for vaccine adjuvants and for stimulating anti-tumor responses. iNKT cells are self-reactive although the structure of the endogenous antigen is controversial. By contrast, bacterial and fungal lipids that engage the T-cell receptor and activate IFNγ from iNKT cells have been identified from both pathogenic and commensal organisms and the responses are in some cases highly protective from pathogens in mice. It is possible that the expanding knowledge of iNKT cell antigens and iNKT cell activation will provide the basis for therapies for patients suffering from infectious and immune diseases and cancer.

  7. Fibroblasts as Efficient Antigen-Presenting Cells in Lymphoid Organs

    Science.gov (United States)

    Kundig, Thomas M.; Bachmann, Martin F.; Dipaolo, Claudio; Simard, John J. L.; Battegay, Manuel; Lother, Heinz; Gessner, Andre; Kuhlcke, Klaus; Ohashi, Pamela S.; Hengartner, Hans; Zinkernagel, Rolf M.

    1995-06-01

    Only so-called "professional" antigen-presenting cells (APCs) of hematopoietic origin are believed capable of inducing T lymphocyte responses. However, fibroblasts transfected with viral proteins directly induced antiviral cytotoxic T lymphocyte responses in vivo, without involvement of host APCs. Fibroblasts induced T cells only in the milieu of lymphoid organs. Thus, antigen localization affects self-nonself discrimination and cell-based vaccine strategies.

  8. Responses of synovial fluid and peripheral blood mononuclear cells to bacterial antigens and autologous antigen presenting cells.

    Science.gov (United States)

    Klasen, I S; Melief, M J; Swaak, T J; Severijnen, A J; Hazenberg, M P

    1993-01-01

    The specificity of T cells in the inflamed joints of patients with rheumatoid arthritis (RA) has been the subject of much study. Bacterial antigens are suspect in the aetiology of rheumatic diseases. The responsiveness of the mononuclear cell fraction of peripheral blood and synovial fluid of patients with RA and of patients with rheumatic diseases other than RA to bacterial antigens such as cell wall fragments of the anaerobic intestinal flora, cell wall fragments of Streptococcus pyogenes, intestinal flora derived peptidoglycan polysaccharide complexes, the 65 kilodalton protein of Mycobacterium tuberculosis, and muramyldipeptide was investigated. No significant difference in response was found to all these bacterial antigens in the synovial fluid of patients with RA compared with the responses in patients with other rheumatic diseases. The highest responsiveness in the synovial fluid of the patients with RA was to the streptococcal cell wall fragments and to the 65 kilodalton protein. Higher responses to several bacterial antigens in the synovial fluid of patients with RA were found compared with peripheral blood from the same patient group. The antigen presenting cell population of the synovial fluid in patients with RA and the patients with other rheumatic diseases was found to be stimulatory for autologous peripheral blood T cells even in the absence of antigen. This suggests an important role for the synovial antigen presenting cell in the aetiology of inflammatory joint diseases. PMID:8447692

  9. Cryptococcus neoformans activates bone marrow-derived conventional dendritic cells rather than plasmacytoid dendritic cells and down-regulates macrophages.

    Science.gov (United States)

    Siegemund, Sabine; Alber, Gottfried

    2008-04-01

    Induction of IL-12 and IL-23 is essential for protective immunity against Cryptococcusneoformans. The contribution of dendritic cells vs. macrophages to IL-12/23 production in response to C. neoformans infection is unclear. Activation of conventional bone marrow-derived dendritic cells (BMDC), plasmacytoid BMDC, and bone marrow-derived macrophages (BMMPhi) was assessed by analyzing cytokine responses and the expression of MHC-II, CD86, and CD80 in each cell type. Cryptococcus neoformans induced the release of IL-12/23p40 by BMDC, but not by BMMPhi, in a TLR2- and TLR4-independent but MyD88-dependent manner. Conventional BMDC rather than plasmacytoid BMDC up-regulated MHC-II and CD86, while BMMPhi down-regulated MHC-II and CD86 in response to C. neoformans. The up-regulation of MHC-II and CD86 on BMDC required MyD88. Our data point to conventional DC as critical IL-12/23-producing antigen-presenting cells during cryptococcosis.

  10. Antigen loading on dendritic cells affects the lell function in stimulating T cells.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the effect of antigen loading on dendritic cells (DC). Methods: DCs collected from peripheral blood monocytes were loaded with a tumor antigen from XG-7 cell line. These DCs were then co-cultured with allogeneic T cells and were compared with those DCs without antigen exposure.

  11. Immunological and clinical significance of HLA class I antigen processing machinery component defects in malignant cells

    Science.gov (United States)

    Concha-Benavente, Fernando; Srivastava, Raghvendra; Ferrone, Soldano; Ferris, Robert L.

    2017-01-01

    Experimental as well as clinical studies demonstrate that the immune system plays a major role in controlling generation and progression of tumors. The cancer immunoediting theory supports the notion that tumor cell immunogenicity is dynamically shaped by the immune system, as it eliminates immunogenic tumor cells in the early stage of the disease and then edits their antigenicity. The end result is the generation of a tumor cell population able to escape from immune recognition and elimination by tumor infiltrating lymphocytes. Two major mechanisms, which affect the target cells and the effector phase of the immune response, play a crucial role in the editing process. One is represented by the downregulation of tumor antigen (TA) processing and presentation because of abnormalities in the HLA class I antigen processing machinery (APM). The other one is represented by the anergy of effector immune infiltrates in the tumor microenvironment caused by aberrant inhibitory signals triggered by immune checkpoint receptor (ICR) ligands, such as programmed death ligand-1 (PD-L1). In this review, we will focus on tumor immune escape mechanisms caused by defects in HLA class I APM component expression and/or function in different types of cancer, with emphasis on head and neck cancer (HNC). We will also discuss the immunological implications and clinical relevance of these HLA class I APM abnormalities. Finally, we will describe strategies to counteract defective TA presentation with the expectation that they will enhance tumor recognition and elimination by tumor infiltrating effector T cells. PMID:27264839

  12. Antioxidants Abrogate Alpha-Tocopherylquinone-Mediated Down-Regulation of the Androgen Receptor in Androgen-Responsive Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Alexandra M Fajardo

    Full Text Available Tocopherylquinone (TQ, the oxidation product of alpha-tocopherol (AT, is a bioactive molecule with distinct properties from AT. In this study, AT and TQ are investigated for their comparative effects on growth and androgenic activity in prostate cancer cells. TQ potently inhibited the growth of androgen-responsive prostate cancer cell lines (e.g., LAPC4 and LNCaP cells, whereas the growth of androgen-independent prostate cancer cells (e.g., DU145 cells was not affected by TQ. Due to the growth inhibitory effects induced by TQ on androgen-responsive cells, the anti-androgenic properties of TQ were examined. TQ inhibited the androgen-induced activation of an androgen-responsive reporter and inhibited the release of prostate specific antigen from LNCaP cells. TQ pretreatment was also found to inhibit AR activation as measured using the Multifunctional Androgen Receptor Screening assay. Furthermore, TQ decreased androgen-responsive gene expression, including TM4SF1, KLK2, and PSA over 5-fold, whereas AT did not affect the expression of androgen-responsive genes. Of importance, the antiandrogenic effects of TQ on prostate cancer cells were found to result from androgen receptor protein down-regulation produced by TQ that was not observed with AT treatment. Moreover, none of the androgenic endpoints assessed were affected by AT. The down-regulation of androgen receptor protein by TQ was abrogated by co-treatment with antioxidants. Overall, the biological actions of TQ were found to be distinct from AT, where TQ was found to be a potent inhibitor of cell growth and androgenic activity in androgen-responsive prostate cancer cells.

  13. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    DEFF Research Database (Denmark)

    Werdelin, O; Mouritsen, S; Petersen, B L;

    1988-01-01

    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic ...

  14. Photoaffinity antigens for human γδ T cells1

    Science.gov (United States)

    Sarikonda, Ghanashyam; Wang, Hong; Puan, Kia-Joo; Liu, Xiao-hui; Lee, Hoi K.; Song, Yongcheng; Distefano, Mark D.; Oldfield, Eric; Prestwich, Glenn D.; Morita, Craig T.

    2009-01-01

    Vγ2Vδ2 T cells comprise the major subset of peripheral blood γ δ T cells in humans and expand during infections by recognizing small, nonpeptide prenyl pyrophosphates. These molecules include (E)-4-hydroxy-3-methyl-but-2-enyl-pyrophosphate (HMBPP), a microbial isoprenoid intermediate, and isopentenyl pyrophosphate (IPP), an endogenous isoprenoid intermediate. Recognition of these nonpeptide antigens is mediated by the Vγ2Vδ2 T cell antigen receptor (TCR). Several findings suggest that prenyl pyrophosphates are presented by an antigen presenting molecule: contact between T cells and APCs is required; the antigens do not bind the Vγ2Vδ2 TCR directly; and antigen recognition is abrogated by TCR mutations in CDRs distant from the putative antigen recognition site. Identification of the putative antigen presenting molecule, however, has been hindered by the inability to achieve stable association of nonpeptide prenyl pyrophosphate antigens with the presenting molecule. In this study, we show that photoaffinity analogs of HMBPP, meta/para-benzophenone-(methylene)-prenyl pyrophosphates (m/p-BZ-(C)-C5-OPP), can cross-link to the surface of tumor cell lines and be presented as antigens to γ δ T cells. Mutant tumor cell lines lacking MHC class I, MHC class II, β2-microglobulin, and CD1, as well as tumor cell lines from a variety of tissues and individuals, will all crosslink to and present m-BZ-C5-OPP. Finally, pulsing of BZ-(C)-C5-OPP is inhibited by IPP and an inactive analog, suggesting that they bind to the same molecule. Taken together, these results suggest that nonpeptide antigens are presented by a novel antigen presenting molecule that is widely distributed, non-polymorphic, but not classical MHC class I, MHC class II, or CD1. This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript

  15. Antigen-presenting cells in human cutaneous leishmaniasis due to Leishmania major

    DEFF Research Database (Denmark)

    ElHassan, A M; Gaafar, A; Theander, T G

    1995-01-01

    , identified morphologically and by their expression of specific cell markers, included Langerhans cells, macrophages, follicular dendritic cells, and interdigitating reticulum cells of the paracortex of lymph nodes. These cells expressed MHC class II antigens and contained Leishmania antigen. Since some...

  16. Analysis of cell surface antigens by Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanovic, I.; Schasfoort, R.B.M.; Terstappen, L.W.M.M.

    2013-01-01

    Surface Plasmon Resonance (SPR) is most commonly used to measure bio-molecular interactions. SPR is used significantly less frequent for measuring whole cell interactions. Here we introduce a method to measure whole cells label free using the specific binding of cell surface antigens expressed on th

  17. Recognition of antigen-specific B-cell receptors from chronic lymphocytic leukemia patients by synthetic antigen surrogates.

    Science.gov (United States)

    Sarkar, Mohosin; Liu, Yun; Morimoto, Jumpei; Peng, Haiyong; Aquino, Claudio; Rader, Christoph; Chiorazzi, Nicholas; Kodadek, Thomas

    2014-12-18

    In patients with chronic lymphocytic leukemia (CLL), a single neoplastic antigen-specific B cell accumulates and overgrows other B cells, leading to immune deficiency. CLL is often treated with drugs that ablate all B cells, leading to further weakening of humoral immunity, and a more focused therapeutic strategy capable of targeting only the pathogenic B cells would represent a significant advance. One approach to this would be to develop synthetic surrogates of the CLL antigens allowing differentiation of the CLL cells and healthy B cells in a patient. Here, we describe nonpeptidic molecules capable of targeting antigen-specific B cell receptors with good affinity and selectivity using a combinatorial library screen. We demonstrate that our hit compounds act as synthetic antigen surrogates and recognize CLL cells and not healthy B cells. Additionally, we argue that the technology we developed can be used to identify other classes of antigen surrogates.

  18. Regulator T cells: specific for antigen and/or antigen receptors?

    Science.gov (United States)

    Rubin, B; de Durana, Y Diaz; Li, N; Sercarz, E E

    2003-05-01

    Adaptive immune responses are regulated by many different molecular and cellular effectors. Regulator T cells are coming to their rights again, and these T cells seem to have ordinary alpha/beta T-cell receptors (TCRs) and to develop in the thymus. Autoimmune responses are tightly regulated by such regulatory T cells, a phenomenon which is beneficial to the host in autoimmune situations. However, the regulation of autoimmune responses to tumour cells is harmful to the host, as this regulation delays the defence against the outgrowth of neoplastic cells. In the present review, we discuss whether regulatory T cells are specific for antigen and/or for antigen receptors. Our interest in these phenomena comes from the findings that T cells produce many more TCR-alpha and TCR-beta chains than are necessary for surface membrane expression of TCR-alphabeta heterodimers with CD3 complexes. Excess TCR chains are degraded by the proteasomes, and TCR peptides thus become available to the assembly pathway of major histocompatibility complex class I molecules. Consequently, do T cells express two different identification markers on the cell membrane, the TCR-alphabeta clonotype for recognition by B-cell receptors and clonotypic TCR-alphabeta peptides for recognition by T cells?

  19. T Cells as Antigen Carriers for Anti-tumor Vaccination.

    Science.gov (United States)

    Traversari, Catia; Russo, Vincenzo

    2016-01-01

    The exploitation of the physiologic processing and presenting machinery of dendritic cells (DCs) by in vivo loading of tumor-associated antigens may improve the immunogenic potential and clinical efficacy of DC-based cancer vaccines. The approach developed by our group was based on the clinical observation that some patients treated with the infusion of donor lymphocytes transduced to express the HSV-TK suicide gene for relapse of hematologic malignancies, after allogeneic hematopoietic stem cell transplantation, developed a T cell-mediated immune response specifically directed against the HSV-TK gene product.We demonstrated that lymphocytes genetically modified to express HSV-TK as well as self/tumor antigens, acting as antigen carriers, efficiently target DCs in vivo in tumor-bearing mice. The infusion of TRP-2-transduced lymphocytes induced the establishment of protective immunity and long-term memory in tumor-bearing mice by cross-presentation of the antigen mediated by the CD11c(+)CD8a(+) DCs subset. A similar approach was applied in a clinical setting. Ten patients affected by MAGE-3(+) metastatic melanoma were treated with autologous lymphocytes retrovirally transduced to express the MAGE-3 tumor antigen. In three patients, the treatment led to the increase of MAGE-3 specific CD8+ and CD4+ effectors and the development of long-term memory, which ultimately correlated with a favorable clinical outcome. Transduced lymphocytes represent an efficient way for in vivo loading of tumor-associated antigens of DCs.

  20. Neocytolysis: physiological down-regulator of red-cell mass

    Science.gov (United States)

    Alfrey, C. P.; Rice, L.; Udden, M. M.; Driscoll, T. B.

    1997-01-01

    It is usually considered that red-cell mass is controlled by erythropoietin-driven bone marrow red-cell production, and no physiological mechanisms can shorten survival of circulating red cells. In adapting to acute plethora in microgravity, astronauts' red-cell mass falls too rapidly to be explained by diminished red-cell production. Ferrokinetics show no early decline in erythropolesis, but red cells radiolabelled 12 days before launch survive normally. Selective destruction of the youngest circulating red cells-a process we call neocytolysis-is the only plausible explanation. A fall in erythropoietin below a threshold is likely to initiate neocytolysis, probably by influencing surface-adhesion molecules. Recognition of neocytolysis will require re-examination of the pathophysiology and treatment of several blood disorders, including the anaemia of renal disease.

  1. Antigen-induced and non-antigen-induced histamine release from rat mast cells sensitized with mouse antiserum.

    Directory of Open Access Journals (Sweden)

    Kurose,Masao

    1981-10-01

    Full Text Available Marked IgE-mediated histamine release from rat mast cells sensitized in vitro with mouse antiserum occurs in the presence of added Ca++ and phosphatidylserine (PS, although a considerable degree of antigen-induced histamine release which may utilize intracellular or cell-bound calcium is also observed. The decay in the responsiveness to Ca++ of the sensitized cells stimulated by antigen in Ca++-free medium in the presence of PS is relatively slow, and maximum release is produced by Ca++ added 1 min after antigen. Histamine release also occurs when Ca++ is added after PS in the absence of antigen to the sensitized cells suspended in Ca++-free medium. Unlike the antigen-induced release, the intensity of this non-antigen-induced release varies depending on both mast-cell and antiserum pools. A heat-labile factor(s, which is different from antigen-specific IgE antibody and is also contained in normal mouse serum, is involved in this reaction. In the antigen-nondependent (PS + Ca++-induced release, no decay in the responsiveness to Ca++ is observed after PS addition. Both the antigen-induced and non-antigen-induced release are completed fairly rapidly and are dependent of temperature, pH and energy.

  2. Downregulation of Akt1 Inhibits Anchorage-Independent Cell Growth and Induces Apoptosis in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xuesong Liu

    2001-01-01

    Full Text Available The serine/threonine kinases, Akti/PKBα, Akt2/PKBβ, and Akt3/PKBγ, play a critical role in preventing cancer cells from undergoing apoptosis. However, the function of individual Akt isoforms in the tumorigenicity of cancer cells is still not well defined. In the current study, we used an AM antisense oligonucleotide (AS to specifically downregulate Akti protein in both cancer and normal cells. Our data indicate that AM AS treatment inhibits the ability of MiaPaCa-2, H460, HCT-15, and HT1080 cells to grow in soft agar. The treatment also induces apoptosis in these cancer cells as demonstrated by FRCS analysis and a caspase activity assay. Conversely, Akti AS treatment has little effect on the cell growth and survival of normal human cells including normal human fibroblast (NHF, fibroblast from muscle (FBM, and mammary gland epithelial 184135 cells. In addition, AM AS specifically sensitizes cancer cells to typical chemotherapeutic agents. Thus, Akti is indispensable for maintaining the tumorigenicity of cancer cells. Inhibition of AM may provide a powerful sensitization agent for chemotherapy specifically in cancer cells.

  3. FGFR4 Downregulation of Cell Adhesion in Prostate Cancer

    Science.gov (United States)

    2008-09-01

    293 cells. Total cell lysate was immunoblotted with anti-FGFR4 (C-16) antibody from SantaCruz . After some more troubleshooting with...antibody from SantaCruz . During month 20-21, we next tried to linearize the pVgRXR plasmid as before, but this time we purified the cut DNA using a...constructs using Lipofectamine 2000 and examined for downstream effects. Whole cell lysates were Western blotted for FGFR4 (C-16, SantaCruz , top) phospho

  4. Self-antigen presentation by dendritic cells in autoimmunity

    Directory of Open Access Journals (Sweden)

    Ann-Katrin eHopp

    2014-02-01

    Full Text Available The operation of both central and peripheral tolerance ensures the prevention of autoimmune diseases. The maintenance of peripheral tolerance requires self-antigen presentation by professional antigen presenting cells (APCs. Dendritic cells (DCs are considered as major APCs involved in this process. The current review discusses the role of DCs in autoimmune diseases, the various factors involved in the induction and maintenance of tolerogenic DC phenotype and pinpoints their therapeutic capacity as well as potential novel targets for future clinical studies.

  5. In Vitro Generation of Antigen-Specific T Cells from Induced Pluripotent Stem Cells of Antigen-Specific T Cell Origin.

    Science.gov (United States)

    Kaneko, Shin

    2016-01-01

    Induced pluripotent stem (iPS) cells derived from T lymphocyte (T-iPS cells) preserve the T cell receptor (TCR) α and β gene rearrangements identical to the original T cell clone. Re-differentiated CD8 single positive αβ T cells from the T-iPS cells exhibited antigen-specific cytotoxicity, improved proliferative response, and elongation of telomere indicating rejuvenation of antigen specific T cell immunity in vitro. To regenerate antigen specific cytotoxic T lymphocytes (CTL), first, we have optimized a method for reprogramming-resistant CD8 T cell clones into T-iPS cells by using sendaiviral vectors. Second, we have optimized stepwise differentiation methods for inducing hematopoietic progenitor cells, T cell progenitors, and functionally matured CD8 single positive CTL. These protocols provide useful in vitro tools and models both for research of antigen-specific T cell immunotherapy and for research of normal and pathological thymopoiesis.

  6. IFN-Gamma Inhibits JC Virus Replication in Glial Cells by Suppressing T-Antigen Expression.

    Directory of Open Access Journals (Sweden)

    Francesca Isabella De-Simone

    Full Text Available Patients undergoing immune modulatory therapies for the treatment of autoimmune diseases such as multiple sclerosis, and individuals with an impaired-immune system, most notably AIDS patients, are in the high risk group of developing progressive multifocal leukoencephalopathy (PML, an often lethal disease of the brain characterized by lytic infection of oligodendrocytes in the central nervous system (CNS with JC virus (JCV. The immune system plays an important regulatory role in controlling JCV reactivation from latent sites by limiting viral gene expression and replication. However, little is known regarding the molecular mechanisms responsible for this regulation.Here, we investigated the impact of soluble immune mediators secreted by activated PBMCs on viral replication and gene expression by cell culture models and molecular virology techniques. Our data revealed that viral gene expression and viral replication were suppressed by soluble immune mediators. Further studies demonstrated that soluble immune mediators secreted by activated PBMCs inhibit viral replication induced by T-antigen, the major viral regulatory protein, by suppressing its expression in glial cells. This unexpected suppression of T-antigen was mainly associated with the suppression of translational initiation. Cytokine/chemokine array studies using conditioned media from activated PBMCs revealed several candidate cytokines with possible roles in this regulation. Among them, only IFN-γ showed a robust inhibition of T-antigen expression. While potential roles for IFN-β, and to a lesser extent IFN-α have been described for JCV, IFN-γ has not been previously implicated. Further analysis of IFN-γ signaling pathway revealed a novel role of Jak1 signaling in control of viral T-antigen expression. Furthermore, IFN-γ suppressed JCV replication and viral propagation in primary human fetal glial cells, and showed a strong anti-JCV activity.Our results suggest a novel role for

  7. Downregulation of PTEN at Corneal Wound Sites Accelerates Wound Healing through Increased Cell Migration

    Science.gov (United States)

    Cao, Lin; Graue-Hernandez, Enrique O.; Tran, Vu; Reid, Brian; Pu, Jin; Mannis, Mark J.

    2011-01-01

    Purpose. The PI3K/Akt pathway is required for cell polarization and migration, whereas the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) has inhibitory effects on the PI3K/Akt pathway. The authors therefore hypothesized that wounding would downregulate PTEN and that this downregulation would enhance wound healing. Methods. In human corneal epithelial (HCE) cell monolayer and rat cornea scratch wound models, the authors investigated PTEN and Akt expression using Western blot and immunofluorescence analyses. The effects of PTEN and PI3K inhibitors dipotassium bisperoxo (picolinato) oxovanadate (bpv(pic)) and LY294002 on cell migration and wound closure were investigated using time-lapse imaging. Finally, the authors investigated the effect of PTEN inhibition on wound healing in whole rat eyes. Results. In HCE cell monolayer and rat cornea, PTEN was downregulated at the wound edges within 30 minutes of wounding. The downregulation of PTEN was causal in a simultaneous increase in Akt activation, which was responsible for a significant increase in individual cell migration rate from 8.8 μm/h to 17.3 μm/h. An increased migration rate was maintained for 20 hours. PTEN inhibition significantly enhanced the wound healing rate in the HCE cell monolayer from 10 minutes onward after treatment and reduced the healing time in eye organ culture from 30 to 20 hours. Conclusions. Injury to the corneal epithelium downregulates the expression of PTEN at wound edges, allowing increased PI3K/Akt signaling, thereby contributing to a significant enhancement of cell migration and wound healing. These results suggest that PTEN inhibition may be an effective treatment for corneal injury. PMID:21212174

  8. Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens.

    Science.gov (United States)

    Richards, Amanda L; Kapp, Linda M; Wang, Xiaohong; Howie, Heather L; Hudson, Krystalyn E

    2016-01-01

    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. While the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  9. Regulatory T cells are Dispensable for Tolerance to RBC Antigens

    Directory of Open Access Journals (Sweden)

    Amanda L Richards

    2016-09-01

    Full Text Available Autoimmune hemolytic anemia (AIHA occurs when pathogenic autoantibodies against red blood cell (RBC antigens are generated. Whilst the basic disease pathology of AIHA is well studied, the underlying mechanism(s behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  10. Stem cell antigen 2 expression in adult and developing mice.

    Science.gov (United States)

    Antica, M; Wu, L; Scollay, R

    1997-01-01

    Stem cell antigen 2 (Sca-2) expression can distinguish the most immature T-lymphocyte precursors in the thymus from the hemopoietic stem cells. Sequence analysis of the Sca-2 protein showed that Sca-2 is a glycosylphosphatidylinositol (GPI) anchored molecule that shares some characteristics with the members of the Ly-6 multigene family, and that it is the same as the thymic shared antigen-1 (TSA-1). Here we extend these studies and critically reassess the expression of the Sca-2/TSA-1 antigen in hematopoietic tissues of adult and developing mice. With more sensitive methods we show that the distribution of Sca-2/TSA-1 differs from existing reports. We find especially high expression of Sca-2/TSA1 at day 14 of fetal development.

  11. Engineered Hydrogen-Bonded Glycopolymer Capsules and Their Interactions with Antigen Presenting Cells.

    Science.gov (United States)

    Kempe, Kristian; Xiang, Sue D; Wilson, Paul; Rahim, Md Arifur; Ju, Yi; Whittaker, Michael R; Haddleton, David M; Plebanski, Magdalena; Caruso, Frank; Davis, Thomas P

    2017-02-22

    Hollow glycopolymer microcapsules were fabricated by hydrogen-bonded layer-by-layer (LbL) assembly, and their interactions with a set of antigen presenting cells (APCs), including dendritic cells (DCs), macrophages (MACs), and myeloid derived suppressor cells (MDSCs), were investigated. The glycopolymers were obtained by cascade postpolymerization modifications of poly(oligo(2-ethyl-2-oxazoline methacrylate)-stat-glycidyl methacrylate) involving the modification of the glycidyl groups with propargylamine and the subsequent attachment of mannose azide by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). Multilayer assembly of the hydrogen-bonding pair (glycopolymer/poly(methacrylic acid) (PMA)) onto planar and particulate supports (SiO2 particles, d = 1.16 μm) yielded stable glycopolymer films upon cross-linking by CuAAC. The silica (SiO2) particle templates were removed yielding hollow monodisperse capsules, as demonstrated by fluorescence and scanning electron microscopy. Cellular uptake studies using flow cytometry revealed the preferential uptake of the capsules by DCs when compared to MACs or MDSCs. Mannosylated capsules showed a cytokine independent cis-upregulation of CD80 specifically on DCs and a trans-downregulation of PDL-1 on MDSCs. Thus, the glycopolymer capsules may have potential as vaccine carriers, as they are able to upregulate costimulatory molecules for immune cell stimulation on DCs and at the same time downregulate immune inhibitory receptors on suppressor APC such as MDSCs.

  12. Dissection of T-cell antigen specificity in human melanoma

    DEFF Research Database (Denmark)

    Andersen, Rikke Sick; Albæk Thrue, Charlotte; Junker, Niels

    2012-01-01

    Tumor-infiltrating lymphocytes (TIL) isolated from melanoma patients and expanded in vitro by interleukin (IL)-2 treatment can elicit therapeutic response after adoptive transfer, but the antigen specificities of the T cells transferred have not been determined. By compiling all known melanoma......-associated antigens and applying a novel technology for high-throughput analysis of T-cell responses, we dissected the composition of melanoma-restricted T-cell responses in 63 TIL cultures. T-cell reactivity screens against 175 melanoma-associated epitopes detected 90 responses against 18 different epitopes...... from different fragments of resected melanoma lesions. In summary, our findings provide an initial definition of T-cell populations contributing to tumor recognition in TILs although the specificity of many tumor-reactive TILs remains undefined....

  13. [BMMSC from blastic phase CML down-regulate leukemia cell apoptosis].

    Science.gov (United States)

    Wang, Ying; Han, Yu-Xiang; Niu, Zhi-Yun; Wang, Xing-Zhe; Hua, Huan; Shang, Yin-Tao; Wang, Fu-Xu; Zhang, Xue-Jun; Luo, Jian-Min

    2014-10-01

    The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMMSC) from patients with chronic myeloid leukemia (CML) in blastic phase (Bp) on K562 cells and the primary CML-Bp cells, and to explore its potential mechanisms. K562 cells and primary CML-Bp cells were co-cultured with BMMSC of different groups; the cell proliferation was detected by MTT method, the cell apoptosis rate and mitochondrial membrane potential were measured by flow cytometry, the expression levels of Caspase-8, Caspase-9, and activated Caspase-3 in cells were measured by Western blot. The results showed that the CML-Bp BMMSC could enhance the survival rate of K562 cells treated with adviamycin (ADM) and display protective effect on K562 cells and primary CML-Bp mononuctear cells, inhibited ADM-induced leukimia cell apoptosis (P < 0.05); as compared with CML-chronic phase (CML-Cp) BMMSC and normal BMMSC, the CML-Bp BMMSC showed the highest protective effect on leukemic cells, the mitochondrial membrane potential of co-cultured cells slightly droped (P < 0.05). In the CML-Bp BMMSC cultured with K562 cells, the expression level of caspase-3 was more down-regulated than that in K562 alone plus ADM group, while the expression of caspase-9 significantly increased (P < 0.05). It is concluded that the CML-Bp BMMSC down-regulates ADM-induced leukemia cell appoptosis, its mechanism may relate with the inhibition of mitochondrial membrane potential drop, the stabilization of unactive expression of caspase-9 and down-regulation of caspase-3 expression.

  14. Molecular structure and biological function of proliferating cell nuclear antigen

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Proliferating cell nuclear antigen (PCNA) is the core component of replication complex in eukaryote.As a processive factor of DNA polymerase delta, PCNA coordinates the replication process by interacting with various replication proteins. PCNA appears to play an essential role in many cell events, such as DNA damage repair, cell cycle regulation, and apoptosis, through the coordination or organization of different partners. PCNA is an essential factor in cell proliferation, and has clinical significance in tumor research. In this article we review the functional structure of PCNA, which acts as a function switch in different cell events.

  15. Uptake of antigen-antibody complexes by human dendritic cells.

    Science.gov (United States)

    Fanger, N A; Guyre, P M; Graziano, R F

    2001-01-01

    Fc receptors specific for IgG (FcγR) potentiate the immune response by facilitating the interaction between myeloid cells and antibody-coated targets (1-3). Monocyte and neutrophil FcyR engagement can lead to the induction of lytic-type mechanisms associated with innate responses. FcyR triggering can also play a key role in adaptive immune responses. For example, FcyR-directed capture and uptake of antigens (Ag) by dendritic cells (DC) results in processing and presentation to naive Ag-specific T cells, leading to their expansion and maturation into effector T-cell populations. This chapter describes methodology currently in use to explore and manipulate antigen-antibody (Ag-Ab) uptake by FcyR expressed on DC.

  16. MHC class II antigen presentation by B cells in health and disease

    NARCIS (Netherlands)

    Souwer, Yuri

    2009-01-01

    MHC class II antigen presentation by B cells is important to activate CD4+ T cells that stimulate the B cell to produce antibodies. Besides this, disruption of MHC class II antigen presentation could play a role in immune escape by tumor cells. This thesis describes MHC class II antigen presentation

  17. Trafficking of B cell antigen in lymph nodes

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Degn, Søren Egedal; Pitcher, Lisa A.

    2011-01-01

    The clonal selection theory first proposed by Macfarlane Burnet is a cornerstone of immunology ( 1 ). At the time, it revolutionized the thinking of immunologists because it provided a simple explanation for lymphocyte specificity, immunological memory, and elimination of self-reactive clones ( 2......, 5 ) have provided new insights into the trafficking of B cells and their antigen. In this review, we summarize these advances in the context of our current view of B cell circulation and activation....

  18. Adsorption of multimeric T cell antigens on carbon nanotubes

    DEFF Research Database (Denmark)

    Fadel, Tarek R; Li, Nan; Shah, Smith;

    2013-01-01

    Antigen-specific activation of cytotoxic T cells can be enhanced up to three-fold more than soluble controls when using functionalized bundled carbon nanotube substrates ((b) CNTs). To overcome the denaturing effects of direct adsorption on (b) CNTs, a simple but robust method is demonstrated...... to stabilize the T cell stimulus on carbon nanotube substrates through non-covalent attachment of the linker neutravidin....

  19. Sulindac sulfide inhibits colon cancer cell growth and downregulates specificity protein transcription factors

    OpenAIRE

    Li, Xi; Pathi, Satya S.; Safe, Stephen

    2015-01-01

    Background Specificity protein (Sp) transcription factors play pivotal roles in maintaining the phenotypes of many cancers. We hypothesized that the antineoplastic effects of sulindac and its metabolites were due, in part, to targeting downregulation of Sp transcription factors. Methods The functional effects of sulindac, sulindac sulfone and sulindac sulfide on colon cancer cell proliferation were determined by cell counting. Effects of these compounds on expression of Sp1, Sp3, Sp4 and pro-...

  20. Can selective MHC downregulation explain the specificity and genetic diversity of NK cell receptors?

    Directory of Open Access Journals (Sweden)

    Paola eCarrillo-Bustamante

    2015-06-01

    Full Text Available Natural killer (NK cells express inhibiting receptors (iNKRs s which specifically bind MHC-I molecules on the surface of healthy cells. When the expression of MHC-I on the cell surface decreases, which might occur during certain viral infections and cancer, iNKRs s lose inhibiting signals and the infected cells become target for NK cell activation (missing-self detection. Although the detection of MHC-I deficient cells can be achieved by conserved receptor-ligand interactions, several iNKRs are encoded by gene families with a remarkable genetic diversity, containing many haplotypes varying in gene content and allelic polymorphism. So far, the biological function of this expansion within the NKR cluster has remained poorly understood. Here, we investigate whether the evolution of diverse iNKRs genes can be driven by a specific viral immunoevasive mechanism: selective MHC downregulation. Several viruses, including EBV, CMV, and HIV, decrease the expression of MHC-I to escape from T cell responses. This downregulation does not always affect all MHC loci in the same way, as viruses target particular MHC molecules. To study the selection pressure of selective MHC downregulation on iNKRs, we have developed an agent-based model simulating an evolutionary scenario of hosts infected with herpes-like viruses that are able to selectively downregulate the expression of MHC-I molecules on the cell surface. We show that iNKRs evolve specificity and, depending on the similarity of MHC alleles within each locus and the differences between the loci, they can specialize to a particular MHC-I locus. The easier it is to classify an MHC allele to its locus, the lower the required diversity of the NKRs. Thus, the diversification of the iNKR cluster depends on the locus specific MHC structure.

  1. Existence of a squamous cell carcinoma antigen-immunoglobulin complex causes a deviation between squamous cell carcinoma antigen concentrations determined using two different immunoassays: first report of squamous cell carcinoma antigen coupling with immunoglobulin A.

    Science.gov (United States)

    Mori, Eriko; Kurano, Makoto; Tobita, Akiko; Shimosaka, Hironori; Yatomi, Yutaka

    2017-01-01

    Background Squamous cell carcinoma antigen is used as a tumour marker and is routinely measured in clinical laboratories. We validated two different immunoassays and found three cases in which the squamous cell carcinoma antigen concentrations deviated greatly between the two immunoassays. Here, we aimed to elucidate the mechanisms responsible for these deviations. Methods The squamous cell carcinoma antigen concentrations were determined using the ARCHITECT SCC (CLIA method) and the ST AIA-PACK SCC (FEIA method). We performed polyethylene glycol precipitation and size exclusion chromatography to assess the molecular weight and spike recovery and absorption tests to examine the presence of an autoantibody. Results Both methods exhibited good performances for the measurement of squamous cell carcinoma antigen, although a correlation test showed large differences in the squamous cell carcinoma antigen concentrations measured using the two methods in three cases. The results of polyethylene glycol treatment and size exclusion chromatography indicated the existence of a large molecular weight squamous cell carcinoma antigen in these three cases. The spike recovery tests suggested the possible presence of an autoantibody against squamous cell carcinoma antigen. Moreover, the absorption test revealed that large squamous cell carcinoma antigen complexes were formed by the association of squamous cell carcinoma antigen with IgG in two cases and with both IgG and IgA in one case. Conclusions This study describes the existence of large molecular weight squamous cell carcinoma antigen that has complexed with immunoglobulin in the serum samples. The reason for the deviations between the two immunoassays might be due to differences of their reactivities against the squamous cell carcinoma antigen immune complexes with their autoantibody. To our knowledge, this is the first report to describe the coupling of squamous cell carcinoma antigen with IgA.

  2. Toxicities of chimeric antigen receptor T cells: recognition and management.

    Science.gov (United States)

    Brudno, Jennifer N; Kochenderfer, James N

    2016-06-30

    Chimeric antigen receptor (CAR) T cells can produce durable remissions in hematologic malignancies that are not responsive to standard therapies. Yet the use of CAR T cells is limited by potentially severe toxicities. Early case reports of unexpected organ damage and deaths following CAR T-cell therapy first highlighted the possible dangers of this new treatment. CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines released by infused CAR T cells can lead to widespread reversible organ dysfunction. CRS is the most common type of toxicity caused by CAR T cells. Neurologic toxicity due to CAR T cells might in some cases have a different pathophysiology than CRS and requires different management. Aggressive supportive care is necessary for all patients experiencing CAR T-cell toxicities, with early intervention for hypotension and treatment of concurrent infections being essential. Interleukin-6 receptor blockade with tocilizumab remains the mainstay pharmacologic therapy for CRS, though indications for administration vary among centers. Corticosteroids should be reserved for neurologic toxicities and CRS not responsive to tocilizumab. Pharmacologic management is complicated by the risk of immunosuppressive therapy abrogating the antimalignancy activity of the CAR T cells. This review describes the toxicities caused by CAR T cells and reviews the published approaches used to manage toxicities. We present guidelines for treating patients experiencing CRS and other adverse events following CAR T-cell therapy.

  3. Downregulation of CXCR4 in Metastasized Breast Cancer Cells and Implication in Their Dormancy.

    Directory of Open Access Journals (Sweden)

    Kentaro Nobutani

    Full Text Available Our understanding of the mechanism of cancer dormancy is emerging, but the underlying mechanisms are not fully understood. Here we analyzed mouse xenograft tumors derived from human breast cancer tissue and the human breast cancer cell line MDA-MB-231 to identify the molecules associated with cancer dormancy. In immunohistological examination using the proliferation marker Ki-67, the tumors included both proliferating and dormant cancer cells, but the number of dormant cells was remarkably increased when they metastasized to the lung. In the gene expression analysis of the orthotopic cancer cells by a single-cell multiplex real-time quantitative reverse transcription PCR followed by flow cytometric analysis, restrained cellular proliferation was associated with downregulation of the chemokine receptor CXCR4. In the immunohistological and flow cytometric analyses, the expression level of CXCR4 in the metastasized cancer cells was decreased compared with that in the cancer cells in orthotopic tumors, although the expression level of the CXCR4 ligand CXCL12 was not reduced in the lung. In addition, the proliferation of the metastasized cancer cells was further decreased by the CXCR4 antagonist administration. In the ex vivo culture of the metastasized cancer cells, the expression level of CXCR4 was increased, and in the xenotransplantation of ex vivo cultured cancer cells, the expression level of CXCR4 was again decreased in the metastasized cancer cells in the lung. These findings indicate that CXCR4 is downregulated in metastasized breast cancer cells and implicated in their dormancy.

  4. Equine herpesvirus type 4 UL56 and UL49.5 proteins downregulate cell surface major histocompatibility complex class I expression independently of each other.

    Science.gov (United States)

    Said, Abdelrahman; Azab, Walid; Damiani, Armando; Osterrieder, Nikolaus

    2012-08-01

    Major histocompatibility complex class I (MHC-I) molecules are critically important in the host defense against various pathogens through presentation of viral peptides to cytotoxic T lymphocytes (CTLs), a process resulting in the destruction of virus-infected cells. Herpesviruses interfere with CTL-mediated elimination of infected cells by various mechanisms, including inhibition of peptide transport and loading, perturbation of MHC-I trafficking, and rerouting and proteolysis of cell surface MHC-I. In this study, we show that equine herpesvirus type 4 (EHV-4) modulates MHC-I cell surface expression through two different mechanisms. First, EHV-4 can lead to a significant downregulation of MHC-I expression at the cell surface through the product of ORF1, a protein expressed with early kinetics from a gene that is homologous to herpes simplex virus 1 UL56. The EHV-4 UL56 protein reduces cell surface MHC-I as early as 4 h after infection. Second, EHV-4 can interfere with MHC-I antigen presentation, starting at 6 h after infection, by inhibition of the transporter associated with antigen processing (TAP) through its UL49.5 protein. Although pUL49.5 has no immediate effect on overall surface MHC-I levels in infected cells, it blocks the supply of antigenic peptides to the endoplasmic reticulum (ER) and transport of peptide-loaded MHC-I to the cell surface. Taken together, our results show that EHV-4 encodes at least two viral immune evasion proteins: pUL56 reduces MHC-I molecules on the cell surface at early times after infection, and pUL49.5 interferes with MHC-I antigen presentation by blocking peptide transport in the ER.

  5. Genomic Typing of Red Cell Antigens

    Science.gov (United States)

    2011-09-01

    Antigen‐Matched  Red  Cells  for  Sickle  Cell  Anemia   Patients  Using  Molecular Typing to Augment Testing: Meghan Delaney, Prashant Gaur, Askale...Storry JR &  Delaney, M. CASE  REPORT OF TESTING AND MANAGEMENT OF BOMBAY  (OH)  PREGNANCY . XXXIst  International  Congress of the ISBT, Berlin, Germany...JK null Phenotype (Manuscript in preparation).  5. Delaney M et al: A Genetic Impossibility? Case report of Bombay (Oh)  pregnancy  with Group AB

  6. TCR Down-Regulation Controls Virus-Specific CD8+ T Cell Responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the antiapoptotic...... molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus...

  7. Bystander T cells in human immune responses to dengue antigens

    Directory of Open Access Journals (Sweden)

    Suwannasaen Duangchan

    2010-09-01

    Full Text Available Abstract Background Previous studies of T cell activation in dengue infection have focused on restriction of specific T cell receptors (TCRs and classical MHC molecules. However, bystander T cell activation, which is TCR independent, occurs via cytokines in other viral infections, both in vitro and in vivo, and enables T cells to bypass certain control checkpoints. Moreover, clinical and pathological evidence has pointed to cytokines as the mediators of dengue disease severity. Therefore, we investigated bystander T cell induction by dengue viral antigen. Results Whole blood samples from 55 Thai schoolchildren aged 13-14 years were assayed for in vitro interferon-gamma (IFN-γ induction in response to inactivated dengue serotype 2 antigen (Den2. The contribution of TCR-dependent and independent pathways was tested by treatment with cyclosporin A (CsA, which inhibits TCR-dependent activation of T cells. ELISA results revealed that approximately 72% of IFN-γ production occurred via the TCR-dependent pathway. The major IFN-γ sources were natural killer (NK (mean ± SE = 55.2 ± 3.3, CD4+T (24.5 ± 3.3 and CD8+T cells (17.9 ± 1.5, respectively, as demonstrated by four-color flow cytometry. Interestingly, in addition to these cells, we found CsA-resistant IFN-γ producing T cells (CD4+T = 26.9 ± 3.6% and CD8+T = 20.3 ± 2.1% implying the existence of activated bystander T cells in response to dengue antigen in vitro. These bystander CD4+ and CD8+T cells had similar kinetics to NK cells, appeared after 12 h and were inhibited by anti-IL-12 neutralization indicating cytokine involvement. Conclusions This study described immune cell profiles and highlighted bystander T cell activation in response to dengue viral antigens of healthy people in an endemic area. Further studies on bystander T cell activation in dengue viral infection may reveal the immune mechanisms that protect or enhance pathogenesis of secondary dengue infection.

  8. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro.

    Directory of Open Access Journals (Sweden)

    Qianqian Guo

    Full Text Available Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs, via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained.

  9. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro

    Science.gov (United States)

    Guo, Qianqian; Wang, Datao; Liu, Zhen; Li, Chunyi

    2015-01-01

    Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs), via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained. PMID:26308075

  10. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro.

    Science.gov (United States)

    Guo, Qianqian; Wang, Datao; Liu, Zhen; Li, Chunyi

    2015-01-01

    Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs), via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained.

  11. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    DEFF Research Database (Denmark)

    La Rocca, Rosanna; Tallerico, Rossana; Hassan, Almosawy Talib;

    2014-01-01

    treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells...... between 700–1800 cm-1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased...

  12. Chimeric Antigen Receptor T Cell Therapy in Hematology.

    Science.gov (United States)

    Ataca, Pınar; Arslan, Önder

    2015-12-01

    It is well demonstrated that the immune system can control and eliminate cancer cells. Immune-mediated elimination of tumor cells has been discovered and is the basis of both cancer vaccines and cellular therapies including hematopoietic stem cell transplantation. Adoptive T cell transfer has been improved to be more specific and potent and to cause less off-target toxicity. Currently, there are two forms of engineered T cells being tested in clinical trials: T cell receptor (TCR) and chimeric antigen receptor (CAR) modified T cells. On 1 July 2014, the United States Food and Drug Administration granted 'breakthrough therapy' designation to anti-CD19 CAR T cell therapy. Many studies were conducted to evaluate the benefits of this exciting and potent new treatment modality. This review summarizes the history of adoptive immunotherapy, adoptive immunotherapy using CARs, the CAR manufacturing process, preclinical and clinical studies, and the effectiveness and drawbacks of this strategy.

  13. Red-blood-cell alloimmunisation in relation to antigens' exposure and their immunogenicity: a cohort study.

    NARCIS (Netherlands)

    Evers, D.; Middelburg, R.A.; Haas, M. de; Zalpuri, S.; Vooght, K.M. De; Kerkhof, D. van de; Visser, O; Pequeriaux, N.C.V.; Hudig, F.; Schonewille, H.; Zwaginga, J.J.; Bom, J.G. Van Der

    2016-01-01

    BACKGROUND: Matching donor red blood cells based on recipient antigens prevents alloimmunisation. Knowledge about the immunogenicity of red-blood-cell antigens can help optimise risk-adapted matching strategies. We set out to assess the immunogenicity of red-blood-cell antigens. METHODS: In an incid

  14. Down-regulation of vimentin expression inhibits carcinoma cell migration and adhesion.

    Science.gov (United States)

    McInroy, Lorna; Määttä, Arto

    2007-08-17

    Vimentin is a type III Intermediate filament protein that is expressed frequently in epithelial carcinomas correlating with invasiveness and poor prognosis. We have analysed migration and adhesion to collagenous matrix of a panel of carcinoma cell lines. In vitro invasiveness was highest in vimentin-positive SW480 colon cancer and MDA-MB-231 breast cancer cells and the role of vimentin in these cell lines was investigated by RNA interference. Down-regulation of vimentin expression resulted in impaired migration in both scratch-wound experiments and in invasion assays through cell culture inserts coated with collagen gel. Compromised migration was observed in both cell lines, whereas cell attachment assays revealed impaired adhesion to fibrillar collagen in MDA-MB-231 cells while the adhesion of vimentin-ablated SW480 cells, that express both vimentin and keratin intermediate filaments was not affected. In conclusion, ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines.

  15. Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

    Science.gov (United States)

    Lee Szeto, Gregory; van Egeren, Debra; Worku, Hermoon; Sharei, Armon; Alejandro, Brian; Park, Clara; Frew, Kirubel; Brefo, Mavis; Mao, Shirley; Heimann, Megan; Langer, Robert; Jensen, Klavs; Irvine, Darrell J.

    2015-05-01

    B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8+T-cells, and not CD4+T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8+T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8+T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8+T-cells, and decoupling of antigen uptake from B-cell activation.

  16. Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Patricio; Soto, Nicolás [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Jorge [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Mendoza, Pablo [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Natalia [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Quest, Andrew F.G. [Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Torres, Vicente A., E-mail: vatorres@med.uchile.cl [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile)

    2015-08-21

    The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo.

  17. siRNA-mediated downregulation of TC21 sensitizes esophageal cancer cells to cisplatin

    Institute of Scientific and Technical Information of China (English)

    Md.Raghibul Hasan; Shyam Singh Chauhan; Rinu Sharma; Ranju Ralhan

    2012-01-01

    AIM:To determine the functional significance of TC21 in esophageal squamous cell carcinoma (ESCC).METHODS:TC21 siRNA transfection was carried out using Hyperfectamine to knock down TC21,and transcripts were analyzed by reverse transcription-polymerase chain reaction and protein by Western blotting.We demonstrated the effect of TC21 downregulation of cell signaling in esophageal cancer cells by assessing the phosphorylation status of its downstream targets,phosphoinositide 3-kinase (PI3K),phosphatase and tensin homolog (PTEN),protein kinase B (pAkt),nuclear factor-κB (NF-κB) and cyclinD1 using specific antibodies.Cell survival analysis after cisplatin treatment was carried out by cell viability assay and cell cycle analysis using flow cytometry.RESULTS:TC21 knockdown in human ESCC cell line TE13 cells,showed only a marginal increase (14.2%) in cell death compared with control cells.The expressions of the signaling proteins PI3K and pAkt,transcription factor NF-κB,and cell cycle protein cyclin D1 were markedly decreased in response to TC21 downregulation,whereas the level of pPTEN,an antagonist of PI3K,was increased.In addition,we evaluated the potential of TC21 as a putative target for sensitizing ESCC cells to the chemotherapeutic agent dsplatin.Increased cell death (38.4%) was observed in cells treated with cisplatin after TC21 knockdown compared with cells which were treated with cisplatin alone (20% cell death).CONCLUSION:Results suggest that TC21 mediates its effects via the PI3K-Akt pathway,NF-κB and cydin D1,and enhances chemoresistance in esophageal cancer cells.

  18. TCR down-regulation boosts T-cell-mediated cytotoxicity and protection against poxvirus infections

    DEFF Research Database (Denmark)

    Hansen, Ann Kathrine; Regner, Matthias; Bonefeld, Charlotte Menne

    2011-01-01

    Cytotoxic T (Tc) cells play a key role in the defense against virus infections. Tc cells recognize infected cells via the T-cell receptor (TCR) and subsequently kill the target cells by one or more cytotoxic mechanisms. Induction of the cytotoxic mechanisms is finely tuned by the activation signals...... from the TCR. To determine whether TCR down-regulation affects the cytotoxicity of Tc cells, we studied TCR down-regulation-deficient CD3¿LLAA mice. We found that Tc cells from CD3¿LLAA mice have reduced cytotoxicity due to a specific deficiency in exocytosis of lytic granules. To determine whether......-regulation critically increases Tc cell cytotoxicity and protection against poxvirus infection....

  19. Correlation of urine cytology with ABO(H) antigenicity in transitional cell carcinoma of the bladder.

    OpenAIRE

    1988-01-01

    Cell surface ABO(H) antigenicity of superficial bladder tumours was assessed by the indirect immunoperoxidase test in 49 patients. Good correlation was obtained between surface antigenicity of tumours and the results of urine cytology. Malignant cells were detected cytologically in 22(56%) of cases with ABO(H) antigen negative tumours which are known to behave more aggressively than ABO(H) antigen positive ones. In contrast, malignant cells were found in the urine cytology of only one (10%) o...

  20. miR-203 downregulates Yes-1 and suppresses oncogenic activity in human oral cancer cells.

    Science.gov (United States)

    Lee, Seul-Ah; Kim, Jae-Sung; Park, Sun-Young; Kim, Heung-Joong; Yu, Sun-Kyoung; Kim, Chun Sung; Chun, Hong Sung; Kim, Jeongsun; Park, Jong-Tae; Go, Daesan; Kim, Do Kyung

    2015-10-01

    The purpose of this study was to elucidate the molecular mechanisms of microRNA-203 (miR-203) as a tumor suppressor in KB human oral cancer cells. MicroRNA microarray results showed that the expression of miR-203 was significantly down-regulated in KB cells compared with normal human oral keratinocytes. The viability of KB cells was decreased by miR-203 in the time- and dose-dependent manners. In addition, over-expressed miR-203 not only increased the nuclear condensation but also significantly increased the apoptotic population of KB cells. These results indicated that the over-expression of miR-203 induced apoptosis of KB cells. Furthermore, the target gene array analyses revealed that the expression of Yes-1, a member of the Src family kinases (SFKs), was significantly down-regulated by miR-203 in KB cells. Moreover, both the mRNA and protein levels of Yes-1 were strongly reduced in KB cells transfected with miR-203. Therefore, these results indicated that Yes-1 is predicted to be a potential target gene of miR-203. Through a luciferase activity assay, miR-203 was confirmed to directly targets the Yes-1 3' untranslated region (UTR) to suppress gene expression. Therefore, our findings indicate that miR-203 induces the apoptosis of KB cells by directly targeting Yes-1, suggesting its application in anti-cancer therapeutics.

  1. Androgen Depletion Induces Senescence in Prostate Cancer Cells through Down-regulation of Skp2

    Directory of Open Access Journals (Sweden)

    Zuzana Pernicová

    2011-06-01

    Full Text Available Although the induction of senescence in cancer cells is a potent mechanism of tumor suppression, senescent cells remain metabolically active and may secrete a broad spectrum of factors that promote tumorigenicity in neighboring malignant cells. Here we show that androgen deprivation therapy (ADT, a widely used treatment for advanced prostate cancer, induces a senescence-associated secretory phenotype in prostate cancer epithelial cells, indicated by increases in senescence-associated β-galactosidase activity, heterochromatin protein 1β foci, and expression of cathepsin B and insulin-like growth factor binding protein 3. Interestingly, ADT also induced high levels of vimentin expression in prostate cancer cell lines in vitro and in human prostate tumors in vivo. The induction of the senescence-associated secretory phenotype by androgen depletion was mediated, at least in part, by down-regulation of S-phase kinase-associated protein 2, whereas the neuroendocrine differentiation of prostate cancer cells was under separate control. These data demonstrate a previously unrecognized link between inhibition of androgen receptor signaling, down-regulation of S-phase kinase-associated protein 2, and the appearance of secretory, tumor-promoting senescent cells in prostate tumors. We propose that ADT may contribute to the development of androgen-independent prostate cancer through modulation of the tissue microenvironment by senescent cells.

  2. Down-regulation of ALKBH2 increases cisplatin sensitivity in H1299 lung cancer cells

    Institute of Scientific and Technical Information of China (English)

    Shuang-shuang WU; Wei XU; Shan LIU; Bo CHEN; Xue-li WANG; Yan WANG; Shi-feng LIU; Jian-qing WU

    2011-01-01

    Aim: To elucidate the combined effect of alkylated DNA repair protein alkB homolog 2 (ALKBH2)-targeting gene therapy and cisplatin (cDDP) chemotherapy on the non-small cell lung cancer (NSCLC)H1299 cell line.Methods: ALKBH2 was down-regulated in H1299 cells by lentivirus-mediated RNA interference (RNAi). Changes in ALKBH2 expression were determined using real-time RT-PCR and Western blotting. Cell viability was evaluated using MTT assay. DNA synthesis in proliferating cells was determined using BrdU incorporation assay. Cell apoptosis was determined using flow cytometry.Results: Lentivirus-mediated ALKBH2 silencing alone did not induce apoptosis or attenuate the growth potential of H1299 cells within five days post-infection. Combined treatment modalities with lentivirus-mediated ALKBH2 down-regulation and cDDP (333 μmol/L)were significantly more potent in inhibiting cell growth and inducing apoptosis than mono-chemotherapy.Conclusion: Combined treatment modalities of ALKBH2 knockdown and cDDP chemotherapy have the potential to improve the efficacy in the treatment of NSCLC.

  3. Pinolenic Acid Downregulates Lipid Anabolic Pathway in HepG2 Cells.

    Science.gov (United States)

    Lee, Ah Ron; Han, Sung Nim

    2016-07-01

    Pine nut oil (PNO) was reported to reduce lipid accumulation in the liver. However, the specific effect of pinolenic acid (18:3, all-cis-Δ5,9,12), a unique component of PNO, on lipid metabolism has not been studied. We hypothesized that pinolenic acid downregulates the lipid anabolic pathway in HepG2 cells. HepG2 cells were incubated in serum-free medium supplemented with 50 μM bovine serum albumin (BSA), palmitic acid, oleic acid, γ-linolenic acid, pinolenic acid, eicosapentaenoic acid (EPA), or α-linolenic acid for 24 h. Lipid accumulation was determined by Oil Red O (ORO) staining. The mRNA levels of genes related to fatty acid biosynthesis (SREBP1c, FAS, SCD1, and ACC1), fatty acid oxidation (ACC2, PPARα, CPT1A, and ACADL), cholesterol synthesis (SREBP2 and HMGCR), and lipoprotein uptake (LDLr) and of genes that may be involved in the downregulation of the lipogenic pathway (ACSL3, ACSL4, and ACSL5) were determined by qPCR. LDLR protein levels were measured by Western blot analysis. The mRNA levels of SREBP1c, FAS, and SCD1 were significantly downregulated by pinolenic acid treatment compared to BSA control (53, 54, and 38 % lower, respectively). In addition, the mRNA levels of HMGCR, ACSL3, and LDLr were significantly lower (30, 30, and 43 % lower, respectively), and ACSL4 tended to be lower in the pinolenic acid group (20 % lower, P = 0.082) relative to the control group. In conclusion, pinolenic acid downregulated the lipid anabolic pathway in HepG2 cells by reducing expression of genes related to lipid synthesis, lipoprotein uptake, and the regulation of the lipogenic pathway.

  4. Downregulation of the transcription factor KLF4 is required for the lineage commitment of T cells

    Institute of Scientific and Technical Information of China (English)

    Xiaomin Wen; Haifeng Liu; Gang Xiao; Xiaolong Liu

    2011-01-01

    The roles of the reprogramming factors Oct4,Sox2,c-Myc and Klf4 in early T cell development are incompletely defined.Here,we show that Klf4 is the only reprogramming factor whose expression is downregulated when early thymic progenitors (ETPs) differentiate into T cells.Enforced expression of Klf4 in uncommitted progenitors severely impaired T cell development mainly at the DN2-to-DN3 transition when T cell lineage commitment occurs and affected the transcription of a variety of genes with crucial functions in early T cell development,including genes involved in microenvironmental signaling (IL-7Rα),Notch target genes (Deltexl),and essential T cell lineage regulatory or inhibitory genes (Bcllla,SpiB,and ldl).The survival of thymocytes and the rearrangement at the Tcrb locus were impaired in the presence of enforced Klf4 expression.The defects in the DN1-to-DN2 and DN2-to-DN3 transitions in Klf4 transgenic mice could not be rescued by the introduction of a TCR transgene,but was partially rescued by restoring the expression of IL-7Rα.Thus,our data indicate that the downregulation of Klf4 is a prerequisite for T cell lineage commitment.

  5. Cell wall anchoring of the Campylobacter antigens to Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Patrycja Anna Kobierecka

    2016-02-01

    Full Text Available Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type Campylobacter jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analysed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ LAB (Lactic Acid Bacteria strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered

  6. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G;

    1998-01-01

    GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN......We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r...

  7. Original encounter with antigen determines antigen-presenting cell imprinting of the quality of the immune response in mice.

    Directory of Open Access Journals (Sweden)

    Valérie Abadie

    Full Text Available BACKGROUND: Obtaining a certain multi-functionality of cellular immunity for the control of infectious diseases is a burning question in immunology and in vaccine design. Early events, including antigen shuttling to secondary lymphoid organs and recruitment of innate immune cells for adaptive immune response, determine host responsiveness to antigens. However, the sequence of these events and their impact on the quality of the immune response remain to be elucidated. Here, we chose to study Modified Vaccinia virus Ankara (MVA which is now replacing live Smallpox vaccines and is proposed as an attenuated vector for vaccination strategies against infectious diseases. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed in vivo mechanisms triggered following intradermal (i.d. and intramuscular (i.m. Modified Vaccinia virus Ankara (MVA administration. We demonstrated significant differences in the antigen shuttling to lymphoid organs by macrophages (MPhis, myeloid dendritic cells (DCs, and neutrophils (PMNs. MVA i.d. administration resulted in better antigen distribution and more sustained antigen-presenting cells (APCs recruitment into draining lymph nodes than with i.m. administration. These APCs, which comprise both DCs and MPhis, were differentially involved in T cell priming and shaped remarkably the quality of cytokine-producing virus-specific T cells according to the entry route of MVA. CONCLUSIONS/SIGNIFICANCE: This study improves our understanding of the mechanisms of antigen delivery and their consequences on the quality of immune responses and provides new insights for vaccine development.

  8. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G

    1998-01-01

    We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r......GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN...

  9. Circadian control of antigen-specific T cell responses

    Directory of Open Access Journals (Sweden)

    Nobis CC

    2016-09-01

    Full Text Available Chloé C Nobis,1–3 Nathalie Labrecque,2–4 Nicolas Cermakian1,5–8 1Douglas Mental Health University Institute, 2Maisonneuve-Rosemont Hospital Research Centre, 3Department of Microbiology, Infectious Diseases and Immunology, 4Department of Medicine, University of Montreal, 5Department of Psychiatry, 6Department of Microbiology and Immunology, 7Department of Neurology and Neurosurgery, 8Department of Physiology, McGill University, Montreal, QC, Canada Abstract: The immune system is composed of two arms, the innate and the adaptive immunity. While the innate response constitutes the first line of defense and is not specific for a particular pathogen, the adaptive response is highly specific and allows for long-term memory of the pathogen encounter. T lymphocytes (or T cells are central players in the adaptive immune response. Various aspects of T cell functions vary according to the time of day. Circadian clocks located in most tissues and cell types generate 24-hour rhythms of various physiological processes. These clocks are based on a set of clock genes, and this timing mechanism controls rhythmically the expression of numerous other genes. Clock genes are expressed in cells of the immune system, including T cells. In this review, we provide an overview of the circadian control of the adaptive immune response, with emphasis on T cells, including their development, trafficking, response to antigen, and effector functions. Keywords: circadian clock, adaptive immune response, T lymphocyte, antigen, cytokine, proliferation

  10. Downregulation of CD44 reduces doxorubicin resistance of CD44+CD24- breast cancer cells

    Directory of Open Access Journals (Sweden)

    Phuc PV

    2011-06-01

    Full Text Available Pham Van Phuc, Phan Lu Chinh Nhan, Truong Hai Nhung, Nguyen Thanh Tam, Nguyen Minh Hoang, Vuong Gia Tue, Duong Thanh Thuy, Phan Kim NgocLaboratory of Stem Cell Research and Application, University of Science, Vietnam National University, Ho Chi Minh, VietnamBackground: Cells within breast cancer stem cell populations have been confirmed to have a CD44+CD24- phenotype. Strong expression of CD44 plays a critical role in numerous types of human cancers. CD44 is involved in cell differentiation, adhesion, and metastasis of cancer cells.Methods: In this study, we reduced CD44 expression in CD44+CD24- breast cancer stem cells and investigated their sensitivity to an antitumor drug. The CD44+CD24- breast cancer stem cells were isolated from breast tumors; CD44 expression was downregulated with siRNAs followed by treatment with different concentrations of the antitumor drug.Results: The proliferation of CD44 downregulated CD44+CD24- breast cancer stem cells was decreased after drug treatment. We noticed treated cells were more sensitive to doxorubicin, even at low doses, compared with the control groups.Conclusions: It would appear that expression of CD44 is integral among the CD44+CD24- cell population. Reducing the expression level of CD44, combined with doxorubicin treatment, yields promising results for eradicating breast cancer stem cells in vitro. This study opens a new direction in treating breast cancer through gene therapy in conjunction with chemotherapy.Keywords: antitumor drugs, breast cancer stem cells, CD44, CD44+CD24- cells, doxorubicin

  11. CHIP mediates down-regulation of nucleobindin-1 in preosteoblast cell line models.

    Science.gov (United States)

    Xue, Fuying; Wu, Yanping; Zhao, Xinghui; Zhao, Taoran; Meng, Ying; Zhao, Zhanzhong; Guo, Junwei; Chen, Wei

    2016-08-01

    Nucleobindin-1 (NUCB1), also known as Calnuc, is a highly conserved, multifunctional protein widely expressed in tissues and cells. It contains two EF-hand motifs which have been shown to play a crucial role in binding Ca(2+) ions. In this study, we applied comparative two-dimensional gel electrophoresis to characterize differentially expressed proteins in HA-CHIP over-expressed and endogenous CHIP depleted MC3T3-E1 stable cell lines, identifying NUCB1 as a novel CHIP/Stub1 targeted protein. NUCB1 interacts with and is down-regulated by CHIP by both proteasomal dependent and independent pathways, suggesting that CHIP-mediated down-regulation of nucleobindin-1 might play a role in osteoblast differentiation. The chaperone protein Hsp70 was found to be important for CHIP and NUCB1 interaction as well as CHIP-mediated NUCB1 down-regulation. Our findings provide new insights into understanding the stability regulation of NUCB1.

  12. Curcumin downregulates homeobox gene NKX3.1 in prostate cancer cell LNCaP

    Institute of Scientific and Technical Information of China (English)

    Hui-na ZHANG; Chun-xiao YU; Peng-ju ZHANG; Wei-wen CHEN; An-li JIANG; Feng KONC; Jing-ti DENG; Jian-ye ZHANG; Charles YF YOUNG

    2007-01-01

    Aim: To elucidate the effect and the mechanisms of curcumin on the expression of the human homeobox gene NKX3.1 in the prostate cancer cell LNCaP. Methods:The expression change of NKX3.1 in cells incubated with varying concentrations of curcumin was observed by Western blotting and RT-PCR. A dual luciferase reporter assay was used to test the effect of curcumin on the activity of the NKX3.11040 bp promoter. Curcumin-treated cells disposed to a designated amount of androgen analog R 1881 and the androgen receptor (AR) antagonist flutamide,then the expression of NKX3.1 or the activity of the NKX3.1 promoter were inves-tigated by Western blotting or reporter gene assay, respectively. Finally, Western blotting and electrophoretic mobility shift assay were performed to demonstrate the effect of curcumin on the expression of AR and its binding activity to the androgen response element (ARE). Results: Curcumin downregulated the ex-pression of NKX3.1 and the activity of the NKX3.1 1040 bp promoter in LNCaP cells. R1881 increased the expression of NKX3.1, and theAR antagonist flutamide decreased the expression of NKX3.1 in LNCaP cells, while curcumin could inhibit androgen-AR mediated induction of NKX3.1 expression. Curcumin decreased the expression of AR and the binding activity to ARE directly. Conclusion: Curcumin could downregulate NKX3.1 expression in LNCaP cells. It could also inhibit the androgen-AR mediated induction of NKX3.1 expression by downregulating AR expression and blocking its DNA binding activity.

  13. Physical and functional association between thymic shared antigen-1/stem cell antigen-2 and the T cell receptor complex.

    Science.gov (United States)

    Kosugi, A; Saitoh, S; Noda, S; Miyake, K; Yamashita, Y; Kimoto, M; Ogata, M; Hamaoka, T

    1998-05-15

    Thymic shared antigen-1 (TSA-1)/stem cell Ag-2 (Sca-2) is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes. We have previously demonstrated that a signal via TSA-1/Sca-2 inhibits T cell receptor (TCR)-mediated T cell activation and apoptosis. To elucidate a molecular mechanism for TSA-1-mediated modulation of the TCR-signaling pathway, we examined whether TSA-1 is physically coupled to the TCR in the present study. TSA-1 was clearly associated with CD3zeta chains in T cell hybridomas, activated T cells, and COS-7 cells transfected with TSA-1 and CD3zeta cDNA. The physical association was confirmed on the surface of T cells in immunoprecipitation and confocal microscopy. The analysis using stable and transient transfectants expressing a transmembrane form of TSA-1 revealed that the association of CD3zeta did not require the GPI anchor of TSA-1. Finally, tyrosine phosphorylation of CD3zeta chains was induced after stimulation with anti-TSA-1, suggesting that a functional association between these two molecules also exists. These results imply that the physical association to CD3zeta underlies a regulatory role of TSA-1/Sca-2 in the TCR-signaling pathway.

  14. Ovatodiolide Inhibits Breast Cancer Stem/Progenitor Cells through SMURF2-Mediated Downregulation of Hsp27

    Science.gov (United States)

    Lu, Kuan-Ta; Wang, Bing-Yen; Chi, Wan-Yu; Chang-Chien, Ju; Yang, Jiann-Jou; Lee, Hsueh-Te; Tzeng, Yew-Min; Chang, Wen-Wei

    2016-01-01

    Cancer stem/progenitor cells (CSCs) are a subpopulation of cancer cells involved in tumor initiation, resistance to therapy and metastasis. Targeting CSCs has been considered as the key for successful cancer therapy. Ovatodiolide (Ova) is a macrocyclic diterpenoid compound isolated from Anisomeles indica (L.) Kuntze with anti-cancer activity. Here we used two human breast cancer cell lines (AS-B145 and BT-474) to examine the effect of Ova on breast CSCs. We first discovered that Ova displayed an anti-proliferation activity in these two breast cancer cells. Ova also inhibited the self-renewal capability of breast CSCs (BCSCs) which was determined by mammosphere assay. Ova dose-dependently downregulated the expression of stemness genes, octamer-binding transcription factor 4 (Oct4) and Nanog, as well as heat shock protein 27 (Hsp27), but upregulated SMAD ubiquitin regulatory factor 2 (SMURF2) in mammosphere cells derived from AS-B145 or BT-474. Overexpression of Hsp27 or knockdown of SMURF2 in AS-B145 cells diminished the therapeutic effect of ovatodiolide in the suppression of mammosphere formation. In summary, our data reveal that Ova displays an anti-CSC activity through SMURF2-mediated downregulation of Hsp27. Ova could be further developed as an anti-CSC agent in the treatment of breast cancer. PMID:27136586

  15. Ovatodiolide Inhibits Breast Cancer Stem/Progenitor Cells through SMURF2-Mediated Downregulation of Hsp27

    Directory of Open Access Journals (Sweden)

    Kuan-Ta Lu

    2016-04-01

    Full Text Available Cancer stem/progenitor cells (CSCs are a subpopulation of cancer cells involved in tumor initiation, resistance to therapy and metastasis. Targeting CSCs has been considered as the key for successful cancer therapy. Ovatodiolide (Ova is a macrocyclic diterpenoid compound isolated from Anisomeles indica (L. Kuntze with anti-cancer activity. Here we used two human breast cancer cell lines (AS-B145 and BT-474 to examine the effect of Ova on breast CSCs. We first discovered that Ova displayed an anti-proliferation activity in these two breast cancer cells. Ova also inhibited the self-renewal capability of breast CSCs (BCSCs which was determined by mammosphere assay. Ova dose-dependently downregulated the expression of stemness genes, octamer-binding transcription factor 4 (Oct4 and Nanog, as well as heat shock protein 27 (Hsp27, but upregulated SMAD ubiquitin regulatory factor 2 (SMURF2 in mammosphere cells derived from AS-B145 or BT-474. Overexpression of Hsp27 or knockdown of SMURF2 in AS-B145 cells diminished the therapeutic effect of ovatodiolide in the suppression of mammosphere formation. In summary, our data reveal that Ova displays an anti-CSC activity through SMURF2-mediated downregulation of Hsp27. Ova could be further developed as an anti-CSC agent in the treatment of breast cancer.

  16. Salinomycin induces cell death via inactivation of Stat3 and downregulation of Skp2.

    Science.gov (United States)

    Koo, K H; Kim, H; Bae, Y-K; Kim, K; Park, B-K; Lee, C-H; Kim, Y-N

    2013-06-27

    Salinomycin has been shown to control breast cancer stem cells, although the mechanisms underlying its anticancer effects are not clear. Deregulation of cell cycle regulators play critical roles in tumorigenesis, and they have been considered as anticancer targets. In this study, we investigated salinomycin effect on cell cycle progression using OVCAR-8 ovarian cancer cell line and multidrug-resistant NCI/ADR-RES and DXR cell lines that are derived from OVCAR-8. Parental OVCAR-8 cells are sensitive to several anticancer drugs, but NCI/ADR-RES and DXR cells are resistant to several anticancer drugs. However, salinomycin caused cell growth inhibition and apoptosis via cell cycle arrest at G1 in all three cell lines. Salinomycin inhibited signal transducer and activator of transcription 3 (Stat3) activity and thus decreased expression of Stat3-target genes, including cyclin D1, Skp2, and survivin. Salinomycin induced degradation of Skp2 and thus accumulated p27Kip1. Knockdown of Skp2 further increased salinomycin-induced G1 arrest, but knockdown of p27Kip1 attenuated salinomycin effect on G1 arrest. Cdh1, an E3 ligase for Skp2, was shifted to nuclear fractions upon salinomycin treatment. Cdh1 knockdown by siRNA reversed salinomycin-induced Skp2 downregulation and p27Kip1 upregulation, indicating that salinomycin activates the APC(Cdh1)-Skp2-p27Kip1 pathway. Concomitantly, si-Cdh1 inhibited salinomycin-induced G1 arrest. Taken together, our data indicate that salinomycin induces cell cycle arrest and apoptosis via downregulation or inactivation of cell cycle-associated oncogenes, such as Stat3, cyclin D1, and Skp2, regardless of multidrug resistance.

  17. Autoantibodies in autoimmune thyroid disease promote immune complex formation with self antigens and increase B cell and CD4+ T cell proliferation in response to self antigens

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Hegedüs, Laszlo; Leslie, Robert Graham Quinton

    2004-01-01

    B cells are centrally involved as antigen-presenting cells in certain autoimmune diseases. To establish whether autoantibodies form immune complexes (IC) with self-antigens in autoimmune thyroid disease (AITD) and promote B cell uptake of self-antigen, sera from patients with Hashimoto......'s thyroiditis (HT), Graves' disease (GD) and healthy controls were incubated with human thyroglobulin (Tg) before adding normal peripheral blood mononuclear cells. The deposition of immunoglobulins and C3 fragments on B cells was then assessed. Inclusion of Tg in serum from HT patients promoted B cell capture...

  18. Do FY antigens act as minor histocompatibility antigens in the graft-versus-host disease paradigm after human leukocyte antigen-identical sibling hematopoietic stem cell transplantation?

    Science.gov (United States)

    Sellami, Mohamed Hichem; Chaabane, Manel; Kaabi, Houda; Torjemane, Lamia; Ladeb, Saloua; Ben Othmane, Tarek; Hmida, Slama

    2012-03-01

    FY antigens are candidate minor histocompatibility antigens relevant to renal allograft rejection, but no data have been reported about their role in graft-versus-host disease (GVHD) incidence after human leukocyte antigen (HLA)-identical siblings hematopoietic stem cell transplantation (HSCT). The aim of this study was to examine the effect of donor/recipient disparity at FY antigens on the incidence of GVHD in Tunisian patients receiving an HLA-identical HSCT. This work enrolled 105 Tunisian pairs of recipients and their HLA-identical sibling donors of HSCs. FY genotyping was performed with the polymerase chain reaction-sequence-specific primer method and donor/recipient disparity for these antigens was analyzed at two levels: incompatibility and nonidentity. The case-control analyses showed no significant correlation between FY disparity and the incidence of either acute or chronic GVHD. Sample size calculation showed that 572 cases and 1716 controls would be necessary to be able to detect a significant association with 80% power and two-sided type I error level of 5% (α=0.05). The lack of association in the studied cohort may be explained by the low immunogenicity of FY antigens in HSCT context, compared with other antigens such as HA-1 and CD31.

  19. T cells expressing an anti-B-cell maturation antigen chimeric antigen receptor cause remissions of multiple myeloma.

    Science.gov (United States)

    Ali, Syed Abbas; Shi, Victoria; Maric, Irina; Wang, Michael; Stroncek, David F; Rose, Jeremy J; Brudno, Jennifer N; Stetler-Stevenson, Maryalice; Feldman, Steven A; Hansen, Brenna G; Fellowes, Vicki S; Hakim, Frances T; Gress, Ronald E; Kochenderfer, James N

    2016-09-29

    Therapies with novel mechanisms of action are needed for multiple myeloma (MM). B-cell maturation antigen (BCMA) is expressed in most cases of MM. We conducted the first-in-humans clinical trial of chimeric antigen receptor (CAR) T cells targeting BCMA. T cells expressing the CAR used in this work (CAR-BCMA) specifically recognized BCMA-expressing cells. Twelve patients received CAR-BCMA T cells in this dose-escalation trial. Among the 6 patients treated on the lowest 2 dose levels, limited antimyeloma activity and mild toxicity occurred. On the third dose level, 1 patient obtained a very good partial remission. Two patients were treated on the fourth dose level of 9 × 10(6) CAR(+) T cells/kg body weight. Before treatment, the first patient on the fourth dose level had chemotherapy-resistant MM, making up 90% of bone marrow cells. After treatment, bone marrow plasma cells became undetectable by flow cytometry, and the patient's MM entered a stringent complete remission that lasted for 17 weeks before relapse. The second patient on the fourth dose level had chemotherapy-resistant MM making up 80% of bone marrow cells before treatment. Twenty-eight weeks after this patient received CAR-BCMA T cells, bone marrow plasma cells were undetectable by flow cytometry, and the serum monoclonal protein had decreased by >95%. This patient is in an ongoing very good partial remission. Both patients treated on the fourth dose level had toxicity consistent with cytokine-release syndrome including fever, hypotension, and dyspnea. Both patients had prolonged cytopenias. Our findings demonstrate antimyeloma activity of CAR-BCMA T cells. This trial was registered to www.clinicaltrials.gov as #NCT02215967.

  20. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Takabe, Piia, E-mail: piia.takabe@uef.fi [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Bart, Geneviève [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Ropponen, Antti [University of Eastern Finland, Institute of Clinical Medicine, 70211 Kuopio (Finland); Rilla, Kirsi; Tammi, Markku; Tammi, Raija; Pasonen-Seppänen, Sanna [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland)

    2015-09-10

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma.

  1. Glucosamine Modulates T Cell Differentiation through Down-regulating N-Linked Glycosylation of CD25.

    Science.gov (United States)

    Chien, Ming-Wei; Lin, Ming-Hong; Huang, Shing-Hwa; Fu, Shin-Huei; Hsu, Chao-Yuan; Yen, B Lin-Ju; Chen, Jiann-Torng; Chang, Deh-Ming; Sytwu, Huey-Kang

    2015-12-04

    Glucosamine has immunomodulatory effects on autoimmune diseases. However, the mechanism(s) through which glucosamine modulates different T cell subsets and diseases remain unclear. We demonstrate that glucosamine impedes Th1, Th2, and iTreg but promotes Th17 differentiation through down-regulating N-linked glycosylation of CD25 and subsequently inhibiting its downstream Stat5 signaling in a dose-dependent manner. The effect of glucosamine on T helper cell differentiation was similar to that induced by anti-IL-2 treatment, further supporting an IL-2 signaling-dependent modulation. Interestingly, excess glucose rescued this glucosamine-mediated regulation, suggesting a functional competition between glucose and glucosamine. High-dose glucosamine significantly decreased Glut1 N-glycosylation in Th1-polarized cells. This finding suggests that both down-regulated IL-2 signaling and Glut1-dependent glycolytic metabolism contribute to the inhibition of Th1 differentiation by glucosamine. Finally, glucosamine treatment inhibited Th1 cells in vivo, prolonged the survival of islet grafts in diabetic recipients, and exacerbated the severity of EAE. Taken together, our results indicate that glucosamine interferes with N-glycosylation of CD25, and thereby attenuates IL-2 downstream signaling. These effects suggest that glucosamine may be an important modulator of T cell differentiation and immune homeostasis.

  2. Hypoxia and Human Genome Stability: Downregulation of BRCA2 Expression in Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Daniele Fanale

    2013-01-01

    Full Text Available Previously, it has been reported that hypoxia causes increased mutagenesis and alteration in DNA repair mechanisms. In 2005, an interesting study showed that hypoxia-induced decreases in BRCA1 expression and the consequent suppression of homologous recombination may lead to genetic instability. However, nothing is yet known about the involvement of BRCA2 in hypoxic conditions in breast cancer. Initially, a cell proliferation assay allowed us to hypothesize that hypoxia could negatively regulate the breast cancer cell growth in short term in vitro studies. Subsequently, we analyzed gene expression in breast cancer cell lines exposed to hypoxic condition by microarray analysis. Interestingly, genes involved in DNA damage repair pathways such as mismatch repair, nucleotide excision repair, nonhomologous end-joining and homologous recombination repair were downregulated. In particular, we focused on the BRCA2 downregulation which was confirmed at mRNA and protein level. In addition, breast cancer cells were treated with dimethyloxalylglycine (DMOG, a cell-permeable inhibitor of both proline and asparaginyl hydroxylases able to induce HIF-1α stabilization in normoxia, providing results comparable to those previously described. These findings may provide new insights into the mechanisms underlying genetic instability mediated by hypoxia and BRCA involvement in sporadic breast cancers.

  3. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  4. Downregulation of the tumor suppressor HSPB7, involved in the p53 pathway, in renal cell carcinoma by hypermethylation

    OpenAIRE

    2014-01-01

    In order to identify genes involved in renal carcinogenesis, we analyzed the expression profile of renal cell carcinomas (RCCs) using microarrays consisting of 27,648 cDNA or ESTs, and found a small heat shock protein, HSPB7, to be significantly and commonly downregulated in RCC. Subsequent quantitative PCR (qPCR) and immunohistochemical (IHC) analyses confirmed the downregulation of HSPB7 in RCC tissues and cancer cell lines in both transcriptional and protein levels. Bisulfite sequencing of...

  5. Nucleolin down-regulation is involved in ADP-induced cell cycle arrest in S phase and cell apoptosis in vascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Wenmeng Wang

    Full Text Available High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC and human aortic endothelial cells (HAEC down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin.

  6. Pattern of distribution of blood group antigens on human epidermal cells during maturation

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Buschard, Karsten; Hakomori, Sen-Itiroh

    1984-01-01

    The distribution in human epidermis of A, B, and H blood group antigens and of a precursor carbohydrate chain, N-acetyl-lactosamine, was examined using immunofluorescence staining techniques. The material included tissue from 10 blood group A, 4 blood group B, and 9 blood group O persons. Murine...... on the lower spinous cells whereas H antigen was seen predominantly on upper spinous cells or on the granular cells. Epithelia from blood group A or B persons demonstrated A or B antigens, respectively, but only if the tissue sections were trypsinized before staining. In such cases A or B antigens were found...... monoclonal antibodies were used to identify H antigen (type 2 chain) and N-acetyl-lactosamine. Human antisera were used to identify A and B antigens. In all groups N-acetyl-lactosamine and H antigen were found on the cell membranes of the spinous cell layer. N-acetyl-lactosamine was present mainly...

  7. Mechanical stress downregulates MHC class I expression on human cancer cell membrane.

    Directory of Open Access Journals (Sweden)

    Rosanna La Rocca

    Full Text Available In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal, depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700-1800 cm(-1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK cells cytotoxic recognition.

  8. Mechanical stress downregulates MHC class I expression on human cancer cell membrane.

    Science.gov (United States)

    La Rocca, Rosanna; Tallerico, Rossana; Talib Hassan, Almosawy; Das, Gobind; Lakshmikanth, Tadepally; Tadepally, Lakshmikanth; Matteucci, Marco; Liberale, Carlo; Mesuraca, Maria; Scumaci, Domenica; Gentile, Francesco; Cojoc, Gheorghe; Perozziello, Gerardo; Ammendolia, Antonio; Gallo, Adriana; Kärre, Klas; Cuda, Giovanni; Candeloro, Patrizio; Di Fabrizio, Enzo; Carbone, Ennio

    2014-01-01

    In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells) was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700-1800 cm(-1), indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK) cells cytotoxic recognition.

  9. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    KAUST Repository

    La Rocca, Rosanna

    2014-12-26

    In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells) was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700–1800 cm−1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK) cells cytotoxic recognition.

  10. VILIP-1 downregulation in non-small cell lung carcinomas: mechanisms and prediction of survival.

    Directory of Open Access Journals (Sweden)

    Jian Fu

    Full Text Available VILIP-1, a member of the neuronal Ca++ sensor protein family, acts as a tumor suppressor gene in an experimental animal model by inhibiting cell proliferation, adhesion and invasiveness of squamous cell carcinoma cells. Western Blot analysis of human tumor cells showed that VILIP-1 expression was undetectable in several types of human tumor cells, including 11 out of 12 non-small cell lung carcinoma (NSCLC cell lines. The down-regulation of VILIP-1 was due to loss of VILIP-1 mRNA transcripts. Rearrangements, large gene deletions or mutations were not found. Hypermethylation of the VILIP-1 promoter played an important role in gene silencing. In most VILIP-1-silent cells the VILIP-1 promoter was methylated. In vitro methylation of the VILIP-1 promoter reduced its activity in a promoter-reporter assay. Transcriptional activity of endogenous VILIP-1 promoter was recovered by treatment with 5'-aza-2'-deoxycytidine (5'-Aza-dC. Trichostatin A (TSA, a histone deacetylase inhibitor, potently induced VILIP-1 expression, indicating that histone deacetylation is an additional mechanism of VILIP-1 silencing. TSA increased histone H3 and H4 acetylation in the region of the VILIP-1 promoter. Furthermore, statistical analysis of expression and promoter methylation (n = 150 primary NSCLC samples showed a significant relationship between promoter methylation and protein expression downregulation as well as between survival and decreased or absent VILIP-1 expression in lung cancer tissues (p<0.0001. VILIP-1 expression is silenced by promoter hypermethylation and histone deacetylation in aggressive NSCLC cell lines and primary tumors and its clinical evaluation could have a role as a predictor of short-term survival in lung cancer patients.

  11. Mycobacterium leprae downregulates the expression of PHEX in Schwann cells and osteoblasts

    Directory of Open Access Journals (Sweden)

    Sandra R Boiça Silva

    2010-08-01

    Full Text Available Neuropathy and bone deformities, lifelong sequelae of leprosy that persist after treatment, result in significant impairment to patients and compromise their social rehabilitation. Phosphate-regulating gene with homologies to endopeptidase on the X chromosome (PHEX is a Zn-metalloendopeptidase, which is abundantly expressed in osteoblasts and many other cell types, such as Schwann cells, and has been implicated in phosphate metabolism and X-linked rickets. Here, we demonstrate that Mycobacterium leprae stimulation downregulates PHEX transcription and protein expression in a human schwannoma cell line (ST88-14 and human osteoblast lineage. Modulation of PHEX expression was observed to a lesser extent in cells stimulated with other species of mycobacteria, but was not observed in cultures treated with latex beads or with the facultative intracellular bacterium Salmonella typhimurium. Direct downregulation of PHEX by M. leprae could be involved in the bone resorption observed in leprosy patients. This is the first report to describe PHEX modulation by an infectious agent.

  12. Antigen Processing by Autoreactive B Cells Promotes Determinant Spreading

    Institute of Scientific and Technical Information of China (English)

    Yang D.Dai; George Carayanniotis; Eli Sercarz

    2005-01-01

    Acute primary immune responses tend to focus on few immunodominant determinants using a very limited number of T cell clones for expansion, whereas chronic inflammatory responses generally recruit a large number of different T cell clones to attack a broader range of determinants of the invading pathogens or the inflamed tissues.In T cell-mediated organ-specific autoimmune disease, a transition from the acute to the chronic phase contributes to pathogenesis, and the broadening process is called determinant spreading. The cellular components catalyzing the spreading reaction are not identified. It has been suggested that autoreactive B cells may play a central role in diversifying autoreactive T cell responses, possibly through affecting antigen processing and presentation. The clonal identity and diversity of the B cells and antibodies seem critical in regulating T cell activity and subsequent tissue damage or repair. Here, we use two autoimmune animal models, experimental autoimmune thyroiditis (EAT)and type 1 diabetes (T1D), to discuss how autoreactive B cells or antibodies alter the processing and presentation of autoantigens to regulate specific T cell response.

  13. Tetrahydrocurcumin inhibits HT1080 cell migration and invasion via downregulation of MMPs and uPA

    Institute of Scientific and Technical Information of China (English)

    Supachai YODKEEREE; Spiridione GARBISA; Pomngarm LIMTRAKUL

    2008-01-01

    Aim: Tetrahydrocurcumin (THC) is an active metabolite of curcumin. It has been reported to have similar pharmacological activity to curcumin. The proteases that participate in extracellular matrix (ECM) degradation are involved in cancer cell metastasis. The present study investigates the effect of an ultimate metabolite of curcumin, THC, on the invasion and motility of highly-metastatic HT1080 human fibrosarcoma cells. Methods: The effect of THC on HTI080 cell invasion and migration was determined using Boyden chamber assay. Cell-adhesion assay was used for examining the binding of cells to ECM molecules. Zymography assay was used to analyze the effect of THC on matrix metalloproteinase (MMP)-2, MMP-9, and urokinase plasminogen activator (uPA) secretion from HT1080 cells. Tissue inhibitor of metalloproteinase (TIMP)-2 and membrane-type 1 matrix metalloproteinase (MT1-MMP) proteins levels were analyzed by Western blotting. Results: Treatment with THC reduced HT1080 cell invasion and migration in a dose-dependent manner. THC also decreased the cell adhesion to Matrigel and laminin-coated plates. Analysis by zymography demonstrated that treatment with THC reduced the levels of MMP-2, MMP-9, and uPA. THC also inhibited the levels of MT1-MMP and TIMP-2 proteins detected by Western blot analysis. Conclusion: Our findings revealed that THC reduced HT1080 cell invasion and migration. The inhibition of cancer cell invasion is associated with the downregulation of ECM degradation enzymes and the inhibition of cell adhesion to ECM proteins.

  14. MiR-9 downregulates CDX2 expression in gastric cancer cells.

    Science.gov (United States)

    Rotkrua, Pichayanoot; Akiyama, Yoshimitsu; Hashimoto, Yutaka; Otsubo, Takeshi; Yuasa, Yasuhito

    2011-12-01

    Ectopic expression of CDX2, a caudal-related homeobox protein, is known to be associated with the development of intestinal metaplasia in the stomach and gastric carcinogenesis. Previously, we reported that DNA methylation was partly responsible for CDX2 silencing in gastric cancer (GC). However, the mechanism underlying the aberrant expression of CDX2 during malignant transformation remained unclear. MicroRNAs (miRNAs) are small non-coding RNAs that function as post-transcriptional regulators. To elucidate the role of miRNAs in CDX2 downregulation in GC cells, putative miRNAs, such as miR-9, were computationally predicted. After exogenous pre-miR-9 precursor transfection, the luciferase activity of a reporter vector containing a part of the 3'-UTR of CDX2 was downregulated in HEK-293T cells. The inverse correlation between the miR-9 and CDX2 protein levels was demonstrated in GC cell lines. By means of miR-9 overexpression and knockdown techniques, the expression levels of the CDX2 protein and downstream target genes (p21, MUC2 and TFF3) were responsively altered in MKN45 and NUGC-3 cells. Transfection of an anti-miR-9 molecule significantly inhibited cell growth by promoting G(1) cell cycle arrest in MKN45 cells similarly to the effect of CDX2 overexpression. Moreover, examination of the miR-9 levels in primary GC tissues revealed that the amounts of miR-9 in the CDX2-negative group were significantly higher than those in the CDX2-positive group (p = 0.004). Therefore, miR-9 might repress CDX2 expression via the binding site in the 3'-UTR, resulting in the promotion of cell proliferation in GCs.

  15. microRNA-143 down-regulates Hexokinase 2 in colon cancer cells

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Jacobsen, Anders; Frankel, Lisa;

    2012-01-01

    -regulated in several cancers including colon cancer. METHODS: To gain insight into the role of miR-143 in colon cancer, we used a microarray-based approach in combination with seed site enrichment analysis to identify miR-143 targets. RESULTS: As expected, transcripts down-regulated upon miR-143 overexpression had...... a significant enrichment of miR-143 seed sites in their 3' UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion. CONCLUSION: We have identified...... and validated HK2 as a miR-143 target. Furthermore, our results indicate that miR-143 mediated down-regulation of HK2 affects glucose metabolism in colon cancer cells. We hypothesize that loss of miR-143-mediated repression of HK2 can promote glucose metabolism in cancer cells, contributing to the shift towards...

  16. Down-Regulation of Bcl-2 Protein Sensitizes NCI 460 Cells to Radiotherapy-Induced Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Dongmei He; Yuan Zhang; Gexiu Liu

    2006-01-01

    OBJECTIVE To determine whether Bcl-2 protein down-regulation can render NCI-460 cells more susceptible to gamma radiation-induced apoptosis by treatment with antisense oligonucleotide (ASODN) against the coding region of Bcl-2 mRNA.METHODS Cell survival was determined using the trypan blue dye exclusion. Expression of the Bcl-2 protein was assayed using immunofluorescence labeling with fluoresce isothiocyanate. Apoptosis was determined by Giemsa staining and flow cytomertry.RESULTS It was found that Bcl-2 ASODN combined with radiation significantly reduced the number of viable cells (P<0.05). There was no difference in cell survival between a nonsense oligodeoxynucleotide/radiation combination and cells treated with radiation alone. Bcl-2 ASODN combined with radiation significantly inhibited expression of the Bcl-2protein in the NCI-H460 cells (P<0.05). Using Giemsa staining, cells treated with Bcl-2 ASODN combined with radiation at 72 h displayed classic apoptotic changes. Apoptotic rates of the NCI-H460 cells treated with Bcl-2 ASODN combined with radiation significantly increased (P<0.05), compared with either a nonsense oligodeoxynucleotide/radiation combination or radiation-treatment cells alone.CONCLUSION ASODN against the coding region of Bcl-2 mRNA increases radiation-induced apoptosis in NCI-H460 cells.

  17. Liposome-coupled antigens are internalized by antigen-presenting cells via pinocytosis and cross-presented to CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Yuriko Tanaka

    Full Text Available We have previously demonstrated that antigens chemically coupled to the surface of liposomes consisting of unsaturated fatty acids were cross-presented by antigen-presenting cells (APCs to CD8+ T cells, and that this process resulted in the induction of antigen-specific cytotoxic T lymphocytes. In the present study, the mechanism by which the liposome-coupled antigens were cross-presented to CD8+ T cells by APCs was investigated. Confocal laser scanning microscopic analysis demonstrated that antigens coupled to the surface of unsaturated-fatty-acid-based liposomes received processing at both MHC class I and class II compartments, while most of the antigens coupled to the surface of saturated-fatty-acid-based liposomes received processing at the class II compartment. In addition, flow cytometric analysis demonstrated that antigens coupled to the surface of unsaturated-fatty-acid-liposomes were taken up by APCs even in a 4°C environment; this was not true of saturated-fatty-acid-liposomes. When two kinds of inhibitors, dimethylamiloride (DMA and cytochalasin B, which inhibit pinocytosis and phagocytosis by APCs, respectively, were added to the culture of APCs prior to the antigen pulse, DMA but not cytochalasin B significantly reduced uptake of liposome-coupled antigens. Further analysis of intracellular trafficking of liposomal antigens using confocal laser scanning microscopy revealed that a portion of liposome-coupled antigens taken up by APCs were delivered to the lysosome compartment. In agreement with the reduction of antigen uptake by APCs, antigen presentation by APCs was significantly inhibited by DMA, and resulted in the reduction of IFN-γ production by antigen-specific CD8+ T cells. These results suggest that antigens coupled to the surface of liposomes consisting of unsaturated fatty acids might be pinocytosed by APCs, loaded onto the class I MHC processing pathway, and presented to CD8+ T cells. Thus, these liposome-coupled antigens

  18. NF-KB downregulation may be involved the depression of tumor cell proliferation mediated by human mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Ling QIAO; Tie-jun ZHAO; Feng-ze WANG; Chang-liang SHAN; Li-hong YE; Xiao-dong ZHANG

    2008-01-01

    Aim:It has been reported that stem cells are able to home to tumorigenesis and inhibit the proliferation of tumor cells.The purpose of our study was to demon-strate the molecular mechanism of the inhibitory proliferation of hepatoma cells and breast cancer cells mediated by human mesenchymal stem cells (hMSCs).Methods:The proliferation of H7402 human hepatoma cells and MCF-7 human breast cancer cells was measured by the 5-bromodeoxyuridine (BrdU) incorpora-tion assay and flow cytometry assay after the treatment with conditioned media from hMSCs culture,such as Z3 cells or BMMS-03 cells.The role of NF-kB or the phosphorylation of inhibitor kBoα (p-IkBα) in the depression of hepatoma or breast cancer cells treated with conditioned media from Z3 cells or BMMS-03 cells was examined by reporter gene assay,quantitative real-time PCR,and Western blot analysis,respectively.Results:The proliferation of H7402 cells and MCF-7 cells was decreased significantly by the BrdU incorporation assay and flow cytometry assay after treatment.The transcriptional activity and mRNA level of NF-kB were downregulated in the treated cells by reporter gene assay and quantitative real-time PCR in a dose-dependent manner.At the protein level,NF-kB and p-IkBα decreased in the treated cells by Western blot analysis.Conclusion:Conditioned media from hMSCs are able to inhibit the proliferation of tumor cells.NF-kB downregulation is one of reasons for the depression of tumor cell proliferation mediated by hMSCs.

  19. An Immunohistochemical Study of Langerhans Cells,T-Cells and the HLA Antigen in Human Cornea

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    The distribution of Langerhans cells (LC),T-cell subsets andHLA antigen in 12 normal and 7 morbid corneas,including 4 of suppurativecorneal ulcer and 3 of uveogenic endophthalmitis,was investigated withmonoclonal antibodies.The results revealed that a small amount of LC andT-cell subsets were present in the limbal region of normal corneas,whilelarge numbers of LC and OKT_4~+ were observed in the corneas of suppurativeulcer.HLA-A,B,C antigens were expressed on the epithelial cells andkeratocytes of the n...

  20. Downregulation of SOK1 promotes the migration of MCF-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xu-Dong, E-mail: xudongchen305@hotmail.com [Key Lab of Molecular Medicine, Ministry of Education, Shanghai Medical College, Fudan University, Shanghai (China); Cho, Chien-Yu [Department of Biochemistry, College of Medicine, National Cheng Kung University, Taiwan (China)

    2011-04-08

    Highlights: {yields} SOK1 is a member of GCK-III subfamily. It is activated by oxidative stress or chemical anoxia. {yields} Barr's group have found that autophosphorylation of SOK1 is triggered by binding to the Golgi matrix protein GM130 and made the cells migration through dimeric adaptor protein 14-3-3. {yields} But what we found is that downregulation of SOK1 promotes cell migration and leads to the upregulation of GM130 and Tyr861 of FAK in MCF-7 cells. -- Abstract: SOK1 is a member of the germinal center kinase (GCK-III) subfamily but little is known about it, particularly with respect to its role in signal transduction pathways relative to tumor metastasis. By stably transfecting SOK1 siRNA into the MCF-7 breast cancer cell line we found that SOK1 promotes the migration of MCF-7 cells, as determined using wound-healing and Boyden chamber assays. However, cell proliferation assays revealed that silencing SOK1 had no effect on cell growth relative to the normal cells. Silencing SOK1 also had an effect on the expression and phosphorylation status of a number of proteins in MCF-7 cells, including FAK and GM130, whereby a decrease in SOK1 led to an increase in the expression of these proteins.

  1. MARCH1 down-regulation in IL-10-activated B cells increases MHC class II expression.

    Science.gov (United States)

    Galbas, Tristan; Steimle, Viktor; Lapointe, Réjean; Ishido, Satoshi; Thibodeau, Jacques

    2012-07-01

    IL-10 is vastly studied for its anti-inflammatory properties on most immune cells. However, it has been reported that IL-10 activates B cells, up-regulates their MHC class II molecules and prevents apoptosis. As MARCH1 was shown to be responsible for the intracellular sequestration of MHC class II molecules in dendritic cells and monocytes in response to IL-10, we set out to clarify the role of this ubiquitin ligase in B cells. Here, we demonstrate in mice that splenic follicular B cells represent the major cell population that up-regulate MHC II molecules in the presence of IL-10. Activation of these cells through TLR4, CD40 or the IL-10 receptor caused the down-regulation of MARCH1 mRNA. Accordingly, B cells from MARCH1-deficient mice do not up-regulate I-A(b) in response to IL-10. In all, our results demonstrate that IL-10 can have opposite effects on MARCH1 regulation in different cell types.

  2. Fra-1 is downregulated in cervical cancer tissues and promotes cervical cancer cell apoptosis by p53 signaling pathway in vitro.

    Science.gov (United States)

    Xiao, Songshu; Zhou, Yanhong; Yi, Wei; Luo, Guijuan; Jiang, Bin; Tian, Qi; Li, Yueran; Xue, Min

    2015-04-01

    Cervical cancer is a potentially preventable disease; however, it is the third most commonly diagnosed cancer and the fourth leading cause of cancer deaths in women worldwide. Cervical cancer is thought to develop through a multistep process involving virus, tumor suppressor genes, proto-oncogenes and immunological factors. It is known that human papillomavirus (HPV) infection is necessary but insufficient to cause malignancy. At present, the etiology of cervical carcinoma remains poorly understood. In this study, we found that the expression of FOS-like antigen-1 (Fra-1) gene was downregulated in cervical cancer compared with the adjacent non-cancerous tissues by RT-qPCR, immunohistochemistry (IHC) and western blotting techniques. To uncover the effect of Fra-1 on cervical cancer, we tested and confirmed that Fra-1 significantly inhibited the proliferation of HeLa cells by MMT assays in vitro. At the same time, overexpression of Fra-1 promoted apoptosis of HeLa cells. To explore the possible mechanism of Fra-1 in cervical cancer, we tested the expression levels of key molecules in p53 signaling pathway by western blotting technology. The results showed that p53 was downregulated in cervical cancer compared with the adjacent non-cancerous tissues, but MDM2 proto-oncogene, E3 ubiquitin protein ligase (MDM2) was upregulated in cervical cancer. In vitro, the p53 was upregulated and MDM2 was downregulated in HeLa cells with Fra-1 overexpression. In summary, our results suggested that Fra-1 expression is low in cervical cancer tissues and promotes apoptosis of cervical cancer cells by p53 signaling pathway.

  3. Sperm associated antigen 9 plays an important role in bladder transitional cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Deepika Kanojia

    Full Text Available BACKGROUND: Majority of bladder cancer deaths are caused due to transitional cell carcinoma (TCC which is the most prevalent and chemoresistant malignancy of urinary bladder. Therefore, we analyzed the role of Sperm associated antigen 9 (SPAG9 in bladder TCC. METHODOLOGY AND FINDINGS: We examined SPAG9 expression and humoral response in 125 bladder TCC patients. Four bladder cancer cell lines were assessed for SPAG9 expression. In addition, we investigated the effect of SPAG9 ablation on cellular proliferation, cell cycle, migration and invasion in UM-UC-3 bladder cancer cells by employing gene silencing approach. Our SPAG9 gene and protein expression analysis revealed SPAG9 expression in 81% of bladder TCC tissue specimens. High SPAG9 expression (>60% SPAG9 positive cells was found to be significantly associated with superficial non-muscle invasive stage (P = 0.042 and low grade tumors (P = 0.002 suggesting SPAG9 putative role in early spread and tumorigenesis. Humoral response against SPAG9 was observed in 95% of patients found positive for SPAG9 expression. All four bladder cancer cell lines revealed SPAG9 expression. In addition, SPAG9 gene silencing in UM-UC-3 cells resulted in induction of G0-G1 arrest characterized by up-regulation of p16 and p21 and consequent down-regulation of cyclin E, cyclin D and cyclin B, CDK4 and CDK1. Further, SPAG9 gene silencing also resulted in reduction in cellular growth, and migration and invasion ability of cancer cells in vitro. CONCLUSIONS: Collectively, our data in clinical specimens indicated that SPAG9 is potential biomarker and therapeutic target for bladder TCC.

  4. An Overview of B-1 Cells as Antigen-Presenting Cells

    Science.gov (United States)

    Popi, Ana F.; Longo-Maugéri, Ieda M.; Mariano, Mario

    2016-01-01

    The role of B cells as antigen-presenting cells (APCs) has been extensively studied, mainly in relation to the activation of memory T cells. Considering the B cell subtypes, the role of B-1 cells as APCs is beginning to be explored. Initially, it was described that B-1 cells are activated preferentially by T-independent antigens. However, some reports demonstrated that these cells are also involved in a T-dependent response. The aim of this review is to summarize information about the ability of B-1 cells to play a role as APCs and to briefly discuss the role of the BCR and toll-like receptor signals in this process. Furthermore, some characteristics of B-1 cells, such as natural IgM production and phagocytic ability, could interfere in the participation of these cells in the onset of an adaptive response. PMID:27148259

  5. Dietary antigens limit mucosal immunity by inducing regulatory T cells in the small intestine.

    Science.gov (United States)

    Kim, Kwang Soon; Hong, Sung-Wook; Han, Daehee; Yi, Jaeu; Jung, Jisun; Yang, Bo-Gie; Lee, Jun Young; Lee, Minji; Surh, Charles D

    2016-02-19

    Dietary antigens are normally rendered nonimmunogenic through a poorly understood "oral tolerance" mechanism that involves immunosuppressive regulatory T (Treg) cells, especially Treg cells induced from conventional T cells in the periphery (pTreg cells). Although orally introducing nominal protein antigens is known to induce such pTreg cells, whether a typical diet induces a population of pTreg cells under normal conditions thus far has been unknown. By using germ-free mice raised and bred on an elemental diet devoid of dietary antigens, we demonstrated that under normal conditions, the vast majority of the small intestinal pTreg cells are induced by dietary antigens from solid foods. Moreover, these pTreg cells have a limited life span, are distinguishable from microbiota-induced pTreg cells, and repress underlying strong immunity to ingested protein antigens.

  6. Tunicamycin promotes apoptosis in leukemia cells through ROS generation and downregulation of survivin expression.

    Science.gov (United States)

    Lim, Eun Jin; Heo, Jeonghoon; Kim, Young-Ho

    2015-08-01

    Tunicamycin (TN), one of the endoplasmic reticulum stress inducers, has been reported to inhibit tumor cell growth and exhibit anticarcinogenic activity. However, the mechanism by which TN initiates apoptosis remains poorly understood. In the present study, we investigated the effect of TN on the apoptotic pathway in U937 cells. We show that TN induces apoptosis in association with caspase-3 activation, generation of reactive oxygen species (ROS), and downregulation of survivin expression. P38 MAPK (mitogen-activated protein kinase) and the generation of ROS signaling pathway play crucial roles in TN-induced apoptosis in U937 cells. We hypothesized that TN-induced activation of p38 MAPK signaling pathway is responsible for cell death. To test this hypothesis, we selectively inhibited MAPK during treatment with TN. Our data demonstrated that inhibitor of p38 (SB), but not ERK (PD) or JNK (SP), partially maintained apoptosis during treatment with TN. Pre-treatment with NAC and GSH markedly prevented cell death, suggesting a role for ROS in this process. Ectopic expression of survivin in U937 cells attenuated TN-induced apoptosis by suppression of caspase-3 cleavage, mitochondrial membrane potential, and cytochrome c release in U937 cells. Taken together, our results show that TN modulates multiple components of the apoptotic response of human leukemia cells and raise the possibility of a novel therapeutic strategy for hematological malignancies.

  7. Expression of interleukin-6 is downregulated by 17-(allylamino)-17-demethoxygeldanamycin in human prostatic carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Ke-hung TSUI; Tsui-hsia FENG; Wen-chi HSIEH; Phei-lang CHANG; Horng-heng JUANG

    2008-01-01

    Aim: Interleukin-6 (IL-6) is a pleiotropic cytokine that is associated with tumor metastasis and prostate cancer. We evaluated the mechanism and effect of 17-(allylamino)-17-demethoxygeldanamycin (17AAG), a novel inhibitor of heat shock protein 90 (Hsp90), on the IL-6 gene expression in human prostatic carcinoma (PC-3) cells. Methods: Quantitative IL-6 and IL-6 receptor (IL-6R) expressions were assessed using RT-PCR. The deregulation of 17AAG and phor-bol 12-myristate 13-acetate (PMA) on the IL-6 gene was determined by ELISA and transient gene expression assays using an IL-6 reporter vector. Results: Although the IL-6R is ubiquitously expressed by prostatic epithelium cells, the IL-6 expression is only found in advanced prostatic carcinoma cells, such as PC-3 and DU145. Further studies using RT-PCR indicated that 17AAG downregulated the gene expression of IL-6. ELISA and the transient gene expression assay revealed that 17AAG blocked the stimulation of PMA of IL-6 gene expression in PC-3 cells. The PMA-induced IL-6 gene expression is dependent on the NF-κB response element. However, the effect of 17AAG appears to be mediated via a region located at -149 to +8 bp upstream of the transcriptional starting site of the IL-6 gene, and might not be through the NF-κB signaling pathway. Conclusion: The present study reveals that IL-6 is transcriptionally downregulated in human prostatic carcinoma cells in response to 17AAG. This result suggests the presence of a novel Hsp90 mediation pathway that is involved in the deregulation on the transcription of the human IL-6 gene in human prostate cancer.

  8. Modes of Antigen Presentation by Lymph Node Stromal Cells and Their Immunological Implications.

    Science.gov (United States)

    Hirosue, Sachiko; Dubrot, Juan

    2015-01-01

    Antigen presentation is no longer the exclusive domain of cells of hematopoietic origin. Recent works have demonstrated that lymph node stromal cell (LNSC) populations, such as fibroblastic reticular cells, lymphatic and blood endothelial cells, not only provide a scaffold for lymphocyte interactions but also exhibit active immunomodulatory roles that are critical to mounting and resolving effective immune responses. Importantly, LNSCs possess the ability to present antigens and establish antigen-specific interactions with T cells. One example is the expression of peripheral tissue antigens, which are presented on major histocompatibility complex (MHC)-I molecules with tolerogenic consequences on T cells. Additionally, exogenous antigens, including self and tumor antigens, can be processed and presented on MHC-I complexes, which result in dysfunctional activation of antigen-specific CD8(+) T cells. While MHC-I is widely expressed on cells of both hematopoietic and non-hematopoietic origins, antigen presentation via MHC-II is more precisely regulated. Nevertheless, LNSCs are capable of endogenously expressing, or alternatively, acquiring MHC-II molecules. Transfer of antigen between LNSC and dendritic cells in both directions has been recently suggested to promote tolerogenic roles of LNSCs on the CD4(+) T cell compartment. Thus, antigen presentation by LNSCs is thought to be a mechanism that promotes the maintenance of peripheral tolerance as well as generates a pool of diverse antigen-experienced T cells for protective immunity. This review aims to integrate the current and emerging literature to highlight the importance of LNSCs in immune responses, and emphasize their role in antigen trafficking, retention, and presentation.

  9. Signal transduction by HLA class II antigens expressed on activated T cells

    DEFF Research Database (Denmark)

    Ødum, Niels; Martin, P J; Schieven, G L;

    1991-01-01

    Human T cells express HLA class II antigens upon activation. Although activated, class II+ T cells can present alloantigens under certain circumstances, the functional role of class II antigens on activated T cells remains largely unknown. Here, we report that cross-linking of HLA-DR molecules ex...

  10. Expression of maturation-specific nuclear antigens in differentiating human myeloid leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Murao, S.; Epstein, A.L.; Clevenger, C.V.; Huberman, E.

    1985-02-01

    The expression of three myeloid-specific nuclear antigens was studied by indirect immunofluorescence with murine monoclonal antibodies in human myeloid (HL-60, ML-2, KG-1, and B-II) leukemia cells treated with chemical inducers of cell differentiation. Treatment of the promyelocytic HL-60 cells with dimethyl sulfoxide or 1,25-dihydroxyvitamin DT induced the cells to acquire a phenotype that resembled that of granulocytes and monocytesmacrophages, respectively. These phenotypes were characterized by changes in cell growth, cell morphology, expression of specific cell surface antigens, and activities of lysozyme and nonspecific esterase enzymes. Induction of these differentiation markers in the HL-60 cells was associated with induction of the myeloid-specific nuclear antigens. The ML-2 cells, which are arrested at the myeloblast-promyelocyte stage, were also susceptible to the induction of cell differentiation and to changes in the expression of the nuclear antigens, but the degree of susceptibility was less than in the HL-60 cells. The less-differentiated KG-1 and B-II myeloid cells were either not responsive or responded only in a limited degree to the induction of cell differentiation or to changes in the expression of the nuclear antigens. The authors suggest that the reactivity of cells with monoclonal antibodies to specific nuclear antigens can be used as a maturational marker in cell differentiation studies. Furthermore, nuclear antigens expressed early in cellular differentiation may provide information about changes in regulatory elements in normal and malignant cells. 40 references, 2 figures, 1 table.

  11. Chemotactic migration of T cells towards dendritic cells promotes the detection of rare antigens.

    Directory of Open Access Journals (Sweden)

    Renske M A Vroomans

    Full Text Available In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data.

  12. Chemotactic migration of T cells towards dendritic cells promotes the detection of rare antigens.

    Science.gov (United States)

    Vroomans, Renske M A; Marée, Athanasius F M; de Boer, Rob J; Beltman, Joost B

    2012-01-01

    In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs) has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs) carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data.

  13. Antigen-activated dendritic cells ameliorate influenza A infections

    Science.gov (United States)

    Boonnak, Kobporn; Vogel, Leatrice; Orandle, Marlene; Zimmerman, Daniel; Talor, Eyal; Subbarao, Kanta

    2013-01-01

    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecule (J-LEAPS) with 15 to 30 amino acid–long peptides derived from influenza virus NP, M, or HA proteins. DCs were stimulated with influenza-J-LEAPS peptides (influenza-J-LEAPS) and injected intravenously into infected mice. Antigen-specific LEAPS-stimulated DCs were effective in reducing influenza virus replication in the lungs and enhancing survival of infected animals. Additionally, they augmented influenza-specific T cell responses in the lungs and reduced the severity of disease by limiting excessive cytokine responses, which are known to contribute to morbidity and mortality following influenza virus infection. Our data demonstrate that influenza-J-LEAPS–pulsed DCs reduce virus replication in the lungs, enhance survival, and modulate the protective immune responses that eliminate the virus while preventing excessive cytokines that could injure the host. This approach shows promise as an adjunct to antiviral treatment of influenza virus infections. PMID:23934125

  14. Slug down-regulation by RNA interference inhibits invasion growth in human esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang Shaoyan

    2011-05-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (ESCC is one of the most aggressive carcinomas of the gastrointestinal tract. We assessed the relevance of Slug in measuring the invasive potential of ESCC cells in vitro and in vivo in immunodeficient mice. Methods We utilized RNA interference to knockdown Slug gene expression, and effects on survival and invasive carcinoma were evaluated using a Boyden chamber transwell assay in vitro. We evaluated the effect of Slug siRNA-transfection and Slug cDNA-transfection on E-cadherin and Bcl-2 expression in ESCC cells. A pseudometastatic model of ESCC in immunodeficient mice was used to assess the effects of Slug siRNA transfection on tumor metastasis development. Results The EC109 cell line was transfected with Slug-siRNA to knockdown Slug expression. The TE13 cell line was transfected with Slug-cDNA to increase Slug expression. EC109 and TE13 cell lines were tested for the expression of apoptosis-related genes bcl-2 and metastasis-related gene E-cadherin identified previously as Slug targets. Bcl-2 expression was increased and E-cadherin was decreased in Slug siRNA-transfected EC109 cells. Bcl-2 expression was increased and E-cadherin was decreased in Slug cDNA-transfected TE13 cells. Invasion of Slug siRNA-transfected EC109 cells was reduced and apoptosis was increased whereas invasion was greater in Slug cDNA-transfected cells. Animals injected with Slug siRNA-transfected EC109 cells exhihited fewer seeded nodes and demonstrated more apoptosis. Conclusions Slug down-regulation promotes cell apoptosis and decreases invasion capability in vitro and in vivo. Slug inhibition may represent a novel strategy for treatment of metastatic ESCC.

  15. Downregulation of MMP1 in MDS-derived mesenchymal stromal cells reduces the capacity to restrict MDS cell proliferation

    Science.gov (United States)

    Zhao, Sida; Zhao, Youshan; Guo, Juan; Fei, Chengming; Zheng, Qingqing; Li, Xiao; Chang, Chunkang

    2017-01-01

    The role of mesenchymal stromal cells (MSCs) in the pathogenesis of myelodysplastic syndromes (MDS) has been increasingly addressed, but has yet to be clearly elucidated. In this investigation, we found that MDS cells proliferated to a greater extent on MDS-derived MSCs compared to normal MSCs. Matrix metalloproteinase 1(MMP1), which was downregulated in MDS-MSCs, was identified as an inhibitory factor of MDS cell proliferation, given that treatment with an MMP1 inhibitor or knock-down of MMP1 in normal MSCs resulted in increased MDS cell proliferation. Further investigations indicated that MMP1 induced apoptosis of MDS cells by interacting with PAR1 and further activating the p38 MAPK pathway. Inhibition of either PAR1 or p38 MAPK can reverse the apoptosis-inducing effect of MMP1. Taken together, these data indicate that downregulation of MMP1 in MSCs of MDS patients may contribute to the reduced capacity of MSCs to restrict MDS cell proliferation, which may account for the malignant proliferation of MDS cells. PMID:28262842

  16. Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer.

    Science.gov (United States)

    Wang, Xiao-Feng; Zhang, Xiao-Wei; Hua, Rui-Xi; Du, Yi-Qun; Huang, Ming-Zhu; Liu, Yong; Cheng, Yu Fang; Guo, Wei-Jian

    2016-09-27

    Mel-18, a polycomb group protein, has been reported to act as a tumor suppressor and be down-regulated in several human cancers including gastric cancer. It was also found that Mel-18 negatively regulates self-renewal of hematopoietic stem cells and breast cancer stem cells (CSCs). This study aimed to clarify its role in gastric CSCs and explore the mechanisms. We found that low-expression of Mel-18 was correlated with poor prognosis and negatively correlated with overexpression of stem cell markers Oct4, Sox2, and Gli1 in 101 gastric cancer tissues. Mel-18 was down-regulated in cultured spheroid cells, which possess CSCs, and overexpression of Mel-18 inhibits cells sphere-forming ability and tumor growth in vivo. Besides, Mel-18 was lower-expressed in ovary metastatic lesions compared with that in primary lesions of gastric cancer, and Mel-18 overexpression inhibited the migration ability of gastric cancer cells. Interestingly, overexpression of Mel-18 resulted in down-regulation of miR-21 in gastric cancer cells and the expression of Mel-18 was negatively correlated with the expression of miR-21 in gastric cancer tissues. Furthermore, miR-21 overexpression partially restored sphere-forming ability, migration potential and chemo-resistance in Mel-18 overexpressing gastric cancer cells. These results suggests Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer cells.

  17. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

    NARCIS (Netherlands)

    Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

    2012-01-01

    Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is par

  18. Regulation of NK-cell function by mucins via antigen-presenting cells.

    Science.gov (United States)

    Laskarin, G; Redzovic, A; Medancic, S Srsen; Rukavina, D

    2010-12-01

    Decidual antigen-presenting cells including dendritic cells (DCs) and CD14(+) macrophages, as mediators of the first encounter with fetal antigens, appear to be critically involved in the initiation of primary immune response by regulating innate- and adaptive immunity. Interleukin-15, produced by them, permits the proliferation and differentiation of CD3(-)CD16(-)CD94(+)NKG2A(+)CD56(+bright) decidual NK cells that identify trophoblast cells. These cells are able to kill them after Th1 cytokine overstimulation and by increasing the release of preformed cytotoxic mediators. Thus, the local microenvironment is a potent modulator of antigen-presenting cell functions. Tumor associated glycoprotein-72 (TAG-72) and mucine 1 (MUC-1) are glycoproteins secreted by uterine epithelial cells. Our hypothesis is that TAG-72 and MUC-1 are the natural ligands for carbohydrate recognition domains (CRDs) of endocytic mannose receptor (MR or CD206) and DC-specific ICAM non-integrin (DC-SIGN or CD209) expressed on decidual CD14(+) macrophages and CD1a(+) DCs. They might be able to condition antigen-presenting cells to produce distinct profiles of cyto/chemokines with consequential reduction in NK-cell numbers and cytotoxic potential leading to insufficient control over trophoblast growth. This hypothesis could explain the disappearance of MUC-1 beneath the attached embryo during the process of successful implantation when tight regulation of trophoblast invasion is needed. As IL-15 is the earliest and the most important factor in NK-cell proliferation, differentiation, and maturation, we expected primarily an increase of IL-15 expression in antigen-presenting cells concomitant with the disappearance of mucins and the enhancement in NK cells numbers and of cytotoxic potential after their close contact with early pregnancy decidual antigen-presenting cells. If our hypothesis is correct, it would contribute to the understanding of the role of mucins in the redirection of immune response

  19. Activation of Type II Cells into Regenerative Stem Cell Antigen-1+ Cells during Alveolar Repair

    Science.gov (United States)

    Kumar, Varsha Suresh; Zhang, Wei; Rehman, Jalees; Malik, Asrar B.

    2015-01-01

    The alveolar epithelium is composed of two cell types: type I cells comprise 95% of the gas exchange surface area, whereas type II cells secrete surfactant, while retaining the ability to convert into type I cells to induce alveolar repair. Using lineage-tracing analyses in the mouse model of Pseudomonas aeruginosa–induced lung injury, we identified a population of stem cell antigen (Sca)-1–expressing type II cells with progenitor cell properties that mediate alveolar repair. These cells were shown to be distinct from previously reported Sca-1–expressing bronchioalveolar stem cells. Microarray and Wnt reporter studies showed that surfactant protein (Sp)-C+Sca-1+ cells expressed Wnt signaling pathway genes, and inhibiting Wnt/β-catenin signaling prevented the regenerative function of Sp-C+Sca-1+ cells in vitro. Thus, P. aeruginosa–mediated lung injury induces the generation of a Sca-1+ subset of type II cells. The progenitor phenotype of the Sp-C+Sca-1+ cells that mediates alveolar epithelial repair might involve Wnt signaling. PMID:25474582

  20. Genistein inhibits the proliferation of human HER2-positive cancer cells by downregulating HER2 receptor

    Directory of Open Access Journals (Sweden)

    Guodong Shen

    2013-07-01

    Full Text Available Functional Foods in Health and Disease 2013; 3(7:291-299Research Article Open AccessGenistein inhibits the proliferation of human HER2-positive cancer cells by downregulating HER2 receptorGuodong Shen, Haiying Yu, Geng Bian, Min Gao, Lingqing Liu, Min Cheng, Gan Shen, Shilian HuGeriatrics Department, Gerontology Institute, Anhui Provincial Hospital; Anhui Provincial Key Laboratory of Tumor Immunotherapy and Nutrition Therapy, Hefei 230001, ChinaCorresponding Author: Shilian Hu, Department of Geriatrics, Anhui Provincial Hospital, No. 17 Lujiang Road, Hefei 230001, China Submission date: June 9, 2013; Acceptance date: July 19, 2013; Publication date: July 20, 2013ABSTRACTBackground: It was well studied that HER2/ErbB2/p185 overexpression in human malignant cancers correlates with poor prognosis and chemo-resistance. Meanwhile, Genistein (4,5,7-trihydroxyisoflavone, a major isoflavone component of soybeans and other leguminous plants, has been shown to exhibit a potent anti-proliferative effect on some sex hormone dependent cancers. Objective: The effects of genistein on the proliferation of human HER2-overexpressing breast and ovarian cancer cell lines were investigated, and the action mechanism was explored.Methods: Western blotting, fluorescence-activated cell sorting (FACS and immunofluorescence methods, cell proliferation assay kit from Promega and cell apoptosis assay kit from Biolegend were used. The dose- or time-response relationship of genistein were observed on the HER2-negative breast cancer cell line MCF-7 or HER2-positive breast cancer cell lines BT-474 and MCF-7/Her2 derived from MCF-7, and ovarian cancer cell line SKOV-3.Results: The addition of genistein ranged from 1-10g/ml in the medium for 48 hours had a marked inhibition on the proliferation of HER2-positive cancer cell lines MCF-7/Her2, BT-474 and SKOV-3, compared with tamoxifen and DMSO control (P<0.01, and a dose-dependent response was presented. However, genistein

  1. Soft matrices downregulate FAK activity to promote growth of tumor-repopulating cells.

    Science.gov (United States)

    Tan, Youhua; Wood, Adam Richard; Jia, Qiong; Zhou, Wenwen; Luo, Junyu; Yang, Fang; Chen, Junwei; Chen, Junjian; Sun, Jian; Seong, Jihye; Tajik, Arash; Singh, Rishi; Wang, Ning

    2017-01-29

    Tumor-repopulating cells (TRCs) are a tumorigenic sub-population of cancer cells that drives tumorigenesis. We have recently reported that soft fibrin matrices maintain TRC growth by promoting histone 3 lysine 9 (H3K9) demethylation and Sox2 expression and that Cdc42 expression influences H3K9 methylation. However, the underlying mechanisms of how soft matrices induce H3K9 demethylation remain elusive. Here we find that TRCs exhibit lower focal adhesion kinase (FAK) and H3K9 methylation levels in soft fibrin matrices than control melanoma cells on 2D rigid substrates. Silencing FAK in control melanoma cells decreases H3K9 methylation, whereas overexpressing FAK in tumor-repopulating cells enhances H3K9 methylation. Overexpressing Cdc42 or RhoA in the presence of FAK knockdown restores H3K9 methylation levels. Importantly, silencing FAK, Cdc42, or RhoA promotes Sox2 expression and proliferation of control melanoma cells in stiff fibrin matrices, whereas overexpressing each gene suppresses Sox2 expression and reduces growth of TRCs in soft but not in stiff fibrin matrices. Our findings suggest that low FAK mediated by soft fibrin matrices downregulates H3K9 methylation through reduction of Cdc42 and RhoA and promotes TRC growth.

  2. Curcumin Promotes KLF5 Proteasome Degradation through Downregulating YAP/TAZ in Bladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2014-08-01

    Full Text Available KLF5 (Krüppel-like factor 5 plays critical roles in normal and cancer cell proliferation through modulating cell cycle progression. In this study, we demonstrated that curcumin targeted KLF5 by promoting its proteasome degradation, but not by inhibiting its transcription in bladder cancer cells. We also demonstrated that lentivirus-based knockdown of KLF5 inhibited cancer cell growth, while over-expression of a Flag-tagged KLF5 could partially reverse the effects of curcumin on cell growth and cyclin D1 expression. Furthermore, we found that curcumin could down-regulate the expression of Hippo pathway effectors, YAP and TAZ, which have been reported to protect KLF5 protein from degradation. Indeed, knockdown of YAP by small interfering RNA caused the attenuation of KLF5 protein, but not KLF5 mRNA, which was reversed by co-incubation with proteasome inhibitor. A xenograft assay in nude mice finally proved the potent inhibitory effects of curcumin on tumor growth and the pro-proliferative YAP/TAZ/KLF5/cyclin D1 axis. Thus, our data indicates that curcumin promotes KLF5 proteasome-dependent degradation through targeting YAP/TAZ in bladder cancer cells and also suggests the therapeutic potential of curcumin in the treatment of bladder cancer.

  3. Role of calcium signaling in down-regulation of aggrecan induced by cyclic tensile strain in annulus fibrosus cells

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; ZHOU Yue; LI Hua-zhuang; CAO Guo-yong; TENG Hai-jun

    2006-01-01

    Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods :The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results:EGTA, gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.

  4. Selection of resistant acute myeloid leukemia SKM-1 and MOLM-13 cells by vincristine-, mitoxantrone- and lenalidomide-induced upregulation of P-glycoprotein activity and downregulation of CD33 cell surface exposure.

    Science.gov (United States)

    Imrichova, D; Messingerova, L; Seres, M; Kavcova, H; Pavlikova, L; Coculova, M; Breier, A; Sulova, Z

    2015-09-18

    Bone marrow cells and peripheral blood mononuclear cells obtained from both acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients contain upregulated levels of cell surface antigen CD33 compared with healthy controls. This difference enables the use of humanized anti-CD33 antibody conjugated to cytotoxic agents for CD33 targeted immunotherapy. However, the expression of the membrane-bound drug transporter P-glycoprotein (P-gp) has been shown to be critical for resistance against the cytotoxicity of a humanized anti-CD33 antibody conjugated to maytansine-derivative DM4. The aim of the present study was to examine whether the expression of P-gp in AML cell lines is associated with changes in CD33 expression. For this purpose, we established drug resistant variants of SKM-1 and MOLM-13 AML cell lines via the selection of parental cells for resistance to vincristine, mitoxantrone and lenalidomide. All three substances induced a multidrug resistance (MDR) phenotype in SKM-1 cells associated with strong upregulation of P-gp and downregulation of CD33. However, in MOLM-13 cells, the upregulation of P-gp and downregulation of CD33 were present only in cells selected for resistance to vincristine and mitoxantrone but not lenalidomide. Inverse expression of P-gp and CD33 were observed in all resistant variants of SKM-1 and MOLM-13 cells. The MDR phenotype of resistant variants of SKM-1 and MOLM-13 cells was associated with alterations in apoptotic regulatory proteins and downregulation of the multidrug resistance associated protein 1 and breast cancer resistance protein.

  5. The dysfunction of CD4(+CD25(+ regulatory T cells contributes to the abortion of mice caused by Toxoplasma gondii excreted-secreted antigens in early pregnancy.

    Directory of Open Access Journals (Sweden)

    Jin-ling Chen

    Full Text Available Toxoplasma gondii is an opportunistic intracellular parasite that is highly prevalent in human and warm-blooded animals throughout the world, leading to potentially severe congenital infections. Although the abortion caused by T. gondii is believed to be dependent on the timing of maternal infection during pregnancy, the mechanism remains unclear. This study was focused on the effects of T. gondii excreted-secreted antigens on pregnant outcomes and CD4(+CD25(+ Foxp3(+ regulatory T cells at different stages of pregnancy. The results showed that in mice the frequency and suppressive function of CD4(+CD25(+ regulatory cells were diminished after injection of T. gondii excreted-secreted antigens at early and intermediate stages of pregnancy. The abortion caused by T. gondii excreted-secreted antigens at early pregnancy could be partly prevented by adoptively transferring of CD4(+CD25(+ cells from the mice injected with T. gondii excreted-secreted antigens at late pregnancy, but not from the mice with the same treatment at early pregnancy. Furthermore, T. gondii excreted-secreted antigens induced apoptosis of CD4(+CD25(+ regulatory cells of mice in early and intermediate stages of pregnancy by down-regulating their Bcl-2 expressions and Bcl-2/Bax ratio. This study provides new insights into the mechanism that T. gondii infection is the high risk factor for abortion in early pregnancy.

  6. Expression of basement membrane antigens in spindle cell melanoma.

    Science.gov (United States)

    Prieto, V G; Woodruff, J M

    1998-07-01

    Spindle cell melanoma (SCM) is an uncommon form of melanoma that may be confused histologically with other tumors, including malignant peripheral nerve sheath tumors (MPNST). Tumors with neural differentiation and melanocytic nevi may both show basement membrane immunohistochemically and at the ultrastructural level. However, most ultrastructural studies of melanoma have failed to demonstrate well formed basement membrane around tumor cells. The presence of basement membrane has been used by some authors as evidence favoring MPNST, as opposed to SCM. To evaluate this distinction immunohistochemically, 22 primary and metastatic cutaneous melanomas having a spindle cell component (SCM) were studied using monoclonal antibodies against laminin and Type IV collagen. S100 protein and HMB45 antigen expression were also studied. All but one of the SCM were reactive for S100 protein in at least 25% of the cells. Thirteen of 20 tumors (65%) were focally reactive with HMB45. Laminin was expressed in 42% of the tumors (only membranous pattern in 3; cytoplasmic and membranous in 5). Seventeen tumors (77%) expressed type IV collagen (only membranous pattern in 7; cytoplasmic and membranous pattern in 10). Laminin and type IV collagen, known components of basement membrane, are often found in SCM. Therefore, their detection cannot be used to distinguish SCM from MPNST.

  7. Neutrophil extracellular traps downregulate lipopolysaccharide-induced activation of monocyte-derived dendritic cells.

    Science.gov (United States)

    Barrientos, Lorena; Bignon, Alexandre; Gueguen, Claire; de Chaisemartin, Luc; Gorges, Roseline; Sandré, Catherine; Mascarell, Laurent; Balabanian, Karl; Kerdine-Römer, Saadia; Pallardy, Marc; Marin-Esteban, Viviana; Chollet-Martin, Sylvie

    2014-12-01

    Polymorphonuclear neutrophils (PMN) play a central role in inflammation and participate in its control, notably by modulating dendritic cell (DC) functions via soluble mediators or cell-cell contacts. Neutrophil extracellular traps (NETs) released by PMN could play a role in this context. To evaluate NET effects on DC maturation, we developed a model based on monocyte-derived DC (moDC) and calibrated NETs isolated from fresh human PMN. We found that isolated NETs alone had no discernable effect on moDC. In contrast, they downregulated LPS-induced moDC maturation, as shown by decreased surface expression of HLA-DR, CD80, CD83, and CD86, and by downregulated cytokine production (TNF-α, IL-6, IL-12, IL-23), with no increase in the expression of tolerogenic DC genes. Moreover, the presence of NETs during moDC maturation diminished the capacity of these moDC to induce T lymphocyte proliferation in both autologous and allogeneic conditions, and modulated CD4(+) T lymphocyte polarization by promoting the production of Th2 cytokines (IL-5 and IL-13) and reducing that of Th1 and Th17 cytokines (IFN-γ and IL-17). Interestingly, the expression and activities of the lymphoid chemokine receptors CCR7 and CXCR4 on moDC were not altered when moDC matured in the presence of NETs. Together, these findings reveal a new role for NETs in adaptive immune responses, modulating some moDC functions and thereby participating in the control of inflammation.

  8. Downregulation of XPF-ERCC1 enhances cisplatin efficacy in cancer cells.

    Science.gov (United States)

    Arora, Sanjeevani; Kothandapani, Anbarasi; Tillison, Kristin; Kalman-Maltese, Vivian; Patrick, Steve M

    2010-07-01

    Bulky cisplatin lesions are repaired primarily by nucleotide excision repair (NER), in which the structure specific endonuclease XPF-ERCC1 is a critical component. It is now known that the XPF-ERCC1 complex has repair functions beyond NER and plays a role in homologous recombination (HR). It has been suggested that expression of ERCC1 correlates with cisplatin drug resistance in non-small cell lung cancer (NSCLC). In our study, using NSCLC, ovarian, and breast cancer cells, we show that the XPF-ERCC1 complex is a valid target to increase cisplatin cytotoxicity and efficacy. We targeted XPF-ERCC1 complex by RNA interference and assessed the repair capacity of cisplatin intrastrand and interstrand crosslinks by ELISA and alkaline comet assay, respectively. We also assessed the repair of cisplatin-ICL-induced double-strand breaks (DSBs) by monitoring gamma-H2AX focus formation. Interestingly, XPF protein levels were significantly reduced following ERCC1 downregulation, but the converse was not observed. The transcript levels were unaffected suggesting that XPF protein stability is likely affected. The repair of both types of cisplatin-DNA lesions was decreased with downregulation of XPF, ERCC1 or both XPF-ERCC1. The ICL-induced DSBs persist in the absence of XPF-ERCC1. The suppression of the XPF-ERCC1 complex significantly decreases the cellular viability which correlates well with the decrease in DNA repair capacity. A double knockdown of XPF-ERCC1 displays the greatest level of cellular cytotoxicity when compared with XPF or ERCC1 alone. The difference in cytotoxicity observed is likely due to the level of total protein complex remaining. These data demonstrate that XPF-ERCC1 is a valid target to enhance cisplatin efficacy in cancer cells by affecting cisplatin-DNA repair pathways.

  9. Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha.

    Science.gov (United States)

    Giacomini, P.; Mottolese, M.; Fraioli, R.; Benevolo, M.; Venturo, I.; Natali, P. G.

    1992-01-01

    Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha. PMID:1503908

  10. The effects of Fasciola hepatica tegumental antigens on mast cell function.

    Science.gov (United States)

    Vukman, Krisztina V; Adams, Paul N; Dowling, David; Metz, Martin; Maurer, Marcus; O'Neill, Sandra M

    2013-06-01

    Fasciola hepatica infection is associated with T helper 2/T regulatory immune responses and increased mast cell numbers. The aim of this study was to examine the interaction between F. hepatica tegumental coat antigen and mast cells in vivo and in vitro. Firstly, BALB/C, C57BL/6 or STAT6(-/-) mice were infected with F. hepatica metacercarie or mice were treated with F. hepatica tegumental coat antigen and then mast cells numbers in the peritoneal cavity and/or the liver were quantified. Also, the proliferation, chemotaxis, degranulation and cytokine secretion of mast cells from bone marrow or from peritoneal exudate cells stimulated with F. hepatica tegumental coat antigen were measured. Finally, we tested whether F. hepatica tegumental coat antigen inhibits degranulation of mast cells in vivo in a passive cutaneous and systemic anaphylaxis mouse model. Mast cell numbers increased in the peritoneal cavity and liver of F. hepatica infected mice, and this was mimicked by injection of F. hepatica tegumental coat antigen in a STAT6(-/-) independent manner. The increase in mast cell number was not the result of F. hepatica tegumental coat antigen-induced proliferation; rather F. hepatica tegumental coat antigen indirectly induces mast cell migration by dendritic cell-derived chemokines. Fasciola hepatica tegumental coat antigen interactions with mast cells do not drive T helper 2 or T regulatory immune responses. These studies on mast cell and F. hepatica tegumental coat antigen interaction may help us to understand the function of mast cells in immunity against F. hepatica and the immunomodulatory effect of F. hepatica tegumental coat antigen on these cells.

  11. Epigenetic regulations in the IFNγ signalling pathway: IFNγ-mediated MHC class I upregulation on tumour cells is associated with DNA demethylation of antigen-presenting machinery genes.

    Science.gov (United States)

    Vlková, Veronika; Štěpánek, Ivan; Hrušková, Veronika; Šenigl, Filip; Mayerová, Veronika; Šrámek, Martin; Šímová, Jana; Bieblová, Jana; Indrová, Marie; Hejhal, Tomáš; Dérian, Nicolas; Klatzmann, David; Six, Adrien; Reiniš, Milan

    2014-08-30

    Downregulation of MHC class I expression on tumour cells, a common mechanism by which tumour cells can escape from specific immune responses, can be associated with coordinated silencing of antigen-presenting machinery genes. The expression of these genes can be restored by IFNγ. In this study we documented association of DNA demethylation of selected antigen-presenting machinery genes located in the MHC genomic locus (TAP-1, TAP-2, LMP-2, LMP-7) upon IFNγ treatment with MHC class I upregulation on tumour cells in several MHC class I-deficient murine tumour cell lines (TC-1/A9, TRAMP-C2, MK16 and MC15). Our data also documented higher methylation levels in these genes in TC-1/A9 cells, as compared to their parental MHC class I-positive TC-1 cells. IFNγ-mediated DNA demethylation was relatively fast in comparison with demethylation induced by DNA methyltransferase inhibitor 5-azacytidine, and associated with increased histone H3 acetylation in the promoter regions of APM genes. Comparative transcriptome analysis in distinct MHC class I-deficient cell lines upon their treatment with either IFNγ or epigenetic agents revealed that a set of genes, significantly enriched for the antigen presentation pathway, was regulated in the same manner. Our data demonstrate that IFNγ acts as an epigenetic modifier when upregulating the expression of antigen-presenting machinery genes.

  12. Analysis of the antibody repertoire of patients with mantle cell lymphoma directed against mantle cell lymphoma-associated antigens

    OpenAIRE

    Zwick, Carsten; Preuss, Klaus-Dieter; Kubuschok, Boris; Held, Gerhard; Ahlgrimm, Manfred; Bittenbring, Joerg; Schubert, Joerg; Neumann, Frank; Pfreundschuh, Michael

    2009-01-01

    Abstract Treatment results of mantle cell lymphomas (MCL) are not satisfactory and novel therapeutic approaches are warranted. Because ?shared? tumor antigens like the group of cancer testis antigens are only rarely expressed in MCL, we applied serological analysis of antigens using recombinant expression cloning (SEREX) to a complementary DNA library derived from five cases of MCL using the sera of eight patients with MCL in order to define MCL-associated antigens that are immunog...

  13. Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zi-xuan [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Rao, Wei [Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Huan [Department of Dermatology, Tangdu Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Nan-ding [Department of Cardiology, Xi' an Traditional Chinese Medicine Hospital, Xi' an, 710032 (China); Si, Jing-Wen; Zhao, Jiao; Li, Jun-chang [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China); Wang, Zong-ren, E-mail: zongren@fmmu.edu.cn [Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, 710032 (China)

    2015-02-13

    Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromal interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future. - Highlights: • Modeled microgravity (MMG) suppressed migration and invasion in U87 cells. • MMG downregulated the SOCE and the expression of Orai1. • SOCE inhibition mimicked the effects of MMG on migration and invasion potentials. • Restoration of SOCE diminished the effects of MMG on migration and invasion.

  14. Red blood cells as innovative antigen carrier to induce specific immune tolerance.

    Science.gov (United States)

    Cremel, Magali; Guérin, Nathalie; Horand, Françoise; Banz, Alice; Godfrin, Yann

    2013-02-25

    The route of administration, the dose of antigen as well as the type of antigen-presenting cells (APCs) targeted are important factors to induce immune tolerance. Despite encouraging results obtained in animal models, intravenous injection of soluble antigen is unsuccessful in human clinical trials on autoimmune disease due to inefficient antigen delivery. To improve antigen delivery, we used mouse red blood cells (RBCs) as antigen vehicles to specifically target APCs which are responsible for removal of senescent RBCs after phagocytosis. In this study, we demonstrated that antigen-delivery by RBCs induced a strong decrease in the humoral response compared with the ovalbumin (OVA) free form in mice. In addition, OVA-loaded RBC treated with [bis(sulphosuccinimidyl)] suberate (BS3), a chemical compound known to enhance RBC phagocytosis, induced an inhibition of antigen-specific T cell responses and an increase in the percentage of regulatory T cells. The state of tolerance induced is long lasting, antigen-specific and sufficiently robust to withstand immunization with antigen mixed with cholera toxin adjuvant. This RBC strategy, which does not abolish the immune system, constitutes an attractive approach for induction of tolerance compared to systemic immunosuppressant therapies already in use.

  15. Oxidative Stress Induces Endothelial Cell Senescence via Downregulation of Sirt6

    Directory of Open Access Journals (Sweden)

    Rong Liu

    2014-01-01

    Full Text Available Accumulating evidence has shown that diabetes accelerates aging and endothelial cell senescence is involved in the pathogenesis of diabetic vascular complications, including diabetic retinopathy. Oxidative stress is recognized as a key factor in the induction of endothelial senescence and diabetic retinopathy. However, specific mechanisms involved in oxidative stress-induced endothelial senescence have not been elucidated. We hypothesized that Sirt6, which is a nuclear, chromatin-bound protein critically involved in many pathophysiologic processes such as aging and inflammation, may have a role in oxidative stress-induced vascular cell senescence. Measurement of Sirt6 expression in human endothelial cells revealed that H2O2 treatment significantly reduced Sirt6 protein. The loss of Sirt6 was associated with an induction of a senescence phenotype in endothelial cells, including decreased cell growth, proliferation and angiogenic ability, and increased expression of senescence-associated β-galactosidase activity. Additionally, H2O2 treatment reduced eNOS expression, enhanced p21 expression, and dephosphorylated (activated retinoblastoma (Rb protein. All of these alternations were attenuated by overexpression of Sirt6, while partial knockdown of Sirt6 expression by siRNA mimicked the effect of H2O2. In conclusion, these results suggest that Sirt6 is a critical regulator of endothelial senescence and oxidative stress-induced downregulation of Sirt6 is likely involved in the pathogenesis of diabetic retinopathy.

  16. Down-Regulation of NDUFB9 Promotes Breast Cancer Cell Proliferation, Metastasis by Mediating Mitochondrial Metabolism.

    Directory of Open Access Journals (Sweden)

    Liang-Dong Li

    Full Text Available Despite advances in basic and clinical research, metastasis remains the leading cause of death in breast cancer patients. Genetic abnormalities in mitochondria, including mutations affecting complex I and oxidative phosphorylation, are found in breast cancers and might facilitate metastasis. Genes encoding complex I components have significant breast cancer prognostic value. In this study, we used quantitative proteomic analyses to compare a highly metastatic cancer cell line and a parental breast cancer cell line; and observed that NDUFB9, an accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (complex I, was down-regulated in highly metastatic breast cancer cells. Furthermore, we demonstrated that loss of NDUFB9 promotes MDA-MB-231 cells proliferation, migration, and invasion because of elevated levels of mtROS, disturbance of the NAD+/NADH balance, and depletion of mtDNA. We also showed that, the Akt/mTOR/p70S6K signaling pathway and EMT might be involved in this mechanism. Thus, our findings contribute novel data to support the hypothesis that misregulation of mitochondrial complex I NADH dehydrogenase activity can profoundly enhance the aggressiveness of human breast cancer cells, suggesting that complex I deficiency is a potential and important biomarker for further basic research or clinical application.

  17. Chloroquine inhibits accessory cell presentation of soluble natural and synthetic protein antigens

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1984-01-01

    was time- and dose-dependent. A brief treatment solely of the accessory cells with the drug compromised their ability to stimulate primed T cells in a subsequent culture provided the accessory cells were treated with chloroquine before their exposure to the antigen. These results suggest that chloroquine......We have studied the in vitro effect of the lysosomotrophic agent, chloroquine, on the presentation of soluble protein antigens by guinea pig accessory cells. Chloroquine inhibited the capacity of antigen-pulsed accessory cells to stimulate proliferation in appropriately primed T cells. The effect...

  18. Regulation of protein synthesis and autophagy in activated dendritic cells: implications for antigen processing and presentation.

    Science.gov (United States)

    Argüello, Rafael J; Reverendo, Marisa; Gatti, Evelina; Pierre, Philippe

    2016-07-01

    Antigenic peptides presented in the context of major histocompatibility complex (MHC) molecules originate from the degradation of both self and non-self proteins. T cells can therefore recognize at the surface of surveyed cells, the self-peptidome produced by the cell itself (mostly inducing tolerance) or immunogenic peptides derived from exogenous origins. The initiation of adaptive immune responses by dendritic cells (DCs), through the antigenic priming of naïve T cells, is associated to microbial pattern recognition receptors engagement. Activation of DCs by microbial product or inflammatory cytokines initiates multiple processes that maximize DC capacity to present exogenous antigens and stimulate T cells by affecting major metabolic and membrane traffic pathways. These include the modulation of protein synthesis, the regulation of MHC and co-stimulatory molecules transport, as well as the regulation of autophagy, that, all together promote exogenous antigen presentation while limiting the display of self-antigens by MHC molecules.

  19. Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines

    DEFF Research Database (Denmark)

    Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

    2016-01-01

    Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is ......Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen....... There is a particular interest in developing robust high-throughput assays as chicken vaccine trials usually comprise many individuals. In many respects, the avian immune system differs from the mammalian, and T cell assessment protocols must be adjusted accordingly to account for, e.g., differences in leukocyte...... responding to the stimulation. This method has been successfully applied to studies of chicken antigen-specific T cells....

  20. Cbln1 downregulates the formation and function of inhibitory synapses in mouse cerebellar Purkinje cells.

    Science.gov (United States)

    Ito-Ishida, Aya; Kakegawa, Wataru; Kohda, Kazuhisa; Miura, Eriko; Okabe, Shigeo; Yuzaki, Michisuke

    2014-04-01

    The formation of excitatory and inhibitory synapses must be tightly coordinated to establish functional neuronal circuitry during development. In the cerebellum, the formation of excitatory synapses between parallel fibers and Purkinje cells is strongly induced by Cbln1, which is released from parallel fibers and binds to the postsynaptic δ2 glutamate receptor (GluD2). However, Cbln1's role, if any, in inhibitory synapse formation has been unknown. Here, we show that Cbln1 downregulates the formation and function of inhibitory synapses between Purkinje cells and interneurons. Immunohistochemical analyses with an anti-vesicular GABA transporter antibody revealed an increased density of interneuron-Purkinje cell synapses in the cbln1-null cerebellum. Whole-cell patch-clamp recordings from Purkinje cells showed that both the amplitude and frequency of miniature inhibitory postsynaptic currents were increased in cbln1-null cerebellar slices. A 3-h incubation with recombinant Cbln1 reversed the increased amplitude of inhibitory currents in Purkinje cells in acutely prepared cbln1-null slices. Furthermore, an 8-day incubation with recombinant Cbln1 reversed the increased interneuron-Purkinje cell synapse density in cultured cbln1-null slices. In contrast, recombinant Cbln1 did not affect cerebellar slices from mice lacking both Cbln1 and GluD2. Finally, we found that tyrosine phosphorylation was upregulated in the cbln1-null cerebellum, and acute inhibition of Src-family kinases suppressed the increased inhibitory postsynaptic currents in cbln1-null Purkinje cells. These findings indicate that Cbln1-GluD2 signaling inhibits the number and function of inhibitory synapses, and shifts the excitatory-inhibitory balance towards excitation in Purkinje cells. Cbln1's effect on inhibitory synaptic transmission is probably mediated by a tyrosine kinase pathway.

  1. Induction of leukemia cell apoptosis by cheliensisin A involves down-regulation of Bcl-2 expression

    Institute of Scientific and Technical Information of China (English)

    Li ZHONG; Chao-ming LI; Xiao-jiang HAO; Li-guang LOU

    2005-01-01

    Aim: To investigate the apoptosis-inducing effect of cheliensisin A (GC-51), a novel styryl-lactone isolated from Goniothalamus cheliensis, on human promyelocytic leukemia HL-60 cells and the mechanism of action involved.Methods: Apoptotic cell death was determined by morphological examination and DNA agarose gel electrophoresis. The activity of caspase-3 was assessed using Western blotting and the expression of Bcl-2 and Bax genes was analyzed using the reverse transcription-polymerase chain reaction (RT-PCR) method. Results:GC-51 significantly inhibited the proliferation of HL-60 cells with an IC50 of 2.4±0.2 μmol/L and effectively induced apoptosis in HL-60 cells. Exposure of HL-60cells to 10 μmol/L GC-51 for 8 h resulted in approximately 53% of the cells under going apoptosis. Caspase-3 was activated in GC-51-treated cells, which was manifested by the appearance of the 17 kDa active form of caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). Meanwhile, GC-51 markedly reduced the expression of the anti-apoptotic gene Bcl-2 and increased the expression of the pro-apoptotic gene Bax. The apoptosis-inducing effect of GC-51 was cAMP dependent protein kinase (PKA) dependent because PKA, but not the protein kinase C, specific inhibitor H-89, blocked the induction of apoptosis by GC-51 in HL-60 cells. Conclusion: The results demonstrate that GC-51 effectively induces apoptosis in HL-60 cells and that this effect is PKA-dependent and involves the downregulation of Bcl-2 expression and the activation of caspase-3.

  2. Downregulation of p70S6K Enhances Cell Sensitivity to Rapamycin in Esophageal Squamous Cell Carcinoma

    Science.gov (United States)

    Lu, Zhaoming; Peng, Kezheng; Wang, Ning; Liu, Hong-Min

    2016-01-01

    It has been demonstrated that mTOR/p70S6K pathway was abnormally activated in many cancers and rapamycin and its analogs can restrain tumor growth through inhibiting this pathway, but some tumors including esophageal squamous cell carcinoma (ESCC) appear to be insensitive to rapamycin in recent studies. In the present study, we explored the measures to improve the sensitivity of ESCC cells to rapamycin and identified the clinical significance of the expression of phosphorylated p70S6K (p-p70S6K). The results showed that, after downregulating the expression of p70S6K and p-p70S6K by p70S6K siRNA, the inhibitory effects of rapamycin on cell proliferation, cell cycle, and tumor growth were significantly enhanced in vitro and in vivo. Furthermore, p-p70S6K had strong positive expression in ESCC tissues and its expression was closely related to lymph node metastasis and the TNM staging. These results indicated that p-p70S6K may participate in the invasion and metastasis in the development of ESCC and downregulation of the expression of p-p70S6K could improve the sensitivity of cells to rapamycin in ESCC. PMID:27595116

  3. Identification of a highly antigenic linear B cell epitope within Plasmodium vivax apical membrane antigen 1 (AMA-1.

    Directory of Open Access Journals (Sweden)

    Lilian Lacerda Bueno

    Full Text Available Apical membrane antigen 1 (AMA-1 is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1 have shown a higher prevalence of specific antibodies to domain II (DII of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs. The B cell epitope comprising the amino acid sequence 290-307 of PvAMA-1 (SASDQPTQYEEEMTDYQK, with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both, respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.

  4. Cyclical cell stretching of skin-derived fibroblasts downregulates connective tissue growth factor (CTGF) production.

    Science.gov (United States)

    Kanazawa, Yuichiro; Nomura, Jun; Yoshimoto, Shinya; Suzuki, Toshikazu; Kita, Kazuko; Suzuki, Nobuo; Ichinose, Masaharu

    2009-01-01

    Delayed healing of skin wounds can be caused by wound instability, whereas appropriate massage or exercise prevents sclerosis and scar contracture. However, the mechanism by which wound healing is related to mechanical stress has not been fully elucidated. The present study aimed to identify whether mechanical stretching of fibroblasts reduces their production of extracellular matrix. We transferred skin fibroblasts into collagen-coated elastic silicone chambers, cultured them on a stretching apparatus, and used RT-PCR to examine the effects of mechanical stretching on the expression levels of 17 genes related to extracellular matrix production and growth factor secretion. We found that connective tissue growth factor (CTGF) was downregulated after 24 hr of cell stretching. Specifically, the CTGF mRNA and protein levels were 50% and 48% of the control levels, respectively. These findings suggest that cyclic stretching of fibroblasts contributes to anti-fibrotic processes by reducing CTGF production.

  5. Downregulation of Th17 cells and the related cytokines with treatment in Kawasaki disease.

    Science.gov (United States)

    Rasouli, Manoochehr; Heidari, Behzad; Kalani, Mehdi

    2014-11-01

    Given the inflammatory nature of Kawasaki disease (KD) and the pro-inflammatory properties of Th17, this study aimed to determine the frequency of Th17 cells and the levels of corresponding cytokines in acute phase of KD and to evaluate their alterations one and eight weeks after treatment. Th17 and the related cytokine levels were measured in 21 KD patients and 42 positive and negative controls, using flow cytometry and ELISA, respectively. Th17, IL-17, IL-22 and IL-23 were significantly higher (P0.05) with the positive controls. Furthermore, Th17, IL-17, IL-22 and IL-23 were significantly higher in patients before treatment than those one and eight weeks after. Considering the downregulation of Th17 and its related cytokines with aspirin and intravenous immunoglobulin therapy implies the probable role of Th17 in KD pathogenesis.

  6. Synthetic antigens reveal dynamics of BCR endocytosis during inhibitory signaling.

    Science.gov (United States)

    Courtney, Adam H; Bennett, Nitasha R; Zwick, Daniel B; Hudon, Jonathan; Kiessling, Laura L

    2014-01-17

    B cells detect foreign antigens through their B cell antigen receptor (BCR). The BCR, when engaged by antigen, initiates a signaling cascade. Concurrent with signaling is endocytosis of the BCR complex, which acts to downregulate signaling and facilitate uptake of antigen for processing and display on the cell surface. The relationship between signaling and BCR endocytosis is poorly defined. Here, we explore the interplay between BCR endocytosis and antigens that either promote or inhibit B cell activation. Specifically, synthetic antigens were generated that engage the BCR alone or both the BCR and the inhibitory co-receptor CD22. The lectin CD22, a member of the Siglec family, binds sialic acid-containing glycoconjugates found on host tissues, inhibiting BCR signaling to prevent erroneous B cell activation. At low concentrations, antigens that can cocluster the BCR and CD22 promote rapid BCR endocytosis; whereas, slower endocytosis occurs with antigens that bind only the BCR. At higher antigen concentrations, rapid BCR endocytosis occurs upon treatment with either stimulatory or inhibitory antigens. Endocytosis of the BCR, in response to synthetic antigens, results in its entry into early endocytic compartments. Although the CD22-binding antigens fail to activate key regulators of antigen presentation (e.g., Syk), they also promote BCR endocytosis, indicating that inhibitory antigens can be internalized. Together, our observations support a functional role for BCR endocytosis in downregulating BCR signaling. The reduction of cell surface BCR levels in the absence of B cell activation should raise the threshold for BCR subsequent activation. The ability of the activating synthetic antigens to trigger both signaling and entry of the BCR into early endosomes suggests strategies for targeted antigen delivery.

  7. Detection of 2 immunoreactive antigens in the cell wall of Sporothrix brasiliensis and Sporothrix globosa.

    Science.gov (United States)

    Ruiz-Baca, Estela; Hernández-Mendoza, Gustavo; Cuéllar-Cruz, Mayra; Toriello, Conchita; López-Romero, Everardo; Gutiérrez-Sánchez, Gerardo

    2014-07-01

    The cell wall of members of the Sporothrix schenckii complex contains highly antigenic molecules which are potentially useful for the diagnosis and treatment of sporotrichosis. In this study, 2 immunoreactive antigens of 60 (Gp60) and 70 kDa (Gp70) were detected in the cell wall of the yeast morphotypes of Sporothrix brasiliensis and Sporothrix globosa.

  8. Decreased signaling competence as a result of receptor overexpression: overexpression of CD4 reduces its ability to activate p56lck tyrosine kinase and to regulate T-cell antigen receptor expression in immature CD4+CD8+ thymocytes.

    OpenAIRE

    Nakayama, T.; Wiest, D L; Abraham, K.M.; Munitz, T I; Perlmutter, R M; Singer, A

    1993-01-01

    Thymic selection of the developing T-cell repertoire occurs in immature CD4+CD8+ thymocytes, with the fate of individual thymocytes determined by the specificity of T-cell antigen receptor they express. However, T-cell antigen receptor expression in immature CD4+CD8+ thymocytes is actively down-regulated in CD4+CD8+ thymocytes by CD4-mediated tyrosine kinase signals that are generated in the thymus as a result of CD4 engagement by intrathymic ligands. In the present study we have examined the...

  9. Human antigen-specific regulatory T cells generated by T cell receptor gene transfer.

    Directory of Open Access Journals (Sweden)

    Todd M Brusko

    Full Text Available BACKGROUND: Therapies directed at augmenting regulatory T cell (Treg activities in vivo as a systemic treatment for autoimmune disorders and transplantation may be associated with significant off-target effects, including a generalized immunosuppression that may compromise beneficial immune responses to infections and cancer cells. Adoptive cellular therapies using purified expanded Tregs represents an attractive alternative to systemic treatments, with results from animal studies noting increased therapeutic potency of antigen-specific Tregs over polyclonal populations. However, current methodologies are limited in terms of the capacity to isolate and expand a sufficient quantity of endogenous antigen-specific Tregs for therapeutic intervention. Moreover, FOXP3+ Tregs fall largely within the CD4+ T cell subset and are thus routinely MHC class II-specific, whereas class I-specific Tregs may function optimally in vivo by facilitating direct tissue recognition. METHODOLOGY/PRINCIPAL FINDINGS: To overcome these limitations, we have developed a novel means for generating large numbers of antigen-specific Tregs involving lentiviral T cell receptor (TCR gene transfer into in vitro expanded polyclonal natural Treg populations. Tregs redirected with a high-avidity class I-specific TCR were capable of recognizing the melanoma antigen tyrosinase in the context of HLA-A*0201 and could be further enriched during the expansion process by antigen-specific reactivation with peptide loaded artificial antigen presenting cells. These in vitro expanded Tregs continued to express FOXP3 and functional TCRs, and maintained the capacity to suppress conventional T cell responses directed against tyrosinase, as well as bystander T cell responses. Using this methodology in a model tumor system, murine Tregs designed to express the tyrosinase TCR effectively blocked antigen-specific effector T cell (Teff activity as determined by tumor cell growth and luciferase reporter

  10. Mesenchymal Stem Cell-Derived Exosomes: Immunomodulatory Evaluation in an Antigen-Induced Synovitis Porcine Model

    Science.gov (United States)

    Casado, Javier G.; Blázquez, Rebeca; Vela, Francisco Javier; Álvarez, Verónica; Tarazona, Raquel; Sánchez-Margallo, Francisco Miguel

    2017-01-01

    Synovitis is an inflammatory process associated with pain, disability, and discomfort, which is usually treated with anti-inflammatory drugs or biological agents. Mesenchymal stem cells (MSCs) have been also successfully used in the treatment of inflammatory-related diseases such as synovitis or arthritis. In the last years, the exosomes derived from MSCs have become a promising tool for the treatment of inflammatory-related diseases and their therapeutic effect is thought to be mediated (at least in part) by their immunomodulatory potential. In this work, we aimed to evaluate the anti-inflammatory effect of these exosomes in an antigen-induced synovitis animal model. To our knowledge, this is the first report where exosomes derived from MSCs have been evaluated in an animal model of synovitis. Our results demonstrated a decrease of synovial lymphocytes together with a downregulation of TNF-α transcripts in those exosome-treated joints. These results support the immunomodulatory effect of these exosomes and point out that they may represent a promising therapeutic option for the treatment of synovitis.

  11. S100A7-downregulation inhibits epidermal growth factor-induced signaling in breast cancer cells and blocks osteoclast formation.

    Directory of Open Access Journals (Sweden)

    Vikram Paruchuri

    Full Text Available S100A7 is a small calcium binding protein, which has been shown to be differentially expressed in psoriatic skin lesions, as well as in squamous cell tumors of the skin, lung and breast. Although its expression has been correlated to HER+ high-grade tumors and to a high risk of progression, the molecular mechanisms of these S100A7-mediated tumorigenic effects are not well known. Here, we showed for the first time that epidermal growth factor (EGF induces S100A7 expression in both MCF-7 and MDA-MB-468 cell lines. We also observed a decrease in EGF-directed migration in shRNA-downregulated MDA-MB-468 cell lines. Furthermore, our signaling studies revealed that EGF induced simultaneous EGF receptor phosphorylation at Tyr1173 and HER2 phosphorylation at Tyr1248 in S100A7-downregulated cell lines as compared to the vector-transfected controls. In addition, reduced phosphorylation of Src at tyrosine 416 and p-SHP2 at tyrosine 542 was observed in these downregulated cell lines. Further studies revealed that S100A7-downregulated cells had reduced angiogenesis in vivo based on matrigel plug assays. Our results also showed decreased tumor-induced osteoclastic resorption in an intra-tibial bone injection model involving SCID mice. S100A7-downregulated cells had decreased osteoclast number and size as compared to the vector controls, and this decrease was associated with variations in IL-8 expression in in vitro cell cultures. This is a novel report on the role of S100A7 in EGF-induced signaling in breast cancer cells and in osteoclast formation.

  12. A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8(+) T Cells.

    Science.gov (United States)

    Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md; Bhattacharya, Pradyot; Ali, Nahid

    2016-06-02

    The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8(+) cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4(+) and CD8(+) T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4(+) and CD8(+) T cells. Furthermore, lymphoid CD8(+) T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8(+) T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8(+) T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

  13. A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

    Science.gov (United States)

    Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md.; Bhattacharya, Pradyot; Ali, Nahid

    2016-06-01

    The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8+ cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4+ and CD8+ T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4+ and CD8+ T cells. Furthermore, lymphoid CD8+ T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8+ T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8+ T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

  14. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Science.gov (United States)

    Howe, Savannah E; Lickteig, Duane J; Plunkett, Kyle N; Ryerse, Jan S; Konjufca, Vjollca

    2014-01-01

    Intestinal epithelial cells (IECs) overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes) play an active role in the uptake (sampling) of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs), which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine). Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  15. FK866-induced NAMPT inhibition activates AMPK and downregulates mTOR signaling in hepatocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Susanne, E-mail: Susanne.Schuster@medizin.uni-leipzig.de [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany); Penke, Melanie; Gorski, Theresa [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany); Gebhardt, Rolf [Institute of Biochemistry, Faculty of Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Weiss, Thomas S. [Children' s University Hospital, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg (Germany); Kiess, Wieland; Garten, Antje [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany)

    2015-03-06

    Background: Nicotinamide phosphoribosyltransferase (NAMPT) is the key enzyme of the NAD salvage pathway starting from nicotinamide. Cancer cells have an increased demand for NAD due to their high proliferation and DNA repair rate. Consequently, NAMPT is considered as a putative target for anti-cancer therapies. There is evidence that AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) become dysregulated during the development of hepatocellular carcinoma (HCC). Here, we investigated the effects of NAMPT inhibition by its specific inhibitor FK866 on the viability of hepatocarcinoma cells and analyzed the effects of FK866 on the nutrient sensor AMPK and mTOR complex1 (mTORC1) signaling. Results: FK866 markedly decreased NAMPT activity and NAD content in hepatocarcinoma cells (Huh7 cells, Hep3B cells) and led to delayed ATP reduction which was associated with increased cell death. These effects could be abrogated by administration of nicotinamide mononucleotide (NMN), the enzyme product of NAMPT. Our results demonstrated a dysregulation of the AMPK/mTOR pathway in hepatocarcinoma cells compared to non-cancerous hepatocytes with a higher expression of mTOR and a lower AMPKα activation in hepatocarcinoma cells. We found that NAMPT inhibition by FK866 significantly activated AMPKα and inhibited the activation of mTOR and its downstream targets p70S6 kinase and 4E-BP1 in hepatocarcinoma cells. Non-cancerous hepatocytes were less sensitive to FK866 and did not show changes in AMPK/mTOR signaling after FK866 treatment. Conclusion: Taken together, these findings reveal an important role of the NAMPT-mediated NAD salvage pathway in the energy homeostasis of hepatocarcinoma cells and suggest NAMPT inhibition as a potential treatment option for HCC. - Highlights: • FK866 increases cell death in p53-deficient hepatocarcinoma cells. • AMPK/mTOR signaling is dysregulated in hepatocarcinoma cells. • FK866-induced NAMPT inhibition activates AMPK

  16. Helminth Excreted/Secreted Antigens Repress Expression of LPS-Induced Let-7i but Not miR-146a and miR-155 in Human Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Luis I. Terrazas

    2013-01-01

    Full Text Available MicroRNAs have emerged as key regulators of immune responses. They influence immune cells' function and probably the outcome of several infections. Currently, it is largely unknown if helminth parasites and their antigens modify host microRNAs expression. The aim of this study was to explore if excreted/secreted antigens of Taenia crassiceps regulate LPS-induced miRNAs expression in human Dendritic Cells. We found that these antigens repressed LPS-let-7i induction but not mir-146a or mir-155 and this correlates with a diminished inflammatory response. This let-7i downregulation in Dendritic Cells constitutes a novel feature of the modulatory activity that helminth-derived antigens exert on their host.

  17. T cells expressing VHH-directed oligoclonal chimeric HER2 antigen receptors

    DEFF Research Database (Denmark)

    Jamnani, Fatemeh Rahimi; Rahbarizadeh, Fatemeh; Shokrgozar, Mohammad Ali;

    2014-01-01

    Adoptive cell therapy with engineered T cells expressing chimeric antigen receptors (CARs) originated from antibodies is a promising strategy in cancer immunotherapy. Several unsuccessful trials, however, highlight the need for alternative conventional binding domains and the better combination...

  18. microRNA-143 down-regulates Hexokinase 2 in colon cancer cells

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Jacobsen, Anders; Frankel, Lisa

    2012-01-01

    a significant enrichment of miR-143 seed sites in their 3' UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion. CONCLUSION: We have identified...... and validated HK2 as a miR-143 target. Furthermore, our results indicate that miR-143 mediated down-regulation of HK2 affects glucose metabolism in colon cancer cells. We hypothesize that loss of miR-143-mediated repression of HK2 can promote glucose metabolism in cancer cells, contributing to the shift towards......ABSTRACT: BACKGROUND: MicroRNAs (miRNAs) are well recognized as gene regulators and have been implicated in the regulation of development as well as human diseases. miR-143 is located at a fragile site on chromosome 5 frequently deleted in cancer, and has been reported to be down...

  19. SPONGIOTIC DERMATITIS WITH A MIXED INFLAMMATORY INFILTRATE OF LYMPHOCYTES, ANTIGEN PRESENTING CELLS, IMMUNOGLOBULINS AND COMPLEMENT

    Directory of Open Access Journals (Sweden)

    Abreu Velez Ana Maria

    2011-04-01

    Full Text Available Background: The clinical and histological presentation of spongiotic dermatitis and its inflammatory infiltrates warrant further investigation. In this case documentation of a patient with cutaneous spongiotic reactivity, we aim to characterize antigen presenting cells, as well as the skin-specific cutaneous lymphocyte antigen population by multiple techniques. Case report: A 30 year old Caucasian female presented with a two week history of blistering and erosions around the vaginal, rectal and axillary areas. Material and Methods: We utilized hematoxylin and eosin histology, direct immunofluorescence, immunohistochemistry and confocal microscopy methods to evaluate the immune reaction patterns of the cutaneous inflammatory cells. Results: In the primary histologic areas of spongiotic dermatitis, a mixed population of B and T lymphocytes was seen. Ki-67 antigen proliferative index staining was accentuated in these areas, correlating with the presence of large numbers of epidermal and dermal antigen presenting cells. Among the antigen presenting cell population, we detected strong positivities with CD1a, Factor XIIIa, myeloid/hystoid antigen, S100, HAM-56, and CD68. Interestingly, immunoglobulins G, D and M and Complement factors C1q and C3 were also strongly expressed in antigen presenting cell areas, including positivity within the spongiotic epidermis and around dermal vessels. Conclusions: We document a heterogeneous population of B and T lymphocytes and the presence of multiple classes of antigen presenting cells, immunoglobulins and complement in and surrounding histologically spongiotic areas; these findings further correlated with increased levels of expression of Ki-67.

  20. Unique interplay between sugar and lipid in determining the antigenic potency of bacterial antigens for NKT cells.

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    Enrico Girardi

    2011-11-01

    Full Text Available Invariant natural killer T (iNKT cells are an evolutionary conserved T cell population characterized by features of both the innate and adaptive immune response. Studies have shown that iNKT cells are required for protective responses to Gram-positive pathogens such as Streptococcus pneumoniae, and that these cells recognize bacterial diacylglycerol antigens presented by CD1d, a non-classical antigen-presenting molecule. The combination of a lipid backbone containing an unusual fatty acid, vaccenic acid, as well as a glucose sugar that is weaker or not stimulatory when linked to other lipids, is required for iNKT cell stimulation by these antigens. Here we have carried out structural and biophysical studies that illuminate the reasons for the stringent requirement for this unique combination. The data indicate that vaccenic acid bound to the CD1d groove orients the protruding glucose sugar for TCR recognition, and it allows for an additional hydrogen bond of the glucose with CD1d when in complex with the TCR. Furthermore, TCR binding causes an induced fit in both the sugar and CD1d, and we have identified the CD1d amino acids important for iNKT TCR recognition and the stability of the ternary complex. The studies show also how hydrogen bonds formed by the glucose sugar can account for the distinct binding kinetics of the TCR for this CD1d-glycolipid complex. Therefore, our studies illuminate the mechanism of glycolipid recognition for antigens from important pathogens.

  1. Effective Delivery of Antigen-Encapsulin Nanoparticle Fusions to Dendritic Cells Leads to Antigen-Specific Cytotoxic T Cell Activation and Tumor Rejection.

    Science.gov (United States)

    Choi, Bongseo; Moon, Hyojin; Hong, Sung Joon; Shin, Changsik; Do, Yoonkyung; Ryu, Seongho; Kang, Sebyung

    2016-08-23

    In cancer immunotherapy, robust and efficient activation of cytotoxic CD8(+) T cell immune responses is a promising, but challenging task. Dendritic cells (DCs) are well-known professional antigen presenting cells that initiate and regulate antigen-specific cytotoxic CD8(+) T cells that kill their target cells directly as well as secrete IFN-γ, a cytokine critical in tumor rejection. Here, we employed recently established protein cage nanoparticles, encapsulin (Encap), as antigenic peptide nanocarriers by genetically incorporating the OT-1 peptide of ovalbumin (OVA) protein to the three different positions of the Encap subunit. With them, we evaluated their efficacy in activating DC-mediated antigen-specific T cell cytotoxicity and consequent melanoma tumor rejection in vivo. DCs efficiently engulfed Encap and its variants (OT-1-Encaps), which carry antigenic peptides at different positions, and properly processed them within phagosomes. Delivered OT-1 peptides were effectively presented by DCs to naïve CD8(+) T cells successfully, resulting in the proliferation of antigen-specific cytotoxic CD8(+) T cells. OT-1-Encap vaccinations in B16-OVA melanoma tumor bearing mice effectively activated OT-1 peptide specific cytotoxic CD8(+) T cells before or even after tumor generation, resulting in significant suppression of tumor growth in prophylactic as well as therapeutic treatments. A large number of cytotoxic CD8(+) T cells that actively produce both intracellular and secretory IFN-γ were observed in tumor-infiltrating lymphocytes collected from B16-OVA tumor masses originally vaccinated with OT-1-Encap-C upon tumor challenges. The approaches we describe herein may provide opportunities to develop epitope-dependent vaccination systems that stimulate and/or modulate efficient and epitope-specific cytotoxic T cell immune responses in nonpathogenic diseases.

  2. Fucoidan induces apoptosis of HepG2 cells by down-regulating p-Stat3.

    Science.gov (United States)

    Roshan, Sadia; Liu, Yun-yi; Banafa, Amal; Chen, Hui-jie; Li, Ke-xiu; Yang, Guang-xiao; He, Guang-yuan; Chen, Ming-jie

    2014-06-01

    Fucoidan is one of the main bioactive components of polysaccharides. The current study was focused on the anti-tumor effects of fucoidan on human heptoma cell line HepG2 and the possible mechanisms. Fucoidan treatment resulted in cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner detected by MTT assay, flow cytometry and fluorescent microscopy. The results of flow cytometric analysis revealed that fucoidan induced G2/M arrest in the cell cycle progression. Hoechst 33258 and Annexin V/PI staining results showed that the apoptotic cell number was increased, which was associated with a dose-dependent up-regulation of Bax and down-regulation of Bcl-2 and p-Stat3. In parallel, the up-regulation of p53 and the increase in reactive oxygen species were also observed, which may play important roles in the inhibition of HepG2 growth by fucoidan. In the meantime, Cyclin B1 and CDK1 were down-regulated by fucoidan treatment. Down-regulation of p-Stat3 by fucoidan resulted in apoptosis and an increase in ROS in response to fucoidan exposure. We therefore concluded that fucoidan induces apoptosis through the down-regulation of p-Stat3. These results suggest that fucoidan may be used as a novel anti-cancer agent for hepatocarcinoma.

  3. 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

    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....... 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...... 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...

  4. Epstein-Barr virus evades CD4+ T cell responses in lytic cycle through BZLF1-mediated downregulation of CD74 and the cooperation of vBcl-2.

    Directory of Open Access Journals (Sweden)

    Jianmin Zuo

    2011-12-01

    Full Text Available Evasion of immune T cell responses is crucial for viruses to establish persistence in the infected host. Immune evasion mechanisms of Epstein-Barr virus (EBV in the context of MHC-I antigen presentation have been well studied. In contrast, viral interference with MHC-II antigen presentation is less well understood, not only for EBV but also for other persistent viruses. Here we show that the EBV encoded BZLF1 can interfere with recognition by immune CD4+ effector T cells. This impaired T cell recognition occurred in the absence of a reduction in the expression of surface MHC-II, but correlated with a marked downregulation of surface CD74 on the target cells. Furthermore, impaired CD4+ T cell recognition was also observed with target cells where CD74 expression was downregulated by shRNA-mediated inhibition. BZLF1 downregulated surface CD74 via a post-transcriptional mechanism distinct from its previously reported effect on the CIITA promoter. In addition to being a chaperone for MHC-II αβ dimers, CD74 also functions as a surface receptor for macrophage Migration Inhibitory Factor and enhances cell survival through transcriptional upregulation of Bcl-2 family members. The immune-evasion function of BZLF1 therefore comes at a cost of induced toxicity. However, during EBV lytic cycle induced by BZLF1 expression, this toxicity can be overcome by expression of the vBcl-2, BHRF1, at an early stage of lytic infection. We conclude that by inhibiting apoptosis, the vBcl-2 not only maintains cell viability to allow sufficient time for synthesis and accumulation of infectious virus progeny, but also enables BZLF1 to effect its immune evasion function.

  5. Blockade of LFA-1 augments in vitro differentiation of antigen-induced Foxp3+ Treg cells

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    Verhagen, Johan; Wraith, David C.

    2014-01-01

    Adoptive transfer of antigen-specific, in vitro-induced Foxp3+ Treg (iTreg) cells protects against autoimmune disease. To generate antigen-specific iTreg cells at high purity, however, remains a challenge. Whereas polyclonal T cell stimulation with anti-CD3 and anti-CD28 antibody yields Foxp3+ iTreg cells at a purity of 90–95%, antigen-induced iTreg cells typically do not exceed a purity of 65–75%, even in a TCR-transgenic model. In a similar vein to thymic Treg cell selection, iTreg cell differentiation is influenced not only by antigen recognition and the availability of TGF-β but also by co-factors including costimulation and adhesion molecules. In this study, we demonstrate that blockade of the T cell integrin Leukocyte Function-associated Antigen-1 (LFA-1) during antigen-mediated iTreg cell differentiation augments Foxp3 induction, leading to approximately 90% purity of Foxp3+ iTreg cells. This increased efficacy not only boosts the yield of Foxp3+ iTreg cells, it also reduces contamination with activated effector T cells, thus improving the safety of adoptive transfer immunotherapy. PMID:25108241

  6. Juglone, isolated from Juglans mandshurica Maxim, induces apoptosis via down-regulation of AR expression in human prostate cancer LNCaP cells.

    Science.gov (United States)

    Xu, Huali; Yu, Xiaofeng; Qu, Shaochun; Sui, Dayun

    2013-06-15

    Juglone is a natural compound which has been isolated from Juglans mandshurica Maxim. Recent studies have shown that juglone had various pharmacological effects such as anti-viral, anti-bacterial and anti-cancer. However, its anti-cancer activity on human prostate cancer LNCaP cell has not been examined. Thus, the current study was designed to elucidate the molecular mechanism of apoptosis induced by juglone in androgen-sensitive prostate cancer LNCaP cells. MTT assay was performed to examine the anti-proliferative effect of juglone. Occurrence of apoptosis was detected by Hoechst 33342 staining and flow cytometry in LNCaP cells treated with juglone for 24h. The result shown that juglone inhibited the growth of LNCaP cells in a dose-dependent manner. Morphological changes of apoptotic body formation after juglone treatment were observed by Hoechst 33342 staining. This apoptotic induction was associated with loss of mitochondrial membrane potential, and caspase-3, -9 activation. Moreover, we found that juglone significantly inhibited the expression levels of androgen receptor (AR) and prostate-specific antigen (PSA) in a dose-dependent manner, as well as abrogated up-regulation of AR and PSA genes with and/or without dihydrotestosterone (DHT). Take together, our results demonstrated that juglone might induce the apoptosis in LNCaP cell via down-regulation of AR expression. Therefore, our results indicated that juglone may be a potential candidate of drug for androgen-sensitive prostate cancer.

  7. Amplified genes may be overexpressed, unchanged, or downregulated in cervical cancer cell lines.

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    Oscar Vazquez-Mena

    Full Text Available Several copy number-altered regions (CNAs have been identified in the genome of cervical cancer, notably, amplifications of 3q and 5p. However, the contribution of copy-number alterations to cervical carcinogenesis is unresolved because genome-wide there exists a lack of correlation between copy-number alterations and gene expression. In this study, we investigated whether CNAs in the cell lines CaLo, CaSki, HeLa, and SiHa were associated with changes in gene expression. On average, 19.2% of the cell-line genomes had CNAs. However, only 2.4% comprised minimal recurrent regions (MRRs common to all the cell lines. Whereas 3q had limited common gains (13%, 5p was entirely duplicated recurrently. Genome-wide, only 15.6% of genes located in CNAs changed gene expression; in contrast, the rate in MRRs was up to 3 times this. Chr 5p was confirmed entirely amplified by FISH; however, maximum 33.5% of the explored genes in 5p were deregulated. In 3q, this rate was 13.4%. Even in 3q26, which had 5 MRRs and 38.7% recurrently gained SNPs, the rate was only 15.1%. Interestingly, up to 19% of deregulated genes in 5p and 73% in 3q26 were downregulated, suggesting additional factors were involved in gene repression. The deregulated genes in 3q and 5p occurred in clusters, suggesting local chromatin factors may also influence gene expression. In regions amplified discontinuously, downregulated genes increased steadily as the number of amplified SNPs increased (p<0.01, Spearman's correlation. Therefore, partial gene amplification may function in silencing gene expression. Additional genes in 1q, 3q and 5p could be involved in cervical carcinogenesis, specifically in apoptosis. These include PARP1 in 1q, TNFSF10 and ECT2 in 3q and CLPTM1L, AHRR, PDCD6, and DAP in 5p. Overall, gene expression and copy-number profiles reveal factors other than gene dosage, like epigenetic or chromatin domains, may influence gene expression within the entirely amplified genome

  8. Amplified genes may be overexpressed, unchanged, or downregulated in cervical cancer cell lines.

    Science.gov (United States)

    Vazquez-Mena, Oscar; Medina-Martinez, Ingrid; Juárez-Torres, Eligia; Barrón, Valeria; Espinosa, Ana; Villegas-Sepulveda, Nicolás; Gómez-Laguna, Laura; Nieto-Martínez, Karem; Orozco, Lorena; Roman-Basaure, Edgar; Muñoz Cortez, Sergio; Borges Ibañez, Manuel; Venegas-Vega, Carlos; Guardado-Estrada, Mariano; Rangel-López, Angélica; Kofman, Susana; Berumen, Jaime

    2012-01-01

    Several copy number-altered regions (CNAs) have been identified in the genome of cervical cancer, notably, amplifications of 3q and 5p. However, the contribution of copy-number alterations to cervical carcinogenesis is unresolved because genome-wide there exists a lack of correlation between copy-number alterations and gene expression. In this study, we investigated whether CNAs in the cell lines CaLo, CaSki, HeLa, and SiHa were associated with changes in gene expression. On average, 19.2% of the cell-line genomes had CNAs. However, only 2.4% comprised minimal recurrent regions (MRRs) common to all the cell lines. Whereas 3q had limited common gains (13%), 5p was entirely duplicated recurrently. Genome-wide, only 15.6% of genes located in CNAs changed gene expression; in contrast, the rate in MRRs was up to 3 times this. Chr 5p was confirmed entirely amplified by FISH; however, maximum 33.5% of the explored genes in 5p were deregulated. In 3q, this rate was 13.4%. Even in 3q26, which had 5 MRRs and 38.7% recurrently gained SNPs, the rate was only 15.1%. Interestingly, up to 19% of deregulated genes in 5p and 73% in 3q26 were downregulated, suggesting additional factors were involved in gene repression. The deregulated genes in 3q and 5p occurred in clusters, suggesting local chromatin factors may also influence gene expression. In regions amplified discontinuously, downregulated genes increased steadily as the number of amplified SNPs increased (p<0.01, Spearman's correlation). Therefore, partial gene amplification may function in silencing gene expression. Additional genes in 1q, 3q and 5p could be involved in cervical carcinogenesis, specifically in apoptosis. These include PARP1 in 1q, TNFSF10 and ECT2 in 3q and CLPTM1L, AHRR, PDCD6, and DAP in 5p. Overall, gene expression and copy-number profiles reveal factors other than gene dosage, like epigenetic or chromatin domains, may influence gene expression within the entirely amplified genome segments.

  9. Diminished Memory T-Cell Expansion Due to Delayed Kinetics of Antigen Expression by Lentivectors.

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    Karina Furmanov

    Full Text Available Memory CD8(+ T lymphocytes play a central role in protective immunity. In attempt to increase the frequencies of memory CD8(+ T cells, repeated immunizations with viral vectors are regularly explored. Lentivectors have emerged as a powerful vaccine modality with relatively low pre-existing and anti-vector immunity, thus, thought to be ideal for boosting memory T cells. Nevertheless, we found that lentivectors elicited diminished secondary T-cell responses that did not exceed those obtained by priming. This was not due to the presence of anti-vector immunity, as limited secondary responses were also observed following heterologous prime-boost immunizations. By dissecting the mechanisms involved in this process, we demonstrate that lentivectors trigger exceptionally slow kinetics of antigen expression, while optimal activation of lentivector-induced T cells relays on durable expression of the antigen. These qualities hamper secondary responses, since lentivector-encoded antigen is rapidly cleared by primary cytotoxic T cells that limit its presentation by dendritic cells. Indeed, blocking antigen clearance by cytotoxic T cells via FTY720 treatment, fully restored antigen presentation. Taken together, while low antigen expression is expected during secondary immunization with any vaccine vector, our results reveal that the intrinsic delayed expression kinetics of lentiviral-encoded antigen, further dampens secondary CD8(+ T-cell expansion.

  10. Curcumin inhibits cell growth and invasion and induces apoptosis through down-regulation of Skp2 in pancreatic cancer cells

    Science.gov (United States)

    Su, Jingna; Zhou, Xiuxia; Wang, Lixia; Yin, Xuyuan; Wang, Zhiwei

    2016-01-01

    Natural polyphenol compound curcumin has been found to exhibit its anticancer activity in a variety of human malignancies including pancreatic cancer (PC). However, the underlying mechanism has not been fully understood. Accumulating evidence has demonstrated that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in the development and progression of human cancers. In this study, we aim to explore the molecular basis of curcumin-induced cell growth inhibition in PC cells.Multiple methods such as CTG assay, Flow cytometry, clonogenic assay, wound healing assay, Transwell invasion assay, Western blotting, and transfection were performed to validate the oncogenic role of curcumin in PC cells. We found that curcumin suppressed cell growth, clonogenic potential, migration and invasion, and induced cell apoptosis and cell cycle arrest. Moreover, we observed thatover-expression of Skp2 significantly promoted cell growth, whereas down-regulation of Skp2 with siRNAs inhibited cell growth. The molecular basis of curcumin-mediated cell growth inhibition we identified is that curcumin significantly suppressed Skp2 expression and subsequently induced p21 expression. These findings suggested thattargeting Skp2 by curcumin could be a promising therapeutic strategy for the treatment of PC patients.

  11. Potent antigen-specific immune response induced by infusion of spleen cells coupled with succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) conjugated antigens.

    Science.gov (United States)

    Guo, Yixian; Werbel, Tyler; Wan, Suigui; Wu, Haitao; Li, Yaohua; Clare-Salzler, Michael; Xia, Chang-Qing

    2016-02-01

    In the present study, we report our recently developed new approach to inducing antigen-specific immune response. We use two nucleophilic substitution "click" chemistry processes to successfully couple protein antigens or peptides to mouse spleen cells or T cells by a heterobifunctional crosslinker, succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) or sulfo-SMCC. SMCC and its water-soluble analog sulfo-SMCC contain N-hydroxysuccinimide (NHS) ester and maleimide groups, which allow stable covalent conjugation of amine- and sulfhydryl-containing molecules in trans. Protein coupling to cells relies on the free sulfhydryls (thiols) on cell surfaces and the free amines on protein antigens. Although the amount of protein coupled to cells is limited due to the limited number of cell surface thiols, the injection of spleen cells coupled with antigenic proteins, such as keyhole limpet hemocyanin (KLH) or ovalbumin (OVA), induces a potent antigen-specific immune response in vivo, which is even stronger than that induced by the injection of a large dose of protein plus adjuvants. In addition, short peptides coupled to purified splenic T cells also potently elicit peptide-specific T cell proliferation in vivo after injection. Further studies show that antigen-coupled spleen cell treatment leads to augmented IFN-γ-producing T cells. Our study provides a unique antigen delivery method that efficiently distributes antigen to the entire immune system, subsequently eliciting a potent antigen-specific immune response with enhanced IFN-γ production. The findings in the present study suggest that this antigen-cell coupling strategy could be employed in immunotherapy for cancers, infectious diseases as well as immune-mediated disorders.

  12. Segmented filamentous bacteria antigens presented by intestinal dendritic cells drive mucosal Th17 cell differentiation.

    Science.gov (United States)

    Goto, Yoshiyuki; Panea, Casandra; Nakato, Gaku; Cebula, Anna; Lee, Carolyn; Diez, Marta Galan; Laufer, Terri M; Ignatowicz, Leszek; Ivanov, Ivaylo I

    2014-04-17

    How commensal microbiota contributes to immune cell homeostasis at barrier surfaces is poorly understood. Lamina propria (LP) T helper 17 (Th17) cells participate in mucosal protection and are induced by commensal segmented filamentous bacteria (SFB). Here we show that MHCII-dependent antigen presentation of SFB antigens by intestinal dendritic cells (DCs) is crucial for Th17 cell induction. Expression of MHCII on CD11c(+) cells was necessary and sufficient for SFB-induced Th17 cell differentiation. Most SFB-induced Th17 cells recognized SFB in an MHCII-dependent manner. SFB primed and induced Th17 cells locally in the LP and Th17 cell induction occurred normally in mice lacking secondary lymphoid organs. The importance of other innate cells was unveiled by the finding that MHCII deficiency in group 3 innate lymphoid cells (ILCs) resulted in an increase in SFB-independent Th17 cell differentiation. Our results outline the complex role of DCs and ILCs in the regulation of intestinal Th17 cell homeostasis.

  13. Detecting Antigen-Specific T Cell Responses: From Bulk Populations to Single Cells

    Directory of Open Access Journals (Sweden)

    Chansavath Phetsouphanh

    2015-08-01

    Full Text Available A new generation of sensitive T cell-based assays facilitates the direct quantitation and characterization of antigen-specific T cell responses. Single-cell analyses have focused on measuring the quality and breadth of a response. Accumulating data from these studies demonstrate that there is considerable, previously-unrecognized, heterogeneity. Standard assays, such as the ICS, are often insufficient for characterization of rare subsets of cells. Enhanced flow cytometry with imaging capabilities enables the determination of cell morphology, as well as the spatial localization of the protein molecules within a single cell. Advances in both microfluidics and digital PCR have improved the efficiency of single-cell sorting and allowed multiplexed gene detection at the single-cell level. Delving further into the transcriptome of single-cells using RNA-seq is likely to reveal the fine-specificity of cellular events such as alternative splicing (i.e., splice variants and allele-specific expression, and will also define the roles of new genes. Finally, detailed analysis of clonally related antigen-specific T cells using single-cell TCR RNA-seq will provide information on pathways of differentiation of memory T cells. With these state of the art technologies the transcriptomics and genomics of Ag-specific T cells can be more definitively elucidated.

  14. Downregulation of Noxa by RAF/MEK inhibition counteracts cell death response in mutant B-RAF melanoma cells.

    Science.gov (United States)

    Basile, Kevin J; Aplin, Andrew E

    2012-01-01

    FDA approval of new therapies in 2011 has greatly expanded the treatment options for metastatic melanoma. Patients with V600 mutant v-raf murine sarcoma viral oncogene homolog B1 (B-RAF) positive metastatic melanoma are now treated with the RAF inhibitor, vemurafenib (Zelboraf) as a first line therapy. Vemurafenib decreases tumor size by at least 30% in approximately 50% of patients and increases progression-free survival and overall patient survival compared to the previous standard-of-care, dacarbazine. However, some patients treated with vemurafenib fail to show significant tumor shrinkage, and most patients who initially respond to the drug eventually show disease progression. Therefore, there is a clinical need to improve efficacy and prevent resistance to vemurafenib. It has been previously shown that cell death resulting from RAF/mitogen-activated protein kinase kinase (MEK) inhibition is largely dependent on increased expression of pro-apoptotic, Bcl-2 homology domain (BH3)-only proteins, such as Bcl-2-like 11 (Bim-EL) and Bcl-2 modifying factor (Bmf). Here, we show that contrary to expression of Bim-EL and Bmf, the pro-apoptotic, BH3-only protein, phorbol-12-myristate-13-acetate-induced protein 1 (Noxa), is strongly downregulated after RAF/MEK inhibition. This downregulation occurs at both the protein and mRNA level of expression and is associated with the inhibition of cell cycle progression. Restoring expression of Noxa in combination with RAF/MEK inhibition enhances cell death. Co-expression of the pro-survival, B-cell CLL/lymphoma 2 (Bcl-2) family member, myeloid cell leukemia sequence 1 (Mcl-1), with Noxa fully mitigates the enhanced cell death associated with increased Noxa expression. These data indicate that manipulating the Noxa/Mcl-1 axis may enhance the efficacy of RAF/MEK inhibitors.

  15. Presentation of antigen by B cells subsets. Pt. 1. Lyb-5{sup +} and Lyb-5{sup -} B cells differ in ability to stimulate specific T cells

    Energy Technology Data Exchange (ETDEWEB)

    Zimecki, M. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Immunologii i Terapii Doswiadczalnej; Whiteley, P.J. [Merck and Co., Inc., Rahway, NJ (United States); Pierce, C.W.; Kapp, J.A. [Harrington Cancer Center, Amarillo (United States). Dept. of Cellular and Molecular Immunology

    1994-12-31

    We have examined the antigen presenting cell (APC) function of different B cells. Resident, peritoneal B cells from normal mice were more efficient than splenic B cells in presenting antigen to CD4{sup +} T cell lines. Peritoneal B cells from X-linked immunodeficient (Xid) mice, by contrast, stimulated no detectable responses. Xid splenic B cells were much less efficient APC than normal splenic B cells. B cells from neonatal mice also were very poor APC until the mice were 3 to 4 weeks old. Xid B cells presented antigen to T cell hybridomas as well as normal B cells showing that they process antigen normally. Thus, the defect is most likely in providing secondary signals. The ability of B cells to present antigen efficiency correlates with the percentage of B cells reported to express the Lyb-5 antigen. Anti-Lyb-5 serum and complement abrogated the APC activity of B cells suggesting that Lyb-5{sup +}, but not Lyb-5{sup -} cells are efficient APC. We also found that activated and resting normal splenic B cells, separated by buoyant density, presented antigen equally. Both populations also contained Lyb-5{sup +} B cells although they were a larger fraction of the activated cells. Lyb-5 is now thought to be an activation antigen rather than a differentiation antigen. If this idea is correct, then our data indicate that anti-Lyb-5 more cleanly separates activated and resting B cells than buoyant density techniques. (author). 38 refs, 7 figs, 1 tab.

  16. Zinc downregulates HIF-1α and inhibits its activity in tumor cells in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Lavinia Nardinocchi

    Full Text Available BACKGROUND: Hypoxia inducible factor-1α (HIF-1α is responsible for the majority of HIF-1-induced gene expression changes under hypoxia and for the "angiogenic switch" during tumor progression. HIF-1α is often upregulated in tumors leading to more aggressive tumor growth and chemoresistance, therefore representing an important target for antitumor intervention. We previously reported that zinc downregulated HIF-1α levels. Here, we evaluated the molecular mechanisms of zinc-induced HIF-1α downregulation and whether zinc affected HIF-1α also in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that zinc downregulated HIF-1α protein levels in human prostate cancer and glioblastoma cells under hypoxia, whether induced or constitutive. Investigations into the molecular mechanisms showed that zinc induced HIF-1α proteasomal degradation that was prevented by treatment with proteasomal inhibitor MG132. HIF-1α downregulation induced by zinc was ineffective in human RCC4 VHL-null renal carcinoma cell line; likewise, the HIF-1αP402/P564A mutant was resistant to zinc treatment. Similarly to HIF-1α, zinc downregulated also hypoxia-induced HIF-2α whereas the HIF-1β subunit remained unchanged. Zinc inhibited HIF-1α recruitment onto VEGF promoter and the zinc-induced suppression of HIF-1-dependent activation of VEGF correlated with reduction of glioblastoma and prostate cancer cell invasiveness in vitro. Finally, zinc administration downregulated HIF-1α levels in vivo, by bioluminescence imaging, and suppressed intratumoral VEGF expression. CONCLUSIONS/SIGNIFICANCE: These findings, by demonstrating that zinc induces HIF-1α proteasomal degradation, indicate that zinc could be useful as an inhibitor of HIF-1α in human tumors to repress important pathways involved in tumor progression, such as those induced by VEGF, MDR1, and Bcl2 target genes, and hopefully potentiate the anticancer therapies.

  17. The downregulation of thioredoxin accelerated Neuro2a cell apoptosis induced by advanced glycation end product via activating several pathways.

    Science.gov (United States)

    Ren, Xiang; Ma, Haiying; Qiu, Yuanyuan; Liu, Bo; Qi, Hui; Li, Zeyu; Kong, Hui; Kong, Li

    2015-08-01

    Thioredoxin (Trx), a 12 kDa protein, has different functions in different cellular environments, playing important anti-oxidative and anti-apoptotic roles and regulating the expression of transcription factors. Advanced glycation end products (AGEs) are a heterogeneous group of irreversible adducts from glucose-protein condensation reactions and are considered crucial to the development of diabetic nephropathy, retinopathy, neurodegeneration and atherosclerosis. The aim of this study was to use a Trx inhibitor to investigate the effects and mechanism of Trx down-regulation on AGE-induced Neuro2a cell apoptosis. Neuro2a cells were cultured in vitro and treated with different conditions. The apoptosis and proliferation of Neuro2a cells were detected using flow cytometry, DNA-Ladder and CCK8 assays. Rho 123 was used to detect the mitochondrial membrane potential. ROS generation and caspase3 activity were detected using a DCFH-DA probe and micro-plate reader. Western blotting and real-time PCR were used to detect the expression of proteins and genes. We found that the down-regulation of thioredoxin could accelerate AGE-induced apoptosis in Neuro2a cells. A possible underlying mechanism is that the down-regulation of thioredoxin stimulated the up-regulation of ASK1, p-JNK, PTEN, and Txnip, as well as the down-regulation of p-AKT, ultimately increasing ROS levels and caspase3 activity.

  18. Phosphorylation of FOXP3 by LCK downregulates MMP9 expression and represses cell invasion.

    Directory of Open Access Journals (Sweden)

    Kumiko Nakahira

    Full Text Available Forkhead Box P3 (FOXP3 is a member of the forkhead/winged helix family of the transcription factors and plays an important role not only as a master gene in T-regulatory cells, but also as a tumor suppressor. In this study, we identified lymphocyte-specific protein tyrosine kinase (LCK, which correlates with cancer malignancy, as a binding partner of FOXP3. FOXP3 downregulated LCK-induced MMP9, SKP2, and VEGF-A expression. We observed that LCK phosphorylated Tyr-342 of FOXP3 by immunoprecipitation and in vitro kinase assay, and the replacement of Tyr-342 with phenylalanine (Y342F abolished the ability to suppress MMP9 expression. Although FOXP3 decreased the invasive ability induced by LCK in MCF-7 cells, Y342F mutation in FOXP3 diminished this suppressive effect. Thus we demonstrate for the first time that LCK upregulates FOXP3 by tyrosine phosphorylation, resulting in decreased MMP9, SKP2, and VEGF-A expression, and suppressed cellular invasion. We consider that further clarification of transcriptional mechanism of FOXP3 may facilitate the development of novel therapeutic approaches to suppress cancer malignancy.

  19. Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Erica M. [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Niu, MengMeng; Bergholz, Johann [Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China); Jim Xiao, Zhi-Xiong, E-mail: jxiao@bu.edu [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China)

    2015-05-29

    The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification. In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.

  20. Down-regulation of HSP27 sensitizes TRAIL-resistant tumor cell to TRAIL-induced apoptosis

    DEFF Research Database (Denmark)

    Zhuang, Hongqin; Jiang, Weiwei; Cheng, Wei

    2010-01-01

    oxygen species or anticancer drugs. Their elevated expressions facilitate cells to survive in stress circumstances. The HSP27 expression is enhanced in many tumor cells, implying that it is involved in tumor progression and the development of treatment resistance in various tumors, including lung cancer...... siRNA on drug sensitization of A549 cells to TRAIL treatment. The results showed that treatment of A549 cells with HSP27 siRNA down-regulated HSP27 expression but did not induce significant apoptosis. However, combination of HSP27 siRNA with TRAIL-induced significant apoptosis in TRAIL-resistant A549...... cells. In addition to inducing caspases activation and apoptosis, combined treatment with HSP27 siRNA and TRAIL also increased JNK and p53 expression and activity. Collectively, these findings provide a conclusion that siRNA targeting of the HSP27 gene specifically down-regulated HSP27 expression in A...

  1. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

    Directory of Open Access Journals (Sweden)

    Martin Kreutz

    Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

  2. Monocyte-induced downregulation of nitric oxide synthase in cultured aortic endothelial cells.

    Science.gov (United States)

    Marczin, N; Antonov, A; Papapetropoulos, A; Munn, D H; Virmani, R; Kolodgie, F D; Gerrity, R; Catravas, J D

    1996-09-01

    -induced inactivation of NO or limited substrate availability were not primarily responsible for the inhibiting effects of monocytes. Western blot analysis revealed reduced quantities of ecNOS in monocyte/endothelium cocultures, as well as in HAECs treated with monocyte-conditioned medium or TNF-alpha. Thus, adhesion of monocytes to endothelial cells and monocyte-derived secretory products downregulate steady state levels of ecNOS, an event associated with attenuated release of biologically active NO. This mechanism may potentially contribute to diminished endothelium-dependent and NO-mediated vasodilation in early atherosclerosis.

  3. Epstein-Barr virus nuclear antigen 2 specifically induces expression of the B-cell activation antigen CD23

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F.; Gregory, C.D.; Rowe, M.; Rickinson, A.B.; Wang, D.; Birkenbach, M.; Kikutani, H.; Kishimoto, T.; Kieff, E.

    1987-05-01

    Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells includes some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation.

  4. Dynamic imaging of experimental Leishmania donovani-induced hepatic granulomas detects Kupffer cell-restricted antigen presentation to antigen-specific CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Lynette Beattie

    2010-03-01

    Full Text Available Kupffer cells (KCs represent the major phagocytic population within the liver and provide an intracellular niche for the survival of a number of important human pathogens. Although KCs have been extensively studied in vitro, little is known of their in vivo response to infection and their capacity to directly interact with antigen-specific CD8(+ T cells. Here, using a combination of approaches including whole mount and thin section confocal microscopy, adoptive cell transfer and intra-vital 2-photon microscopy, we demonstrate that KCs represent the only detectable population of mononuclear phagocytes within granulomas induced by Leishmania donovani infection that are capable of presenting parasite-derived peptide to effector CD8(+ T cells. This restriction of antigen presentation to KCs within the Leishmania granuloma has important implications for the identification of new candidate vaccine antigens and for the design of novel immuno-therapeutic interventions.

  5. Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

    Institute of Scientific and Technical Information of China (English)

    Anna Oksaharju; Matti Kankainen; Riina A Kekkonen; Ken A Lindstedt; Petri T Kovanen; Riitta Korpela; Minja Miettinen

    2011-01-01

    AIM: To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.METHODS: Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L.rhamnosus ) GG (LGG(R)), L. rhamnosus Lc705 (Lc705),Propionibacterium freudenreichii ssp. shermanii JS (PJS) and Bifidobacterium animalis ssp. lactis Bb12 (Bb12) and their combination for 3 or 24 h, and were subjected to global microarray analysis using an Affymetrix GeneChip(R) Human Genome U133 Plus 2.0 Array. The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.RESULTS: LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G, respectively)and histamine H4 receptor. LGG, Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation, and on several genes that encoded proteins with a pro-inflammatory impact, such as interleukin (IL)-8 and tumour necrosis factor alpha. Also genes that encoded proteins with anti-inflammatory functions, such as IL-10, were upregulated. CONCLUSION: Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes, and by inducing a pro-inflammatory response.

  6. Towards efficient cancer immunotherapy: advances in developing artificial antigen-presenting cells

    NARCIS (Netherlands)

    Eggermont, L.J.; Paulis, L.E.M.; Tel, J.; Figdor, C.G.

    2014-01-01

    Active anti-cancer immune responses depend on efficient presentation of tumor antigens and co-stimulatory signals by antigen-presenting cells (APCs). Therapy with autologous natural APCs is costly and time-consuming and results in variable outcomes in clinical trials. Therefore, development of artif

  7. Axotomy induces MHC class I antigen expression on rat nerve cells

    DEFF Research Database (Denmark)

    Maehlen, J; Schröder, H D; Klareskog, L;

    1988-01-01

    Immunomorphological staining demonstrates that class I major histocompatibility complex (MHC)-coded antigen expression can be selectively induced on otherwise class I-negative rat nerve cells by peripheral axotomy. Induction of class I as well as class II antigen expression was simultaneously see...

  8. Interplay between carbohydrate and lipid in recognition of glycolipid antigens by natural killer T cells.

    Science.gov (United States)

    Pei, Bo; Vela, Jose Luis; Zajonc, Dirk; Kronenberg, Mitchell

    2012-04-01

    Natural killer T (NKT) cells are a T cell subpopulation that were named originally based on coexpression of receptors found on natural killer (NK) cells, cells of the innate immune system, and by T lymphocytes. The maturation and activation of NKT cells requires presentation of glycolipid antigens by CD1d, a cell surface protein distantly related to the major histocompatibility complex (MHC)-encoded antigen presenting molecules. This specificity distinguishes NKT cells from most CD4(+) and CD8(+) T cells that recognize peptides presented by MHC class I and class II molecules. The rapid secretion of a large amount of both Th1 and Th2 cytokines by activated NKT cells endows them with the ability to play a vital role in the host immune defense against various microbial infections. In this review, we summarize progress on identifying the sources of microbe-derived glycolipid antigens recognized by NKT cells and the biochemical basis for their recognition.

  9. Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry.

    Science.gov (United States)

    Shi, Zi-xuan; Rao, Wei; Wang, Huan; Wang, Nan-ding; Si, Jing-wen; Zhao, Jiao; Li, Jun-chang; Wang, Zong-ren

    2015-02-13

    Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromal interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future.

  10. Cisplatin and ultra-violet-C synergistically down-regulate receptor tyrosine kinases in human colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Kawaguchi Junji

    2012-07-01

    Full Text Available Abstract Background Platinum-containing anti-cancer drugs such as cisplatin are widely used for patients with various types of cancers, however, resistance to cisplatin is observed in some cases. Whereas we have recently reported that high dose UV-C (200 J/m² induces colorectal cancer cell proliferation by desensitization of EGFR, which leads oncogenic signaling in these cells, in this study we investigated the combination effect of low dose cisplatin (10 μM and low dose UV-C (10 J/m² on cell growth and apoptosis in several human colorectal cancer cells, SW480, DLD-1, HT29 and HCT116. Results The combination inhibited cell cycle and colony formation, while either cisplatin or UV-C alone had little effect. The combination also induced apoptosis in these cells. In addition, the combination caused the downregulation of EGFR and HER2. Moreover, UV-C alone caused the transient internalization of the EGFR, but with time EGFR recycled back to the cell surface, while cisplatin did not affect its localization. Surprisingly, the combination caused persistent internalization of the EGFR, which results in the lasting downregulation of the EGFR. Conclusions The combination of low dose cisplatin and low dose UV-C synergistically exerted anti-cancer effect by down-regulating RTK, such as EGFR and HER2. These findings may provide a novel strategy for the treatment of patients with colorectal cancer.

  11. How T-cells use large deviations to recognize foreign antigens

    CERN Document Server

    Zint, Natali; Hollander, Frank den

    2008-01-01

    A stochastic model for the activation of T-cells is analysed. T-cells are part of the immune system and recognize foreign antigens against a background of the body's own molecules. The model under consideration is a slight generalization of a model introduced by Van den Berg, Rand and Burroughs in 2001, and is capable of explaining how this recognition works on the basis of rare stochastic events. With the help of a refined large deviation theorem and numerical evaluation it is shown that, for a wide range of parameters, T-cells can distinguish reliably between foreign antigens and self-antigens.

  12. A fibroblast-associated antigen: Characterization in fibroblasts and immunoreactivity in smooth muscle differentiated stromal cells

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Celis, Julio E.; van Deurs, Bo

    1992-01-01

    Fibroblasts with smooth muscle differentiation are frequently derived from human breast tissue. Immunofluorescence cytochemistry of a fibroblast-associated antigen recognized by a monoclonal antibody (MAb), 1B10, was analyzed with a view to discriminating smooth muscle differentiated fibroblasts...... from vascular smooth muscle cells. The antigen was detected on the cell surface and in cathepsin D-positive and acridine orange-accumulating vesicular compartments of fibroblasts. Ultrastructurally, the antigen was revealed in coated pits and in endosomal and lysosomal structures. 1B10 recognized three...... immunoreactivity was specific to fibroblasts and smooth muscle differentiated fibroblasts within the context of vascular smooth muscle cells....

  13. Lycium barbarum L. Polysaccharide (LBP Reduces Glucose Uptake via Down-Regulation of SGLT-1 in Caco2 Cell

    Directory of Open Access Journals (Sweden)

    Huizhen Cai

    2017-02-01

    Full Text Available Lycium barbarum L. polysaccharide (LBP is prepared from Lycium barbarum L. (L. barbarum, which is a traditional Chinese medicine. LPB has been shown to have hypoglycemic effects. In order to gain some mechanistic insights on the hypoglycemic effects of LBP, we investigated the uptake of LBP and its effect on glucose absorption in the human intestinal epithelial cell line Caco2 cell. The uptake of LBP through Caco2 cell monolayer was time-dependent and was inhibited by phloridzin, a competitive inhibitor of SGLT-1. LPB decreased the absorption of glucose in Caco2 cell, and down-regulated the expression of SGLT-1. These results suggest that LBP might be transported across the human intestinal epithelium through SGLT-1 and it inhibits glucose uptake via down-regulating SGLT-1.

  14. Cytotoxicity of calotropin is through caspase activation and downregulation of anti-apoptotic proteins in K562 cells.

    Science.gov (United States)

    Wang, Shih-Chung; Lu, Mei-Chin; Chen, Hsiu-Lin; Tseng, Hsing-I; Ke, Yu-Yuan; Wu, Yang-Chang; Yang, Pei-Yu

    2009-12-01

    Calotropin is one of cardenolides isolated from milkweed used for medicinal purposes in many Asian countries. Whereas calotropin possesses cytotoxicity against several cancer cells, the mechanisms of action remain unclear. We set out to evaluate the cytotoxic mechanism of calotropin on human chronic myeloid leukemia K562 cells. Calotropin inhibited the growth of K562 cells in a time- and dose-dependent manner by G(2)/M phase arrest. It upregulated the expression of p27 leading to this arrest by downregulating the G2/M regulatory proteins, cyclins A and B, and by upregulating the cdk inhibitor, p27. Furthermore, it downregulated anti-apoptotic signaling (XIAP and survivin) and survival pathways (p-Akt and NFkappaB), leading to caspase-3 activation which resulted in the induction of apoptosis. In all, calotropin exerted its anticancer activity on K562 cells by modulating the pro-survival signaling that leads to induction of apoptosis.

  15. Endothelial progenitor cell down-regulation in a mouse model of Kawasaki disease

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-feng; DU Zhong-dong; CHEN Zhi; LU Dun-xiang; LI Li; GUAN Yun-qian; WAN Sui-gui

    2012-01-01

    Background Cardiovascular complications of Kawasaki disease (KD) are a common cause of heart disease in pediatric populations.Previous studies have suggested a role for endothelial progenitor cells (EPCs) in coronary artery lesions associated with KD.However,long-term observations of EPCs during the natural progression of this disorder are lacking.Using an experimental model of KD,we aimed to determine whether the coronary artery lesions are associated with down-regulation of EPCs.Methods To induce KD,C57BL/6 mice were administered an intraperitoneal injection of Lactobacillus casei cell wall extract (LCWE; phosphate buffered saline used as control vehicle).Study groups included:group A (14 days following LCWE injection),group B (56 days following LCWE injection) and group C (controls).Numbers of circulating EPCs (positively staining for both CD34 and FIk-1 while staining negative for CD45) were evaluated using flow cytometry.Bone marrow mononuclear cells were cultured in vitro to expand EPCs for functional analysis.In vitro EPC proliferation,adhesion and migration were assessed.Results The model was shown to exhibit similar coronary artery lesions to KD patients with coronary aneurysms.Numbers of circulating EPCs decreased significantly in the KD models (groups A and B) compared to controls ((0.017±0.008)% VS.(0.028±0.007)%,P<0.05 and (0.016±0.007)% vs.(0.028±0.007)%,P <0.05).Proliferative,adhesive and migratory properties of EPCs were markedly impaired in groups A and B.Conclusion Coronary artery lesions in KD occur as a consequence of impaired vascular injury repair,resulting from excess consumption of EPCs together with a functional impairment of bone marrow EPCs and their precursors.

  16. Infant intestinal Enterococcus faecalis down-regulates inflammatory responses in human intestinal cell lines

    Institute of Scientific and Technical Information of China (English)

    Shugui Wang; Lydia Hui Mei Ng; Wai Ling Chow; Yuan Kun Lee

    2008-01-01

    AIM:To investigate the ability of Lactic acid bacteria (LAB)to modulate inflammatory reaction in human intestinal celllines(Caco-2,HT-29 and HCT 116).Different strains of LAB isolatedfrom new born infants and fermented milk,together withthestrains obtained from culture collectionsweretested.METHODS:LABs were treated with human intestinal cell lines.ELISA was used to detect IL-8 and TGF-β protein secretion.Cytokines and Toll like receptors (TLRs) gene expression were assessed using RT-PCR.Conditional medium,sonicated bacteria and UV killed bacteria were used to find the effecter molecules on the bacteria.Carbohydrate oxidation and protein digestion were applied to figure out the molecules'residues.Adhesion assays were further carried out.RESULTS:It was found that Enterococcus faecalis is the main immune modulator among the LABs by downregulation of IL-8 secretion and upregulation of TGF-β.Strikingly,the effect was only observed in four strains of E.faecalis out of the 27 isolated and tested.This implies strain dependent immunomodulation in the host.In addition,E.faecalis may regulate inflammatory responses through TLR3,TLR4,TLR9 and TRAF6.Carbohydrates on the bacterial cell surface are involved in both its adhesion to intestinal cells and regulation of inflammatory responses in the host.CONCLUSION:These data provide a case for the modulation of intestinal mucosal immunity in which specific strains of E.faecalis have uniquely evolved to maintain colonic homeostasis and regulate inflammatoryresponses.

  17. The Balance between CD8(+) T Cell-Mediated Clearance of AAV-Encoded Antigen in the Liver and Tolerance Is Dependent on the Vector Dose.

    Science.gov (United States)

    Kumar, Sandeep R P; Hoffman, Brad E; Terhorst, Cox; de Jong, Ype P; Herzog, Roland W

    2017-04-05

    The liver continuously receives antigens from circulation and the gastrointestinal tract. A complex immune regulatory system has evolved in order to both limit inflammation and promote tolerance in the liver. Although in situ immune tolerance mechanisms enable successful gene therapy and liver transplantation, at the same time they facilitate chronic infections by pathogens such as hepatitis viruses. It is, however, poorly understood why hepatocytes infected with hepatitis viruses or transduced with adeno-associated virus (AAV)-based vectors may be rejected by CD8(+) T cells several months later. We found that hepatic transfer of limited doses of an AAV-ovalbumin vector rapidly induced antigen-specific CD8(+) T cells that only became functionally competent after >2 months. At this time, CD8(+) T cells had downregulated negative checkpoint markers, e.g., the programmed death 1 [PD-1] receptor, and upregulated expression of relevant cytokines. At further reduced vector dose, only intrahepatic rather than systemic CD8(+) T cell responses occurred, showing identical delay in antigen clearance. In contrast, PD-1-deficient mice rapidly cleared ovalbumin. Interestingly, higher vector dose directed sustained transgene expression without CD8(+) T cell responses. Regulatory T cells, IL-10 expression, and Fas-L contributed to high-dose tolerance. Thus, viral vector doses profoundly impact CD8(+) T cell responses.

  18. Red Blood Cell Antigen Genotyping for Sickle Cell Disease, Thalassemia, and Other Transfusion Complications.

    Science.gov (United States)

    Fasano, Ross M; Chou, Stella T

    2016-10-01

    Since the discovery of the ABO blood group in the early 20th century, more than 300 blood group antigens have been categorized among 35 blood group systems. The molecular basis for most blood group antigens has been determined and demonstrates tremendous genetic diversity, particularly in the ABO and Rh systems. Several blood group genotyping assays have been developed, and 1 platform has been approved by the Food and Drug Administration as a "test of record," such that no phenotype confirmation with antisera is required. DNA-based red blood cell (RBC) phenotyping can overcome certain limitations of hemagglutination assays and is beneficial in many transfusion settings. Genotyping can be used to determine RBC antigen phenotypes in patients recently transfused or with interfering allo- or autoantibodies, to resolve discrepant serologic typing, and/or when typing antisera are not readily available. Molecular RBC antigen typing can facilitate complex antibody evaluations and guide RBC selection for patients with sickle cell disease (SCD), thalassemia, and autoimmune hemolytic anemia. High-resolution RH genotyping can identify variant RHD and RHCE in patients with SCD, which have been associated with alloimmunization. In the future, broader access to cost-efficient, high-resolution RBC genotyping technology for both patient and donor populations may be transformative for the field of transfusion medicine.

  19. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection.

    Science.gov (United States)

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-12-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection.

  20. Lactogenic differentiation of HC11 cells is not accompanied by downregulation of AP-2 transcription factor genes

    Directory of Open Access Journals (Sweden)

    Schorle Hubert

    2008-06-01

    Full Text Available Abstract Background During pregnancy the mammary epithelium undergoes a complex developmental process which culminates in the generation of the milk-secreting epithelium. Secretory epithelial cells display lactogenic differentiation which is characterized by the expression of milk protein genes, such as beta-casein or whey acidic protein (WAP. Transcription factors AP-2alpha and AP-2gamma are downregulated during lactation, and their overexpression in transgenic mice impaired the secretory differentiation of the mammary epithelium, resulting in lactation failure. To explore whether the downregulation of AP-2alpha and AP-2gamma is of functional significance for lactogenic differentiation, we analyzed the expression of the AP-2 family members during the lactogenic differentiation of HC11 mammary epithelial cells in vitro. Differentiation of HC11 cells was induced following established protocols by applying the lactogenic hormones prolactin, dexamethasone and insulin. Findings HC11 cells express all AP-2 family members except AP-2delta. Using RT-PCR we could not detect a downregulation of any of these genes during the lactogenic differentiation of HC11 cells in vitro. This finding was confirmed for AP-2alpha and AP-2gamma using Northern analysis. Differentiating HC11 cells displayed lower expression levels of milk protein genes than mammary glands of mid-pregnant or lactating mice. Conclusion The extent of lactogenic differentiation of HC11 cells in vitro is limited compared to mammary epithelium undergoing secretory differentiation in vivo. Downregulation of AP-2 transcription factor genes is not required for lactogenic differentiation of HC11 cells but may functionally be involved in aspects of lactogenic differentiation in vivo that are not reflected by the HC11 system.

  1. Akt regulates drug-induced cell death through Bcl-w downregulation.

    Directory of Open Access Journals (Sweden)

    Michela Garofalo

    Full Text Available Akt is a serine threonine kinase with a major role in transducing survival signals and regulating proteins involved in apoptosis. To find new interactors of Akt involved in cell survival, we performed a two-hybrid screening in yeast using human full-length Akt c-DNA as bait and a murine c-DNA library as prey. Among the 80 clones obtained, two were identified as Bcl-w. Bcl-w is a member of the Bcl-2 family that is essential for the regulation of cellular survival, and that is up-regulated in different human tumors, such as gastric and colorectal carcinomas. Direct interaction of Bcl-w with Akt was confirmed by immunoprecipitation assays. Subsequently, we addressed the function of this interaction: by interfering with the activity or amount of Akt, we have demonstrated that Akt modulates the amount of Bcl-w protein. We have found that inhibition of Akt activity may promote apoptosis through the downregulation of Bcl-w protein and the consequential reduction in interaction of Bcl-w with pro-apoptotic members of the Bcl-2 family. Our data provide evidence that Bcl-w is a new member of the Akt pathway and that Akt may induce anti-apoptotic signals at least in part through the regulation of the amount and activity of Bcl-w.

  2. ENA/VASP downregulation triggers cell death by impairing axonal maintenance in hippocampal neurons.

    Science.gov (United States)

    Franco, D Lorena; Rezával, Carolina; Cáceres, Alfredo; Schinder, Alejandro F; Ceriani, M Fernanda

    2010-06-01

    Neurodegenerative diseases encompass a broad variety of motor and cognitive disorders that are accompanied by death of specific neuronal populations or brain regions. Cellular and molecular mechanisms underlying these complex disorders remain largely unknown. In a previous work we searched for novel Drosophila genes relevant for neurodegeneration and singled out enabled (ena), which encodes a protein involved in cytoskeleton remodeling. To extend our understanding on the mechanisms of ENA-triggered degeneration we now investigated the effect of silencing ena ortholog genes in mouse hippocampal neurons. We found that ENA/VASP downregulation led to neurite retraction and concomitant neuronal cell death through an apoptotic pathway. Remarkably, this retraction initially affected the axonal structure, showing no effect on dendrites. Reduction in ENA/VASP levels blocked the neuritogenic effect of a specific RhoA kinase (ROCK) inhibitor, thus suggesting that these proteins could participate in the Rho-signaling pathway. Altogether these observations demonstrate that ENA/VASP proteins are implicated in the establishment and maintenance of the axonal structure and that a change on their expression levels triggers neuronal degeneration.

  3. Inhibition of ErbB-2 induces TFF3 downregulation in breast cancer cell lines.

    Science.gov (United States)

    Yue, Lu; Xiang, Jinyu; Shen, Zan; Wang, Zhihao; Yao, Yasai; Zhou, Quan; Ding, Aiping; Qiu, Wensheng

    2014-07-01

    ErbB-2 gene plays an important role in carcinoma formation whose overexpression was observed in many types of tumors, including breast cancer. Dysregulation of Trefoil factor 3 (TFF3), which is thought to function in the development and progression of breast cancer, was found to be upregulated in ErbB2-overexpressing breast cancers and cells. However, a putative interaction between ErbB-2 and TFF3 in breast cancer remains unknown. To determine whether TFF3 has an important role in breast tumor, its levels were measured by immunohistochemistry in 130 cases of breast infiltrating duct carcinoma and 30 cases of normal breast tissue with a specific monoclonal antibody raised against human TFF3. Patients who were positive for ErbB-2 also had high expression levels of TFF3 (p TFF3 by real-time polymerase chain reaction and Western blotting, respectively. Compared with the control groups, ErbB-2 mRNA expression was decreased in the Lenti-ShERBB2 infection group, and Western blotting indicated a concordant ErbB-2 protein reduction. On the other hand, TFF3 expression at both mRNA and protein levels was significantly downregulated by ErbB-2 silencing in SK-BR-3. These findings are a proof of the foundation for a certain relationships of ErbB-2 and TFF3, which may serve as novel therapeutic markers of ErbB2-overexpressing breast cancers in the future.

  4. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Directory of Open Access Journals (Sweden)

    Eric F Tewalt

    2009-05-01

    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation

  5. Hepatitis B Virus Down-Regulates Expressions of MHC Class ⅠMolecules on Hepatoplastoma Cell Line

    Institute of Scientific and Technical Information of China (English)

    Yongyan Chen; Min Cheng; ,Zhigang Tian

    2006-01-01

    Chronic HBV infection is associated with a 100-fold high risk of developing hepatocellular carcinoma. Tumor recognition is of the most importance during the immune surveillance process that prevents cancer development in humans. In the present study, the expressions of MHC class Ⅰ molecules on hepatoplastoma cell line HepG2.2.15 were investigated to indicate the possible effects of HBV on the immune recognition during HBV-associated hepatocellular carcinoma. It was found that the expressions of MHC class Ⅰ molecules HLA-ABC, HLA-E and MICA were much lower in HepG2.2.15 cells compared with HepG2 cells. The expressing HBV in human hepatoplastoma cell line significantly down-regulated the expressions of MHC class Ⅰ molecules. Additionally, it was observed that in murine chronic HBsAg carriers the expression of classical MHC-Ⅰ molecule on hepatocytes was down-regulated. These results demonstrated that HBV might affect the immune recognition during HBV-associated hepatoceilular carcinoma such as the recognition of CD8+ T, NK-CTL and NK cells and prevent the immune surveillance against tumors. However, the effects of HBV down-regulation of MHC class Ⅰ molecules on the target cells in vivo should be further studied.

  6. A human T cell clone that mediates the monocyte procoagulant response to specific sensitizing antigen.

    Science.gov (United States)

    Schwartz, B S; Reitnauer, P J; Hank, J A; Sondel, P M

    1985-09-01

    A panel of human purified protein derivative of the tubercle bacillus (PPD)-reactive T cell clones was derived by cloning out of soft agar followed by cultivation on inactivated feeder cells in the presence of interleukin-2. 1 of 4 clones tested was able to mediate an increase in monocyte procoagulant activity (PCA) in response to PPD. All four clones had identical surface marker phenotypes (T4+, T8-) and proliferated in response to antigen. The reactive T cell clone possessed no PCA of its own, but upon being presented with PPD was able to instruct monocytes to increase their expression of PCA. Antigen presentation could be performed only by autologous monocytes; allogeneic monocytes from donors unrelated to the donor of the reactive clone could not present antigen to cells of the clone in a way that would initiate the procoagulant response. Cells of the reactive clone did not mediate increased monocyte PCA in response to Candida, even though peripheral blood mononuclear cells from the donor demonstrated increased PCA to both Candida and PPD. Thus, the PCA response to specific antigen can be mediated by a single clone of cells that shows specificity in the recognition of both antigen and antigen presenting cell.

  7. Immune Responses of Dendritic Cells Loaded with Antigens from Apoptotic Cholangiocarcinoma Cells Caused by γ-Irradation

    Institute of Scientific and Technical Information of China (English)

    WUGang; HANBenli; PEIXuetao

    2002-01-01

    Objective:To investigate the induction cytotoxic T cells(CTLs) with antitumor activity and therapeutic efficacy after dendritic cells(DCs) acquired antigen from apoptotic cholangiocarcinoma cells caused by γ-irradiation. Methods:DCs from peripheral blood mononuclear cells (PBMC) that maintain the antigen capturing and processing capacity charateristic of immature cells have been established in vitro, using granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). Then, in cholangiocarcinoma cells apoptosis was induced by γ-irradiation. The experimental groups were as follows:(1)coculture of DCs and apoptotic cancer cells and T cells;(2)coculture of DCs and necrotic cancer cells and T cells;(3)coculture of DCs, cultured cancer cell and T cells. They are cocultured for 7 days.DCs and T cells were riched, isolated and their antitumor response was tested. Results:The cells had typical dendritic morphology, expressed high levels of CDla and B7, acquired antigen from apoptotic cells caused by γ-irradiation and induced an increased T cell stimulatory capacity in mixed lymphocyte reactions (MLR). Conclusion:DCs obtained from PBMCs using GM-CSF and IL-4 can efficiently present antigen derived from apoptotic cells caused by γ-irradiation and efficiently induce T cells.This strategy, therefore, may present an effective approach to transduce DCs with antigen.

  8. Chimeric Antigen Receptor T Cell (Car T Cell Therapy In Hematology

    Directory of Open Access Journals (Sweden)

    Pinar Ataca

    2015-12-01

    Full Text Available It is well demonstrated that immune system can control and eliminate cancer cells. Immune-mediated elimination of tumor cells has been discovered and is the basis of both cancer vaccines and cellular therapies including hematopoietic stem cell transplantation (HSCT. Adoptive T cell transfer has been improved to be more specific and potent and cause less off-target toxicities. Currently, there are two forms of engineered T cells being tested in clinical trials: T cell receptor (TCR and chimeric antigen receptor (CAR modified T cells. On July 1, 2014, the United States Food and Drug Administration granted ‘breakthrough therapy’ designation to anti-CD19 CAR T cell therapy. Many studies were conducted to evaluate the beneficiaries of this exciting and potent new treatment modality. This review summarizes the history of adoptive immunotherapy, adoptive immunotherapy using CARs, the CAR manufacturing process, preclinical-clinical studies, effectiveness and drawbacks of this strategy.

  9. Docking of B-cell epitope antigen to specific hepatitis B antibody

    Indian Academy of Sciences (India)

    R Rajkannan; E J Padma Malar

    2007-09-01

    The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the crystal structure of monoclonal antibody specific for the pres1 region of the hepatitis B virus. At the optimized docked conformation, the interactions between the amino acids of antigen and antibody were examined. It is found that the docked complex is stabilized by 59.3 kcal/mol. The stability of the docked antigen-antibody complex is due to hydrogen bonding and van der Waals interactions. The amino acids of the antigen and antibody responsible for the interaction were identified.

  10. In vivo requirement for Atg5 in antigen presentation by dendritic cells.

    Science.gov (United States)

    Lee, Heung Kyu; Mattei, Lisa M; Steinberg, Benjamin E; Alberts, Philipp; Lee, Yun Hee; Chervonsky, Alexander; Mizushima, Noboru; Grinstein, Sergio; Iwasaki, Akiko

    2010-02-26

    Autophagy is known to be important in presentation of cytosolic antigens on MHC class II (MHC II). However, the role of autophagic process in antigen presentation in vivo is unclear. Mice with dendritic cell (DC)-conditional deletion in Atg5, a key autophagy gene, showed impaired CD4(+) T cell priming after herpes simplex virus infection and succumbed to rapid disease. The most pronounced defect of Atg5(-/-) DCs was the processing and presentation of phagocytosed antigens containing Toll-like receptor stimuli for MHC class II. In contrast, cross-presentation of peptides on MHC I was intact in the absence of Atg5. Although induction of metabolic autophagy did not enhance MHC II presentation, autophagic machinery was required for optimal phagosome-to-lysosome fusion and subsequent processing of antigen for MHC II loading. Thus, our study revealed that DCs utilize autophagic machinery to optimally process and present extracellular microbial antigens for MHC II presentation.

  11. Focused specificity of intestinal TH17 cells towards commensal bacterial antigens.

    Science.gov (United States)

    Yang, Yi; Torchinsky, Miriam B; Gobert, Michael; Xiong, Huizhong; Xu, Mo; Linehan, Jonathan L; Alonzo, Francis; Ng, Charles; Chen, Alessandra; Lin, Xiyao; Sczesnak, Andrew; Liao, Jia-Jun; Torres, Victor J; Jenkins, Marc K; Lafaille, Juan J; Littman, Dan R

    2014-06-05

    T-helper-17 (TH17) cells have critical roles in mucosal defence and in autoimmune disease pathogenesis. They are most abundant in the small intestine lamina propria, where their presence requires colonization of mice with microbiota. Segmented filamentous bacteria (SFB) are sufficient to induce TH17 cells and to promote TH17-dependent autoimmune disease in animal models. However, the specificity of TH17 cells, the mechanism of their induction by distinct bacteria, and the means by which they foster tissue-specific inflammation remain unknown. Here we show that the T-cell antigen receptor (TCR) repertoire of intestinal TH17 cells in SFB-colonized mice has minimal overlap with that of other intestinal CD4(+) T cells and that most TH17 cells, but not other T cells, recognize antigens encoded by SFB. T cells with antigen receptors specific for SFB-encoded peptides differentiated into RORγt-expressing TH17 cells, even if SFB-colonized mice also harboured a strong TH1 cell inducer, Listeria monocytogenes, in their intestine. The match of T-cell effector function with antigen specificity is thus determined by the type of bacteria that produce the antigen. These findings have significant implications for understanding how commensal microbiota contribute to organ-specific autoimmunity and for developing novel mucosal vaccines.

  12. Detection of Rare Antigen Presenting Cells through T cell-intrinsic meandering motility, mediated by Myo1g

    OpenAIRE

    Gérard, Audrey; Patino-Lopez, Genaro; Beemiller, Peter; Nambiar, Rajalakshmi; Ben-Aissa, Khadija; Liu, Yin; Totah, Fadi J.; Tyska, Matthew J.; Shaw, Stephen; Krummel, Matthew F.

    2014-01-01

    To mount an immune response, T lymphocytes must successfully search for foreign material bound to the surface of antigen-presenting cells. How T cells optimize their chances of encountering and responding to these antigens is unknown. T cell motility in tissues resembles a random or Levy walk and is regulated in part by external factors including chemokines and lymph node topology, but motility parameters such as speed and propensity to turn may also be cell-intrinsic. Here we found that the ...

  13. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.

  14. Survival of ovarian cancer patients overexpressing the tumour antigen p53 is diminished in case of MHC class I down-regulation

    NARCIS (Netherlands)

    Leffers, Ninke; Lambeck, Annechien J. A.; de Graeff, Pauline; Bijlsma, Astrid Y.; Daemen, Toos; van der Zee, Ate G. J.; Nijman, Hans W.

    2008-01-01

    Objectives. The adaptive immune system seems to play an essential role in the natural course of ovarian cancer. Aim of this study was to establish whether disease-specific survival for patients expressing the tumour antigen p53 is influenced by MHC class I expression or the presence of p53 autoantib

  15. Survival of ovarian cancer patients overexpressing the tumour antigen p53 is diminished in case of MHC class I down-regulation.

    NARCIS (Netherlands)

    Leffers, N.; Lambeck, A.J.A.; Graeff, P de; Bijlsma, A.Y.; Daemen, T.; Zee, A.G. van der; Nijman, H.W.

    2008-01-01

    OBJECTIVES: The adaptive immune system seems to play an essential role in the natural course of ovarian cancer. Aim of this study was to establish whether disease-specific survival for patients expressing the tumour antigen p53 is influenced by MHC class I expression or the presence of p53 autoantib

  16. Down-regulation of adipogenesis of mesenchymal stem cells by oscillating high-gradient magnetic fields and mechanical vibration

    Science.gov (United States)

    Zablotskii, V.; Lunov, O.; Novotná, B.; Churpita, O.; Trošan, P.; HoláÅ, V.; Syková, E.; Dejneka, A.; Kubinová, Š.

    2014-09-01

    Nowadays, the focus in medicine on molecular genetics has resulted in a disregard for the physical basis of treatment even though many diseases originate from changes in cellular mechanics. Perturbations of the cellular nanomechanics promote pathologies, including cardiovascular disease and cancer. Furthermore, whilst the biological and therapeutic effects of magnetic fields are a well-established fact, to date the underlying mechanisms remain obscure. Here, we show that oscillating high-gradient magnetic field (HGMF) and mechanical vibration affect adipogenic differentiation of mesenchymal stem cells by the transmission of mechanical stress to the cell cytoskeleton, resulting in F-actin remodelling and subsequent down-regulation of adipogenic genes adiponectin, PPARγ, and AP2. Our findings propose an insight into the regulation of cellular nanomechanics, and provide a basis for better controlled down-regulation of stem cell adipogenesis by HGMF, which may facilitate the development of challenging therapeutic strategies suitable for the remote control of biological systems.

  17. Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

    Directory of Open Access Journals (Sweden)

    Gomez Bianca P

    2012-10-01

    Full Text Available Abstract Background Merkel cell carcinoma (MCC is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV. The MCPyV-encoded large T (LT antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT, as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the

  18. Deviating the level of proliferating cell nuclear antigen in Trypanosoma brucei elicits distinct mechanisms for inhibiting proliferation and cell cycle progression.

    Science.gov (United States)

    Valenciano, Ana L; Ramsey, Aaron C; Mackey, Zachary B

    2015-01-01

    The DNA replication machinery is spatially and temporally coordinated in all cells to reproduce a single exact copy of the genome per division, but its regulation in the protozoan parasite Trypanosoma brucei is not well characterized. We characterized the effects of altering the levels of proliferating cell nuclear antigen, a key component of the DNA replication machinery, in bloodstream form T. brucei. This study demonstrated that tight regulation of TbPCNA levels was critical for normal proliferation and DNA replication in the parasite. Depleting TbPCNA mRNA reduced proliferation, severely diminished DNA replication, arrested the synthesis of new DNA and caused the parasites to accumulated in G2/M. Attenuating the parasite by downregulating TbPCNA caused it to become hypersensitive to hydroxyurea. Overexpressing TbPCNA in T. brucei arrested proliferation, inhibited DNA replication and prevented the parasite from exiting G2/M. These results indicate that distinct mechanisms of cell cycle arrest are associated with upregulating or downregulating TbPCNA. The findings of this study validate deregulating intra-parasite levels of TbPCNA as a potential strategy for therapeutically exploiting this target in bloodstream form T. brucei.

  19. Proliferating cell nuclear antigen and Ki-67 immunohistochemistry of oligodendrogliomas with special reference to prognosis

    DEFF Research Database (Denmark)

    HEEGAARD, S.; Sommer, Helle Mølgaard; BROHOLM, H.;

    1995-01-01

    Background. The biologic behavior of oligodendrogliomas is somewhat unpredictable. A supplementary prognostic factor is, therefore, desirable. Methods. Thirty-two pure supratentorial oligodendrogliomas were investigated using proliferating cell nuclear antigen (PCNA) and Ki-67 immunohistochemical...

  20. Antigen selection in B-cell lymphomas--tracing the evidence.

    Science.gov (United States)

    Sutton, Lesley-Ann; Agathangelidis, Andreas; Belessi, Chrysoula; Darzentas, Nikos; Davi, Frederic; Ghia, Paolo; Rosenquist, Richard; Stamatopoulos, Kostas

    2013-12-01

    While signaling through the B cell receptor (BcR) facilitates B cell development and maintenance, it also carries intertwined risks for the development of lymphomas since malignant B cells can exploit these pathways in order to trigger and fuel clonal expansion. This corruption of the normal B cell response to antigens, leading to sustained BcR signaling, has given great impulse to investigate in detail the role of antigen in lymphomas. Suffice it to conclude from such studies, largely immunogenetics based, that the evidence implicating antigens (exogenous or self) in lymphoma development is substantial and that lymphomagenesis is functionally driven and dynamic, rather than a simple stochastic process. As the paradigm of antigen-driven lymphoma evolves, further investigation will be paramount to the identification of the inciting agent(s) that may be responsible for immunoproliferative neoplasms and also for the development of therapeutic agents targeting effectors of the BcR signaling pathway.

  1. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1.

    Science.gov (United States)

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-11-03

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp.

  2. Tandem CAR T cells targeting HER2 and IL13Rα2 mitigate tumor antigen escape.

    Science.gov (United States)

    Hegde, Meenakshi; Mukherjee, Malini; Grada, Zakaria; Pignata, Antonella; Landi, Daniel; Navai, Shoba A; Wakefield, Amanda; Fousek, Kristen; Bielamowicz, Kevin; Chow, Kevin K H; Brawley, Vita S; Byrd, Tiara T; Krebs, Simone; Gottschalk, Stephen; Wels, Winfried S; Baker, Matthew L; Dotti, Gianpietro; Mamonkin, Maksim; Brenner, Malcolm K; Orange, Jordan S; Ahmed, Nabil

    2016-08-01

    In preclinical models of glioblastoma, antigen escape variants can lead to tumor recurrence after treatment with CAR T cells that are redirected to single tumor antigens. Given the heterogeneous expression of antigens on glioblastomas, we hypothesized that a bispecific CAR molecule would mitigate antigen escape and improve the antitumor activity of T cells. Here, we created a CAR that joins a HER2-binding scFv and an IL13Rα2-binding IL-13 mutein to make a tandem CAR exodomain (TanCAR) and a CD28.ζ endodomain. We determined that patient TanCAR T cells showed distinct binding to HER2 or IL13Rα2 and had the capability to lyse autologous glioblastoma. TanCAR T cells exhibited activation dynamics that were comparable to those of single CAR T cells upon encounter of HER2 or IL13Rα2. We observed that TanCARs engaged HER2 and IL13Rα2 simultaneously by inducing HER2-IL13Rα2 heterodimers, which promoted superadditive T cell activation when both antigens were encountered concurrently. TanCAR T cell activity was more sustained but not more exhaustible than that of T cells that coexpressed a HER2 CAR and an IL13Rα2 CAR, T cells with a unispecific CAR, or a pooled product. In a murine glioblastoma model, TanCAR T cells mitigated antigen escape, displayed enhanced antitumor efficacy, and improved animal survival. Thus, TanCAR T cells show therapeutic potential to improve glioblastoma control by coengaging HER2 and IL13Rα2 in an augmented, bivalent immune synapse that enhances T cell functionality and reduces antigen escape.

  3. MiR-378 Promotes the Migration of Liver Cancer Cells by Down-Regulating Fus Expression

    Directory of Open Access Journals (Sweden)

    Jichun Ma

    2014-12-01

    Full Text Available Background: miR-378 regulates osteoblast differentiation and participates in tumor cell self-renewal and chemo-resistance. However, the function of miR-378 in liver cancer cell migration has not been reported to date. Methods: miR-378 expression was examined using real-time quantitative PCR. HepG2 cell migration and liver cell invasion were examined using wound-healing and cell invasion assays. Additionally, HepG2 cell metastasis was analyzed in nude mice. Results: miR-378 over-expression enhances HepG2 cell proliferation, migration and liver cell invasion. Typical metastatic lesions were found in the livers of mice injected with miR-378-transfected cells, and high levels of the CMV promoter were detected in the nodules, indicating that miR-378 promoted the metastasis of the tumor cells to the liver. We also demonstrated that miR-378 down-regulated Fus expression. Conclusions: Our results suggested that miR-378 enhanced cell migration and metastasis by down-regulating Fus expression.

  4. Down-regulation of PPARgamma1 suppresses cell growth and induces apoptosis in MCF-7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Wallis Natalie K

    2008-12-01

    Full Text Available Abstract Background Peroxisome proliferator-activated receptor gamma (PPARγ is a member of the nuclear hormone receptor superfamily and is highly expressed in many human tumors including breast cancer. PPARγ has been identified as a potential target for breast cancer therapy based on the fact that its activation by synthetic ligands affects the differentiation, proliferation, and apoptosis of cancer cells. However, the controversial nature of current studies and disappointing results from clinical trials raise questions about the contribution of PPARγ signaling in breast cancer development in the absence of stimulation by exogenous ligands. Recent reports from both in vitro and in vivo studies are inconsistent and suggest that endogenous activation of PPARγ plays a much more complex role in initiation and progression of cancer than previously thought. Results We have previously demonstrated that an increase in expression of PPARγ1 in MCF-7 breast cancer cells is driven by a tumor-specific promoter. Myc-associated zinc finger protein (MAZ was identified as a transcriptional mediator of PPARγ1 expression in these cells. In this study, using RNA interference (RNAi to inhibit PPARγ1 expression directly or via down-regulation of MAZ, we report for the first time that a decrease in PPARγ1 expression results in reduced cellular proliferation in MCF-7 breast cancer cells. Furthermore, we demonstrate that these changes in proliferation are associated with a significant decrease in cell transition from G1 to the S phase. Using a dominant-negative mutant of PPARγ1, Δ462, we confirmed that PPARγ1 acts as a pro-survival factor and showed that this phenomenon is not limited to MCF-7 cells. Finally, we demonstrate that down-regulation of PPARγ1 expression leads to an induction of apoptosis in MCF-7 cells, confirmed by analyzing Bcl-2 expression and PARP-1 cleavage. Conclusion Thus, these findings suggest that an increase in PPARγ1 signaling

  5. Engineering antigen-specific T cells from genetically modified human hematopoietic stem cells in immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Scott G Kitchen

    Full Text Available There is a desperate need for effective therapies to fight chronic viral infections. The immune response is normally fastidious at controlling the majority of viral infections and a therapeutic strategy aimed at reestablishing immune control represents a potentially powerful approach towards treating persistent viral infections. We examined the potential of genetically programming human hematopoietic stem cells to generate mature CD8+ cytotoxic T lymphocytes that express a molecularly cloned, "transgenic" human anti-HIV T cell receptor (TCR. Anti-HIV TCR transduction of human hematopoietic stem cells directed the maturation of a large population of polyfunctional, HIV-specific CD8+ cells capable of recognizing and killing viral antigen-presenting cells. Thus, through this proof-of-concept we propose that genetic engineering of human hematopoietic stem cells will allow the tailoring of effector T cell responses to fight HIV infection or other diseases that are characterized by the loss of immune control.

  6. T cell re-targeting to EBV antigens following TCR gene transfer: CD28-containing receptors mediate enhanced antigen-specific IFNgamma production

    NARCIS (Netherlands)

    N. van der Schaft (Niels); B. Lankiewicz (Birgit); H.A. Drexhage (Hemmo); C.A. Berrevoets (Cor); D.J. Moss (Denis); V. Levitsky (Victor); M. Bonneville (Marc); S.P. Lee (Steven); A.J. McMichael (Andrew); J.W. Gratama (Jan-Willem); R.L.H. Bolhuis (Reinder); R.A. Willemsen (Ralph); J.E.M.A. Debets (Reno)

    2006-01-01

    textabstractAbstract EBV is associated with a broad range of malignancies. Adoptive immunotherapy of these tumors with EBV-specific CTL proved useful. We generated a panel of primary human T cells specific to various EBV antigens (i.e. Epstein-Barr nuclear antigen 3A, 3B and BamHI-M leftward reading

  7. Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates

    Science.gov (United States)

    2011-01-01

    cell responses to Shigella antigens elicited in volunteers immunized with live attenuated Shigella flexneri 2a oral vaccine candidates J.K. Simona,b... Shigella ;. B cell memory; Immunoglobulin lgA; Mucosal immunity Abstract We studied the induction of antigen-specific lgA memory B cells (BM) in...volunteers who received live attenuated Shigella flexneri 2a vaccines. Subjects ingested a single oral dose of 107 , 108 or 109 CFU of S. flexneri 2a with

  8. Expression of stage-specific embryonic antigen-4 (SSEA-4) defines spontaneous loss of epithelial phenotype in human solid tumor cells.

    Science.gov (United States)

    Sivasubramaniyan, Kavitha; Harichandan, Abhishek; Schilbach, Karin; Mack, Andreas F; Bedke, Jens; Stenzl, Arnulf; Kanz, Lothar; Niederfellner, Gerhard; Bühring, Hans-Jörg

    2015-08-01

    Stage-specific embryonic antigen-4 (SSEA-4) is a glycosphingolipid, which is overexpressed in some cancers and has been linked to disease progression. However, little is known about the functions of SSEA-4 and the characteristics of SSEA-4 expressing tumor cells. Our studies identified SSEA-4 expression on a subpopulation of cells in many solid tumor cell lines but not in leukemic cell lines. Fluorescence-activated cell sorting-sorted SSEA-4(+) prostate cancer cells formed fibroblast-like colonies with limited cell-cell contacts, whereas SSEA-4(-) cells formed cobblestone-like epithelial colonies. Only colonies derived from SSEA-4(+) cells were enriched for pluripotent embryonic stem cell markers. Moreover, major epithelial cell-associated markers Claudin-7, E-cadherin, ESRP1 and GRHL2 were down-regulated in the SSEA-4(+) fraction of DU145 and HCT-116 cells. Similar to cell lines, SSEA-4(+) primary prostate tumor cells also showed down-regulation of epithelial cell-associated markers. In addition, they showed up-regulation of epithelial-to-mesenchymal transition as well as mesenchymal markers. Furthermore, SSEA-4(+) cells escape from adhesive colonies spontaneously and form invadopodia-like migratory structures, in which SSEA-4, cortactin as well as active pPI3K, pAkt and pSrc are enriched and colocalized. Finally, SSEA-4(+) cells displayed strong tumorigenic ability and stable knockdown of SSEA-4 synthesis resulted in decreased cellular adhesion to different extracellular matrices. In conclusion, we introduce SSEA-4 as a novel marker to identify heterogeneous, invasive subpopulations of tumor cells. Moreover, increased cell-surface SSEA-4 expression is associated with the loss of cell-cell interactions and the gain of a migratory phenotype, suggesting an important role of SSEA-4 in cancer invasion by influencing cellular adhesion to the extracellular matrix.

  9. Combinational targeting offsets antigen escape and enhances effector functions of adoptively transferred T cells in glioblastoma.

    Science.gov (United States)

    Hegde, Meenakshi; Corder, Amanda; Chow, Kevin K H; Mukherjee, Malini; Ashoori, Aidin; Kew, Yvonne; Zhang, Yi Jonathan; Baskin, David S; Merchant, Fatima A; Brawley, Vita S; Byrd, Tiara T; Krebs, Simone; Wu, Meng Fen; Liu, Hao; Heslop, Helen E; Gottschalk, Stephen; Gottachalk, Stephen; Yvon, Eric; Ahmed, Nabil

    2013-11-01

    Preclinical and early clinical studies have demonstrated that chimeric antigen receptor (CAR)-redirected T cells are highly promising in cancer therapy. We observed that targeting HER2 in a glioblastoma (GBM) cell line results in the emergence of HER2-null tumor cells that maintain the expression of nontargeted tumor-associated antigens. Combinational targeting of these tumor-associated antigens could therefore offset this escape mechanism. We studied the single-cell coexpression patterns of HER2, IL-13Rα2, and EphA2 in primary GBM samples using multicolor flow cytometry and immunofluorescence, and applied a binomial routine to the permutations of antigen expression and the related odds of complete tumor elimination. This mathematical model demonstrated that cotargeting HER2 and IL-13Rα2 could maximally expand the therapeutic reach of the T cell product in all primary tumors studied. Targeting a third antigen did not predict an added advantage in the tumor cohort studied. We therefore generated bispecific T cell products from healthy donors and from GBM patients by pooling T cells individually expressing HER2 and IL-13Rα2-specific CARs and by making individual T cells to coexpress both molecules. Both HER2/IL-13Rα2-bispecific T cell products offset antigen escape, producing enhanced effector activity in vitro immunoassays (against autologous glioma cells in the case of GBM patient products) and in an orthotopic xenogeneic murine model. Further, T cells coexpressing HER2 and IL-13Rα2-CARs exhibited accentuated yet antigen-dependent downstream signaling and a particularly enhanced antitumor activity.

  10. Downregulation of the autophagy protein ATG-7 correlates with distinct sphingolipid profile in MCF-7 cells sensitized to photodamage

    Science.gov (United States)

    Separovic, Duska; Kelekar, Ameeta; Tarca, Adi L.; Bielawski, Jacek; Kessel, David

    2009-06-01

    The objective of this study was to determine the sphingolipid (SL) profile in autophagy-defective cells and overall cell death after PDT with Pc 4 (PDT). Human breast cancer MCF-7 cells with downregulated autophagy protein ATG-7 and their scrambled controls (Scr) were used. Exposure of ATG-7 knockdown cells to PDT led to defective processing of the autophagy marker LC3, and increased overall cell killing. In both cell types PDT evoked an early (2 h) increase in ceramides and dihydroceramides (DHceramides). When the two cell types were compared regarding time (2 and 24 h) and treatment conditions (with and without PDT), the levels of several ceramides and DHceramides were reduced, whereas the concentrations of C14-ceramide, C16-ceramide and C12-DHceramide were higher in ATG-7 knockdown cells. The data imply that the SL profile might be a marker of autophagy-deficiency in cells sensitized to PDT.

  11. Protection from anti-TCR/CD3-induced apoptosis in immature thymocytes by a signal through thymic shared antigen-1/stem cell antigen-2

    OpenAIRE

    1996-01-01

    During T cell development in the thymus, the expression of thymic shared antigen-1 (TSA-1)/stem cell antigen-2 (Sca-2), a glycosylphosphatidylinositol (GPI)-anchored differentiation antigen, is developmentally regulated. The expression level of TSA-1 is the highest in most immature CD4- CD8- thymocytes, high in CD4+ CD8+ thymocytes, but barely detectable in mature CD4+ CD8- or CD4- CD8- thymocytes and peripheral T cells. We have previously shown that surface TSA-1 expression in peripheral T c...

  12. Protocatechualdehyde possesses anti-cancer activity through downregulating cyclin D1 and HDAC2 in human colorectal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jin Boo [Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742 (United States); Lee, Seong-Ho, E-mail: slee2000@umd.edu [Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Protocatechualdehyde (PCA) suppressed cell proliferation and induced apoptosis in human colorectal cancer cells. Black-Right-Pointing-Pointer PCA enhanced transcriptional downregulation of cyclin D1 gene. Black-Right-Pointing-Pointer PCA suppressed HDAC2 expression and activity. Black-Right-Pointing-Pointer These findings suggest that anti-cancer activity of PCA may be mediated by reducing HDAC2-derived cyclin D1 expression. -- Abstract: Protocatechualdehyde (PCA) is a naturally occurring polyphenol found in barley, green cavendish bananas, and grapevine leaves. Although a few studies reported growth-inhibitory activity of PCA in breast and leukemia cancer cells, the underlying mechanisms are still poorly understood. Thus, we performed in vitro study to investigate if treatment of PCA affects cell proliferation and apoptosis in human colorectal cancer cells and define potential mechanisms by which PCA mediates growth arrest and apoptosis of cancer cells. Exposure of PCA to human colorectal cancer cells (HCT116 and SW480 cells) suppressed cell growth and induced apoptosis in dose-dependent manner. PCA decreased cyclin D1 expression in protein and mRNA level and suppressed luciferase activity of cyclin D1 promoter, indicating transcriptional downregulation of cyclin D1 gene by PCA. We also observed that PCA treatment attenuated enzyme activity of histone deacetylase (HDAC) and reduced expression of HDAC2, but not HDAC1. These findings suggest that cell growth inhibition and apoptosis by PCA may be a result of HDAC2-mediated cyclin D1 suppression.

  13. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA2

    Directory of Open Access Journals (Sweden)

    Jaeyoung Lim

    2014-04-01

    Full Text Available In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3 inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with growth arrest. CD133+ ovarian cancer stemlike cells were preferentially susceptible to VEGFR3-mediated growth inhibition. VEGFR3 inhibition–mediated down-regulation of BRCA gene expression reversed chemotherapy resistance and restored chemosensitivity in resistant cell lines in which a BRCA2 mutation had reverted to wild type. Finally, we demonstrate that tumor-associated macrophages are a primary source of VEGF-C in the tumor microenvironment. Our studies suggest that VEGFR3 inhibition may be a pharmacologic means to downregulate BRCA genes and improve the outcomes of patients with BRCA wild-type tumors.

  14. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Directory of Open Access Journals (Sweden)

    Savannah E Howe

    Full Text Available Intestinal epithelial cells (IECs overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes play an active role in the uptake (sampling of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs, which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine. Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  15. TGF-β1-mediated Smad3 enhances PD-1 expression on antigen-specific T cells in cancer

    Science.gov (United States)

    Park, Benjamin V.; Freeman, Zachary T.; Ghasemzadeh, Ali; Chattergoon, Michael A.; Rutebemberwa, Alleluiah; Steigner, Jordana; Winter, Matthew E.; Huynh, Thanh V.; Sebald, Suzanne M.; Lee, Se-Jin; Pan, Fan; Pardoll, Drew M.; Cox, Andrea L.

    2017-01-01

    Programmed Death-1 (PD-1) is a co-inhibitory receptor that down-regulates the activity of tumor-infiltrating lymphocytes (TIL) in cancer and of virus-specific T cells in chronic infection. The molecular mechanisms driving high PD-1 expression on TIL have not been fully investigated. We demonstrate that transforming growth factor-β1 (TGF-β1) directly enhances antigen-induced PD-1 expression through Smad3-dependent, Smad2-independent transcriptional activation in T cells in vitro and in TIL in vivo. The PD-1hi subset seen in CD8+ TIL is absent in Smad3-deficient tumor-specific CD8+ TIL, resulting in enhanced cytokine production by TIL and in draining lymph nodes and of anti-tumor activity. In addition to TGF-β1’s previously known effects on T cell function, our findings suggest that TGF-β1 mediates T cell suppression via PD-1 upregulation in the TME. They highlight bidirectional crosstalk between effector TIL and TGF-β-producing cells that upregulates multiple components of the PD-1 signaling pathway to inhibit anti-tumor immunity. PMID:27683557

  16. Modulation of TCR-mediated signaling pathway by thymic shared antigen-1 (TSA-1)/stem cell antigen-2 (Sca-2).

    Science.gov (United States)

    Saitoh, S; Kosugi, A; Noda, S; Yamamoto, N; Ogata, M; Minami, Y; Miyake, K; Hamaoka, T

    1995-12-15

    Thymic shared antigen-1 (TSA-1) is a glycosyl-phosphatidylinositol (GPI)-anchored differentiation Ag expressed on murine lymphocytes, and is identical to stem cell Ag-2 (Sca-2). Using newly established mAb against TSA-1/Sca-2, we have previously shown that surface TSA-1 expression is induced upon activation in T cells, and that anti-TSA-1 inhibits IL-2 production induced by anti-CD3 stimulation in T cell hybridomas. In the present study, we have analyzed the functional role of TSA-1 during T cell activation using normal T cells, T cell hybridomas, and transfected Jurkat cell lines that expressed either GPI-anchored or transmembrane form of TSA-1. Anti-TSA-1 inhibited IL-2 production from normal T cells stimulated with soluble anti-CD3 plus accessory cells. Anti-TSA-1 exhibited the inhibitory effect on T cells, but not on accessory cells, because anti-TSA-1 inhibited IL-2 production in Jurkat cells transfected with TSA-1 cDNA, but not in control transfectant. A transmembrane form of TSA-1 was expressed in Jurkat cells by fusing the extracellular portion of TSA-1 to the transmembrane and cytoplasmic regions of the class 1 Db. The analysis using this transfectant revealed that anti-TSA-1-mediated inhibition of IL-2 production did not require the GPI anchor of TSA-1. Finally, in addition to the inhibition of IL-2 production, tyrosine phosphorylation of CD3 zeta-chains observed following TCR stimulation, one of the important early activation events, was markedly reduced by anti-TSA-1. These results imply that TSA-1/Sca-2 plays an important regulatory role in the TCR signaling pathway of activated T cells in addition to its role in T cell differentiation.

  17. 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.

  18. Cytotoxicity of tumor antigen specific human T cells is unimpaired by arginine depletion.

    Directory of Open Access Journals (Sweden)

    Markus Munder

    Full Text Available Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8(+ T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i CD8(+ T cells with specificity against the MART-1aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii clonal CMV pp65aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8(+ T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-γ and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activation-induced effector functions in the context of arginine deficiency.

  19. Successive Administration of Streptococcus Type 5 Group A Antigens and S. typhimurium Antigenic Complex Corrects Elevation of Serum Cytokine Concentration and Number of Bone Marrow Stromal Pluripotent Cells in CBA Mice Induced by Each Antigen Separately.

    Science.gov (United States)

    Gorskaya, Yu F; Danilova, T A; Grabko, V I; Nesterenko, V G

    2015-12-01

    Administration of bacterial antigens to CBA mice induced an increase in serum concentration of virtually all cytokines with a peak in 4 h after administration of S. typhimurium antigens and in 7 h after administration of streptococcus antigens. In 20 h, cytokine concentrations returned to the control level or were slightly below it. In 4 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, we observed a significant decrease in serum concentrations of IFN-γ, IL-10, GM-CSF, IL-12, and TNF-α, in comparison with injection S. typhimurium antigens alone and IL-5, IL-10, GM-CSF, and TNF-α in comparison with injection of streptococcus antigens alone; the concentrations of IL-2 and IFN-γ, in contrast, increased by 1.5 times in this case. In 20 h after administration of S. typhimurium antigens, the number of multipotential stromal cells (MSC) in the bone marrow and their cloning efficiency (ECF-MSC) increased by 4.8 and 4.4 times, respectively, in comparison with the control, while after administration of streptococcus antigens by 2.6 and 2.4 times, respectively. In 20 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, these parameters increased by 3.2 and 2.9 times, respectively, in comparison with the control, i.e. the observed increase in the level of MSC count and ECF-MSC is more consistent with the response of the stromal tissue to streptococcus antigens. Thus, successive administration of two bacterial antigens corrected both serum cytokine profiles and MSC response to administration of each antigen separately, which indicates changeability of the stromal tissue in response to changes in the immune response.

  20. Antigen-induced regulatory T cells in HBV chronically infected patients.

    Science.gov (United States)

    Barboza, Luisa; Salmen, Siham; Goncalves, Loredana; Colmenares, Melisa; Peterson, Darrell; Montes, Henry; Cartagirone, Raimondo; Gutiérrez, Maria del Carmen; Berrueta, Lisbeth

    2007-11-10

    T cell response against HBV is vigorous in patients with acute hepatitis who clear the virus, whereas it is weak and narrowly focused in patients with chronic disease. We report that following incubation with HBcAg, a population of CD4+FoxP3+ cells expressing phenotypic markers of both natural and induced Tregs, can be antigen-induced from peripheral mononuclear cells. Conversely, naive and naturally immune subjects did not increase CD4+FoxP3+ Tregs following stimulation with HBcAg, supporting the idea that natural Tregs are able to respond specifically to HBV antigen. Furthermore, increased frequencies of antigen-induced CD4+FoxP3+IL-10+ Tregs correlated with viral load, suggesting that antigen-induced Tregs could contribute to an inadequate response against the virus, leading to chronic infection and support the view that specific natural Tregs may be implicated in host immune tolerance during HBV infection.

  1. Collagen I-induced dendritic cells activation is regulated by TNF- production through down-regulation of IRF4

    Indian Academy of Sciences (India)

    Barun Poudel; Hyeon-Hui Ki; Young-Mi Lee; Dae-Ki Kim

    2015-03-01

    Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)-, interleukin (IL)-1 and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF- on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF- inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF- production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF- therapeutics for several inflammatory diseases.

  2. Interaction between antigen presenting cells and autoreactive T cells derived from BXSB mice with murine lupus

    Institute of Scientific and Technical Information of China (English)

    Peng Yang; Bo Li; Ping Lv; Yan Zhang; XiaoMing Gao

    2007-01-01

    Systemic lupus erythematosus (SLE) is a typical autoimmune disease involving multiple systems and organs. Ample evidence suggests that autoreactive T cells play a pivotal role in the development of this autoimmune disorder. This study was undertaken to investigate the mechanisms of interaction between antigen presenting cells (APCs) and an autoreactive T cell (ATL1) clone obtained from lupus-prone BXSB mice. ATL1 cells, either before or after γ-ray irradiation, were able to activate naive B cells, as determined by B cell proliferation assays. Macrophages from BXSB mice were able to stimulate the proliferation of resting ATL1 cells at a responder/stimulator (R/S) ratio of 1/2.5. Dendritic cells (DCs) were much more powerful stimulators for ATL1 cells on a per cell basis. The T cell stimulating ability of macrophages and B cells, but not DCs, was sensitive toγ-ray irradiation. Monoclonal antibodies against mouse MHC-Ⅱand CD4 were able to block DC-mediated stimulation of ATL1 proliferation, indicating cognate recognition between ATL1 and APCs. Our data suggest that positive feedback loops involving macrophages, B cells and autoreactive T cells may play a pivotal role in keeping the momentum of autoimmune responses leading to autoimmune diseases.

  3. Expression of tumor antigens on primary ovarian cancer cells compared to established ovarian cancer cell lines

    Science.gov (United States)

    Kloudová, Kamila; Hromádková, Hana; Partlová, Simona; Brtnický, Tomáš; Rob, Lukáš; Bartůňková, Jiřina; Hensler, Michal; Halaška, Michael J.; Špíšek, Radek; Fialová, Anna

    2016-01-01

    In order to select a suitable combination of cancer cell lines as an appropriate source of antigens for dendritic cell-based immunotherapy of ovarian cancer, we analyzed the expression level of 21 tumor associated antigens (BIRC5, CA125, CEA, DDX43, EPCAM, FOLR1, Her-2/neu, MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A10, MAGE-A12, MUC-1, NY-ESO-1, PRAME, p53, TPBG, TRT, WT1) in 4 established ovarian cancer cell lines and in primary tumor cells isolated from the high-grade serous epithelial ovarian cancer tissue. More than 90% of tumor samples expressed very high levels of CA125, FOLR1, EPCAM and MUC-1 and elevated levels of Her-2/neu, similarly to OVCAR-3 cell line. The combination of OV-90 and OVCAR-3 cell lines showed the highest overlap with patients' samples in the TAA expression profile. PMID:27323861

  4. In vitro expansion of antigen-specific CD8(+) T cells distorts the T-cell repertoire.

    Science.gov (United States)

    Koning, Dan; Costa, Ana I; Hasrat, Raiza; Grady, Bart P X; Spijkers, Sanne; Nanlohy, Nening; Keşmir, Can; van Baarle, Debbie

    2014-03-01

    Short-term in vitro expansion of antigen-specific T cells is an appreciated assay for the analysis of small memory T-cell populations. However, how well short-term expanded T cells represent the direct ex vivo situation remains to be elucidated. In this study we compared the clonality of Epstein-Barr virus (EBV) and cytomegalovirus (CMV)-specific CD8(+) T cells directly ex vivo and after in vitro stimulation with antigen. Our data show that the antigen-specific T cell repertoire significantly alters after in vitro culture. Clear shifts in clonotype hierarchy were observed, with the most dominant ex vivo clonotype decreasing after stimulation at the expense of several previously subdominant clonotypes. Notably, these alterations were more pronounced in polyclonal T-cell populations compared to mono- or oligoclonal repertoires. Furthermore, TCR diversity significantly increased after culture with antigen. These results suggest that the T-cell repertoire is highly subjective to variation after in vitro stimulation with antigen. Hence, although short-term expansion of T cells provides a simple and efficient tool to examine antigen-specific immune responses, caution is required if T-cell populations are expanded prior to detailed, clonotypic analyses or other repertoire-based investigations.

  5. The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis

    Directory of Open Access Journals (Sweden)

    Roberta O. Pinheiro

    2004-09-01

    Full Text Available Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg but not L. braziliensis promastigotes (LbAg contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.A Leishmania amazonensis é o principal agente etiológico da leishmaniose cutânea difusa, uma doença associada a respostas imunes anérgicas. Neste estudo nós mostramos que o extrato bruto de promastigotas de Leishmania amazonensis (LaAg, mas não de L. braziliensis (LbAg, contém substâncias que suprimem respostas proliferativas, espontâneas e mitogênicas, de células T. As substâncias supressoras no LaAg são termo-resistentes (100°C/1h e parcialmente dependentes da atividade de proteases. A anergia de células T não foi devida à diminuição na produção de fatores de crescimento, uma vez que não foi revertida pela adição de: IL-2, IL-4, IFN-gama ou IL-12. O LaAg não inibiu a ativação de células T induzida por anti-CD3, sugerindo que a anergia

  6. Presentation of antigen by B cell subsets. Pt. 4. Defective T-B cell signalling causes inability to present antigen by B cells from immunodeficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Zimecki, Michal [Polish Academy of Sciences, Wroclaw (Poland). Institute of Immunology and Experimental Therapy; Kapp, Judith A. [Emory Univ., Atlanta, GA (United States). School of Medicine

    1994-12-31

    The purpose of this study was to investigate differences in T-B cell signalling between B cells from normal and immunodeficient mice. B cell blasts from normal and immunodeficient mice expressed comparable levels of membrane-associated IL-1. B cells from normal, but not immunodeficient mice, prefixed with glutar-aldehyde and cultured with thymocytes or a T cell line BK33, induce in T cells production of a factor which causes release of IL-1 by macrophages. This factor, preincubated with B cells from immunodeficient mice significantly enhances their APC function. Furthermore, this cytokine induces expression of Lyb-5 alloantigen on B cells from immunodeficient mice. This effect could be blocked by neutralizing antibodies to IL-6 but not to IL-2, IL-4 or GM-CSF. We conclude that immature B cells from immunodeficient (CBA/N x BALB/c)F{sub 1} mice are unable to stimulate interacting T cells to produce IL-6 and therefore are inefficient antigen presenting cells. (author). 30 refs, 2 figs, 3 tabs.

  7. A new Kupffer cell receptor mediating plasma clearance of carcinoembryonic antigen by the rat.

    Science.gov (United States)

    Toth, C A; Thomas, P; Broitman, S A; Zamcheck, N

    1982-05-15

    Native human carcinoembryonic antigen is rapidly removed from the circulation by the rat liver Kupffer cell after intravenous injection. The molecule is subsequently transferred to the hepatocyte in an immunologically identifiable form. Carcinoembryonic antigen has a circulatory half-life of 3.7 (+/- 0.8) min, and cellular entry is by receptor-mediated endocytosis. Non-specific fluid pinocytosis and phagocytosis can be excluded as possible mechanisms by the kinetics of clearance and failure of colloidal carbon to inhibit uptake. Substances with known affinity for the hepatic receptors for mannose, N-acetylglucosamine, fucose and galactose all fail to inhibit carcinoembryonic antigen clearance. After two cycles of the Smith degradation, carcinoembryonic antigen is still able to inhibit clearance of the native molecule. Receptor specificity is apparently not dependent on those non-reducing terminal sugars of the native molecule. Performic acid-oxidized carcinoembryonic antigen also inhibits clearance of carcinoembryonic antigen in vivo. Receptor binding is not dependent on tertiary protein conformation. Non-specific cross-reacting antigen, a glycoprotein structurally similar to carcinoembryonic antigen, is cleared by the same mechanism.

  8. N-methylhemeanthidine chloride, a novel Amaryllidaceae alkaloid, inhibits pancreatic cancer cell proliferation via down-regulating AKT activation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Guoli; Yao, Guangmin; Zhan, Guanqun; Hu, Yufeng [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Yue, Ming [Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Cheng, Ling; Liu, Yaping; Ye, Qi [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Qing, Guoliang [Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Zhang, Yonghui, E-mail: zhangyh@mails.tjmu.edu.cn [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Liu, Hudan, E-mail: hudanliu@hust.edu.cn [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China)

    2014-11-01

    We previously reported the isolation of a novel Amaryllidaceae alkaloid, N-methylhemeanthidine chloride (NMHC), from Zephyranthes candida, which exhibits potent cytotoxicity in a spectrum of tumor cells. However, the mechanism of action remains unclear. Using multiple cell lines derived from human pancreatic cancer, one of the most mortal and refractory human malignancies, we further studied the NMHC-mediated cytotoxicity and found that it induced drastic cytotoxicity in pancreatic cancer cells whereas an insignificant effect on a noncancerous cell line. The NMHC-mediated growth inhibition was more severe than the first-line chemotherapeutic agent gemcitabine, leading to cell cycle arrest, apoptotic death and decreased glycolysis. NMHC exerted its function through down-regulating AKT activation, and the ectopic expression of activated AKT rescued the growth inhibition. Consistently, NMHC injections in a pancreatic cancer xenograft model manifested the anti-tumor effect in vivo. Engrafted tumor cells underwent AKT attenuation and apoptotic death upon treatments. As such, we here demonstrate the AKT inhibition may be one of the mechanisms by which NMHC decreases tumor cell survival rate in vitro and in vivo. Our data thereby suggest that NMHC holds great promise as a potent chemotherapeutic agent against pancreatic cancer and sheds new light on obtaining such agents from natural products toward therapeutic purposes. - Highlights: • N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid. • NMHC exhibits potent anti-neoplastic activity. • NMHC leads to cell cycle arrest, apoptotic death and decreased metabolism. • NMHC down-regulates the AKT signaling pathway.

  9. Bone marrow mesenchymal stromal cells affect the cell cycle arrest effect of genotoxic agents on acute lymphocytic leukemia cells via p21 down-regulation.

    Science.gov (United States)

    Zhang, Yiran; Hu, Kaimin; Hu, Yongxian; Liu, Lizhen; Wang, Binsheng; Huang, He

    2014-09-01

    The effect of bone marrow microenvironment on the cell cycle of acute lymphocytic leukemia (ALL) and the underlying mechanism has not been elucidated. In this study, we found that in normal condition, bone marrow mesenchymal stromal cells (BM-MSCs) had no significant effect on the cell cycle and apoptosis of ALL; in the condition when the cell cycle of ALL was blocked by genotoxic agents, BM-MSCs could increase the S-phase cell ratio and decrease the G2/M phase ratio of ALL. Besides, BM-MSCs could protect ALL cells from drug-induced apoptosis. Then, we proved that BM-MSCs affect the cell cycle arrest effect of genotoxic agents on ALL cells via p21 down-regulation. Moreover, our results indicated that activation of Wnt/β-catenin and Erk pathways might be involved in the BM-MSC-induced down-regulation of p21 in ALL cells. Targeting microenvironment-related signaling pathway may therefore be a potential novel approach for ALL therapy.

  10. MicroRNA-218 is deleted and downregulated in lung squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Morgan R Davidson

    Full Text Available MicroRNAs (miRNAs are a family of small, non-coding RNA species functioning as negative regulators of multiple target genes including tumour suppressor genes and oncogenes. Many miRNA gene loci are located within cancer-associated genomic regions. To identify potential new amplified oncogenic and/or deleted tumour suppressing miRNAs in lung cancer, we inferred miRNA gene dosage from high dimensional arrayCGH data. From miRBase v9.0 (http://microrna.sanger.ac.uk, 474 human miRNA genes were physically mapped to regions of chromosomal loss or gain identified from a high-resolution genome-wide arrayCGH study of 132 primary non-small cell lung cancers (NSCLCs (a training set of 60 squamous cell carcinomas and 72 adenocarcinomas. MiRNAs were selected as candidates if their immediately flanking probes or host gene were deleted or amplified in at least 25% of primary tumours using both Analysis of Copy Errors algorithm and fold change (≥ ± 1.2 analyses. Using these criteria, 97 miRNAs mapped to regions of aberrant copy number. Analysis of three independent published lung cancer arrayCGH datasets confirmed that 22 of these miRNA loci showed directionally concordant copy number variation. MiR-218, encoded on 4p15.31 and 5q35.1 within two host genes (SLIT2 and SLIT3, in a region of copy number loss, was selected as a priority candidate for follow-up as it is reported as underexpressed in lung cancer. We confirmed decreased expression of mature miR-218 and its host genes by qRT-PCR in 39 NSCLCs relative to normal lung tissue. This downregulation of miR-218 was found to be associated with a history of cigarette smoking, but not human papilloma virus. Thus, we show for the first time that putative lung cancer-associated miRNAs can be identified from genome-wide arrayCGH datasets using a bioinformatics mapping approach, and report that miR-218 is a strong candidate tumour suppressing miRNA potentially involved in lung cancer.

  11. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax.

    Science.gov (United States)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-12-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion-induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo.

  12. PD1 blockade reverses the suppression of melanoma antigen-specific CTL by CD4+ CD25(Hi) regulatory T cells.

    Science.gov (United States)

    Wang, Wenshi; Lau, Roy; Yu, Daohai; Zhu, Weiwei; Korman, Alan; Weber, Jeffrey

    2009-09-01

    Regulatory CD4(+)CD25(Hi) T cells (Treg) and programmed death-1 (PD-1) molecule have emerged as pivotal players in immune regulation. However, the underlying mechanisms by which they impact antigen-specific CD8(+) immune responses in cancer patients and how they interact with each other under physiologic conditions remain unclear. Herein, we examined the relationship of PD-1 and its abrogation to the function of Treg in patients with melanoma using short-term in vitro assays to generate melanoma-specific T cells. We identified Treg in the circulation of vaccinated melanoma patients and detected PD-1 expression on vaccine-induced melanoma antigen-specific CTLs, as well as on and within Treg from patients' peripheral blood. Programmed death ligand (PD-L) 1 expression was also detected on patients' Treg. PD-1 blockade promoted the generation of melanoma antigen-specific CTLs and masked their inhibition by Treg. The mechanisms by which PD-1 blockade mediated immune enhancement included direct augmentation of melanoma antigen-specific CTL proliferation, heightening their resistance to inhibition by Treg and direct limitation of the inhibitory ability of Treg. PD-1 blockade reversed the increased expression of PD-1 and PD-L1 on melanoma antigen-specific CTL by Treg, rescued INF-gamma and IL-2 or INF-gamma and tumor necrosis factor-alpha co-expression and expression of IL-7 receptor by melanoma antigen-specific CTL which were diminished by Treg. PD-1 blockade also resulted in down-regulation of intracellular FoxP3 expression by Treg. These data suggest that PD-1 is importantly implicated in the regulation of Treg function in melanoma patients.

  13. PD1 blockade reverses the suppression of melanoma antigen-specific CTL by CD4+CD25Hi regulatory T cells

    Science.gov (United States)

    Lau, Roy; Yu, Daohai; Zhu, Weiwei; Korman, Alan; Weber, Jeffrey

    2009-01-01

    Regulatory CD4+CD25Hi T cells (Treg) and programmed death-1 (PD-1) molecule have emerged as pivotal players in immune regulation. However, the underlying mechanisms by which they impact antigen-specific CD8+ immune responses in cancer patients and how they interact with each other under physiologic conditions remain unclear. Herein, we examined the relationship of PD-1 and its abrogation to the function of Treg in patients with melanoma using short-term in vitro assays to generate melanoma-specific T cells. We identified Treg in the circulation of vaccinated melanoma patients and detected PD-1 expression on vaccine-induced melanoma antigen-specific CTLs, as well as on and within Treg from patients’ peripheral blood. Programmed death ligand (PD-L) 1 expression was also detected on patients’ Treg. PD-1 blockade promoted the generation of melanoma antigen-specific CTLs and masked their inhibition by Treg. The mechanisms by which PD-1 blockade mediated immune enhancement included direct augmentation of melanoma antigen-specific CTL proliferation, heightening their resistance to inhibition by Treg and direct limitation of the inhibitory ability of Treg. PD-1 blockade reversed the increased expression of PD-1 and PD-L1 on melanoma antigen-specific CTL by Treg, rescued INF-γ and IL-2 or INF-γ and tumor necrosis factor-α co-expression and expression of IL-7 receptor by melanoma antigen-specific CTL which were diminished by Treg. PD-1 blockade also resulted in down-regulation of intracellular FoxP3 expression by Treg. These data suggest that PD-1 is importantly implicated in the regulation of Treg function in melanoma patients. PMID:19651643

  14. Vitamin D controls T cell antigen receptor signaling and activation of human T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak-Wismann, Martin; Schjerling, Peter

    2010-01-01

    Phospholipase C (PLC) isozymes are key signaling proteins downstream of many extracellular stimuli. Here we show that naive human T cells had very low expression of PLC-gamma1 and that this correlated with low T cell antigen receptor (TCR) responsiveness in naive T cells. However, TCR triggering...... led to an upregulation of approximately 75-fold in PLC-gamma1 expression, which correlated with greater TCR responsiveness. Induction of PLC-gamma1 was dependent on vitamin D and expression of the vitamin D receptor (VDR). Naive T cells did not express VDR, but VDR expression was induced by TCR...... signaling via the alternative mitogen-activated protein kinase p38 pathway. Thus, initial TCR signaling via p38 leads to successive induction of VDR and PLC-gamma1, which are required for subsequent classical TCR signaling and T cell activation....

  15. Downregulation of CD147 expression alters cytoskeleton architecture and inhibits gelatinase production and SAPK pathway in human hepatocellular carcinoma cells

    Directory of Open Access Journals (Sweden)

    Weng Yuan-Yuan

    2008-10-01

    Full Text Available Abstract Background CD147 plays a critical role in the invasive and metastatic activity of hepatocellular carcinoma (HCC cells by stimulating the surrounding fibroblasts to express matrix metalloproteinases (MMPs. Tumor cells adhesion to extracellular matrix (ECM proteins is the first step to the tumor metastasis. MMPs degrade the ECM to promote tumor metastasis. The aim of this study is to investigate the effects of small interfering RNA (siRNA against CD147 (si-CD147 on hepatocellular carcinoma cells' (SMMC-7721 architecture and functions. Methods Flow cytometry and western blot assays were employed to detect the transfection efficiency of si-CD147. Confocal microscopy was used to determine the effects of si-CD147 on SMMC-7721 cells' cytoskeleton. Invasion assay, gelatin zymography and cell adhesion assay were employed to investigate the effects of si-CD147 on SMMC-7721 cells' invasion, gelatinase production and cell adhesive abilities. Western blot assay was utilized to detect the effects of si-CD147 on focal adhesion kinase (FAK, vinculiln and mitogen-activated protein kinase (MAPK expression in SMMC-7721 cells. Results Downregulation of CD147 gene induced the alteration of SMMC-7721 cell cytoskeleton including actin, microtubule and vimentin filaments, and inhibited gelatinase production and expression, cells invasion, FAK and vinculin expression. si-CD147 also blocked SMMC-7721 cells adhesion to collagen IV and phosphorylation level of SAPK/JNKs. SAPK/JNKs inhibitor SP600125 inhibited gelatinase production and expression. Conclusion CD147 is required for normal tumor cell architecture and cell invasion. Downregulation of CD147 affects HCC cell structure and function. Moreover, the alteration of cell behavior may be related to SAPK/JNK Pathway. siRNA against CD147 may be a possible new approach for HCC gene therapy.

  16. Hepatitis C virus and ethanol alter antigen presentation in liver cells

    Institute of Scientific and Technical Information of China (English)

    Natalia A Osna

    2009-01-01

    Alcoholic patients have a high incidence of hepatitis Cvirus (HCV) infection. Alcohol consumption enhances the severity of the HCV disease course and worsens the outcome of chronic hepatitis C. The accumulation of virally infected cells in the liver is related to the HCVinduced inability of the immune system to recognizeinfected cells and to develop the immune responses. This review covers the effects of HCV proteins and ethanol on major histocompatibility complex (MHC) classⅠ- and class Ⅱ-restricted antigen presentation. Here, we discuss the liver which functions as an immune privilege organ; factors, which affect cleavage and loading of antigenic peptides onto MHC classⅠand class Ⅱ in hepatocytes and dendritic cells, and the modulating effects of ethanol and HCV on antigen presentation by liver cells. Altered antigen presentation in the liver limits the ability of the immune system to clear HCV and infected cells and contributes to disease progression. HCV by itself affects dendritic cell function, switching their cytokine profile to the suppressive phenotype of interleukin-10 (IL-10) and transforming growth factor beta (TGFβ) predominance,preventing cell maturation and allostimulation capacity.The synergistic action of ethanol with HCV results in the suppression of MHC class Ⅱ-restricted antigen presentation. In addition, ethanol metabolism and HCV proteins reduce proteasome function and interferon signaling, thereby suppressing the generation of peptides for MHC classⅠ-restricted antigen presentation.Collectively, ethanol exposure further impairs antigen presentation in HCV-infected liver cells, which may provide a partial explanation for exacerbations and the poor outcome of HCV infection in alcoholics.

  17. Diverse endogenous antigens for mouse NKT cells: self-antigens that are not glycosphingolipids.

    Science.gov (United States)

    Pei, Bo; Speak, Anneliese O; Shepherd, Dawn; Butters, Terry; Cerundolo, Vincenzo; Platt, Frances M; Kronenberg, Mitchell

    2011-02-01

    NKT cells with an invariant Ag receptor (iNKT cells) represent a highly conserved and unique subset of T lymphocytes having properties of innate and adaptive immune cells. They have been reported to regulate a variety of immune responses, including the response to cancers and the development of autoimmunity. The development and activation of iNKT cells is dependent on self-Ags presented by the CD1d Ag-presenting molecule. It is widely believed that these self-Ags are glycosphingolipids (GSLs), molecules that contain ceramide as the lipid backbone. In this study, we used a variety of methods to show that mammalian Ags for mouse iNKT cells need not be GSLs, including the use of cell lines deficient in GSL biosynthesis and an inhibitor of GSL biosynthesis. Presentation of these Ags required the expression of CD1d molecules that could traffic to late endosomes, the site where self-Ag is acquired. Extracts of APCs contain a self-Ag that could stimulate iNKT cells when added to plates coated with soluble, rCD1d molecules. The Ag(s) in these extracts are resistant to sphingolipid-specific hydrolase digestion, consistent with the results using live APCs. Lyosphosphatidylcholine, a potential self-Ag that activated human iNKT cell lines, did not activate mouse iNKT cell hybridomas. Our data indicate that there may be more than one type of self-Ag for iNKT cells, that the self-Ags comparing mouse and human may not be conserved, and that the search to identify these molecules should not be confined to GSLs.

  18. Rheumatoid arthritis and its association with HLA-DR antigens. I. Cell mediated immune response against connective tissue antigens.

    Science.gov (United States)

    Vullo, C M; Pesoa, S A; Onetti, C M; Riera, C M

    1987-04-01

    HLA-DR antigens and cellular sensitivity to native bovine type I and type II collagen and proteoglycans were examined in patients with classic rheumatoid arthritis (RA) and normal individuals. Fifty eight percent of patients with RA (n = 88) and 28% of normals (n = 52) were DR4+ (pc less than 0.01). DR4 phenotype was significantly increased in patients with severe disease stages (III-IV), as defined by the ARA criteria, in contrast to those showing mild disease stages (I-II) (p less than 0.05). Furthermore, peripheral blood mononuclear cells from 55 patients and 30 controls were evaluated for the in vitro production of leukocyte inhibitory factor in response to native type I and type II collagen and proteoglycans. By using this assay, cells from the arthritic group exhibited a statistically significant response when stimulated with native type I collagen and proteoglycans. The cellular immune response was not associated with any particular HLA-DR antigens, or to the disease stage or severity.

  19. Down-regulated expression of NPM1 in IMS-M2 cell line by (-)-epigallocatechin-3-gallate

    Institute of Scientific and Technical Information of China (English)

    Hoang Thanh Chi; Bui Thi Kim Ly; Hoang Anh Vu; Yuko Sato; Phu Chi Dung; Phan Thi Xinh

    2014-01-01

    Objective: To investigate the inhibited effect of epigallocatechin-3-gallate (EGCG) on the expression of NPM1 in IMS-M2 cells harboring the NPM1 mutations.Methods:Cell proliferation assay was performed to test the effects of EGCG on cell growth of IMS-M2 cells harboring the NPM1 mutations. Western blot analysis were performed to test the protein expression of NPM1, AKT, those associated with apoptosis. Results: EGCG can down-regulate the expression of NPM1 in IMS-M2 cells harboring the NPM1 mutations. Moreover, EGCG also suppressed the cell proliferation and induced apoptosis in IMS-M2 cells.Conclusions:The results suggested that EGCG could be considered as a reagent for treatment of AML patients with NPM1 mutations.

  20. Antigen-presenting cells in parotid glands contain cystatin D originating from acinar cells.

    Science.gov (United States)

    Nashida, Tomoko; Sato, Ritsuko; Haga-Tsujimura, Maiko; Yoshie, Sumio; Yoshimura, Ken; Imai, Akane; Shimomura, Hiromi

    2013-02-01

    Cystatin D encoded by Cst5 is a salivary classified type II cystatin. We investigated the dynamism of cystatin D by examining the distribution of cystatin D protein and mRNA in rats, to identify novel functions. The simultaneous expression of Cst5 and cystatin D was observed in parotid glands, however in situ hybridization showed that only acinar cells produced cystatin D. Synthesized cystatin D was localized in small vesicles and secreted from the apical side to the saliva, and from the basolateral side to the extracellular region, a second secretory pathway for cystatin D. We also identified antigen-presenting cells in the parotid glands that contained cystatin D without the expression of Cst5, indicating the uptake of cystatin D from the extracellular region. Cystatin D was detected in blood serum and renal tubular cells with megalin, indicating the circulation of cystatin D through the body and uptake by renal tubular cells. Thus, the novel dynamism of cystatin D was shown and a function for cystatin D in the regulation of antigen-presenting cell activity was proposed.

  1. Effects of downregulation of SIRT3 expression on proliferation and apoptosis in esophageal squamous cell carcinoma EC9706 cells and its molecular mechanisms.

    Science.gov (United States)

    Yang, Mei; Yang, Chunsong; Pei, Yuhua

    2014-01-01

    To investigate the effect of downregulation of SIRT3 expression on cell proliferation and invasion in esophageal squamous cell carcinoma (ESCC) EC9706 cells, and to explore its possible molecular mechanisms, we transfected siRNA targeting SIRT3 into EC9706 cells, and then divided cells into three groups: untreated, control siRNA and SIRT3 siRNA groups. The expression levels of SIRT3 protein were detected in different groups by western blotting. The effect of SIRT3 siRNA on cell proliferation was investigated using the CCK-8 kit. The changes of cell apoptosis were examined by flow cytometry. Finally, the expression levels of cell proliferation and apoptosis related proteins such as p21, Bcl-2 and Bax were determined by western blotting. SIRT3 siRNA effectively down-regulated the expression of SIRT3 protein in EC9706 cells, and the reduced expression of SIRT3 significantly inhibited cell proliferation and induced cell apoptosis. Most notably, the SIRT3 depletion markedly increased the expressions of p21 and Bax proteins but reduced Bcl-2 protein expression. The proliferation inhibition and apoptosis of EC9706 cells mediated by SIRT3 downregulation may be closely associated with the expression levels of p21, Bcl-2 and Bax proteins.

  2. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available BACKGROUND: Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species. METHODS AND FINDINGS: We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity. CONCLUSIONS: The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  3. Low antigenicity of hematopoietic progenitor cells derived from human ES cells

    Directory of Open Access Journals (Sweden)

    Eun-Mi Kim

    2010-02-01

    Full Text Available Eun-Mi Kim1, Nicholas Zavazava1,21Department of Internal Medicine, University of Iowa and Veterans Affairs Medical Center, Iowa City, Iowa, USA; 2Immunology Graduate Program, University of Iowa, Iowa City, Iowa, USAAbstract: Human embryonic stem (hES cells are essential for improved understanding of diseases and our ability to probe new therapies for use in humans. Currently, bone marrow cells and cord blood cells are used for transplantation into patients with hematopoietic malignancies, immunodeficiencies and in some cases for the treatment of autoimmune diseases. However, due to the high immunogenicity of these hematopoietic cells, toxic regimens of drugs are required for preconditioning and prevention of rejection. Here, we investigated the efficiency of deriving hematopoietic progenitor cells (HPCs from the hES cell line H13, after co-culturing with the murine stromal cell line OP9. We show that HPCs derived from the H13 ES cells poorly express major histocompatibility complex (MHC class I and no detectable class II antigens (HLA-DR. These characteristics make hES cell-derived hematopoietic cells (HPCs ideal candidates for transplantation across MHC barriers under minimal immunosuppression.Keywords: human embryonic stem cells, H13, hematopoiesis, OP9 stromal cells, immunogenicity

  4. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Science.gov (United States)

    Yazıcı, Serkan; Bülbül Başkan, Emel; Budak, Ferah; Oral, Barbaros; Adim, Şaduman Balaban; Ceylan Kalin, Zübeyde; Özkaya, Güven; Aydoğan, Kenan; Saricaoğlu, Hayriye; Tunali, Şükran

    2015-01-01

    We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF). 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC) criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP) and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+), B cells (HLA-DR+, CD19+, and HLA-DR+CD19+), NKT cells (CD3+CD16+CD56+), and NK cells (CD3−CD16+CD56+). The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression. PMID:26788525

  5. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Directory of Open Access Journals (Sweden)

    Serkan Yazıcı

    2015-01-01

    Full Text Available We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF. 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+, B cells (HLA-DR+, CD19+, and HLA-DR+CD19+, NKT cells (CD3+CD16+CD56+, and NK cells (CD3−CD16+CD56+. The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression.

  6. Down-Regulation of Notchl and NF-κB by Curcumin in Breast Cancer Cells MDA-MB-231

    Institute of Scientific and Technical Information of China (English)

    LONG Li; CAO You-de

    2008-01-01

    Objective:To test whether the down-regulation of Notch1 gene expression by curcumin could inhibit cell growth and induce apoptosis,which may be associated mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods:Breast cancer cell lines MDA-MB-231 were cultured in vitro and treated with different dosages of curcumin(0,1.25,5.0,20.0μmol/L)for dose-dependent assay and different time(0,24,48,72 h)at the dosage of 5.0μmol/L for time course assay.The changes of the mRNA and protein expression of Notch1 and NF-κB were measured by RT-PCR and Western Blot,and MTT assay was used to measure the change of proliferation. Results:The mRNA and protein levels of Notch 1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin(P<0.05),and with the extension of time course(P<0.05).These changes suggested a dose- and time-dependent manner.The proliferation rate of cells also was significantly inhibited(P<0.05). Conclusion:The current results show that the Notch-1 signaling pathway is associated mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer.

  7. Production of Exocytic Vesicular Antigens by Primary Liver Cell Cultures

    Science.gov (United States)

    1990-05-08

    microbial symbionts which occur naturally in the gut and on mucous membranes. Another method invclves the use of synthetic peptides which mimic...Streptococcus pneumoniae, hepatitis B virus, Plasmodium spp. and dengue virus, which are creating tremendous burdens worldwide [32]. Most of the...place in the immune system when an antibody’s unique antigen-binding peptide sequence (the idiotype) stimulates production of another antibody directed

  8. Antigen-activated dendritic cells ameliorate influenza A infections

    OpenAIRE

    2013-01-01

    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecu...

  9. Antigen-bound C3b and C4b enhance antigen-presenting cell function in activation of human T-cell clones.

    Science.gov (United States)

    Arvieux, J; Yssel, H; Colomb, M G

    1988-10-01

    The effect of complement fragments C3b and C4b, on the triggering of antigen-specific human T-cell clones by Epstein-Barr virus-transformed human lymphoblastoid B cells (LCL) when these fragments are covalently coupled to the antigen tetanus toxin (TT) is described. TT was chemically cross-linked to purified C3b [(TT-C3b)n], C4b [(TT-C4b)n] or bovine serum albumin [(TT-BSA)n] as a control. T-cell activation was quantified by tritiated thymidine incorporation and 51Cr release. (TT-C3b)n and (TT-C4b)n induced proliferative responses comparable to (TT-BSA)n but at 18-25 and 4-6 lower concentrations, respectively. This enhancing effect required the covalent cross-linking of the complement fragments to the antigen and involved intracellular processing of the latter by LCL. Antigen presentation was similarly enhanced when measuring the cytotoxic activity of a helper T-cell clone against LCL previously pulsed with (TT-C3b)n or (TT-C4b)n compared with (TT-BSA)n. Binding studies, carried out on LCL using TT radiolabelled with 125I before cross-linking, indicated that (TT-C3b)n and (TT-C4b)n gave three- to four-fold more binding than (TT-BSA)n. Addition of antibodies against CR1 and CR2 or proteolytic removal of these complement receptors with trypsin inhibited by about 60% the enhancing effect of TT-bound C3b and C4b in both binding and functional assays. These results indicate that binding of C3b or C4b to antigen enhances antigen-specific proliferative and cytotoxic responses of T cells by targeting opsonized antigen onto complement receptors CR1 and CR2 of LCL. The putative significance of these findings in terms of regulation of immune responses by complement is discussed.

  10. Mitofusin 2 Downregulation Triggers Pulmonary Artery Smooth Muscle Cell Proliferation and Apoptosis Imbalance in Rats With Hypoxic Pulmonary Hypertension Via the PI3K/Akt and Mitochondrial Apoptosis Pathways.

    Science.gov (United States)

    Fang, Xia; Chen, Xi; Zhong, Guangwei; Chen, Qiong; Hu, Chengping

    2016-02-01

    During hypoxia-induced pulmonary hypertension (HPH), pulmonary artery smooth muscle cells (PASMCs) proliferate as part of the characteristic pulmonary vascular remodeling. We investigated the expression of mitofusin 2(Mfn2) and its role in maintaining the balance between PASMC proliferation and apoptosis during hypoxia. In an experimental model of HPH, we exposed rats to hypoxia (10% ± 0.5% O2) or room air for 4 weeks. We found that Mfn2 messenger RNA and protein levels were reduced and that proliferating cell nuclear antigen protein expression was upregulated in HPH rat lung tissues. We also exposed primary cultured PASMCs from rat pulmonary arterioles to normoxia (21% O2/5% CO2) or hypoxia (2.5% O2/5% CO2) for 24 hours. We found that PASMC proliferation increased under hypoxic conditions and that more hypoxic cells than normoxic cells entered the S + G2/M phase. Additionally, phosphorylated Akt and proliferating cell nuclear antigen expression increased, whereas Mfn2 expression, cleaved caspase 9 expression, and the ratio of mitochondrial to cytosolic cytochrome C expression each decreased. These hypoxia-induced effects were reversed in PASMCs by Mfn2 overexpression and by phosphatidylinositide 3-kinases (PI3K) inhibition. Our results indicate that downregulation of Mfn2 in HPH may activate the PI3K/Akt pathway, thereby causing more cells to enter the S + G2/M phase of the cell cycle and inhibiting the mitochondrial apoptosis pathway.

  11. Macrophages transfer antigens to dendritic cells by releasing exosomes containing dead-cell-associated antigens partially through a ceramide-dependent pathway to enhance CD4(+) T-cell responses.

    Science.gov (United States)

    Xu, Yingping; Liu, Yi; Yang, Chunqing; Kang, Li; Wang, Meixiang; Hu, Jingxia; He, Hao; Song, Wengang; Tang, Hua

    2016-10-01

    Defects in rapid clearance of apoptotic cells lead to an accumulation of dead cells (late apoptotic or secondary necrotic cells), which results in an aberrant immune response. However, little is known about whether and how macrophages (Mφs) cooperate with dendritic cells (DCs) in the presentation of dead-cell-associated antigens in this process. By transferring high numbers of dead cells to mimic a failure of apoptotic cell clearance in vivo, we found that Mφs and neutrophils were the predominant phagocytes in the uptake of dead cells in the spleen. Moreover, both Mφs and DCs were required for an optimal CD4(+) T-cell response triggered by dead-cell-associated antigens. Importantly, although Mφs alone had a poor capacity for antigen presentation, they could transfer phagocytosed antigens to DCs for potent antigen presentation to enhance T-cell responses. Finally, we found that exosomes released from Mφs acted as a transmitter to convey antigens to DCs partially in a ceramide-dependent manner, since treatment with the neutral sphingomyelinase inhibitor GW4869 and spiroepoxide resulted in a significant reduction of T-cell proliferation in vitro and in vivo. These findings point to a novel pathway of cross-talk between Mφs and DCs, which will be helpful to explain possible mechanisms for autoimmune diseases characterized by increased rates of apoptosis.

  12. Endotoxin-induced basal respiration alterations of renal HK-2 cells: A sign of pathologic metabolism down-regulation

    Energy Technology Data Exchange (ETDEWEB)

    Quoilin, C., E-mail: cquoilin@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium); Mouithys-Mickalad, A. [Center of Oxygen Research and Development, Department of Chemistry, University of Liege, 4000 Liege (Belgium); Duranteau, J. [Department of Anaesthesia and Surgical ICU, CHU Bicetre, University Paris XI Sud, 94275 Le Kremlin Bicetre (France); Gallez, B. [Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Universite catholique de Louvain, 1200 Brussels (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer A HK-2 cells model of inflammation-induced acute kidney injury. Black-Right-Pointing-Pointer Two oximetry methods: high resolution respirometry and ESR spectroscopy. Black-Right-Pointing-Pointer Oxygen consumption rates of renal cells decrease when treated with LPS. Black-Right-Pointing-Pointer Cells do not recover normal respiration when the LPS treatment is removed. Black-Right-Pointing-Pointer This basal respiration alteration is a sign of pathologic metabolism down-regulation. -- Abstract: To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal tubular epithelial cells (HK-2) both by high-resolution respirometry and electron spin resonance spectroscopy. These two complementary methods have shown that HK-2 cells exhibit a decreased oxygen consumption rate when treated with LPS. Surprisingly, this cellular respiration alteration persists even after the stress factor was removed. We suggested that this irreversible decrease in renal oxygen consumption after LPS challenge is related to a pathologic metabolic down-regulation such as a lack of oxygen utilization by cells.

  13. Isolation of the phagocytosis-inducing IgG-binding antigen on senescent somatic cells

    Science.gov (United States)

    Kay, Marguerite M. B.

    1981-02-01

    To remove senescent red blood cells (RBCs) from the circulation, macrophages must distinguish them from mature RBCs. That is achieved by a specific recognition system1,2. An antigen that develops on the surface of a senescing RBC is recognized and bound by the Fab region1 of an IgG autoantibody in the serum2. Subsequently the Fc region of the autoantibody is recognized and bound by a macrophage3, which proceeds to phagocytose the RBC. The antigenic molecule can be extracted from senescent but not young RBCs with Triton X-100 (ref. 4), although 10-30% as much antigen can be extracted from middle-aged as from senescent RBCs4. I have now used IgG autoantibodies eluted from senescent RBCs to isolate and purify the IgG-binding antigen on senescent RBCs, andto detect the antigen on other somatic cells. The antigen is a ~=62,000-Mr protein which is present on stored platelets, lymphocytes and neutrophils, and on cultured human adult liver and embryonic kidney cells, as well as senescent RBCs.

  14. Development of an algorithm for production of inactivated arbovirus antigens in cell culture.

    Science.gov (United States)

    Goodman, C H; Russell, B J; Velez, J O; Laven, J J; Nicholson, W L; Bagarozzi, D A; Moon, J L; Bedi, K; Johnson, B W

    2014-11-01

    Arboviruses are medically important pathogens that cause human disease ranging from a mild fever to encephalitis. Laboratory diagnosis is essential to differentiate arbovirus infections from other pathogens with similar clinical manifestations. The Arboviral Diseases Branch (ADB) reference laboratory at the CDC Division of Vector-Borne Diseases (DVBD) produces reference antigens used in serological assays such as the virus-specific immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Antigen production in cell culture has largely replaced the use of suckling mice; however, the methods are not directly transferable. The development of a cell culture antigen production algorithm for nine arboviruses from the three main arbovirus families, Flaviviridae, Togaviridae, and Bunyaviridae, is described here. Virus cell culture growth and harvest conditions were optimized, inactivation methods were evaluated, and concentration procedures were compared for each virus. Antigen performance was evaluated by the MAC-ELISA at each step of the procedure. The antigen production algorithm is a framework for standardization of methodology and quality control; however, a single antigen production protocol was not applicable to all arboviruses and needed to be optimized for each virus.

  15. Downregulation of ROCK2 through Nanocomplex Sensitizes the Cytotoxic Effect of Temozolomide in U251 Glioma Cells

    OpenAIRE

    Xiaojun Wen; Amin Huang; Zhonglin Liu; Yunyun Liu; Jingyang Hu; Jun Liu; Xintao Shuai

    2014-01-01

    OBJECTIVE: Rho-associated coiled-coil kinase 2 (ROCK2) is an attractive therapeutic target because it is overexpressed in many malignancies, including glioma. Therefore, we designed the current study to determine whether the downregulation of ROCK2 would sensitize the cytotoxic effect of temozolomide (TMZ) in U251 cells. METHODS: Glycol-polyethyleneimine (PEG-PEI) was used to deliver siROCK2 to U251 cells, and the physical characteristics of the PEG-PEI/siROCK2 complex (referred to as the siR...

  16. A sharp T-cell antigen receptor signaling threshold for T-cell proliferation

    Science.gov (United States)

    Au-Yeung, Byron B.; Zikherman, Julie; Mueller, James L.; Ashouri, Judith F.; Matloubian, Mehrdad; Cheng, Debra A.; Chen, Yiling; Shokat, Kevan M.; Weiss, Arthur

    2014-01-01

    T-cell antigen receptor (TCR) signaling is essential for activation, proliferation, and effector function of T cells. Modulation of both intensity and duration of TCR signaling can regulate these events. However, it remains unclear how individual T cells integrate such signals over time to make critical cell-fate decisions. We have previously developed an engineered mutant allele of the critical T-cell kinase zeta-chain-associated protein kinase 70 kDa (Zap70) that is catalytically inhibited by a small molecule inhibitor, thereby blocking TCR signaling specifically and efficiently. We have also characterized a fluorescent reporter Nur77–eGFP transgenic mouse line in which T cells up-regulate GFP uniquely in response to TCR stimulation. The combination of these technologies unmasked a sharp TCR signaling threshold for commitment to cell division both in vitro and in vivo. Further, we demonstrate that this threshold is independent of both the magnitude of the TCR stimulus and Interleukin 2. Similarly, we identify a temporal threshold of TCR signaling that is required for commitment to proliferation, after which T cells are able to proliferate in a Zap70 kinase-independent manner. Taken together, our studies reveal a sharp threshold for the magnitude and duration of TCR signaling required for commitment of T cells to proliferation. These results have important implications for understanding T-cell responses to infection and optimizing strategies for immunomodulatory drug delivery. PMID:25136127

  17. 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...... that these cells are relatively immature lymphoid cells, CALLA+ cells do not appear to contain either myeloid precursor cells (CFU-G/M) or the earliest lymphoid stem cells. Udgivelsesdato: 1983-Jan-1...

  18. Comparison of microglia and infiltrating CD11c+ cells as antigen presenting cells for T cell proliferation and cytokine response

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Løbner, Morten; Cédile, Oriane

    2014-01-01

    BACKGROUND: Tissue-resident antigen-presenting cells (APC) exert a major influence on the local immune environment. Microglia are resident myeloid cells in the central nervous system (CNS), deriving from early post-embryonic precursors, distinct from adult hematopoietic lineages. Dendritic cells...... but detectable levels of all these cytokines. Transforming growth factor beta expression was similar in all three populations. Although CNS-resident and blood-derived CD11c+ cells showed equivalent ability to induce proliferation of myelin oligodendrocyte glycoprotein-immunised CD4+ T cells, CD11c+ microglia...

  19. Cationic liposomes promote antigen cross-presentation in dendritic cells by alkalizing the lysosomal pH and limiting the degradation of antigens.

    Science.gov (United States)

    Gao, Jie; Ochyl, Lukasz J; Yang, Ellen; Moon, James J

    2017-01-01

    Cationic liposomes (CLs) have been widely examined as vaccine delivery nanoparticles since they can form complexes with biomacromolecules, promote delivery of antigens and adjuvant molecules to antigen-presenting cells (APCs), and mediate cellular uptake of vaccine components. CLs are also known to trigger antigen cross-presentation - the process by which APCs internalize extracellular protein antigens, degrade them into minimal CD8(+) T-cell epitopes, and present them in the context of major histocompatibility complex-I (MHC-I). However, the precise mechanisms behind CL-mediated induction of cross-presentation and cross-priming of CD8(+) T-cells remain to be elucidated. In this study, we have developed two distinct CL systems and examined their impact on the lysosomal pH in dendritic cells (DCs), antigen degradation, and presentation of peptide:MHC-I complexes to antigen-specific CD8(+) T-cells. To achieve this, we have used 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as the prototypical components of CLs with tertiary amine groups and compared the effect of CLs and anionic liposomes on lysosomal pH, antigen degradation, and cross-presentation by DCs. Our results showed that CLs, but not anionic liposomes, elevated the lysosomal pH in DCs and reduced antigen degradation, thereby promoting cross-presentation and cross-priming of CD8(+) T-cell responses. These studies shed new light on CL-mediated cross-presentation and suggest that intracellular fate of vaccine components and subsequent immunological responses can be controlled by rational design of nanomaterials.

  20. Cationic liposomes promote antigen cross-presentation in dendritic cells by alkalizing the lysosomal pH and limiting the degradation of antigens

    Science.gov (United States)

    Gao, Jie; Ochyl, Lukasz J; Yang, Ellen; Moon, James J

    2017-01-01

    Cationic liposomes (CLs) have been widely examined as vaccine delivery nanoparticles since they can form complexes with biomacromolecules, promote delivery of antigens and adjuvant molecules to antigen-presenting cells (APCs), and mediate cellular uptake of vaccine components. CLs are also known to trigger antigen cross-presentation – the process by which APCs internalize extracellular protein antigens, degrade them into minimal CD8+ T-cell epitopes, and present them in the context of major histocompatibility complex-I (MHC-I). However, the precise mechanisms behind CL-mediated induction of cross-presentation and cross-priming of CD8+ T-cells remain to be elucidated. In this study, we have developed two distinct CL systems and examined their impact on the lysosomal pH in dendritic cells (DCs), antigen degradation, and presentation of peptide:MHC-I complexes to antigen-specific CD8+ T-cells. To achieve this, we have used 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as the prototypical components of CLs with tertiary amine groups and compared the effect of CLs and anionic liposomes on lysosomal pH, antigen degradation, and cross-presentation by DCs. Our results showed that CLs, but not anionic liposomes, elevated the lysosomal pH in DCs and reduced antigen degradation, thereby promoting cross-presentation and cross-priming of CD8+ T-cell responses. These studies shed new light on CL-mediated cross-presentation and suggest that intracellular fate of vaccine components and subsequent immunological responses can be controlled by rational design of nanomaterials. PMID:28243087

  1. Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines.

    Science.gov (United States)

    Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

    2016-01-01

    Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is a particular interest in developing robust high-throughput assays as chicken vaccine trials usually comprise many individuals. In many respects, the avian immune system differs from the mammalian, and T cell assessment protocols must be adjusted accordingly to account for, e.g., differences in leukocyte subsets.The carboxyfluorescein succinimidyl ester (CFSE) method described in this chapter has been adapted to chicken cells. In this test, cells of interest are stained with CFSE. The succinimidyl ester group covalently binds to cellular amines forming fluorescent conjugates that are retained in the cells even throughout division. This leads to daughter cells containing half the fluorescence of their parents. When lymphocytes are loaded with CFSE prior to ex vivo stimulation with specific antigen, the measurement of serial halving of its fluorescence by flow cytometry identifies the cells responding to the stimulation. This method has been successfully applied to studies of chicken antigen-specific T cells.

  2. Characterization of the interface of the bone marrow stromal cell antigen 2-Vpu protein complex via computational chemistry.

    Science.gov (United States)

    Zhou, Jinming; Zhang, Zhixin; Mi, Zeyun; Wang, Xin; Zhang, Quan; Li, Xiaoyu; Liang, Chen; Cen, Shan

    2012-02-14

    Bone marrow stromal cell antigen 2 (BST-2) inhibits the release of enveloped viruses from the cell surface. Various viral counter measures have been discovered, which allow viruses to escape BST-2 restriction. Human immunodeficiency virus type 1 (HIV-1) encodes viral protein U (Vpu) that interacts with BST-2 through their transmembrane domains and causes the downregulation of cell surface BST-2. In this study, we used a computer modeling method to establish a molecular model to investigate the binding interface of the transmembrane domains of BST-2 and Vpu. The model predicts that the interface is composed of Vpu residues I6, A10, A14, A18, V25, and W22 and BST-2 residues L23, I26, V30, I34, V35, L41, I42, and T45. Introduction of mutations that have been previously reported to disrupt the Vpu-BST-2 interaction led to a calculated higher binding free energy (MMGBSA), which supports our molecular model. A pharmacophore was also generated on the basis of this model. Our results provide a precise model that predicts the detailed interaction occurring between the transmembrane domains of Vpu and BST-2 and should facilitate the design of anti-HIV agents that are able to disrupt this interaction.

  3. Pros and Cons of Antigen-Presenting Cell Targeted Tumor Vaccines

    Directory of Open Access Journals (Sweden)

    Cleo Goyvaerts

    2015-01-01

    Full Text Available In therapeutic antitumor vaccination, dendritic cells play the leading role since they decide if, how, when, and where a potent antitumor immune response will take place. Since the disentanglement of the complexity and merit of different antigen-presenting cell subtypes, antitumor immunotherapeutic research started to investigate the potential benefit of targeting these subtypes in situ. This review will discuss which antigen-presenting cell subtypes are at play and how they have been targeted and finally question the true meaning of targeting antitumor-based vaccines.

  4. In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination.

    Science.gov (United States)

    Bonifaz, Laura C; Bonnyay, David P; Charalambous, Anna; Darguste, Dara I; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K; Moltedo, Bruno; Moran, Thomas M; Steinman, Ralph M

    2004-03-15

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic alpha-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the alphaDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell-mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models.

  5. A Single Subset of Dendritic Cells Controls the Cytokine Bias of Natural Killer T Cell Responses to Diverse Glycolipid Antigens

    Science.gov (United States)

    Arora, Pooja; Baena, Andres; Yu, Karl O.A.; Saini, Neeraj K.; Kharkwal, Shalu S.; Goldberg, Michael F.; Kunnath-Velayudhan, Shajo; Carreño, Leandro J.; Venkataswamy, Manjunatha M.; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R.; Jervis, Peter J.; Veerapen, Natacha; Besra, Gurdyal S.; Porcelli, Steven A.

    2014-01-01

    Summary Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α+ DEC-205+ dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α+ dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses. PMID:24412610

  6. A single subset of dendritic cells controls the cytokine bias of natural killer T cell responses to diverse glycolipid antigens.

    Science.gov (United States)

    Arora, Pooja; Baena, Andres; Yu, Karl O A; Saini, Neeraj K; Kharkwal, Shalu S; Goldberg, Michael F; Kunnath-Velayudhan, Shajo; Carreño, Leandro J; Venkataswamy, Manjunatha M; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R; Jervis, Peter J; Veerapen, Natacha; Besra, Gurdyal S; Porcelli, Steven A

    2014-01-16

    Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α(+) DEC-205(+) dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α(+) dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses.

  7. MiR-525-3p enhances the migration and invasion of liver cancer cells by downregulating ZNF395.

    Directory of Open Access Journals (Sweden)

    Fei Pang

    Full Text Available Liver cancer is one of leading causes of cancer-related deaths. A deeper mechanistic understanding of liver cancer could lead to the development of more effective therapeutic strategies. In our previous work, we screened 646 miRNAs and identified 11 that regulate liver cancer cell migration. The current study shows that miR-525-3p is frequently up-regulated in liver cancer tissues, and enhanced expression of miR-525-3p can promote liver cancer cell migration and invasion. Zinc finger protein 395 (ZNF395 is the direct functional target gene for miR-525-3p, and it is frequently down-regulated in liver cancer tissues. High expression of ZNF395 can significantly inhibit while knockdown of ZNF395 expression can markedly enhance the migration and invasion of liver cancer cells, suggesting that ZNF395 suppresses metastasis in liver cancer. Down-regulation of ZNF395 can mediate miR-525-3p induced liver cancer cell migration and invasion. In conclusion, miR-525-3p promotes liver cancer cell migration and invasion by directly targeting ZNF395, and the fact that miR-525-3p and ZNF395 both play important roles in liver cancer progression makes them potential therapeutic targets.

  8. Histone Deacetylase (HDAC Inhibitors Down-Regulate Endothelial Lineage Commitment of Umbilical Cord Blood Derived Endothelial Progenitor Cells

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    Horia Maniu

    2012-11-01

    Full Text Available To test the involvement of histone deacetylases (HDACs activity in endothelial lineage progression, we investigated the effects of HDAC inhibitors on endothelial progenitors cells (EPCs derived from umbilical cord blood (UCB. Adherent EPCs, that expressed the endothelial marker proteins (PCAM-1, CD105, CD133, and VEGFR2 revealed by flow cytometry were treated with three HDAC inhibitors: Butyrate (BuA, Trichostatin A (TSA, and Valproic acid (VPA. RT-PCR assay showed that HDAC inhibitors down-regulated the expression of endothelial genes such as VE-cadherin, CD133, CXCR4 and Tie-2. Furthermore, flow cytometry analysis illustrated that HDAC inhibitors selectively reduce the expression of VEGFR2, CD117, VE-cadherin, and ICAM-1, whereas the expression of CD34 and CD45 remained unchanged, demonstrating that HDAC is involved in endothelial differentiation of progenitor cells. Real-Time PCR demonstrated that TSA down-regulated telomerase activity probably via suppression of hTERT expression, suggesting that HDAC inhibitor decreased cell proliferation. Cell motility was also decreased after treatment with HDAC inhibitors as shown by wound-healing assay. The balance of acethylation/deacethylation kept in control by the activity of HAT (histone acetyltransferases/HDAC enzymes play an important role in differentiation of stem cells by regulating proliferation and endothelial lineage commitment.

  9. Targeting proliferating cell nuclear antigen and its protein interactions induces apoptosis in multiple myeloma cells.

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    Rebekka Müller

    Full Text Available Multiple myeloma is a hematological cancer that is considered incurable despite advances in treatment strategy during the last decade. Therapies targeting single pathways are unlikely to succeed due to the heterogeneous nature of the malignancy. Proliferating cell nuclear antigen (PCNA is a multifunctional protein essential for DNA replication and repair that is often overexpressed in cancer cells. Many proteins involved in the cellular stress response interact with PCNA through the five amino acid sequence AlkB homologue 2 PCNA-interacting motif (APIM. Thus inhibiting PCNA's protein interactions may be a good strategy to target multiple pathways simultaneously. We initially found that overexpression of peptides containing the APIM sequence increases the sensitivity of cancer cells to contemporary therapeutics. Here we have designed a cell-penetrating APIM-containing peptide, ATX-101, that targets PCNA and show that it has anti-myeloma activity. We found that ATX-101 induced apoptosis in multiple myeloma cell lines and primary cancer cells, while bone marrow stromal cells and primary healthy lymphocytes were much less sensitive. ATX-101-induced apoptosis was caspase-dependent and cell cycle phase-independent. ATX-101 also increased multiple myeloma cells' sensitivity against melphalan, a DNA damaging agent commonly used for treatment of multiple myeloma. In a xenograft mouse model, ATX-101 was well tolerated and increased the anti-tumor activity of melphalan. Therefore, targeting PCNA by ATX-101 may be a novel strategy in multiple myeloma treatment.

  10. HIV-1 Trans Infection of CD4+ T Cells by Professional Antigen Presenting Cells

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    Charles R. Rinaldo

    2013-01-01

    Full Text Available Since the 1990s we have known of the fascinating ability of a complex set of professional antigen presenting cells (APCs; dendritic cells, monocytes/macrophages, and B lymphocytes to mediate HIV-1 trans infection of CD4+ T cells. This results in a burst of virus replication in the T cells that is much greater than that resulting from direct, cis infection of either APC or T cells, or trans infection between T cells. Such APC-to-T cell trans infection first involves a complex set of virus subtype, attachment, entry, and replication patterns that have many similarities among APC, as well as distinct differences related to virus receptors, intracellular trafficking, and productive and nonproductive replication pathways. The end result is that HIV-1 can sequester within the APC for several days and be transmitted via membrane extensions intracellularly and extracellularly to T cells across the virologic synapse. Virus replication requires activated T cells that can develop concurrently with the events of virus transmission. Further research is essential to fill the many gaps in our understanding of these trans infection processes and their role in natural HIV-1 infection.

  11. Downregulated ECRG4 is associated with poor prognosis in renal cell cancer and is regulated by promoter DNA methylation.

    Science.gov (United States)

    Luo, Liya; Wu, Jianting; Xie, Jun; Xia, Lingling; Qian, Xuemin; Cai, Zhiming; Li, Zesong

    2016-01-01

    Esophageal cancer-related gene 4 (ECRG4) has been proposed as a putative tumor suppressor gene in several tumors. However, the role and regulation of ECRG4 in the pathogenesis of human renal cancer remain largely unknown. Our current study revealed that expression of ECRG4 is downregulated in renal cell lines and renal cancer tissues. ECRG4 expression was significantly associated with histological grade of tumors (p renal cancer patients. Silencing of ECRG4 expression in renal cell lines was associated with its promoter methylation. Moreover, ectopic expression of ECRG4 markedly inhibited cell proliferation and invasion in renal cancer cell lines. These results indicated that ECRG4 is frequently silenced by the methylation of promoter in renal cell cancers. ECRG4 may be a tumor suppressor in renal cancer and serve as a prognostic marker.

  12. The clinical value of squamous cell carcinoma antigen in cancer of the uterine cervix

    NARCIS (Netherlands)

    de Bruijn, HWA; Duk, JM; van der Zee, AGJ; Pras, E; Willemse, PHB; Hollema, H; Mourits, MJE; de Vries, EGE; Aalders, JG; Boonstra, J.

    1998-01-01

    A review is given of the clinical use and interpretation of serum tumor marker levels during the treatment of patients with cancer of the uterine cervix, Pretreatment serum squamous cell carcinoma (SCC) antigen provides a new prognostic factor in early stage squamous cell carcinoma of the uterine ce

  13. Robust and Accurate Discrimination of Self/Non-Self Antigen Presentations by Regulatory T Cell Suppression

    Science.gov (United States)

    Furusawa, Chikara; Yamaguchi, Tomoyuki

    2016-01-01

    The immune response by T cells usually discriminates self and non-self antigens, even though the negative selection of self-reactive T cells is imperfect and a certain fraction of T cells can respond to self-antigens. In this study, we construct a simple mathematical model of T cell populations to analyze how such self/non-self discrimination is possible. The results demonstrate that the control of the immune response by regulatory T cells enables a robust and accurate discrimination of self and non-self antigens, even when there is a significant overlap between the affinity distribution of T cells to self and non-self antigens. Here, the number of regulatory T cells in the system acts as a global variable controlling the T cell population dynamics. The present study provides a basis for the development of a quantitative theory for self and non-self discrimination in the immune system and a possible strategy for its experimental verification. PMID:27668873

  14. Diversification of the antigen-specific T cell receptor repertoire after varicella zoster vaccination.

    Science.gov (United States)

    Qi, Qian; Cavanagh, Mary M; Le Saux, Sabine; NamKoong, Hong; Kim, Chulwoo; Turgano, Emerson; Liu, Yi; Wang, Chen; Mackey, Sally; Swan, Gary E; Dekker, Cornelia L; Olshen, Richard A; Boyd, Scott D; Weyand, Cornelia M; Tian, Lu; Goronzy, Jörg J

    2016-03-30

    Diversity and size of the antigen-specific T cell receptor (TCR) repertoire are two critical determinants for successful control of chronic infection. Varicella zoster virus (VZV) that establishes latency during childhood can escape control mechanisms, in particular with increasing age. We examined the TCR diversity of VZV-reactive CD4 T cells in individuals older than 50 years by studying three identical twin pairs and three unrelated individuals before and after vaccination with live attenuated VZV. Although all individuals had a small number of dominant T cell clones, the breadth of the VZV-specific repertoire differed markedly. A genetic influence was seen for the sharing of individual TCR sequences from antigen-reactive cells but not for repertoire richness or the selection of dominant clones. VZV vaccination favored the expansion of infrequent VZV antigen-reactive TCRs, including those from naïve T cells with lesser boosting of dominant T cell clones. Thus, vaccination does not reinforce the in vivo selection that occurred during chronic infection but leads to a diversification of the VZV-reactive T cell repertoire. However, a single-booster immunization seems insufficient to establish new clonal dominance. Our results suggest that repertoire analysis of antigen-specific TCRs can be an important readout to assess whether a vaccination was able to generate memory cells in clonal sizes that are necessary for immune protection.

  15. T Cell Receptors that Recognize the Tyrosinase Tumor Antigen | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute, Surgery Branch, Tumor Immunology Section, is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize T Cells Attacking Cancer: T Cell Receptors that Recognize the Tyrosinase Tumor Antigen

  16. Squamous cell carcinoma antigen isoforms in serum from cervical cancer patients

    NARCIS (Netherlands)

    Roijer, E; de Bruijn, HWA; Dahlen, U; ten Hoor, K; Lundin, M; Nilsson, K; Soderstrom, K; Nilsson, O

    2006-01-01

    Squamous cell carcinoma antigen (SCCA) is a serological marker of squamous cell carcinomas (SCC). To study whether any of the SCCA isoforms would provide additional and more specific/sensitive clinical information than total SCCA, immunoassays specific for the different forms of SCCA (free SCCA2, to

  17. Discovering naturally processed antigenic determinants that confer protective T cell immunity

    DEFF Research Database (Denmark)

    Gilchuk, Pavlo; Spencer, Charles T; Conant, Stephanie B;

    2013-01-01

    CD8+ T cells (TCD8) confer protective immunity against many infectious diseases, suggesting that microbial TCD8 determinants are promising vaccine targets. Nevertheless, current T cell antigen identification approaches do not discern which epitopes drive protective immunity during active infectio...

  18. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  19. Antigen-Experienced T cells Limit the Priming of Naïve T cells During Infection with Leishmania major1

    Science.gov (United States)

    Gray, Peter M.; Reiner, Steven L.; Smith, Deborah F.; Kaye, Paul M.; Scott, Phillip

    2009-01-01

    One mechanism to control immune responses following infection is to rapidly down regulate antigen presentation, which has been observed in acute viral and bacterial infections. Here we describe experiments designed to address whether antigen presentation is decreased after an initial response to Leishmania major. Naïve α-β-Leishmania-specific (ABLE) T cell receptor transgenic T cells were adoptively transferred into mice at various times after L. major infection to determine the duration of presentation of parasite-derived antigens. ABLE T cells responded vigorously at the initiation of infection, but the ability to prime these cells quickly diminished, independent of IL-10, regulatory T cells or antigen load. However, antigen-experienced clonal and polyclonal T cell populations could respond, indicating that the diminution in naïve ABLE cell responses was not due to lack of antigen presentation. Since naïve T cell priming could be restored by removal of the endogenous T cell population, or adoptive transfer of antigen pulsed dendritic cells, it appears that T cells that have previously encountered antigen during infection compete with naïve antigen-specific T cells. These results suggest that during L. major infection antigen-experienced T cells, rather than naïve T cells, may be primarily responsible for sustaining the immune response. PMID:16818747

  20. In Vivo Targeting of Antigens to Maturing Dendritic Cells via the DEC-205 Receptor Improves T Cell Vaccination

    Science.gov (United States)

    Bonifaz, Laura C.; Bonnyay, David P.; Charalambous, Anna; Darguste, Dara I.; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K.; Moltedo, Bruno; Moran, Thomas M.; Steinman, Ralph M.

    2004-01-01

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell–mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models. PMID:15024047

  1. Viral vector-mediated downregulation of RhoA increases survival and axonal regeneration of retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Jan Christoph Koch

    2014-09-01

    Full Text Available The Rho/ROCK pathway is a promising therapeutic target in neurodegenerative and neurotraumatic diseases. Pharmacological inhibition of various pathway members has been shown to promote neuronal regeneration and survival. However, because pharmacological inhibitors are inherently limited in their specificity, shRNA-mediated approaches can add more information on the function of each single kinase involved. Thus, we generated adeno-associated viral vectors (AAV to specifically downregulate RhoA via shRNA. We found that specific knockdown of RhoA promoted neurite outgrowth of retinal ganglion cells (RGC grown on the inhibitory substrate CSPG as well as neurite regeneration of primary midbrain neurons after scratch lesion. In the rat optic nerve crush model in vivo, downregulation of RhoA significantly enhanced axonal regeneration compared to control. Moreover, survival of RGCs transduced with AAV expressing RhoA-shRNA was substantially increased at two weeks after optic nerve axotomy.Compared to previous data using pharmacological inhibitors to target RhoA, its upstream regulator Nogo or its main downstream target ROCK2, the specific effects of RhoA downregulation shown here were more pronounced in regard to promoting RGC survival while the stimulatory effects on neurite outgrowth were rather moderate. Taken together, we show here that specific knockdown of RhoA substantially increases neuronal survival after optic nerve axotomy and modestly increases neurite outgrowth in vitro and axonal regeneration after optic nerve crush.

  2. Isolation and characterization of antigen-Ia complexes involved in T cell recognition

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M

    1986-01-01

    Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes, it is he......Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes...... with glutaraldehyde revealed that the ovalbumin peptide was cross-linked solely to the alpha chain of I-Ad. Planar membranes containing I-Ad-OVA complexes stimulated a T cell response with 2 X 10(4) less antigen than required when uncomplexed antigen was used, thus demonstrating the biologic importance...

  3. miR-382-5p Controls Hematopoietic Stem Cell Differentiation Through the Downregulation of MXD1.

    Science.gov (United States)

    Zini, Roberta; Rossi, Chiara; Norfo, Ruggiero; Pennucci, Valentina; Barbieri, Greta; Ruberti, Samantha; Rontauroli, Sebastiano; Salati, Simona; Bianchi, Elisa; Manfredini, Rossella

    2016-10-01

    microRNAs are key regulators of gene expression that control stem cell fate by posttranscriptional downregulation of hundreds of target genes through seed pairing in their 3' untranslated region. In fact, miRNAs tightly regulate fundamental stem cell processes, like self-renewal, proliferation, and differentiation; therefore, miRNA deregulation may contribute to the development of solid tumors and hematological malignancies. miR-382-5p has been found to be upregulated in patients with myeloid neoplasms, but its role in normal hematopoiesis is still unknown. In this study, we demonstrated that miR-382-5p overexpression in CD34(+) hematopoietic stem/progenitor cells (HSPCs) leads to a significant decrease of megakaryocyte precursors coupled to increase of granulocyte ones. Furthermore, by means of a computational analysis using different prediction algorithms, we identified several putative mRNA targets of miR-382-5p that are downregulated upon miRNA overexpression (ie, FLI1, GATA2, MAF, MXD1, RUNX1, and SGK1). Among these, we validated MXD1 as real target of miR-382-5p by luciferase reporter assay. Finally, we showed that MXD1 knockdown mimics the effects of miR-382-5p overexpression on granulocyte and megakaryocyte differentiation of CD34(+) cells. Overall, our results demonstrated that miR-382-5p expression favors the expansion of granulocyte lineage and impairs megakaryocyte commitment through MXD1 downregulation. Therefore, our data showed for the first time that the miR-382-5p/MXD1 axis plays a critical role in myelopoiesis by affecting the lineage choice of CD34(+) HSPCs.

  4. Vesnarinone downregulates CXCR4 expression via upregulation of Krüppel-like factor 2 in oral cancer cells

    Directory of Open Access Journals (Sweden)

    Uchida Daisuke

    2009-08-01

    Full Text Available Abstract Background We have demonstrated that the stromal cell-derived factor-1 (SDF-1; CXCL12/CXCR4 system is involved in the establishment of lymph node metastasis in oral squamous cell carcinoma (SCC. Chemotherapy is a powerful tool for the treatment of oral cancer, including oral SCC; however, the effects of chemotherapeutic agents on the expression of CXCR4 are unknown. In this study, we examined the expression of CXCR4 associated with the chemotherapeutic agents in oral cancer cells. Results The expression of CXCR4 was examined using 3 different chemotherapeutic agents; 5-fluorouracil, cisplatin, and vesnarinone (3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl-1-piperazinyl]-2-(1H-quinolinone in B88, a line of oral cancer cells that exhibits high levels of CXCR4 and lymph node metastatic potential. Of the 3 chemotherapeutic agents that we examined, only vesnarinone downregulated the expression of CXCR4 at the mRNA as well as the protein level. Vesnarinone significantly inhibited lymph node metastasis in tumor-bearing nude mice. Moreover, vesnarinone markedly inhibited 2.7-kb human CXCR4 promoter activity, and we identified the transcription factor, Krüppel-like factor 2 (KLF2, as a novel vesnarinone-responsive molecule, which was bound to the CXCR4 promoter at positions -300 to -167 relative to the transcription start site. The forced-expression of KLF2 led to the downregulation of CXCR4 mRNA and impaired CXCR4 promoter activity. The use of siRNA against KLF2 led to an upregulation of CXCR4 mRNA. Conclusion These Results indicate that vesnarinone downregulates CXCR4 via the upregulation of KLF2 in oral cancer.

  5. Long-term in vivo provision of antigen-specific T cell immunity by programming hematopoietic stem cells

    Science.gov (United States)

    Yang, Lili; Baltimore, David

    2005-03-01

    A method to genetically program mouse hematopoietic stem cells to develop into functional CD8 or CD4 T cells of defined specificity in vivo is described. For this purpose, a bicistronic retroviral vector was engineered that efficiently delivers genes for both and chains of T cell receptor (TCR) to hematopoietic stem cells. When modified cell populations were used to reconstruct the hematopoietic lineages of recipient mice, significant percentages of antigen-specific CD8 or CD4 T cells were observed. These cells expressed normal surface markers and responded to peptide antigen stimulation by proliferation and cytokine production. Moreover, they could mature into memory cells after peptide stimulation. Using TCRs specific for a model tumor antigen, we found that the recipient mice were able to partially resist a challenge with tumor cells carrying the antigen. By combining cells modified with CD8- and CD4-specific TCRs, and boosting with dendritic cells pulsed with cognate peptides, complete suppression of tumor could be achieved and even tumors that had become established would regress and be eliminated after dendritic cell/peptide immunization. This methodology of "instructive immunotherapy" could be developed for controlling the growth of human tumors and attacking established pathogens.

  6. Antigen-engaged B cells undergo chemotaxis toward the T zone and form motile conjugates with helper T cells.

    Directory of Open Access Journals (Sweden)

    Takaharu Okada

    2005-06-01

    Full Text Available Interactions between B and T cells are essential for most antibody responses, but the dynamics of these interactions are poorly understood. By two-photon microscopy of intact lymph nodes, we show that upon exposure to antigen, B cells migrate with directional preference toward the B-zone-T-zone boundary in a CCR7-dependent manner, through a region that exhibits a CCR7-ligand gradient. Initially the B cells show reduced motility, but after 1 d, motility is increased to approximately 9 microm/min. Antigen-engaged B cells pair with antigen-specific helper T cells for 10 to more than 60 min, whereas non-antigen-specific interactions last less than 10 min. B cell-T cell conjugates are highly dynamic and migrate extensively, being led by B cells. B cells occasionally contact more than one T cell, whereas T cells are strictly monogamous in their interactions. These findings provide evidence of lymphocyte chemotaxis in vivo, and they begin to define the spatiotemporal cellular dynamics associated with T cell-dependent antibody responses.

  7. Expression of I-A and I-E,C region-coded Ia antigens on functional B cell subpopulations.

    Science.gov (United States)

    Frelinger, J A; Hibbler, F J; Hill, S W

    1978-12-01

    Ia antigens from specific subregions have been examined on functional B cell populations. Expression of both I-A and I-E,C region antigens was demonstrated on cells required for both lipopolysaccharide mitogenesis and polyclonal activation. Similar I-A and I-E,C subregion expression was found on cells required for response to the T-independent antigen, polyvinylpyrrolidone. TNP-specific IgM and hen egg lysozyme-specific IgG plaque-forming cells also express I-A and I-E,C region antigens. No evidence was found for an Ia- population responsive in the systems tested. Further, no evidence of preferential expression of I-A or I-E,C region antigens was observed in any system examined. Therefore, it appears that B cells express both I-A and I-E,C region-coded Ia antigens.

  8. Signal transduction and downregulation of C-MET in HGF stimulated low and highly metastatic human osteosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Husmann, Knut, E-mail: khusmann@research.balgrist.ch [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Ducommun, Pascal [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Division of Plastic Surgery and Hand Surgery, Department of Surgery, University Hospital Zurich, Zurich (Switzerland); Sabile, Adam A.; Pedersen, Else-Marie; Born, Walter; Fuchs, Bruno [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland)

    2015-09-04

    The poor outcome of osteosarcoma (OS), particularly in patients with metastatic disease and a five-year survival rate of only 20%, asks for more effective therapeutic strategies targeting malignancy-promoting mechanisms. Dysregulation of C-MET, its ligand hepatocyte growth factor (HGF) and the fusion oncogene product TPR-MET, first identified in human MNNG-HOS OS cells, have been described as cancer-causing factors in human cancers. Here, the expression of these molecules at the mRNA and the protein level and of HGF-stimulated signaling and downregulation of C-MET was compared in the parental low metastatic HOS and MG63 cell lines and the respective highly metastatic MNNG-HOS and 143B and the MG63-M6 and MG63-M8 sublines. Interestingly, expression of TPR-MET was only observed in MNNG-HOS cells. HGF stimulated the phosphorylation of Akt and Erk1/2 in all cell lines investigated, but phospho-Stat3 remained at basal levels. Downregulation of HGF-stimulated Akt and Erk1/2 phosphorylation was much faster in the HGF expressing MG63-M8 cells than in HOS cells. Degradation of HGF-activated C-MET occurred predominantly through the proteasomal and to a lesser extent the lysosomal pathway in the cell lines investigated. Thus, HGF-stimulated Akt and Erk1/2 signaling as well as proteasomal degradation of HGF activated C-MET are potential therapeutic targets in OS. - Highlights: • Expression of TPR-MET was only observed in MNNG-HOS cells. • HGF stimulated the phosphorylation of Akt and Erk1/2 but not of Stat3 in osteosarcoma cell lines. • Degradation of HGF-activated C-MET occurred predominantly through the proteasomal pathway.

  9. Manufacture of clinical-grade CD19-specific T cells stably expressing chimeric antigen receptor using Sleeping Beauty system and artificial antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Harjeet Singh

    Full Text Available Adoptive transfer of T cells expressing a CD19-specific chimeric antigen receptor (CAR is being evaluated in multiple clinical trials. Our current approach to adoptive immunotherapy is based on a second generation CAR (designated CD19RCD28 that signals through a CD28 and CD3-ζ endodomain. T cells are electroporated with DNA plasmids from the Sleeping Beauty (SB transposon/transposase system to express this CAR. Stable integrants of genetically modified T cells can then be retrieved when co-cultured with designer artificial antigen presenting cells (aAPC in the presence of interleukin (IL-2 and 21. Here, we reveal how the platform technologies of SB-mediated transposition and CAR-dependent propagation on aAPC were adapted for human application. Indeed, we have initiated clinical trials in patients with high-risk B-lineage malignancies undergoing autologous and allogeneic hematopoietic stem-cell transplantation (HSCT. We describe the process to manufacture clinical grade CD19-specific T cells derived from healthy donors. Three validation runs were completed in compliance with current good manufacturing practice for Phase I/II trials demonstrating that by 28 days of co-culture on γ-irradiated aAPC ∼10(10 T cells were produced of which >95% expressed CAR. These genetically modified and propagated T cells met all quality control testing and release criteria in support of infusion.

  10. The impact of T cell intrinsic antigen adaptation on peripheral immune tolerance.

    Directory of Open Access Journals (Sweden)

    Nevil J Singh

    2006-10-01

    Full Text Available Overlapping roles have been ascribed for T cell anergy, clonal deletion, and regulation in the maintenance of peripheral immunological tolerance. A measurement of the individual and additive impacts of each of these processes on systemic tolerance is often lacking. In this report we have used adoptive transfer strategies to tease out the unique contribution of T cell intrinsic receptor calibration (adaptation in the maintenance of tolerance to a systemic self-antigen. Adoptively transferred naïve T cells stably calibrated their responsiveness to a persistent self-antigen in both lymphopenic and T cell-replete hosts. In the former, this state was not accompanied by deletion or suppression, allowing us to examine the unique contribution of adaptation to systemic tolerance. Surprisingly, adapting T cells could chronically help antigen-expressing B cells, leading to polyclonal hypergammaglobulinemia and pathology, in the form of mild arthritis. The helper activity mediated by CD40L and cytokines was evident even if the B cells were introduced after extended adaptation of the T cells. In contrast, in the T cell-replete host, neither arthritis nor autoantibodies were induced. The containment of systemic pathology required host T cell-mediated extrinsic regulatory mechanisms to synergize with the cell intrinsic adaptation process. These extrinsic mechanisms prevented the effector differentiation of the autoreactive T cells and reduced their precursor frequency, in vivo.

  11. SIV antigen immunization induces transient antigen-specific T cell responses and selectively activates viral replication in draining lymph nodes in retroviral suppressed rhesus macaques

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    Barry Peter A

    2011-07-01

    Full Text Available Abstract Background HIV infection causes a qualitative and quantitative loss of CD4+ T cell immunity. The institution of anti-retroviral therapy (ART restores CD4+ T cell responses to many pathogens, but HIV-specific responses remain deficient. Similarly, therapeutic immunization with HIV antigens of chronically infected, ART treated subjects results in poor induction of HIV-specific CD4 responses. In this study, we used a macaque model of ART treatment during chronic infection to study the virologic consequences of SIV antigen stimulation in lymph nodes early after immunization. Rhesus CMV (RhCMV seropositive, Mamu A*01 positive rhesus macaques were chronically infected with SIVmac251 and treated with ART. The immune and viral responses to SIV gag and RhCMV pp65 antigen immunization in draining lymph nodes and peripheral blood were analyzed. Animals were immunized on contralateral sides with SIV gag and RhCMV pp65 encoding plasmids, which allowed lymph nodes draining each antigen to be obtained at the same time from the same animal for direct comparison. Results We observed that both SIV and RhCMV immunizations stimulated transient antigen-specific T cell responses in draining lymph nodes. The RhCMV-specific responses were potent and sustained (50 days post-immunization in the periphery, while the SIV-specific responses were transient and extinguished quickly. The SIV antigen stimulation selectively induced transient SIV replication in draining lymph nodes. Conclusions The data are consistent with a model whereby viral replication in response to SIV antigen stimulation limits the generation of SIV antigen-specific responses and suggests a potential mechanism for the early loss and poor HIV-specific CD4+ T cell response observed in HIV-infected individuals.

  12. HCA520, A NOVEL TUMOR ASSOCIATED ANTIGEN, INVOLVED IN CELL PROLIFERATION AND APOPTOSIS

    Institute of Scientific and Technical Information of China (English)

    杨美香; 曲迅; 刘福利; 郑广娟

    2003-01-01

    Objective: Tumor associated antigen encoding gene HCA520 (AF146019) was identified by screening a human hepatocellular carcinoma expressing cDNA library using SEREX technique. In this experiment we studied the effect of HCA520 on cell proliferation and apoptosis. Methods: Gene HCA520 was gained by PCR and transfected into 293 cells. The stable expression cells were obtained by G418 selection. The cell proliferation was measured by [3H]-TdR uptake and apoptosis assay was measured by FACS. Results: Eukaryotic expression plasmid pcDNA3-HCA520 was constructed and its stable transfectants were obtained. Overexpression of HCA520 inhibited the cell proliferation and enhanced cell apoptosis after serum deprivation. Conclusion: HCA520 is a novel tumor associated antigen that can affect cell proliferation and apoptosis.

  13. The perivascular phagocyte of the mouse pineal gland: An antigen-presenting cell

    DEFF Research Database (Denmark)

    Møller, Morten; Rath, Martin F; Klein, David C

    2006-01-01

    The perivascular space of the rat pineal gland is known to contain phagocytic cells that are immunoreactive for leukocyte antigens, and thus they appear to belong to the macrophage/microglial cell line. These cells also contain MHC class II proteins. We investigated this cell type in the pineal...... gland of mice. Actively phagocytosing cells with a prominent lysosomal system were found in the pericapillary spaces of the mouse pineal gland following intravenous injection of horseradish peroxidase. The cells also exhibited strong acid phosphatase activity. Perivascular cells were immunopositive...... for MHC class II protein and for CD68, a marker of monocytes/phagocytes. This study verifies that perivascular phagocytes with antigen-presenting properties are present in the mouse pineal gland....

  14. Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses.

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    Shayla K Shorter

    Full Text Available T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL, have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4 are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant.

  15. Downregulation of retinoic acid receptor-β2expression is linked to aberrant methylation in esophageal squamous cell carcinoma cell lines

    Institute of Scientific and Technical Information of China (English)

    Zhong-Min Liu; Fang Ding; Ming-Zhou Guo; Li-Yong Zhang; Min Wu; Zhi-Hua Liu

    2004-01-01

    AIM: To study the role of hypermethylation in the loss ofretinoic acid receptorβ2(RARβ2) in esophageal squamous cell carcinoma (ESCC).METHODS: The role of hypermethylation in RAR,β2 gene silencing in 6 ESCC cell lines was determined by methylationspecific PCR (MSP), and its methylation status was compared with RARβ2 mRNA expression by RT-PCR. The MSP results were confirmed by bisulfite sequencing of RARβ2promoter regions. RESULTS: Methylation was detected in 4 of the 6 cell lines, and the expression of RARβ2was markedly downregulated in 3 of the 4 methylated cell lines. The expression of RARβ2was restored in one RARβ2-downregulated cell line with the partial demethylation of promoter region of RARβ after 5aza-2'-deoxycytidine (5-aza-dc) treatment.CONCLUSION: The methylation of the 5' region may play an important role in the downregulation of RARβ2 in someESCC cell lines, suggesting that multiple mechanisms contribute to the loss of RARβ2expression in ESCC cell lines. This study may have clinical applications for treatment and prevention of ESCC.

  16. Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

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    Benencia Fabian

    2008-04-01

    Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

  17. Pathway-selective suppression of chemokine receptor signaling in B cells by LPS through downregulation of PLC-β2.

    Science.gov (United States)

    Shirakawa, Aiko-Konno; Liao, Fang; Zhang, Hongwei H; Hedrick, Michael N; Singh, Satya P; Wu, Dianqing; Farber, Joshua M

    2010-11-01

    Lymphocyte activation leads to changes in chemokine receptor expression. There are limited data, however, on how lymphocyte activators can alter chemokine signaling by affecting downstream pathways. We hypothesized that B cell-activating agents might alter chemokine responses by affecting downstream signal transducers, and that such effects might differ depending on the activator. We found that activating mouse B cells using either anti-IgM or lipopolysaccharide (LPS) increased the surface expression of CCR6 and CCR7 with large increases in chemotaxis to their cognate ligands. By contrast, while anti-IgM also led to enhanced calcium responses, LPS-treated cells showed only small changes in calcium signaling as compared with cells that were freshly isolated. Of particular interest, we found that LPS caused a reduction in the level of B-cell phospholipase C (PLC)-β2 mRNA and protein. Data obtained using PLC-β2(-/-) mice showed that the β2 isoform mediates close to one-half the chemokine-induced calcium signal in resting and anti-IgM-activated B cells, and we found that calcium signals in the LPS-treated cells were boosted by increasing the level of PLC-β2 using transfection, consistent with a functional effect of downregulating PLC-β2. Together, our results show activator-specific effects on responses through B-cell chemokine receptors that are mediated by quantitative changes in a downstream signal-transducing protein, revealing an activity for LPS as a downregulator of PLC-β2, and a novel mechanism for controlling chemokine-induced signals in lymphocytes.

  18. Limited transplantation of antigen-expressing hematopoietic stem cells induces long-lasting cytotoxic T cell responses.

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    Warren L Denning

    Full Text Available Harnessing the ability of cytotoxic T lymphocytes (CTLs to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4-6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8+ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS.

  19. Molecular characterization of antigen-peptide pulsed dendritic cells: immature dendritic cells develop a distinct molecular profile when pulsed with antigen peptide.

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    Amy X Yang

    Full Text Available As dendritic cells (DCs are the most potent professional antigen-presenting cells, they are being tested as cancer vaccines for immunotherapy of established cancers. Although numerous studies have characterized DCs by their phenotype and function, few have identified potential molecular markers of antigen presentation prior to vaccination of host. In this study we generated pre-immature DC (piDC, immature DC (iDC, and mature DC (mDC from human peripheral blood monocytes (PBMC obtained from HLA-A2 healthy donors, and pulsed them with human papillomavirus E7 peptide (p11-20, a class I HLA-A2 binding antigen. We then characterized DCs for cell surface phenotype and gene expression profile by microarray technology. We identified a set of 59 genes that distinguished three differentiation stages of DCs (piDC, iDC and mDC. When piDC, iDC and mDC were pulsed with E7 peptide for 2 hrs, the surface phenotype did not change, however, iDCs rather than mDCs showed transcriptional response by up-regulation of a set of genes. A total of 52 genes were modulated in iDC upon antigen pulsing. Elongation of pulse time for iDCs to 10 and 24 hrs did not significantly bring further changes in gene expression. The E7 peptide up-modulated immune response (KPNA7, IGSF6, NCR3, TREM2, TUBAL3, IL8, NFKBIA, pro-apoptosis (BTG1, SEMA6A, IGFBP3 and SRGN, anti-apoptosis (NFKBIA, DNA repair (MRPS11, RAD21, TXNRD1, and cell adhesion and cell migration genes (EPHA1, PGF, IL8 and CYR61 in iDCs. We confirmed our results by Q-PCR analysis. The E7 peptide but not control peptide (PADRE induced up-regulation of NFKB1A gene only in HLA-A2 positive iDCs and not in HLA-A2 negative iDCs. These results suggest that E7 up-regulation of genes is specific and HLA restricted and that these genes may represent markers of antigen presentation and help rapidly assess the quality of dendritic cells prior to administration to the host.

  20. Cord Blood Derived CD4+CD25high T Cells Become Functional Regulatory T Cells upon Antigen Encounter

    Science.gov (United States)

    Mayer, Elisabeth; Bannert, Christina; Gruber, Saskia; Klunker, Sven; Spittler, Andreas; Akdis, Cezmi A.

    2012-01-01

    Background: Upon antigen exposure, cord blood derived T cells respond to ubiquitous environmental antigens by high proliferation. To date it remains unclear whether these “excessive” responses relate to different regulatory properties of the putative T regulatory cell (Treg) compartment or even expansion of the Treg compartment itself. Methods: Cord blood (>37 week of gestation) and peripheral blood (healthy controls) were obtained and different Treg cell subsets were isolated. The suppressive potential of Treg populations after antigen exposure was evaluated via functional inhibition assays ([3H]thymidine incorporation assay and CFSE staining) with or without allergen stimulation. The frequency and markers of CD4+CD25highFoxP3+ T cells were characterized by mRNA analysis and flow cytometry. Results: Cord blood derived CD4+CD25high cells did not show substantial suppressor capacity upon TCR activation, in contrast to CD4+CD25high cells freshly purified from adult blood. This could not be explained by a lower frequency of FoxP3+CD4+CD25highcells or FOXP3 mRNA expression. However, after antigen-specific stimulation in vitro, these cells showed strong proliferation and expansion and gained potent suppressive properties. The efficiency of their suppressive capacity can be enhanced in the presence of endotoxins. If T-cells were sorted according to their CD127 expression, a tiny subset of Treg cells (CD4+CD25+CD127low) is highly suppressive even without prior antigen exposure. Conclusion: Cord blood harbors a very small subset of CD4+CD25high Treg cells that requires antigen-stimulation to show expansion and become functional suppressive Tregs. PMID:22272233

  1. The peripheral blood fibrocyte is a potent antigen-presenting cell capable of priming naive T cells in situ.

    Science.gov (United States)

    Chesney, J; Bacher, M; Bender, A; Bucala, R

    1997-06-10

    Recent studies have identified a novel population of blood-borne cells, termed fibrocytes, that have a distinct cell surface phenotype (collagen+/CD13(+)/CD34(+)/CD45(+)), rapidly enter sites of tissue injury, and synthesize connective tissue matrix molecules. We found by flow cytometry that purified human fibrocytes express each of the known surface components that are required for antigen presentation, including class II major histocompatability complex molecules (HLA-DP, -DQ, and -DR), the costimulatory molecules CD80 and CD86, and the adhesion molecules CD11a, CD54, and CD58. Human fibrocytes induced antigen-presenting cell-dependent T cell proliferation when cultured with specific antigen and this proliferative activity was significantly higher than that induced by monocytes and nearly as high as that induced by purified dendritic cells. Mouse fibrocytes also were found to express the surface components required for antigen presentation and to function as potent APCs in vitro. Mouse fibrocytes pulsed in vitro with the HIV-proteins p24 or gp120 and delivered to a site of cutaneous injury were found to migrate to proximal lymph nodes and to specifically prime naive T cells. These data suggest that fibrocytes play an early and important role in the initiation of antigen-specific immunity.

  2. Cathepsin B in antigen-presenting cells controls mediators of the Th1 immune response during Leishmania major infection.

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    Iris J Gonzalez-Leal

    2014-09-01

    Full Text Available Resistance and susceptibility to Leishmania major infection in the murine model is determined by the capacity of the host to mount either a protective Th1 response or a Th2 response associated with disease progression. Previous reports involving the use of cysteine cathepsin inhibitors indicated that cathepsins B (Ctsb and L (Ctsl play important roles in Th1/Th2 polarization during L. major infection in both susceptible and resistant mouse strains. Although it was hypothesized that these effects are a consequence of differential patterns of antigen processing, the mechanisms underlying these differences were not further investigated. Given the pivotal roles that dendritic cells and macrophages play during Leishmania infection, we generated bone-marrow derived dendritic cells (BMDC and macrophages (BMM from Ctsb-/- and Ctsl-/- mice, and studied the effects of Ctsb and Ctsl deficiency on the survival of L. major in infected cells. Furthermore, the signals used by dendritic cells to instruct Th cell polarization were addressed: the expression of MHC class II and co-stimulatory molecules, and cytokine production. We found that Ctsb-/- BMDC express higher levels of MHC class II molecules than wild-type (WT and Ctsl-/- BMDC, while there were no significant differences in the expression of co-stimulatory molecules between cathepsin-deficient and WT cells. Moreover, both BMDC and BMM from Ctsb-/- mice significantly up-regulated the levels of interleukin 12 (IL-12 expression, a key Th1-inducing cytokine. These findings indicate that Ctsb-/- BMDC display more pro-Th1 properties than their WT and Ctsl-/- counterparts, and therefore suggest that Ctsb down-regulates the Th1 response to L. major. Moreover, they propose a novel role for Ctsb as a regulator of cytokine expression.

  3. Cathepsin B in antigen-presenting cells controls mediators of the Th1 immune response during Leishmania major infection.

    Science.gov (United States)

    Gonzalez-Leal, Iris J; Röger, Bianca; Schwarz, Angela; Schirmeister, Tanja; Reinheckel, Thomas; Lutz, Manfred B; Moll, Heidrun

    2014-09-01

    Resistance and susceptibility to Leishmania major infection in the murine model is determined by the capacity of the host to mount either a protective Th1 response or a Th2 response associated with disease progression. Previous reports involving the use of cysteine cathepsin inhibitors indicated that cathepsins B (Ctsb) and L (Ctsl) play important roles in Th1/Th2 polarization during L. major infection in both susceptible and resistant mouse strains. Although it was hypothesized that these effects are a consequence of differential patterns of antigen processing, the mechanisms underlying these differences were not further investigated. Given the pivotal roles that dendritic cells and macrophages play during Leishmania infection, we generated bone-marrow derived dendritic cells (BMDC) and macrophages (BMM) from Ctsb-/- and Ctsl-/- mice, and studied the effects of Ctsb and Ctsl deficiency on the survival of L. major in infected cells. Furthermore, the signals used by dendritic cells to instruct Th cell polarization were addressed: the expression of MHC class II and co-stimulatory molecules, and cytokine production. We found that Ctsb-/- BMDC express higher levels of MHC class II molecules than wild-type (WT) and Ctsl-/- BMDC, while there were no significant differences in the expression of co-stimulatory molecules between cathepsin-deficient and WT cells. Moreover, both BMDC and BMM from Ctsb-/- mice significantly up-regulated the levels of interleukin 12 (IL-12) expression, a key Th1-inducing cytokine. These findings indicate that Ctsb-/- BMDC display more pro-Th1 properties than their WT and Ctsl-/- counterparts, and therefore suggest that Ctsb down-regulates the Th1 response to L. major. Moreover, they propose a novel role for Ctsb as a regulator of cytokine expression.

  4. Antibodies to new beta cell antigen ICA12 in Latvian diabetes patients.

    Science.gov (United States)

    Shtauvere-Brameus, A; Hagopian, W; Rumba, I; Sanjeevi, C B

    2002-04-01

    In Latvia diabetes mellitus is diagnosed using the WHO's clinical criteria, and assays for the detection of autoantibodies are not available. In consequence, slowly progressive autoimmune diabetes or LADA is likely to be missed. Antibodies to GAD65 and IA-2 are the major immunological markers in autoimmune diabetes. Recently, a new beta cell antigen, called ICA12, has been identified, which has a homology to the SOX family of transcription factors. The aim of the study was to analyze the prevalence of ICA12 antibodies in diabetes mellitus patients and controls from Latvia and to see whether this antigen is important in revealing autoimmunity when antibodies against major antigens are not present. We studied 88 IDDM patients and 100 NIDDM patients as well as controls for the prevalence of GAD65, IA-2, and ICA12 antibodies by radioligand binding assay (RIA) using (35)S-labeled islet antigens. We found ICA12Abs in 26 of 88 IDDM patients (30%) vs. 4% in healthy controls (4/100) and in 9 of 100 NIDDM patients (9%) vs. 2% controls (2/100). ICA12Abs alone are present in only 3% (3/88) of the patients with IDDM and 1% (1/100) of the NIDDM patients. We conclude that ICA12 represents the minor antigens in autoimmune diabetes and that, as a minor antigen, ICA12 alone does not contribute significantly in revealing new cases of autoimmunity.

  5. Triptolide inhibits the proliferation of prostate cancer cells and down-regulates SUMO-specific protease 1 expression.

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    Weiwei Huang

    Full Text Available Recently, traditional Chinese medicine and medicinal herbs have attracted more attentions worldwide for its anti-tumor efficacy. Celastrol and Triptolide, two active components extracted from the Chinese herb Tripterygium wilfordii Hook F (known as Lei Gong Teng or Thunder of God Vine, have shown anti-tumor effects. Celastrol was identified as a natural 26 s proteasome inhibitor which promotes cell apoptosis and inhibits tumor growth. The effect and mechanism of Triptolide on prostate cancer (PCa is not well studied. Here we demonstrated that Triptolide, more potent than Celastrol, inhibited cell growth and induced cell death in LNCaP and PC-3 cell lines. Triptolide also significantly inhibited the xenografted PC-3 tumor growth in nude mice. Moreover, Triptolide induced PCa cell apoptosis through caspases activation and PARP cleavage. Unbalance between SUMOylation and deSUMOylation was reported to play an important role in PCa progression. SUMO-specific protease 1 (SENP1 was thought to be a potential marker and therapeutical target of PCa. Importantly, we observed that Triptolide down-regulated SENP1 expression in both mRNA and protein levels in dose-dependent and time-dependent manners, resulting in an enhanced cellular SUMOylation in PCa cells. Meanwhile, Triptolide decreased AR and c-Jun expression at similar manners, and suppressed AR and c-Jun transcription activity. Furthermore, knockdown or ectopic SENP1, c-Jun and AR expression in PCa cells inhibited the Triptolide anti-PCa effects. Taken together, our data suggest that Triptolide is a natural compound with potential therapeutic value for PCa. Its anti-tumor activity may be attributed to mechanisms involving down-regulation of SENP1 that restores SUMOylation and deSUMOyaltion balance and negative regulation of AR and c-Jun expression that inhibits the AR and c-Jun mediated transcription in PCa.

  6. Downregulation of Epidermal Growth Factor Receptor Expression Contributes to α-TEA's Proapoptotic Effects in Human Ovarian Cancer Cell Lines

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    Ming-Chieh Shun

    2010-01-01

    Full Text Available RRR-α-tocopherol derivative α-TEA (RRR-α-tocopherol ether-linked acetic acid analog has been shown to be a potent antitumor agent both in vivo and in vitro. In this study, we investigated the effects of α-TEA on the expression of epidermal growth factor receptor (EGFR family members, ErbB1, 2 and 3, and the role of ErbB 2 and 3 in α-TEA-induced apoptosis and suppression of Akt, FLIP and survivin in the cisplatin-sensitive (A2780S and -resistant (A2780/CP70R human ovarian cancer cell lines. Data show that α-TEA's ability to induced apoptosis was associated with reduced expression of ErbB1 (cisplatin-resistant cells, 2 and 3 (both cell types and reduced levels of the phosphorylated (active form of Akt; as well as, reduced levels of FLIP and survivin proteins in both cell types. Ectopic overexpression and siRNA knockdown studies showed that ErbB2, ErbB3, Akt, FLIP and survivin are involved in α-TEA-induce apoptosis and that α-TEA downregulates FLIP and survivin via suppression of pAkt, which is mediated by ErbB2 and ErB3. Thus, α-TEA is a potent pro-apoptotic agent for both cisplatin-sensitive and -resistant ovarian cancer cell lines in cell culture and it produces cell death, at least in part, by downregulation of members of the EGFR family.

  7. Down-regulation of malignant potential by alpha linolenic acid in human and mouse colon cancer cells.

    Science.gov (United States)

    Chamberland, John P; Moon, Hyun-Seuk

    2015-03-01

    Omega-3 fatty acids (also called ω-3 fatty acis or n-3 fatty acid) are polyunsaturated fatty acids (PUFAs) with a double bond (C=C) at the third carbon atom from the end of the carbon chain. Numerous test tube and animal studies have shown that omega-3 fatty acids may prevent or inhibit the growth of cancers, suggesting that omega-3 fatty acids are important in cancer physiology. Alpha-linolenic acid (ALA) is one of an essential omega-3 fatty acid and organic compound found in seeds (chia and flaxseed), nuts (notably walnuts), and many common vegetable oils. ALA has also been shown to down-regulate cell proliferation of prostate, breast, and bladder cancer cells. However, direct evidence that ALA suppresses to the development of colon cancer has not been studied. Also, no previous studies have evaluated whether ALA may regulate malignant potential (adhesion, invasion and colony formation) in colon cancer cells. In order to address the questions above, we conducted in vitro studies and evaluated whether ALA may down-regulate malignant potential in human (HT29 and HCT116) and mouse (MCA38) colon cancer cell lines. We observed that treatment with 1-5 mM of ALA inhibits cell proliferation, adhesion and invasion in both human and mouse colon cancer cell lines. Interestingly, we observed that ALA did not decrease total colony numbers when compared to control. By contrast, we found that size of colony was significantly changed by ALA treatment when compared to control in all colon cancer cell lines. We suggest that our data enhance our current knowledge of ALA's mechanism and provide crucial information to further the development of new therapies for the management or chemoprevention of colon cancer.

  8. Thymosin beta-4 knockdown in IEC-6 normal intestinal epithelial cells induces DNA re-replication via downregulating Emi1.

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    Chao, Ta-Chung; Chen, Ke-Jay; Tang, Mei-Chuan; Chan, Li-Chuan; Chen, Po-Min; Tzeng, Cheng-Hwai; Su, Yeu

    2014-11-01

    Thymosin β4 (Tβ4 ) is a multifunctional protein already used clinically to treat various diseases; however, the promoting effect of this protein on tumor malignancy should not be neglected. Here, we assessed whether Tβ4 alteration influences normal intestinal epithelial cells because Tβ4 is deemed a novel target for treating colorectal cancer (CRC). For this purpose, we examined the consequences of shRNA-mediated knockdown of Tβ4 in IEC-6 normal rat small intestinal cells and found that inhibiting Tβ4 expression significantly suppressed their growth and induced apoptosis in some cells. Flow cytometric analysis further revealed a marked decrease of G0/G1 population but a drastic increase of polyploid ones in these cells. The increase of polyploidy likely resulted from DNA re-replication because not only the de novo DNA synthesis was greatly increased but also the expression levels of Cdc6 (a replication-licensing factor), cyclin A, and phosphorylated-checkpoint kinase 1 were all dramatically elevated. Moreover, marked reductions in both RNA and protein levels of Emi1 (early mitotic inhibitor 1) were also detected in Tβ4 -downregulated IEC-6 cells which might be accounted by the downregulation of E2F1, a transcription factor capable of inducing Emi1 expression, mediated by glycogen synthase-3β (GSK-3β). To our best knowledge, this is the first report showing that inhibiting Tβ4 expression triggers DNA re-replication in normal intestinal epithelial cells, suggesting that this G-actin sequester may play a crucial role in maintaining genome stability in these cells. More importantly, clinical oncologists should take this novel activity into consideration when design CRC therapy based on targeting Tβ4 .

  9. Downregulation of AKT3 Increases Migration and Metastasis in Triple Negative Breast Cancer Cells by Upregulating S100A4.

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    Astrid Grottke

    Full Text Available Treatment of breast cancer patients with distant metastases represents one of the biggest challenges in today's gynecological oncology. Therefore, a better understanding of mechanisms promoting the development of metastases is of paramount importance. The serine/threonine kinase AKT was shown to drive cancer progression and metastasis. However, there is emerging data that single AKT isoforms (i.e. AKT1, AKT2 and AKT3 have different or even opposing functions in the regulation of cancer cell migration in vitro, giving rise to the hypothesis that inhibition of distinct AKT isoforms might have undesirable effects on cancer dissemination in vivo.The triple negative breast cancer cell line MDA-MB-231 was used to investigate the functional roles of AKT in migration and metastasis. AKT single and double knockdown cells were generated using isoform specific shRNAs. Migration was analyzed using live cell imaging, chemotaxis and transwell assays. The metastatic potential of AKT isoform knockdown cells was evaluated in a subcutaneous xenograft mouse model in vivo.Depletion of AKT3, but not AKT1 or AKT2, resulted in increased migration in vitro. This effect was even more prominent in AKT2,3 double knockdown cells. Furthermore, combined downregulation of AKT2 and AKT3, as well as AKT1 and AKT3 significantly increased metastasis formation in vivo. Screening for promigratory proteins revealed that downregulation of AKT3 increases the expression of S100A4 protein. In accordance, depletion of S100A4 by siRNA approach reverses the increased migration induced by knockdown of AKT3.We demonstrated that knockdown of AKT3 can increase the metastatic potential of triple negative breast cancer cells. Therefore, our results provide a rationale for the development of AKT isoform specific inhibitors.

  10. Expression of the Gastrin-Releasing Peptide Receptor, the Prostate Stem Cell Antigen and the Prostate-Specific Membrane Antigen in Lymph Node and Bone Metastases of Prostate Cancer

    NARCIS (Netherlands)

    Ananias, Hildo J. K.; van den Heuvel, Marius C.; Helfrich, Wijnand; de Jong, Igle J.

    2009-01-01

    OBJECTIVE. Cell membrane antigens like the gastrin-releasing peptide receptor (GRPR), the prostate stem cell antigen (PSCA), and the prostate-specific membrane antigen (PSMA), expressed in prostate cancer, are attractive targets for new therapeutic and diagnostic applications. Therefore, we investig

  11. Evaluation of germ-cell kinetics in infertile patients with proliferating cell nuclear antigen proliferating index

    Institute of Scientific and Technical Information of China (English)

    Li ZENG; Xiang-Tian KONG; Jin-Wei SU; Tong-Li XIA; Yan-Qun NA; Ying-Lu GUO

    2001-01-01

    To explore the usefulness of proliferating cell nuclear antigen proliferating index (PCNA PI) in the pathological diagnosis and treatment of male infertility. Methods: Testicular biopsy specimen obtained from 48 cases of male infertility and 2 normal controls were fixed and embedded. The sections were stained with anti-PCNA monoclonal antibodies or haematoxylin/eosin. Proliferating index (PI), expressed as the percentage of germ-cell nuclei positively stained with PCNA antibody, was assessed from more than 20 seminiferous tubules or 600 germ-cells. Results: The infertile patients were divided into 4 groups: Group 1, normal spermatogenesis ( 14 cases); Group 2, hypospermatogenesis (16 cases); Group 3, germinal arrest (10 cases); Group 4, Sertoli cell only syndrome (8 cases). The PCNA PI of normal control testis was 86.5% (mean value). Group 3 had a significantly lower PCNA PI (29.8%) than normal testis; Group 1 and 2 had similar Pis (82.3% and 82.3%, respectively) as the control testis. PI of the negative control (Group 4) was 0 as no germ-cells were found. Conclusion: PCNA PI is useful for assessing germ-cell kinetics, especially for pathological diagnosis of germinal arrest which is difficult to differentiate by routine HE staining technique. In germinal arrest, there is a significantly lowered PCNA PI, which is an indication of DNA synthesis deterioration, suggesting the use of therapies be different from those for hypospermatogenesis.

  12. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

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    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.

  13. DESC1, a novel tumor suppressor, sensitizes cells to apoptosis by downregulating the EGFR/AKT pathway in esophageal squamous cell carcinoma.

    Science.gov (United States)

    Ng, Hoi Yan; Ko, Josephine Mun-Yee; Yu, Valen Zhuoyou; Ip, Joseph Chok Yan; Dai, Wei; Cal, Santiago; Lung, Maria Li

    2016-06-15

    Esophageal cancer is ranked as the eighth most common cancer and the sixth leading cause of cancer deaths worldwide. To identify candidate tumor suppressor genes related to esophageal squamous cell carcinoma (ESCC) development, a cDNA microarray analysis was performed using paired tumor and nontumor tissue samples from ESCC patients. Differentially expressed in squamous cell carcinoma 1 (DESC1), which belongs to the Type II transmembrane serine protease family, was frequently downregulated in ESCC. This study aims to elucidate the molecular mechanism for the tumor suppressive function of DESC1 in ESCC. We show that DESC1 reduced cell viability and sensitized cells to apoptosis, when cells were under apoptotic stimuli. The proapoptotic effect of DESC1 was mediated through downregulating AKT1 activation and the restoration of AKT activation by the introduction of the constitutively active AKT, myr-AKT, abolished the apoptosis-sensitizing effect of DESC1. DESC1 also reduced EGFR protein level, which was abrogated when the proteolytic function of DESC1 was lost, suggesting that DESC1 cleaved EGFR and downregulated the EGFR/AKT pathway to favor apoptosis. The transmembrane localization and the structural domains provide an opportunity for DESC1 to interact with the extracellular environment. The importance of such interaction was highlighted by the finding that DESC1 reduced cell colony formation ability in three-dimensional culture. In line with this, DESC1 reduced tumor growth kinetics in the in vivo orthotopic tumorigenesis assay. Taken together, our novel findings suggest how DESC1 may suppress ESCC development by sensitizing cells to apoptosis under an apoptotic stimulus through downregulating the EGFR/AKT signaling pathway.

  14. Up-regulation of HLA class-I antigen expression and antigen-specific CTL response in cervical cancer cells by the demethylating agent hydralazine and the histone deacetylase inhibitor valproic acid

    Directory of Open Access Journals (Sweden)

    Lizano-Soberón Marcela

    2006-12-01

    Full Text Available Abstract Background DNA hypermethylation and histone deacetylation are epigenetic events that contribute to the absence or downregulated expression of different components of the tumor recognition complex. These events affect the processing and presentation of antigenic peptides to CTLs by HLA class-I molecules. In this work evaluated the effect of the DNA hypomethylating agent hydralazine and the histone deacetylase inhibitor valproic acid, on the expression of HLA class-I molecules and on the antigen-specific immune recognition of cervical cancer cells. Methods Cell lines C33A (HPV-, CaSki (HPV-16+ and MS751 (HPV-18+ were treated with hydralazine and valproic acid to assess the expression of HLA class-I molecules by flow cytometry and RT-PCR. Promoter methylation of HLA class-I -A, -B and C, was also evaluated by Methylation-Specific PCR. Primary cervical tumors of four HLA-A*0201 allele patients were typed for HPV and their CTL's stimulated in vitro with the T2 cell line previously loaded with 50 μM of the HPV peptides. Cytotoxicity of stimulated CTL's was assayed against Caski and MS751 cells pre-treated with hydralazine and valproic acid. Results Valproic acid and hydralazine/valproic acid up-regulated the constitutive HLA class-I expression as evaluated by flow cytometry and RT-PCR despite constitutive promoter demethylation at these loci. Hydralazine and valproic acid in combination but no IFN-gamma hyperacetylated histone H4 as evaluated by ChiP assay. The antigenic immune recognition of CaSki and MS751 cells by CTLs specific to HPV-16/18 E6 and E7-derived epitopes, was increased by VA and H/VA and the combination of H/VA/IFN-gamma. Conclusion These results support the potential use of hydralazine and valproic acid as an adjuvant for immune intervention in cervical cancer patients whenever clinical protocols based on tumor antigen recognition is desirable, like in those cases where the application of E6 and E7 based therapeutic vaccines

  15. Structural characteristics of an antigen required for its interaction with Ia and recognition by T cells

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S;

    1987-01-01

    A detailed analysis of the residues within an immunogenic peptide that endow it with the capacity to interact with Ia and to be recognized by T cells is presented. Ia interacts with only a few of the peptide residues and overall exhibits a very broad specificity. Some residues appear to interact...... both with Ia and with T cells, leading to a model in which a peptide antigen is 'sandwiched' between Ia and the T-cell receptor....

  16. Nanoscale Patterning of Antigen on Silicon Substrate to Examine Mast Cell Activation

    Science.gov (United States)

    2002-04-01

    Examine Mast Cell Activation DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE...Materials Research Society N4.3 Nanoscale Patterning of Antigen on Silicon Substrate to Examine Mast Cell Activation Reid N. Orth", Min Wu2 , Theodore G...nanometer scale to spatially control the stimulation of specific immunoreceptors on RBL mast cells . This work was motivated by previous research to

  17. Antigen-presenting cells transfected with Hsp65 messenger RNA fail to treat experimental tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, C.D.; Trombone, A.P.F.; Lorenzi, J.C.C.; Almeida, L.P.; Gembre, A.F.; Padilha, E. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Ramos, S.G. [Departamento de Patologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Silva, C.L.; Coelho-Castelo, A.A.M. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-09-21

    In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis.

  18. Mapping of B-Cell Epitopes in a Trypanosoma cruzi Immunodominant Antigen Expressed in Natural Infections

    Science.gov (United States)

    Lesénéchal, Mylène; Becquart, Laurence; Lacoux, Xavier; Ladavière, Laurent; Baida, Renata C. P.; Paranhos-Baccalà, Glaucia; da Silveira, José Franco

    2005-01-01

    Tc40 is an immunodominant antigen present in natural Trypanosoma cruzi infections. This immunogen was thoroughly mapped by using overlapping amino acid sequences identified by gene cloning and chemical peptide synthesis. To map continuous epitopes of the Tc40 antigen, an epitope expression library was constructed and screened with sera from human chagasic patients. A major, linear B-cell epitope spanning residues 403 to 426 (PAKAAAPPAA) was identified in the central domain of Tc40. A synthetic peptide spanning this region reacted strongly with 89.8% of the serum samples from T. cruzi-infected individuals. This indicates that the main antigenic site is defined by the linear sequence of the peptide rather than a conformation-dependent structure. The major B-cell epitope of Tc40 shares a high degree of sequence identity with T. cruzi ribosomal and RNA binding proteins, suggesting the existence of cross-reactivity among these molecules. PMID:15699429

  19. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies agai

  20. Dichotomy of the human T cell response to Leishmania antigens. I. Th1-like response to Leishmania major promastigote antigens in individuals recovered from cutaneous leishmaniasis

    DEFF Research Database (Denmark)

    Kemp, M; Hey, A S; Kurtzhals, J A

    1994-01-01

    The T cell response to antigens from Leishmania major promastigotes was investigated in peripheral blood mononuclear cells from Sudanese individuals with a history of cutaneous leishmaniasis (CL), Sudanese individuals with positive DTH reaction in the leishmanin skin test but with no history...

  1. Large, but not small, antigens require time- and temperature-dependent processing in accessory cells before they can be recognized by T cells

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1986-01-01

    of antigen presentation we used the proliferative response of appropriately primed T cells during a co-culture with the paraformaldehyde-fixed and antigen-exposed presenting cells. We demonstrate that the large synthetic polypeptide antigen, dinitrophenyl-poly-L-lysine, requires processing. After an initial...... time-lag of 30 min this antigen is fully processed within 2 to 4 of culture at 37 degrees C. In contrast, the immunogenic heptapeptide, angiotensin III, can be presented by pre-fixed accessory cells, viz. without any prior processing. Antigen processing was found to be temperature...

  2. Phenotype of Antigen Unexperienced TH Cells in the Inflamed Central Nervous System in Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Franck, Sophia; Paterka, Magdalena; Birkenstock, Jerome; Zipp, Frauke; Siffrin, Volker; Witsch, Esther

    2016-11-10

    Multiple sclerosis is a chronic, disseminated inflammation of the central nervous system which is thought to be driven by autoimmune T cells. Genetic association studies in multiple sclerosis and a large number of studies in the animal model of the disease support a role for effector/memory T helper cells. However, the mechanisms underlying relapses, remission and chronic progression in multiple sclerosis or the animal model experimental autoimmune encephalomyelitis, are not clear. In particular, there is only scarce information on the role of central nervous system-invading naive T helper cells in these processes. By applying two-photon laser scanning microscopy we could show in vivo that antigen unexperienced T helper cells migrated into the deep parenchyma of the inflamed central nervous system in experimental autoimmune encephalomyelitis, independent of their antigen specificity. Using flow cytometric analyses of central nervous system-derived lymphocytes we found that only antigen-specific, formerly naive T helper cells became activated during inflammation of the central nervous system encountering their corresponding antigen.

  3. CD8α− Dendritic Cells Induce Antigen-Specific T Follicular Helper Cells Generating Efficient Humoral Immune Responses

    Directory of Open Access Journals (Sweden)

    Changsik Shin

    2015-06-01

    Full Text Available Recent studies on T follicular helper (Tfh cells have significantly advanced our understanding of T cell-dependent B cell responses. However, little is known about the early stage of Tfh cell commitment by dendritic cells (DCs, particularly by the conventional CD8α+ and CD8α− DC subsets. We show that CD8α− DCs localized at the interfollicular zone play a pivotal role in the induction of antigen-specific Tfh cells by upregulating the expression of Icosl and Ox40l through the non-canonical NF-κB signaling pathway. Tfh cells induced by CD8α− DCs function as true B cell helpers, resulting in significantly increased humoral immune responses against various human pathogenic antigens, including Yersinia pestis LcrV, HIV Gag, and hepatitis B surface antigen. Our findings uncover a mechanistic role of CD8α− DCs in the initiation of Tfh cell differentiation and thereby provide a rationale for investigating CD8α− DCs in enhancing antigen-specific humoral immune responses for improving vaccines and therapeutics.

  4. Reduction of ammonia and lactate through the coupling of glutamine synthetase selection and downregulation of lactate dehydrogenase-A in CHO cells.

    Science.gov (United States)

    Noh, Soo Min; Park, Jin Hyoung; Lim, Myung Sin; Kim, Jong Won; Lee, Gyun Min

    2017-02-01

    Chinese hamster ovary (CHO) cell cultivation for production of therapeutic proteins is accompanied by production of metabolic wastes, mostly ammonia and lactate. To reduce ammonia production, the glutamine synthetase (GS) system was used to develop therapeutic monoclonal antibody (mAb)-producing CHO cells (SM-0.025). Additionally, the lactate dehydrogenase-A (LDH-A) was downregulated with shRNA to reduce lactate production in SM-0.025. The resulting mAb-producing cell lines (#2, #46, and #52) produced less ammonia than the host cell line during the exponential phase due to GS protein overexpression. LDH-A downregulation in SM-0.025 not only reduced lactate production but also further reduced ammonia production. Among the three LDH-A-downregulated clones, clone #2 had the highest mAb production along with significantly reduced specific lactate and ammonia production rates compared to those in SM-0.025. Waste reduction increased the galactosylation level of N-glycosylation, which improved mAb quality. LDH-A downregulation was also successfully applied to the host cell lines (CHO K1 and GS knockout CHO-K1). However, LDH-A downregulated host cells could not survive the pool-selection process wherein glutamine was excluded and methionine sulfoximine was added to the media. Taken together, LDH-A downregulation in the mAb-producing cell line generated with the GS system successfully reduced both ammonia and lactate levels, improving mAb galactosylation. However, LDH-A downregulation could not be applied to host cell lines because it hampered the selection process of the GS system.

  5. Topotecan inhibits cancer cell migration by down-regulation of chemokine CC motif receptor 7 and matrix metalloproteinases

    Institute of Scientific and Technical Information of China (English)

    Sen-sen LIN; Li SUN; Yan-kai ZHANG; Ren-ping ZHAO; Wen-lu LIANG; Sheng-tao YUAN; Lu-yong ZHANG

    2009-01-01

    Aim: The aim of this study was to investigate the effect of topotecan (TPT) on cancer cell migration.Methods: Growth inhibition of TPT was analyzed by MTT assay, and cancer cell migration was measured by transwell double chamber assay. To verify the effect of TPT on the chemokine receptors CXCR4 and CCR7, quantitative PCR, semi-quantitative PCR and Western blot analysis were performed. The secretion of MMP-2 and MMP-9 was detected by enzyme-linked immunosorbent assay (ELISA) and gelatin zymography. To evaluate possible contributions of CCR7 to MMP secretion, the overexpression vectors pcDNA3.1+-CCR7 and CCR7 siRNA were transiently transfected into MDA-MB-435 cells.Results: TPT inhibited cancer cell migration in a dose-dependent manner. Additionally, TPT significantly decreased the expression of CCR7 in both MDA-MB-435 and MDA-MB-231 cells and moderately reduced the expression of CXCR4 in MDA-MB-435 cells. The secretion of MMPs (MMP-2, MMP-9) was also inhibited by TPT. Overexpression of CCR7 increased the secretion of MMP-2/9 and cancer cell migration, whereas knockdown of CCR7 reduced active MMP-2/9 production and migration of MDA-MB-435 cells.Conclusion: TPT inhibited cancer cell migration by down-regulation of CCR7 and MMPs (MMP-2 and MMP-9).

  6. Enhancement of survivin gene downregulation and cell apoptosis by a novel combination: liposome microbubbles and ultrasound exposure.

    Science.gov (United States)

    Chen, Zhiyi; Liang, Kun; Liu, Jianhua; Xie, Mingxing; Wang, Xinfang; Lü, Qing; Zhang, Jing; Fang, Lingyun

    2009-12-01

    Ultrasound-mediated microbubble destruction (sonoporation) is an efficient and safe nonviral technique for gene delivery. In the present work, we hypothesized that short hairpin RNA (shRNA) interference therapy targeting human Survivin gene could be transfected by the novel combination of ultrasound exposure (USE) and liposome microbubbles (LM). ShRNA vectors targeting Survivin were constructed and transfected under USE and LM conditions. The optimal transfection efficiency and cell injury were compared with those of polyethylenimine (PEI)-mediated transfection in different cancer cell lines (HeLa, HepG2, Ishikawa, MCF-7, and B16-F10). The effects of gene downregulation and cell apoptosis were further investigated. The results indicated that P + USE + LM group could significantly increase the gene expression as compared with plasmid group, plasmid + USE group, plasmid + LM group (P < 0.001). The transfection efficiency of the novel combination was nearly equal to PEI-mediated transfection in some cancer cell lines while the cell viability did not decrease markedly. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis also confirmed that Survivin mRNA and protein expression could be knocked down significantly by shRNA transfection under USE and LM condition (P < 0.001). This is the first study to verify the role of shRNA therapy in vitro with novel combination of USE and LM. We concluded that this nonviral technique would be valuable in the gene transfection of shRNA and Survivin gene downregulation would lead to apparent cell apoptosis.

  7. Chimeric antigen receptor T cells: a novel therapy for solid tumors.

    Science.gov (United States)

    Yu, Shengnan; Li, Anping; Liu, Qian; Li, Tengfei; Yuan, Xun; Han, Xinwei; Wu, Kongming

    2017-03-29

    The chimeric antigen receptor T (CAR-T) cell therapy is a newly developed adoptive antitumor treatment. Theoretically, CAR-T cells can specifically localize and eliminate tumor cells by interacting with the tumor-associated antigens (TAAs) expressing on tumor cell surface. Current studies demonstrated that various TAAs could act as target antigens for CAR-T cells, for instance, the type III variant epidermal growth factor receptor (EGFRvIII) was considered as an ideal target for its aberrant expression on the cell surface of several tumor types. CAR-T cell therapy has achieved gratifying breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. The third generation of CAR-T demonstrates increased antitumor cytotoxicity and persistence through modification of CAR structure. In this review, we summarized the preclinical and clinical progress of CAR-T cells targeting EGFR, human epidermal growth factor receptor 2 (HER2), and mesothelin (MSLN), as well as the challenges for CAR-T cell therapy.

  8. MicroRNA-224 inhibits proliferation and migration of breast cancer cells by down-regulating Fizzled 5 expression.

    Science.gov (United States)

    Liu, Feng; Liu, Yang; Shen, Jingling; Zhang, Guoqiang; Han, Jiguang

    2016-08-02

    The Wnt/β-catenin signaling is crucial for the proliferation and migration of breast cancer cells. However, the expression of microRNA-224 (miR-224) in the different types of breast cancers and its role in the Wnt/β-catenin signaling and the proliferation and migration of breast cancer cells are poorly understood. In this study, the levels of miR-224 in different types of breast cancer tissues and cell lines were examined by quantitative RT-PCR and the potential targets of miR-224 in the Wnt/β-catenin signaling were investigated. The effects of altered miR-224 expression on the frequency of CD44+CD24- cancer stem-like cells (CSC), proliferation and migration of MCF-7 and MDA-MB-231 cells were examined by flow cytometry, MTT and transwell migration. We found that the levels of miR-224 expression in different types of breast cancer tissues and cell lines were associated inversely with aggressiveness of breast cancers. Enhanced miR-224 expression significantly reduced the fizzled 5-regulated luciferase activity in 293T cells, fizzled 5 expression in MCF-7 and MDA-MB-231 cells, the β-dependent luciferase activity in MCF-7 cells, and the nuclear translocation of β-catenin in MDA-MB-231 cells. miR-224 inhibition significantly increased the percentages of CSC in MCF-7 cells and enhanced proliferation and migration of MCF-7 cells. Enhanced miR-224 expression inhibited proliferation and migration of MDA-MB-231 cells, and the growth of implanted breast cancers in vivo. Induction of Frizzled 5 over-expression mitigated the miR-224-mediated inhibition of breast cancer cell proliferation. Collectively, these data indicated that miR-224 down-regulated the Wnt/β-catenin signaling possibly by binding to Frizzled 5 and inhibited proliferation and migration of breast cancer cells.

  9. [The surface glycolipid antigen specific for the internal cell mass of the mouse blastocyst and of the stem cells of murine teratocarcinoma F9].

    Science.gov (United States)

    Anfimova, M L; Bannikov, G A; Troianovskiĭ, S M

    1989-01-01

    A new monoclonal antibody that recognizes a new antigen on the surface of mouse teratocarcinoma F9 stem cells has been described. This antigen is a glycolipid as demonstrated by inhibition of immunofluorescence by different monosaccharides, glycoproteins and glycolipid fraction of F9 cells as well as by chemical analysis. Immunofluorescent staining of in vitro cultivated preimplantation mouse embryos has demonstrated that this antigen is specific only of internal cell mass cells of late blastocyst.

  10. Antigen-induced recruitment of eosinophils: importance of CD4+ T cells, IL5, and mast cells.

    Science.gov (United States)

    Hom, J T; Estridge, T

    1994-12-01

    Eosinophils of sensitized mice readily recruit to the site of antigen challenge. In the present study, experiments were performed to determine the involvement of different cell types in the antigen-induced recruitment of eosinophils. We demonstrated that a single treatment with anti-L3T4 monoclonal antibody (mAb) on the day of allergen challenge significantly decreased antigen-induced recruitment of eosinophils. Treatments with anti-L3T4 mAb during the sensitization period also caused a substantial reduction in the migration of eosinophils into the site of challenge with antigen. Thus, it appears that both stages of eosinophil recruitment, sensitization and antigen-challenge, are dependent upon the presence of L3T4+ T cells. Moreover, while treatments with anti-IL5 mAb blocked eosinophil migration, anti-IL2 mAb failed to alter the antigen-induced recruitment of eosinophils. In addition, significant numbers of eosinophils from the mast-cell-deficient mice were found to migrate into the peritoneal cavities upon allergen challenge. Eosinophil migration was also observed in several mouse strains of different H-2 haplotypes. The present findings suggest that CD4+ T cells and IL5 but not IL2 may play important roles in modulating the recruitment of eosinophils. Moreover, the involvement of mast cells does not appear to be essential for eosinophil migration. Finally, the development of antigen-induced recruitment of eosinophils is probably not under the immunogenetic regulation by genes within the H-2 complex.

  11. Down-regulation of heat shock protein HSP90ab1 in radiation-damaged lung cells other than mast cells.

    Science.gov (United States)

    Haase, Michael G; Geyer, Peter; Fitze, Guido; Baretton, Gustavo B

    2014-05-01

    Ionizing radiation (IR) leads to fibrosing alveolitis (FA) after a lag period of several weeks to months. In a rat model, FA starts at 8 weeks after IR. Before that, at 5.5 weeks after IR, the transcription factors Sp1 (stimulating protein 1) and AP-1 (activator protein 1) are inactivated. To find genes/proteins that were down-regulated at that time, differentially expressed genes were identified in a subtractive cDNA library and verified by quantitative RT-PCR (reverse transcriptase polymerase chain reaction), western blotting and immunohistochemistry (IH). The mRNA of the molecular chaperone HSP90AB1 (heat shock protein 90 kDa alpha, class B member 1) was down-regulated 5.5 weeks after IR. Later, when FA manifested, HSP90ab1 protein was down-regulated by more than 90% in lung cells with the exception of mast cells. In most mast cells of the normal lung, both HSP90ab1 and HSP70, another major HSP, show a very low level of expression. HSP70 was massively up-regulated in all mast cells three months after irradiation whereas HSP90AB1 was up-regulated only in a portion of mast cells. The strong changes in the expression of central molecular chaperones may contribute to the well-known disturbance of cellular functions in radiation-damaged lung tissue.

  12. Dimethylfumarate inhibits melanoma cell proliferation via p21 and p53 induction and bcl-2 and cyclin B1 downregulation.

    Science.gov (United States)

    Kaluzki, Irina; Hrgovic, Igor; Hailemariam-Jahn, Tsige; Doll, Monika; Kleemann, Johannes; Valesky, Eva Maria; Kippenberger, Stefan; Kaufmann, Roland; Zoeller, Nadja; Meissner, Markus

    2016-10-01

    Recent evidence suggests that dimethylfumarate (DMF), known as a highly potent anti-psoriatic agent, might have anti-tumorigenic properties in melanoma. It has recently been demonstrated that DMF inhibits melanoma proliferation by apoptosis and cell cycle inhibition and therefore inhibits melanoma metastasis. Nonetheless, the underlying mechanisms remain to be evaluated. To elucidate the effects of DMF on melanoma cell lines (A375, SK-Mel), we first performed cytotoxicity assays. No significant lactatedehydogenase (LDH) release could be found. In further analysis, we showed that DMF suppresses melanoma cell proliferation in a concentration-dependent manner. To examine whether these effects are conveyed by apoptotic mechanisms, we studied the amount of apoptotic nucleosomes and caspase 3/7 activity using ELISA analysis. Significant apoptosis was induced by DMF in both cell lines, and this could be paralleled with bcl-2 downregulation and PARP-1 cleavage. We also performed cell cycle analysis and found that DMF induced concentration-dependent arrests of G0/G1 as well as G2/M. To examine the underlying mechanisms of cell cycle arrest, we analyzed the expression profiles of important cell cycle regulator proteins such as p53, p21, cyclins A, B1, and D1, and CDKs 3, 4, and 6. Interestingly, DMF induced p53 and p21 yet inhibited cyclin B1 expression in a concentration-dependent manner. Other cell cycle regulators were not influenced by DMF. The knockdown of DMF induced p53 via siRNA led to significantly reduced apoptosis but had no influence on cell cycle arrest. We examined the adhesion of melanoma cells on lymphendothelial cells during DMF treatment and found a significant reduction in interaction. These data provide evidence that DMF inhibits melanoma proliferation by reinduction of important cell cycle inhibitors leading to a concentration-dependent G0/G1 or G2/M cell cycle arrest and induction of apoptosis via downregulation of bcl-2 and induction of p53 and PARP-1

  13. Downregulation of NPM-ALK by siRNA causes anaplastic large cell lymphoma cell growth inhibition and augments the anti cancer effects of chemotherapy in vitro.

    Science.gov (United States)

    Hsu, Faye Yuan-yi; Zhao, Yi; Anderson, W French; Johnston, Patrick B

    2007-06-01

    The fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), results from the chromosome translocation t(2;5)(p23;q25) and is present in 50-70 percent of anaplastic large-cell lymphomas (ALCLs). NPM-ALK is a constitutively activated kinase that transforms cells through stimulating several mitogenic signaling pathways. To examine if the NPM-ALK is a potential therapeutic target in ALCL, we used siRNA to specifically downregulate the expression of the NPM-ALK in ALCL cell lines. In this report, we demonstrated viability loss in t(2;5)-positive ALCL cell lines, SUDHL-1 and Karpas 299 cells, but not in lymphoma cell lines without the chromosome translocation, Jurkat and Granta 519 cells. Further study demonstrated that the downregulation of NPM-ALK resulted in decreased cell proliferation and increased cell apoptosis. When used in combination with chemotherapeutic agents, such as doxorubicin, the inhibition of the NPM-ALK augments the chemosensitivity of the tumor cells. These results revealed the importance of continuous expression of NPM-ALK in maintaining the growth of ALCL cells. Our data also suggested that the repression of the fusion gene might be a potential novel therapeutic strategy for NPM-ALK positive ALCLs.

  14. Modulation of Immune Responses by Exosomes Derived from Antigen-Presenting Cells

    Science.gov (United States)

    Shenoda, Botros B.; Ajit, Seena K.

    2016-01-01

    Exosome-mediated signaling is important in mediating the inflammatory response. To exert their biological or pathophysiological functions in the recipient cells, exosomes deliver a diverse array of biomacromolecules including long and short coding and non-coding RNAs, proteins, and lipids. Exosomes secreted by antigen-presenting cells can confer therapeutic benefits by attenuating or stimulating the immune response. Exosomes play a crucial role in carrying and presenting functional major histocompatibility peptide complexes to modulate antigen-specific T cell responses. Exosomes from Dendritic Cells (DCs) can activate T and B cells and have been explored for their immunostimulatory properties in cancer therapy. The immunosuppressive properties of exosomes derived from macrophages and DCs can reduce inflammation in animal models for several inflammatory disorders. This review focuses on the protective role of exosomes in attenuating inflammation or augmenting immune response, emphasizing studies on exosomes derived from DCs and macrophages. PMID:27660518

  15. Efficient induction of CD25- iTreg by co-immunization requires strongly antigenic epitopes for T cells

    Directory of Open Access Journals (Sweden)

    Li Jinyao

    2011-05-01

    Full Text Available Abstract Background We previously showed that co-immunization with a protein antigen and a DNA vaccine coding for the same antigen induces CD40low IL-10high tolerogenic DCs, which in turn stimulates the expansion of antigen-specific CD4+CD25-Foxp3+ regulatory T cells (CD25- iTreg. However, it was unclear how to choose the antigen sequence to maximize tolerogenic antigen presentation and, consequently, CD25- iTreg induction. Results In the present study, we demonstrated the requirement of highly antigenic epitopes for CD25- iTreg induction. Firstly, we showed that the induction of CD25- iTreg by tolerogenic DC can be blocked by anti-MHC-II antibody. Next, both the number and the suppressive activity of CD25- iTreg correlated positively with the overt antigenicity of an epitope to activate T cells. Finally, in a mouse model of dermatitis, highly antigenic epitopes derived from a flea allergen not only induced more CD25- iTreg, but also more effectively prevented allergenic reaction to the allergen than did weakly antigenic epitopes. Conclusions Our data thus indicate that efficient induction of CD25- iTreg requires highly antigenic peptide epitopes. This finding suggests that highly antigenic epitopes should be used for efficient induction of CD25- iTreg for clinical applications such as flea allergic dermatitis.

  16. Down-regulation of msrb3 and destruction of normal auditory system development through hair cell apoptosis in zebrafish.

    Science.gov (United States)

    Shen, Xiaofang; Liu, Fei; Wang, Yingzhi; Wang, Huijun; Ma, Jing; Xia, Wenjun; Zhang, Jin; Jiang, Nan; Sun, Shaoyang; Wang, Xu; Ma, Duan

    2015-01-01

    Hearing defects can significantly influence quality of life for those who experience them. At this time, 177 deafness genes have been cloned, including 134 non-syndromic hearing-loss genes. The methionine sulfoxide reductase B3 (Ahmed et al., 2011) gene (also called DFNB74) is one such newly discovered hearing-loss gene. Within this gene c.265 T>G and c.55 T>C mutations are associated with autosomal recessive hearing loss. However, the biological role and mechanism underlying how it contributes to deafness is unclear. Thus, to better understand this mutation, we designed splicing morpholinos for the purpose of down-regulating msrb3 in zebrafish. Morphants exhibited small, tiny, fused, or misplaced otoliths and abnormal numbers of otoliths. Down-regulation of msrb3 also caused shorter, thinner, and more crowded cilia. Furthermore, L1-8 neuromasts were reduced and disordered in the lateral line system; hair cells in each neuromast underwent apoptosis. Co-injection with human MSRB3 mRNA partially rescued auditory system defects, but mutant MSRB3 mRNA could not. Thus, msrb3 is instrumental for auditory system development in zebrafish and MSRB3-related deafness may be caused by promotion of hair cell apoptosis.

  17. Rapamycin Inhibits Lymphatic Endothelial Cell Tube Formation by Downregulating Vascular Endothelial Growth Factor Receptor 3 Protein Expression

    Directory of Open Access Journals (Sweden)

    Yan Luo

    2012-03-01

    Full Text Available Mammalian target of rapamycin (mTOR controls lymphangiogenesis. However, the underlying mechanism is not clear. Here we show that rapamycin suppressed insulin-like growth factor 1 (IGF-1- or fetal bovine serum (FBS-stimulated lymphatic endothelial cell (LEC tube formation, an in vitro model of lymphangiogenesis. Expression of a rapamycin-resistant and kinase-active mTOR (S2035T, mTOR-T, but not a rapamycin-resistant and kinase-dead mTOR (S2035T/D2357E, mTOR-TE, conferred resistance to rapamycin inhibition of LEC tube formation, suggesting that rapamycin inhibition of LEC tube formation is mTOR kinase activity dependent. Also, rapamycin inhibited proliferation and motility in the LECs. Furthermore, we found that rapamycin inhibited protein expression of VEGF receptor 3 (VEGFR-3 by inhibiting protein synthesis and promoting protein degradation of VEGFR-3 in the cells. Down-regulation of VEGFR-3 mimicked the effect of rapamycin, inhibiting IGF-1- or FBS-stimulated tube formation, whereas over-expression of VEGFR-3 conferred high resistance to rapamycin inhibition of LEC tube formation. The results indicate that rapamycin inhibits LEC tube formation at least in part by downregulating VEGFR-3 protein expression.

  18. Antigen-sensitized CD4+CD62Llow memory/effector T helper 2 cells can induce airway hyperresponsiveness in an antigen free setting

    Directory of Open Access Journals (Sweden)

    Nagatani Katsuya

    2005-05-01

    Full Text Available Abstract Background Airway hyperresponsiveness (AHR is one of the most prominent features of asthma, however, precise mechanisms for its induction have not been fully elucidated. We previously reported that systemic antigen sensitization alone directly induces AHR before development of eosinophilic airway inflammation in a mouse model of allergic airway inflammation, which suggests a critical role of antigen-specific systemic immune response itself in the induction of AHR. In the present study, we examined this possibility by cell transfer experiment, and then analyzed which cell source was essential for this process. Methods BALB/c mice were immunized with ovalbumin (OVA twice. Spleen cells were obtained from the mice and were transferred in naive mice. Four days later, AHR was assessed. We carried out bronchoalveolar lavage (BAL to analyze inflammation and cytokine production in the lung. Fluorescence and immunohistochemical studies were performed to identify T cells recruiting and proliferating in the lung or in the gut of the recipient. To determine the essential phenotype, spleen cells were column purified by antibody-coated microbeads with negative or positive selection, and transferred. Then, AHR was assessed. Results Transfer of spleen cells obtained from OVA-sensitized mice induced a moderate, but significant, AHR without airway antigen challenge in naive mice without airway eosinophilia. Immunization with T helper (Th 1 elicited antigen (OVA with complete Freund's adjuvant did not induce the AHR. Transferred cells distributed among organs, and the cells proliferated in an antigen free setting for at least three days in the lung. This transfer-induced AHR persisted for one week. Interleukin-4 and 5 in the BAL fluid increased in the transferred mice. Immunoglobulin E was not involved in this transfer-induced AHR. Transfer of in vitro polarized CD4+ Th2 cells, but not Th1 cells, induced AHR. We finally clarified that CD4+CD62Llow memory

  19. Antigen-Specific Th17 Cells Are Primed by Distinct and Complementary Dendritic Cell Subsets in Oropharyngeal Candidiasis.

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    Kerstin Trautwein-Weidner

    2015-10-01

    Full Text Available Candida spp. can cause severe and chronic mucocutaneous and systemic infections in immunocompromised individuals. Protection from mucocutaneous candidiasis depends on T helper cells, in particular those secreting IL-17. The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood. Here we generated a Candida-specific TCR transgenic mouse reactive to a novel endogenous antigen that is conserved in multiple distant species of Candida, including the clinically highly relevant C. albicans and C. glabrata. Using TCR transgenic T cells in combination with an experimental model of oropharyngeal candidiasis (OPC we investigated antigen presentation and Th17 priming by different subsets of dendritic cells (DCs present in the infected oral mucosa. Candida-derived endogenous antigen accesses the draining lymph nodes and is directly presented by migratory DCs. Tissue-resident Flt3L-dependent DCs and CCR2-dependent monocyte-derived DCs collaborate in antigen presentation and T cell priming during OPC. In contrast, Langerhans cells, which are also present in the oral mucosa and have been shown to prime Th17 cells in the skin, are not required for induction of the Candida-specific T cell response upon oral challenge. This highlights the functional compartmentalization of specific DC subsets in different tissues. These data provide important new insights to our understanding of tissue-specific antifungal immunity.

  20. The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells

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    Eiden Maribeth V

    2011-07-01

    Full Text Available Abstract Background Over the last several decades it has been noted, using a variety of different methods, that cells infected by a specific gammaretrovirus are resistant to infection by other retroviruses that employ the same receptor; a phenomenon termed receptor interference. Receptor masking is thought to provide an earlier means of blocking superinfection, whereas receptor down regulation is generally considered to occur in chronically infected cells. Results We used replication-competent GFP-expressing viruses containing either an amphotropic murine leukemia virus (A-MLV or the gibbon ape leukemia virus (GALV envelope. We also constructed similar viruses containing fluorescence-labeled Gag proteins for the detection of viral particles. Using this repertoire of reagents together with a wide range of antibodies, we were able to determine the presence and availability of viral receptors, and detect viral envelope proteins and particles presence on the cell surface of chronically infected cells. Conclusions A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies, indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However, receptor masking does not completely prevent A-MLV or GALV superinfection.

  1. Down-regulation of β-catenin Nuclear Localization by Aspirin Correlates with Growth Inhibition of Jurkat Cell Line

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this study, we examined the effects of aspirin on the growth rates, subcellar distribution of β-catenin protein, the expression of β-catenin/TCF signaling pathway target gene cyclinD1 mRNA,and cell cycle of Jurkat cell line (Human T-acute lymphoblastic leukemia). Our results showed that the treatment with aspirin inhibited the growth of Jurkat cell line. Jurkat cells treated with 3 mmol/L of aspirin could significantly decrease nuclear localization of β-catenin, and at 5 mmol/L of aspirin,the nuclear localization of β-catenin was undetectable. QRT-PCR showed that the target gene cyclinD1 mRNA expression was gradually decreased with the dosage of aspirin. Aspirin induced G0/G1cell cycle arrest in Jurkat cells. We are led to conclude that aspirin acts through β-catenin-independent mechanisms. The effects of aspirin include down-regulation of β-catenin nuclear localization and G0/G1 cell cycle arrest, which might serve as a means of growth inhibition in aspirin-treated human Jurkat cell line.

  2. Inhibition of Cell Survival by Curcumin Is Associated with Downregulation of Cell Division Cycle 20 (Cdc20 in Pancreatic Cancer Cells

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    Yu Zhang

    2017-02-01

    Full Text Available Pancreatic cancer is one of the most aggressive human tumors in the United States. Curcumin, a polyphenol derived from the Curcuma longa plant, has been reported to exert its antitumor activity in pancreatic cancer. However, the molecular mechanisms of curcumin-mediated tumor suppressive function have not been fully elucidated. In the current study, we explore whether curcumin exhibits its anti-cancer function through inhibition of oncoprotein cell division cycle 20 (Cdc20 in pancreatic cancer cells. We found that curcumin inhibited cell growth, enhanced apoptosis, induced cell cycle arrest and retarded cell invasion in pancreatic cancer cells. Moreover, we observed that curcumin significantly inhibited the expression of Cdc20 in pancreatic cancer cells. Furthermore, our results demonstrated that overexpression of Cdc20 enhanced cell proliferation and invasion, and abrogated the cytotoxic effects induced by curcumin in pancreatic cancer cells. Consistently, downregulation of Cdc20 promoted curcumin-mediated anti-tumor activity. Therefore, our findings indicated that inhibition of Cdc20 by curcumin could be useful for the treatment of pancreatic cancer patients.

  3. Three-day dendritic cells for vaccine development: Antigen uptake, processing and presentation

    Directory of Open Access Journals (Sweden)

    Schendel Dolores J

    2010-09-01

    Full Text Available Abstract Background Antigen-loaded dendritic cells (DC are capable of priming naïve T cells and therefore represent an attractive adjuvant for vaccine development in anti-tumor immunotherapy. Numerous protocols have been described to date using different maturation cocktails and time periods for the induction of mature DC (mDC in vitro. For clinical application, the use of mDC that can be generated in only three days saves on the costs of cytokines needed for large scale vaccine cell production and provides a method to produce cells within a standard work-week schedule in a GMP facility. Methods In this study, we addressed the properties of antigen uptake, processing and presentation by monocyte-derived DC prepared in three days (3d mDC compared with conventional DC prepared in seven days (7d mDC, which represent the most common form of DC used for vaccines to date. Results Although they showed a reduced capacity for spontaneous antigen uptake, 3d mDC displayed higher capacity for stimulation of T cells after loading with an extended synthetic peptide that requires processing for MHC binding, indicating they were more efficient at antigen processing than 7d DC. We found, however, that 3d DC were less efficient at expressing protein after introduction of in vitro transcribed (ivtRNA by electroporation, based on published procedures. This deficit was overcome by altering electroporation parameters, which led to improved protein expression and capacity for T cell stimulation using low amounts of ivtRNA. Conclusions This new procedure allows 3d mDC to replace 7d mDC for use in DC-based vaccines that utilize long peptides, proteins or ivtRNA as sources of specific antigen.

  4. Nematode-Derived Proteins Suppress Proliferation and Cytokine Production of Antigen-Specific T Cells via Induction of Cell Death

    Science.gov (United States)

    Hartmann, Wiebke; Brenz, Yannick; Kingsley, Manchang Tanyi; Ajonina-Ekoti, Irene; Brattig, Norbert W.; Liebau, Eva; Breloer, Minka

    2013-01-01

    In order to establish long-lasting infections in their mammalian host, filarial nematodes have developed sophisticated strategies to dampen their host’s immune response. Proteins that are actively secreted by the parasites have been shown to induce the expansion of regulatory T cells and to directly interfere with effector T cell function. Here, we analyze the suppressive capacity of Onchocercavolvulus-derived excreted/secreted proteins. Addition of two recombinant O. volvulus proteins, abundant larval transcript-2 (OvALT-2) and novel larval transcript-1 (OvNLT-1) to cell cultures of T cell receptor transgenic CD4+ and CD8+ T cells suppressed antigen-specific stimulation in vitro. Ovalbumin-specific CD4+ DO11.10 and OT-II T cells that had been stimulated with their cognate antigen in the presence of OvALT-2 or OvNLT-1 displayed reduced DNA synthesis quantified by 3H-thymidine incorporation and reduced cell division quantified by CFSE dilution. Furthermore, the IL-2 and IFN-γ response of ovalbumin-specific CD8+ OT-I T cells was suppressed by OvALT-2 and OvNLT-1. In contrast, another recombinant O. volvulus protein, microfilariae surface-associated antigen (Ov103), did not modulate T cell activation, thus serving as internal control for non-ESP-mediated artifacts. Suppressive capacity of the identified ESP was associated with induction of apoptosis in T cells demonstrated by increased exposure of phosphatidylserine on the plasma membrane. Of note, the digestion of recombinant proteins with proteinase K did not abolish the suppression of antigen-specific proliferation although the suppressive capacity of the identified excreted/secreted products was not mediated by low molecular weight contaminants in the undigested preparations. In summary, we identified two suppressive excreted/secreted products from O. volvulus, which interfere with the function of antigen-specific T cells in vitro. PMID:23861729

  5. Nematode-derived proteins suppress proliferation and cytokine production of antigen-specific T cells via induction of cell death.

    Directory of Open Access Journals (Sweden)

    Wiebke Hartmann

    Full Text Available In order to establish long-lasting infections in their mammalian host, filarial nematodes have developed sophisticated strategies to dampen their host's immune response. Proteins that are actively secreted by the parasites have been shown to induce the expansion of regulatory T cells and to directly interfere with effector T cell function. Here, we analyze the suppressive capacity of Onchocercavolvulus-derived excreted/secreted proteins. Addition of two recombinant O. volvulus proteins, abundant larval transcript-2 (OvALT-2 and novel larval transcript-1 (OvNLT-1 to cell cultures of T cell receptor transgenic CD4(+ and CD8(+ T cells suppressed antigen-specific stimulation in vitro. Ovalbumin-specific CD4(+ DO11.10 and OT-II T cells that had been stimulated with their cognate antigen in the presence of OvALT-2 or OvNLT-1 displayed reduced DNA synthesis quantified by (3H-thymidine incorporation and reduced cell division quantified by CFSE dilution. Furthermore, the IL-2 and IFN-γ response of ovalbumin-specific CD8(+ OT-I T cells was suppressed by OvALT-2 and OvNLT-1. In contrast, another recombinant O. volvulus protein, microfilariae surface-associated antigen (Ov103, did not modulate T cell activation, thus serving as internal control for non-ESP-mediated artifacts. Suppressive capacity of the identified ESP was associated with induction of apoptosis in T cells demonstrated by increased exposure of phosphatidylserine on the plasma membrane. Of note, the digestion of recombinant proteins with proteinase K did not abolish the suppression of antigen-specific proliferation although the suppressive capacity of the identified excreted/secreted products was not mediated by low molecular weight contaminants in the undigested preparations. In summary, we identified two suppressive excreted/secreted products from O. volvulus, which interfere with the function of antigen-specific T cells in vitro.

  6. Activated human nasal epithelial cells modulate specific antibody response against bacterial or viral antigens.

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    Chiou-Yueh Yeh

    Full Text Available Nasal mucosa is an immune responsive organ evidenced by eliciting both specific local secretory IgA and systemic IgG antibody responses with intra-nasal administration of antigens. Nevertheless, the role of nasal epithelial cells in modulating such responses is unclear. Human nasal epithelial cells (hNECs obtained from sinus mucosa of patients with chronic rhinosinusitis were cultured in vitro and firstly were stimulated by Lactococcus lactis bacterium-like particles (BLPs in order to examine their role on antibody production. Secondly, both antigens of immunodominant protein IDG60 from oral Streptococcus mutans and hemagglutinin (HA from influenza virus were tested to evaluate the specific antibody response. Stimulated hNECs by BLPs exhibited a significant increase in the production of interleukin-6 (IL-6, and thymic stromal lymphopoietin (TSLP. Conditioned medium of stimulated hNECs has effects on enhancing the proliferation of CD4+ T cells together with interferon-γ and IL-5 production, increasing the costimulatory molecules on dendritic cells and augmenting the production of IDG60 specific IgA, HA specific IgG, IgA by human peripheral blood lymphocytes. Such production of antigen specific IgG and IgA is significantly counteracted in the presence of IL-6 and TSLP neutralizing antibodies. In conclusion, properly stimulated hNECs may impart immuno-modulatory effects on the antigen-specific antibody response at least through the production of IL-6 and TSLP.

  7. Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells

    Science.gov (United States)

    Ngugi, Daniel; Lizundia, Regina; Hostettler, Isabel; Woods, Kerry; Ballingall, Keith; MacHugh, Niall D.; Morrison, W. Ivan; Weir, Willie; Shiels, Brian; Werling, Dirk

    2016-01-01

    As part of an international effort to develop vaccines for Theileria lestoquardi, we undertook a limited screen to test T. lestoquardi orthologues of antigens recognised by CD8+ T lymphocyte responses against T. annulata and T. parva in cattle. Five MHC defined sheep were immunized by live T. lestoquardi infection and their CD8+ T lymphocyte responses determined. Thirteen T. lestoquardi orthologues of T. parva and T. annulata genes, previously shown to be targets of CD8+ T lymphocyte responses of immune cattle, were expressed in autologous fibroblasts and screened for T cell recognition using an IFNγ assay. Genes encoding T. lestoquardi antigens Tl8 (putative cysteine proteinase, 349 aa) or Tl9 (hypothetical secreted protein, 293 aa) were recognise by T cells from one animal that displayed a unique MHC class I genotype. Antigenic 9-mer peptide epitopes of Tl8 and Tl9 were identified through peptide scans using CD8+ T cells from the responding animal. These experiments identify the first T. lestoquardi antigens recognised by CD8+ T cell responses linked to specific MHC class I alleles. PMID:27611868

  8. MHC-based detection of antigen-specific CD8(+) T cell responses

    DEFF Research Database (Denmark)

    Hadrup, Sine Reker; Schumacher, Nana Maria Pii

    2010-01-01

    The hallmark of adaptive immunity is its ability to recognise a wide range of antigens and technologies that capture this diversity are therefore of substantial interest. New methods have recently been developed that allow the parallel analysis of T cell reactivity against vast numbers of differe...

  9. Aspergillus galactomannan antigen levels in allogeneic haematopoietic stem cell transplant recipients given total parenteral nutrition.

    NARCIS (Netherlands)

    Blijlevens, N.M.A.; Donnelly, J.P.; Meis, J.F.G.M.; Verweij, P.E.; Pauw, B.E. de

    2002-01-01

    False-positive tests for Aspergillus galactomannan have been reported in neutropenic patients. We failed to detect any circulating antigen during the 2 weeks following allogeneic haematopoietic stem cell transplantation of 12 patients who had severe mucositis but were unable to eat.

  10. Defining the HLA class I-associated viral antigen repertoire from HIV-1-infected human cells

    DEFF Research Database (Denmark)

    Ternette, Nicola; Yang, Hongbing; Partridge, Thomas

    2016-01-01

    % of the identified sequences originated from viral protein regions for which T-cell responses have previously been reported but for which the precise HLA class I-binding sequences have not yet been defined. These results validate and expand the current knowledge of virus-specific antigenic peptide presentation...

  11. Tolerization of an established αb-crystallin-reactive T-cell response by intravenous antigen

    NARCIS (Netherlands)

    Verbeek, R.; Mark, K. van der; Wawrousek, E.F.; Plomp, A.C.; Noort, J.M. van

    2007-01-01

    Tolerance induction to prevent activation of a naïve T-cell repertoire has been well documented in rodents and can be readily achieved by intravenous, oral or intranasal administration of antigen in the absence of adjuvants. In autoimmune diseases such as multiple sclerosis (MS) the presence of an e

  12. CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis

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    Kanin Salao

    2016-05-01

    Full Text Available Intracellular chloride channel protein 1 (CLIC1 participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs, the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs from germline CLIC1 gene-deleted (CLIC1−/− and wild-type (CLIC1+/+ mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1−/− BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1−/− cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1−/− BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases.

  13. 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...

  14. Expression Patterns of Cancer-Testis Antigens in Human Embryonic Stem Cells and Their Cell Derivatives Indicate Lineage Tracks

    OpenAIRE

    Nadya Lifantseva; Anna Koltsova; Tatyana Krylova; Tatyana Yakovleva; Galina Poljanskaya; Olga Gordeeva

    2011-01-01

    Pluripotent stem cells can differentiate into various lineages but undergo genetic and epigenetic changes during long-term cultivation and, therefore, require regular monitoring. The expression patterns of cancer-testis antigens (CTAs) MAGE-A2, -A3, -A4, -A6, -A8, -B2, and GAGE were examined in undifferentiated human embryonic stem (hES) cells, their differentiated derivatives, teratocarcinoma (hEC) cells, and cancer cell lines of neuroectodermal and mesodermal origin. Undifferentiated hES ce...

  15. Affinity for self antigen selects Treg cells with distinct functional properties.

    Science.gov (United States)

    Wyss, Lena; Stadinski, Brian D; King, Carolyn G; Schallenberg, Sonja; McCarthy, Nicholas I; Lee, Jun Young; Kretschmer, Karsten; Terracciano, Luigi M; Anderson, Graham; Surh, Charles D; Huseby, Eric S; Palmer, Ed

    2016-09-01

    The manner in which regulatory T cells (Treg cells) control lymphocyte homeostasis is not fully understood. We identified two Treg cell populations with differing degrees of self-reactivity and distinct regulatory functions. We found that GITR(hi)PD-1(hi)CD25(hi) (Triple(hi)) Treg cells were highly self-reactive and controlled lympho-proliferation in peripheral lymph nodes. GITR(lo)PD-1(lo)CD25(lo) (Triple(lo)) Treg cells were less self-reactive and limited the development of colitis by promoting the conversion of CD4(+) Tconv cells into induced Treg cells (iTreg cells). Although Foxp3-deficient (Scurfy) mice lacked Treg cells, they contained Triple(hi)-like and Triple(lo)-like CD4(+) T cells zsuper> T cells infiltrated the skin, whereas Scurfy Triple(lo)CD4(+) T cells induced colitis and wasting disease. These findings indicate that the affinity of the T cell antigen receptor for self antigen drives the differentiation of Treg cells into distinct subsets with non-overlapping regulatory activities.

  16. HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells.

    Science.gov (United States)

    Varma, Sandeep R; Sundaram, R; Gopumadhavan, S; Vidyashankar, Satyakumar; Patki, Pralhad S

    2013-01-01

    HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000  μ g/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380  μ g/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections.

  17. Salinomycin induces cell death via inactivation of Stat3 and downregulation of Skp2

    OpenAIRE

    Koo, K H; Kim, H.; Bae, Y-K; Kim, K.; Park, B-K; Lee, C-H; Kim, Y-N

    2013-01-01

    Salinomycin has been shown to control breast cancer stem cells, although the mechanisms underlying its anticancer effects are not clear. Deregulation of cell cycle regulators play critical roles in tumorigenesis, and they have been considered as anticancer targets. In this study, we investigated salinomycin effect on cell cycle progression using OVCAR-8 ovarian cancer cell line and multidrug-resistant NCI/ADR-RES and DXR cell lines that are derived from OVCAR-8. Parental OVCAR-8 cells are sen...

  18. Cocaine enhances HIV-1 replication in CD4+ T cells by down-regulating MiR-125b.

    Directory of Open Access Journals (Sweden)

    Chinmay K Mantri

    Full Text Available The main objective of this study was to examine effects of cocaine on HIV-1 replication in primary CD4+ T cells. Cocaine a commonly used drug among HIV-1 positive individuals serves as a cofactor for HIV-1 infection and progression to acquired immunodeficiency syndrome (AIDS. Accumulating evidence suggest that cocaine increases HIV-1 replication in cell cultures, peripheral blood mononuclear cells (PBMCs and animal models. Intriguingly, there are no studies on cocaine-induced alterations in HIV-1 replication in primary CD4+ T cells that serve as the main targets for HIV-1 replication in vivo. In this report, we demonstrate cocaine-induced enhancement of HIV-1 replication in primary CD4+ T cells isolated from human PBMCs. To decipher a potential mechanism, we examined whether cocaine targets the innate antiviral immunity of CD4+ T cells mediated by cellular microRNAs (miRNAs. This is because recently a network of anti-HIV miRNAs in CD4+ T cells is highlighted to suppress viral replication. Our genome wide miRNA expression analysis indicated downregulation of several anti-HIV miRNAs (miR-28, miR-125b, miR-150, miR-223, and miR-382 in cocaine treated CD4+ T cells. However, our real-time quantitative PCR analysis revealed significant downregulation of miR-125b only. Our results illustrated that miR-125b knockdown enhances HIV-1 replication, whereas overexpression of miR-125b decreases HIV-1 replication in these cells. Therefore, we believe miR-125b is a key player for the cocaine induced enhancement of HIV-1 replication in CD4+ T cells. Since, miR-125b targets the 3' UTR regions of HIV-1 transcripts and inhibits viral protein translation, our data suggest modulation of post entry steps of HIV-1 by cocaine. Given that a plethora of studies suggest that cocaine regulates HIV entry, our results implicate a potentially novel mechanism by which cocaine can increase viral replication in CD4+ T cells.

  19. RNAi‑mediated knockdown of PRL‑3 inhibits cell invasion and downregulates ERK 1/2 expression in the human gastric cancer cell line, SGC‑7901.

    Science.gov (United States)

    Cao, Yi; Tu, Yi; Mei, Jinhong; Li, Zhengrong; Jie, Zhigang; Xu, Shan; Xu, Linlin; Wang, Shanshan; Xiong, Yifeng

    2013-06-01

    The deregulated expression of members of the phophatase of regenerating liver (PRL) family is important in the metastatic progression of multiple human cancers; however, the underlying mechanisms are not well understood. Previous studies have demonstrated that PRLs are able to enhance the activation of extracellular signal‑regulated kinase 1/2 (ERK 1/2) in cancer cells, which may contribute to tumor metastasis. However, the effect of PRL‑3 activation in gastric cancer (GC) remains unclear. The present study aimed to investigate whether the downregulation of PRL‑3 by small interfering RNA (siRNA) was able to inhibit cell motility and affect ERK 1/2 expression in human GC. The results demonstrated that the downregulation of PRL‑3 expression by siRNA in human GC cells significantly inhibited cell invasion and migration in vitro; accordingly, inhibition of PRL‑3 also prevented ERK1/2 protein and mRNA expression, and reduced the mRNA level of matrix metalloproteinase‑7 (MMP‑7), the downstream target of ERK 1/2 signaling. Our data demonstrated that RNAi‑mediated downregulation of PRL‑3 expression leads to potent antitumor activity in human GC. Furthermore, ERK 1/2 and MMP‑7 may contribute to the carcinogenesis and development of human GC in combination with PRL‑3.

  20. Inflammatory environment and oxidized LDL convert circulating human proangiogenic cells into functional antigen-presenting cells.

    Science.gov (United States)

    Vinci, Maria Cristina; Piacentini, Luca; Chiesa, Mattia; Saporiti, Federica; Colombo, Gualtiero I; Pesce, Maurizio

    2015-09-01

    The function of human circulating PACs has been described extensively. However, little focus has been placed on understanding how these cells differ in their functions in the presence of microenvironments mimicking vascular inflammation. We hypothesized that exposure to proinflammatory cytokines or the oxLDL, an autoantigen abundant in advanced atherosclerotic plaques, converts PACs into immune-modulating/proinflammatory cells. Hence, we examined the effect of oxLDL and inflammatory stimuli on their phenotype by use of a functional genomics model based on secretome and whole genome transcriptome profiling. PACs obtained from culturing a PBMC fraction in angiogenic medium were primed with DC differentiation cytokines and then exposed to proinflammatory cytokines or oxLDL. Under these conditions, PACs converted into APCs, expressed maturation markers CD80 and CD83, and showed an increased up-regulation of CD86. APCcy and APCox induced a robust T cell BrdU incorporation. Despite a similar ability to induce lymphocyte proliferation, APCcy and APCox differed for the secretory pathway and mRNA expression. Analysis of the differentially expressed genes identified 4 gene "clusters," showing reciprocal modulation in APCcy vs. APCox, justifying, according to functional genomics analyses, a different putative function of the cells in antigen processing. Together, these data show that treatment with inflammatory cytokines or oxLDL converts human PAC phenotypes and functions into that of APCs with similar lymphocyte-activating ability but distinct maturation degree and paracrine functions.

  1. Inhibitory activities of microalgal extracts against Epstein-Barr Virus (EBV antigen expression in lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Koh Yih Yih

    2014-01-01

    Full Text Available The inhibitory activities of microalgal extracts against the expression of three EBV antigens, latent membrane protein (LMP1, Epstein-Barr nuclear antigen (EBNA1 and Z Epstein-Barr reactivation activator (ZEBRA were assessed by immunocytochemistry. The observation that the methanol extracts and their fractions from Ankistrodesmus convolutus, Synechococcus elongatus and Spirulina platensis exhibited inhibitory activity against EBV proteins in three Burkitt’s lymphoma cell lines at concentrations as low as 20 μg/ml suggests that microalgae could be a potential source of antiviral compounds against EBV.

  2. Effective expansion of forkhead box P3⁺ regulatory T cells via early secreted antigenic target 6 and antigen 85 complex B from Mycobacterium tuberculosis.

    Science.gov (United States)

    Wu, Ying-E; Du, Zhong-Ren; Cai, Ying-Mu; Peng, Wen-Guang; Zheng, Gao-Zhe; Zheng, Geng-Long; Wu, Li-Biao; Li, Ke

    2015-04-01

    The expansion of CD4+ CD25+ forkhead box (FOX)P3+ regulatory T (Treg) cells has been observed in patients with Mycobacterium (M.) tuberculosis; however, the mechanism of expansion remains to be elucidated. The aim of the present study was to examine the role of the early secreted antigenic target 6(ESAT‑6) and antigen 85 complex B (Ag85B) from M. tuberculosis on Treg cell expansion. To investigate the sensitivity of peripheral blood cultures to the M. tuberculosis ESAT‑6 and Ag85B antigens, the proportion of circulating CD4+ CD25+ FOXP3+ Treg cells was determined using flow cytometry and the levels of FOXP3 mRNA were determined using reverse transcription quantitative polymerase chain reaction. The mRNA levels of FOXP3 and the proportion of circulating CD4+ CD25+ FOXP3+ Treg cells were increased in multiplicitous drug‑resistant tuberculosis patients compared with those in healthy controls and patients with latent tuberculosis (TB) infection (LTBI) (Ptuberculosis antigens ESAT‑6 and Ag85B induced CD4+ CD25+ FOXP3+ Treg‑cell expansion, particularly in patients with LTBI. These findings indicated that CD4+ CD25+ FOXP3+ Treg cells may have a primary role in the failure of the host immune system to eradicate M. tuberculosis.

  3. Detection of cells captured with antigens on shear horizontal surface-acoustic-wave sensors.

    Science.gov (United States)

    Hao, Hsu-Chao; Chang, Hwan-You; Wang, Tsung-Pao; Yao, Da-Jeng

    2013-02-01

    Techniques to separate cells are widely applied in immunology. The technique to separate a specific antigen on a microfluidic platform involves the use of a shear horizontal surface-acoustic-wave (SH-SAW) sensor. With specific antibodies conjugated onto the surface of the SH-SAW sensors, this technique can serve to identify specific cells in bodily fluids. Jurkat cells, used as a target in this work, provide a model of cells in small abundance (1:1000) for isolation and purification with the ultimate goal of targeting even more dilute cells. T cells were separated from a mixed-cell medium on a chip (Jurkat cells/K562 cells, 1/1000). A novel microchamber was developed to capture cells during the purification, which required a large biosample. Cell detection was demonstrated through the performance of genetic identification on the chip.

  4. Inhibition of effector antigen-specific T cells by intradermal administration of heme oxygenase-1 inducers.

    Science.gov (United States)

    Simon, Thomas; Pogu, Julien; Rémy, Séverine; Brau, Frédéric; Pogu, Sylvie; Maquigneau, Maud; Fonteneau, Jean-François; Poirier, Nicolas; Vanhove, Bernard; Blancho, Gilles; Piaggio, Eliane; Anegon, Ignacio; Blancou, Philippe

    2017-03-22

    Developing protocols aimed at inhibiting effector T cells would be key for the treatment of T cell-dependent autoimmune diseases including type 1 autoimmune diabetes (T1D) and multiple sclerosis (MS). While heme oxygenase-1 (HO-1) inducers are clinically approved drugs for non-immune-related diseases, they do have immunosuppressive properties when administered systemically in rodents. Here we show that HO-1 inducers inhibit antigen-specific effector T cells when injected intradermally together with the T cell cognate antigens in mice. This phenomenon was observed in both a CD8(+) T cell-mediated model of T1D and in a CD4(+) T cell-dependent MS model. Intradermal injection of HO-1 inducers induced the recruitment of HO-1(+) monocyte-derived dendritic cell (MoDCs) exclusively to the lymph nodes (LN) draining the site of intradermal injection. After encountering HO-1(+)MoDCs, effector T-cells exhibited a lower velocity and a reduced ability to migrate towards chemokine gradients resulting in impaired accumulation to the inflamed organ. Intradermal co-injection of a clinically approved HO-1 inducer and a specific antigen to non-human primates also induced HO-1(+) MoDCs to accumulate in dermal draining LN and to suppress delayed-type hypersensitivity. Therefore, in both mice and non-human primates, HO-1 inducers delivered locally inhibited effector T-cells in an antigen-specific manner, paving the way for repositioning these drugs for the treatment of immune-mediated diseases.

  5. Berberine Induces Apoptosis in p53-Null Leukemia Cells by Down-Regulating XIAP at the Post-Transcriptional Level

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2013-11-01

    Full Text Available Background: Berberine exerts anticancer activities both in vitro and in vivo through different mechanisms. However, the underlying molecular mechanisms of berberine induced p53-independent apoptosis remain unclear. Methods: The p53-null leukemia cell line EU-4 cells were exposed to berberine. Then the cell viability and apoptosis were determined. Western blot and PCR were employed to detect the expression of apoptosis related protein, XIAP and MDM2. Small interfering RNA (siRNA was applied to knock down endogenous expression of MDM2 and XIAP. Results: Berberine induced p53-independent, XIAP-mediated apoptotic cell death in p53-null leukemia cells. Treatment with berberine resulted in suppression of XIAP protein in a dose- and time- dependent manner. Berberine induced down-regulation of XIAP protein involving inhibition of MDM2 expression and a proteasome-dependent pathway. Moreover, inhibition of XIAP by berberine or siRNA increased the sensitivity of leukemia cells to doxorubicin-induced apoptosis. Conclusion: Our findings characterize the molecular mechanisms of berberine-induced caspase activation and subsequent apoptosis, and berberine may be a novel candidate inducer of apoptosis in leukemia cells, which normally lack p53 expression.

  6. RNA interference targeting CD147 inhibits the invasion of human cervical squamous carcinoma cells by downregulating MMP-9.

    Science.gov (United States)

    Fan, Xiaobin; Wu, Weiguang; Shi, Haixia; Han, Jianqiu

    2013-07-01

    Cervical squamous carcinoma is a highly invasive tumour that has a great capacity to metastasise. Extracellular matrix metalloproteinase inducer (EMMPRIN or CD147), a member of the immunoglobulin superfamily, is a widely distributed cell surface glycoprotein. It is highly expressed on malignant tumour cell surfaces, including human cervical squamous carcinoma. It also plays a critical role in the invasive and metastatic activity of malignant cells by stimulating the expression of matrix metalloproteinases (MMPs). The anti-invasive effect of small interfering RNA (siRNA) against CD147 on human cervical squamous carcinoma cells and its possible pathways has been investigated. The downregulation of CD147 by transfection with siRNA resulted in MMP-9 expression and decreased activity in the cervical squamous carcinoma cell line SiHa. In vitro analysis showed that the invasive capacity of SiHa cells decreased. Thus CD147 inhibition and subsequent MMP-9 deletion may have anti-tumour effects by inhibiting the invasiveness of human cervical squamous carcinoma cells.

  7. N-Acetyl-L-Cystein downregulates beta-amyloid precursor protein gene transcription in human neuroblastoma cells.

    Science.gov (United States)

    Studer, R; Baysang, G; Brack, C

    2001-01-01

    The causes for the sporadic form of Alzheimer's disease (AD) are still poorly understood, except from the fact that age is an important risk factor. The main component of the characteristic amyloid plaques in brains of AD patients are Abeta peptides, derivatives of the amyloid precursor protein APP. Oxidative stress may contribute to the aetiology of AD by dysregulation of APP metabolism. Overexpression of the APP gene could result in an increased secretion of neurotoxic Abeta peptides, while preventing the overexpression might be protective. We here report that the antioxidant N-Acetyl-L-Cystein (NAC) downregulates APP gene transcription in human neuroblastoma cells. The effect is reversible when cells are returned to NAC free medium. These results open up new possibilities for the development of therapeutic agents that intervene at the transcriptional level.

  8. Simvastatin downregulated C35 expression and inhibited the proliferation of colon cancer cells Lovo and HT29 in vitro.

    Science.gov (United States)

    Li, Min; Huang, Yong; Dong, Xuan; Wei, Qingkuan; Li, Jin; Sun, Hui; Li, Chenchen; Qi, Conghu; Yang, Jingyu

    2016-07-19

    The aim of this study was to investigate the antitumor effect of simvastatin in human colon cancer and the possible underlying mechanism. We found that simvastatin dose-dependently inhibited the proliferation of human colon cancer cells Lovo and HT29 using a MTT assay. Real-time PCR and Western blotting assays showed that simvastatin significantly suppressed C35 expression at both mRNA and protein levels. Since C35 is known to have a significant oncogenic role in cancer development via promoting cell proliferation and migration, results obtained in the current study imply that downregulation of C35 expression might be involved in the antitumor effect of simvastatin on colon cancer.

  9. T cell responses to hepatitis B surface antigen are detectable in non-vaccinated individuals

    Institute of Scientific and Technical Information of China (English)

    Martin R Weihrauch; Michael von Bergwelt-Baildon; Milos Kandic; Martin Weskott; Winfried Klamp; Joachim R(o)sier; Joachim L Schultze

    2008-01-01

    AIM: To evaluate, whether humoral hepatitis-B-vaccine non-responders also fail to mount a T cell response and to compare these results to normal vaccinees.METHODS: Fourty-seven health care employees were enrolled in this study including all available nonresponders (n = 13) with an anti-HBsAg titer 1000 kU/L as controls.PBMC from all subjects were analyzed by IFN-γ and IL-4 ELISPOT assays for the presence of hepatitis B surface antigen (HBsAg) reactive T cells.RESULTS: Non-responders and low-responders had no or only very limited T cell responses, respectively.Individuals responding to vaccination with the induction of a high anti-HBsAg titer showed a strong T cell response after the third vaccination.Surprisingly, these individuals showed response even before the first vaccination.T cell response to control antigens and mitogens was similar in all groups.CONCLUSION: Our data suggest that there is no general immune deficiency in non-/low-responders.Thus,we hypothesize that the induction of anti-HBsAg responses by vaccination is significantly dependent on the pre-existing T cell repertoire against the specific antigen rather than the presence of a general T cell defect.

  10. Going viral: chimeric antigen receptor T-cell therapy for hematological malignancies.

    Science.gov (United States)

    Gill, Saar; June, Carl H

    2015-01-01

    On July 1, 2014, the United States Food and Drug Administration granted 'breakthrough therapy' designation to CTL019, the anti-CD19 chimeric antigen receptor T-cell therapy developed at the University of Pennsylvania. This is the first personalized cellular therapy for cancer to be so designated and occurred 25 years after the first publication describing genetic redirection of T cells to a surface antigen of choice. The peer-reviewed literature currently contains the outcomes of more than 100 patients treated on clinical trials of anti-CD19 redirected T cells, and preliminary results on many more patients have been presented. At last count almost 30 clinical trials targeting CD19 were actively recruiting patients in North America, Europe, and Asia. Patients with high-risk B-cell malignancies therefore represent the first beneficiaries of an exciting and potent new treatment modality that harnesses the power of the immune system as never before. A handful of trials are targeting non-CD19 hematological and solid malignancies and represent the vanguard of enormous preclinical efforts to develop CAR T-cell therapy beyond B-cell malignancies. In this review, we explain the concept of chimeric antigen receptor gene-modified T cells, describe the extant results in hematologic malignancies, and share our outlook on where this modality is likely to head in the near future.

  11. Effect of Exogenous Ghrelin on Cell Differentiation Antigen 40 Expression in Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    Min ZHANG; Fang YUAN; Hui CHEN; Xingbiao QIU; Weiyi FANG

    2007-01-01

    Ghrelin is a brain-gut peptide that serves as a natural ligand for growth hormone secretagogue receptor (GHSR). It also exists abundantly in the cardiovascular system. In order to evaluate the possible role of ghrelin in the development of atherosclerosis, the effect of ghrelin on the expression of cell differentiation antigen 40 (CD40) were studied. Human umbilical vein endothelial cell (HUVEC) line-ECV 304 was pretreated with different concentrations of ghrelin, des-acyl ghrelin or [d-Lys]-GHRP-6 (a ghrelin receptor antagonist), and then induced with tumor necrosis factor-α (TNF-α) and interferon γ (IFN-γ). The mRNA levels of CD40 were analyzed by reverse transcription-polymerase chain reaction, and the expressions of CD40 protein in the cells were measured by flow cytometry (FCM) and Western blotting. The results showed that exogenous ghrelin could significantly inhibit TNF-α/IFN-γinduced CD40 expression in HUVEC cells in a concentration-dependent manner. When treated with 1000 ng/ml of ghrelin, the mRNA level of CD40 in the cells was decreased by approximately 77%, but when treated with both 1000 ng/ml of ghrelin and 1000 ng/ml of [d-Lys]-GHRP-6, the mRNA level of CD40 in the cells was decreased by only 42%,suggesting that [d-Lys]-GHRP-6 could counteract the inhibitory effect of ghrelin in these cells. However,CD40 expression was not inhibited by des-acyl ghrelin at 1000 ng/ml. The results in protein expression analysis detected by FCM and Western blotting further confirmed these results. Our results suggested that in the cardiovascular system, ghrelin not only has an anti-inflammatory effect, but also has a significant immunoregulatory effect that may be mediated through the GHSR-1 a receptor.

  12. Ethanol Metabolism Alters Major Histocompatibility Complex Class I-Restricted Antigen Presentation In Liver Cells

    Science.gov (United States)

    Osna, Natalia A.; White, Ronda L.; Thiele, Geoffrey M.; Donohue, Terrence M.

    2009-01-01

    The proteasome is a major enzyme that cleaves proteins for antigen presentation. Cleaved peptides traffic to the cell surface, where they are presented in the context of MHC class I. Recognition of these complexes by cytotoxic T lymphocytes is crucial for elimination of cells bearing “non-self” proteins. Our previous studies revealed that ethanol suppresses proteasome function in ethanol-metabolizing liver cells. We hypothesized that proteasome suppression reduces the hydrolysis of antigenic peptides, thereby decreasing the presentation of the peptide-MHC class I-complexes on the cell surface. To test this, we used the mouse hepatocyte cell line (CYP2E1/ADH-transfected HepB5 cells) or primary mouse hepatocytes, both derived from livers of C57Bl/6 mice, which present the ovalbumin peptide, SIINFEKL, complexed with H2Kb. To induce H2Kb expression, HepB5 cells were treated with interferon gamma (IFNγ) and then exposed to ethanol. In these cells, ethanol metabolism decreased not only proteasome activity, but also hydrolysis of the C-extended peptide, SIINFEKL-TE and the presentation of SIINFEKL-H2Kb complexes measured after the delivery of SIINFEKL-TE to cytoplasm. The suppressive effects of ethanol were, in part, attributed to ethanol-elicited impairment of IFNγ signaling. However, in primary hepatocytes, even in the absence of IFNγ, we observed a similar decline in proteasome activity and antigen presentation after ethanol exposure. We conclude that proteasome function is directly suppressed by ethanol metabolism and indirectly, by preventing the activating effects of IFNγ. Ethanol-elicited reduction in proteasome activity contributes to the suppression of SIINFEKL-H2Kb presentation on the surface of liver cells. Immune response to viral antigens plays a crucial role in the pathogenesis of hepatitis C or B viral infections (HCV and HBV, respectively). Professional antigen-presenting cells (dendritic cells and macrophages) are responsible for priming the

  13. Studies of the antigenicity and immunogenicity of bromelain-pretreated red blood cells.

    Science.gov (United States)

    Cox, K O; Baddams, H; Evans, A

    1977-02-01

    The effects of the proteolytic enzyme bromelain (Br) on the antigenicity and immunogenicity of sheep and mouse red blood cells (RBC) have been investigated. The results presented support the previous claim that there are antigens present on Br RBC that are not present in an exposed form on untreated RBC and that Br RBC have lost some of the antigens present on the surface of normal RBC. The susceptibility of Br RBC to osmotic lysis was very similar to that of normal RBC, implying that the modified RBC were not more fragile than normal RBC. Injection of mice with Br mouse-RBC did not increase the unusually high "background" number of cells producing IgM antibodies against Br mouse-RBC and mice did not mount delayed-type hypersensitivity reactions against Br mouse-RBC, either before or after sensitizing injections of Br mouse-RBC. However, mouse-RBC and Br mouse-RBC elicited similar antibody responses in rabbits and guinea pigs. Although mice appeared unresponsive to Br mouse-RBC injections, delayed-type hypersensitivity responses and antibody production in primary and secondary responses were of similar levels irrespective of whether sheep-RBC or Br sheep-RBC were used as immunogens. From these studies it appears that mice have B-cells producing antibodies against the "new" antigens on Br mouse-RBC, but there are no T-cells that respond to these antigens by way of "helper" activity in antibody production or by way of cell-mediated immune reactions.

  14. Dendritic cells engineered to express defined allo-HLA peptide complexes induce antigen-specific cytotoxic T cells efficiently killing tumour cells

    DEFF Research Database (Denmark)

    Stronen, E; Abrahamsen, I W; Gaudernack, G;

    2009-01-01

    presented by a non-self human leucocyte antigen (HLA) molecule and transferred to cancer patients expressing that HLA molecule. Obtaining allo-restricted CTL of high-avidity and low cross-reactivity has, however, proven difficult. Here, we show that dendritic cells transfected with mRNA encoding HLA-A*0201...... and efficiently killed HLA-A*0201(+) melanoma cells, whilst sparing HLA-A*0201(+) B-cells. Allo-restricted CTL specific for peptides from the leukaemia-associated antigens CD33 and CD19 were obtained with comparable efficiency. Collectively, the results show that dendritic cells engineered to express defined allo......Most tumour-associated antigens (TAA) are non-mutated self-antigens. The peripheral T cell repertoire is devoid of high-avidity TAA-specific cytotoxic T lymphocytes (CTL) due to self-tolerance. As tolerance is major histocompatibility complex-restricted, T cells may be immunized against TAA...

  15. Metformin increases antitumor activity of MEK inhibitors through GLI1 downregulation in LKB1 positive human NSCLC cancer cells

    Science.gov (United States)

    Della Corte, Carminia Maria; Ciaramella, Vincenza; Mauro, Concetta Di; Castellone, Maria Domenica; Papaccio, Federica; Fasano, Morena; Sasso, Ferdinando Carlo; Martinelli, Erika; Troiani, Teresa; De Vita, Ferdinando; Orditura, Michele; Bianco, Roberto; Ciardiello, Fortunato; Morgillo, Floriana

    2016-01-01

    Purpose Metformin, widely used as antidiabetic drug, showed antitumoral effects expecially in combination with chemotherapy. Our group recently has demonstrated that metformin and gefitinib are synergistic in LKB1-wild-type NSCLC cells. In these models, metformin as single agent induced an activation and phosphorylation of mitogen-activated-protein-kinase (MAPK) through an increased C-RAF/B-RAF heterodimerization. Experimental design Since single agent metformin enhances proliferating signals through the RAS/RAF/MAPK pathway, and several MEK inhibitors (MEK-I) demonstrated clinical efficacy in combination with other agents in NSCLC, we tested the effects of metformin plus MEK-I (selumetinib or pimasertib) on proliferation, invasiveness, migration abilities in vitro and in vivo in LKB1 positive NSCLC models harboring KRAS wild type and mutated gene. Results The combination of metformin with MEK-I showed a strong anti-proliferative and proapoptotic effect in Calu-3, H1299, H358 and H1975 human NSCLC cell lines, independently from the KRAS mutational status. The combination reduced the metastatic behaviour of NSCLC cells, via a downregulation of GLI1 trascritional activity, thus affecting the transition from an epithelial to a mesenchymal phenotype. Metformin and MEK-Is combinations also decreased the production and activity of MMP-2 and MMP-9 by reducing the NF-jB (p65) binding to MMP-2 and MMP-9 promoters. Conclusions Metformin potentiates the antitumor activity of MEK-Is in human LKB1-wild-type NSCLC cell lines, independently from the KRAS mutational status, through GLI1 downregulation and by reducing the NF-jB (p65)-mediated transcription of MMP-2 and MMP-9. PMID:26673006

  16. miR-126 is downregulated in cystic fibrosis airway epithelial cells and regulates TOM1 expression.

    LENUS (Irish Health Repository)

    Oglesby, Irene K

    2010-02-15

    Cystic fibrosis (CF) is one of the most common lethal genetic diseases in which the role of microRNAs has yet to be explored. Predicted to be regulated by miR-126, TOM1 (target of Myb1) has been shown to interact with Toll-interacting protein, forming a complex to regulate endosomal trafficking of ubiquitinated proteins. TOM1 has also been proposed as a negative regulator of IL-1beta and TNF-alpha-induced signaling pathways. MiR-126 is highly expressed in the lung, and we now show for the first time differential expression of miR-126 in CF versus non-CF airway epithelial cells both in vitro and in vivo. MiR-126 downregulation in CF bronchial epithelial cells correlated with a significant upregulation of TOM1 mRNA, both in vitro and in vivo when compared with their non-CF counterparts. Introduction of synthetic pre-miR-126 inhibited luciferase activity in a reporter system containing the full length 3\\'-untranslated region of TOM1 and resulted in decreased TOM1 protein production in CF bronchial epithelial cells. Following stimulation with LPS or IL-1beta, overexpression of TOM1 was found to downregulate NF-kappaB luciferase activity. Conversely, TOM1 knockdown resulted in a significant increase in NF-kappaB regulated IL-8 secretion. These data show that miR-126 is differentially regulated in CF versus non-CF airway epithelial cells and that TOM1 is a miR-126 target that may have an important role in regulating innate immune responses in the CF lung. To our knowledge, this study is the first to report of a role for TOM1 in the TLR2\\/4 signaling pathways and the first to describe microRNA involvement in CF.

  17. miR-125b suppresses the proliferation and migration of osteosarcoma cells through down-regulation of STAT3

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li-hong; Li, Hui; Li, Jin-ping; Zhong, Hui; Zhang, Han-chon; Chen, Jia [Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410010 (China); Xiao, Tao, E-mail: xiaotaoxyl@163.com [Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410010 (China)

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer miR-125b is frequently down-regulated in osteosarcoma samples and human osteosarcoma cell lines. Black-Right-Pointing-Pointer Ectopic restoration of miR-125b suppresses cell proliferation and migration in vitro. Black-Right-Pointing-Pointer STAT3 is the direct and functional downstream target of miR-125b. Black-Right-Pointing-Pointer STAT3 can bind to the promoter region of miR-125b and serves as a transactivator. -- Abstract: There is accumulating evidence that microRNAs are involved in multiple processes in development and tumor progression. Abnormally expressed miR-125b was found to play a fundamental role in several types of cancer; however, whether miR-125b participates in regulating the initiation and progress of osteosarcoma still remains unclear. Here we demonstrate that miR-125b is frequently down-regulated in osteosarcoma samples and human osteosarcoma cell lines. The ectopic restoration of miR-125b expression in human osteosarcoma cells suppresses proliferation and migration in vitro and inhibits tumor formation in vivo. We further identified signal transducer and activator of transcription 3 (STAT3) as the direct and functional downstream target of miR-125b. Interestingly, we discovered that the expression of miR-125b is regulated by STAT3 at the level of transcription. STAT3 binds to the promoter region of miR-125b in vitro and serves as a transactivator. Taken together, our findings point to an important role in the molecular etiology of osteosarcoma and suggest that miR-125b is a potential target in the treatment of osteosarcoma.

  18. Sonic hedgehog initiates cochlear hair cell regeneration through downregulation of retinoblastoma protein

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Na [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Department of Otolaryngology and Program in Neuroscience, Harvard Medical School and Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114 (United States); Chen, Yan [Central Laboratory, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Wang, Zhengmin [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Institute of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Chen, Guoling [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Lin, Qin [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Department of Otolaryngology, First Affiliated Hospital of Fujian Medical University, Otolaryngology Institute of Fujian Province, Fuzhou (China); Chen, Zheng-Yi, E-mail: Zheng-yi_chen@meei.harvard.edu [Department of Otolaryngology and Program in Neuroscience, Harvard Medical School and Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114 (United States); Li, Huawei, E-mail: hwli@shmu.edu.cn [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Institute of Biomedical Sciences, Fudan University, Shanghai 200032 (China)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer Shh activation in neonatal cochleae enhances sensory cell proliferation. Black-Right-Pointing-Pointer Proliferating supporting cells can transdifferentiate into hair cells. Black-Right-Pointing-Pointer Shh promotes proliferation by transiently modulating pRb activity. Black-Right-Pointing-Pointer Shh inhibits pRb by inhibiting transcription and increasing phosphorylation of pRb. -- Abstract: Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration.

  19. Application of an enzyme-labeled antigen method for visualizing plasma cells producing antibodies against Strep A, a carbohydrate antigen of Streptococcus pyogenes, in recurrent tonsillitis.

    Science.gov (United States)

    Onouchi, Takanori; Mizutani, Yasuyoshi; Shiogama, Kazuya; Inada, Ken-ichi; Okada, Tatsuyoshi; Naito, Kensei; Tsutsumi, Yutaka

    2015-01-01

    Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders.

  20. Human tumour antigens defined by cytotoxicity and proliferative responses of cultured lymphoid cells

    Science.gov (United States)

    Vose, Brent M.; Bonnard, Guy D.

    1982-03-01

    The long-term goal of many laboratories has been to develop cellular reagents having specific reactivity against human tumour cells. Such immune cells should prove useful for defining the antigenicity of human malignancies and may have important therapeutic potential, as has been clearly shown in some animal models1. Here we describe methods of initiating continued lymphocyte cultures (CLC) having specific anti-tumour reactivity using conditioned media containing interleukin-2 (IL-2).

  1. Molecular effects of bioactive fraction of Curcuma mangga (DLBS4847) as a downregulator of 5α-reductase activity pathways in prostatic epithelial cells.

    Science.gov (United States)

    Karsono, Agung Heru; Tandrasasmita, Olivia Mayasari; Tjandrawinata, Raymond R

    2014-01-01

    DLBS4847 is a standardized bioactive fraction of Curcuma mangga. In this study, we used prostate cancer (PC)-3 as the cell line to study the effects of DLBS4847 on prostatic cell viability, as well as related molecular changes associated with the decreased cell number. The observation revealed that DLBS4847 inhibited the growth of PC3 cells through downregulation of the 5α-reductase (5AR) pathway. At the transcription level, 5AR1 and androgen-receptor gene expressions were downregulated in a dose-dependent manner. Furthermore, 5AR-1 and dihydrotestosterone expression were also downregulated at the protein level. A microarray study was also performed to see the effects of DLBS4847 on differential gene expressions in prostate cancer 3 cells. Among others, DLBS4847 downregulated genes related to prostate growth and hypertrophy. Our results suggested that DLBS4847 could potentially become an alternative treatment for prostate disorders, such as benign prostatic hyperplasia. In this regard, DLBS4847 exerts its growth inhibition partially through downregulation of the 5AR pathway.

  2. Molecular effects of bioactive fraction of Curcuma mangga (DLBS4847 as a downregulator of 5α-reductase activity pathways in prostatic epithelial cells

    Directory of Open Access Journals (Sweden)

    Karsono AH

    2014-06-01

    Full Text Available Agung Heru Karsono, Olivia Mayasari Tandrasasmita, Raymond R TjandrawinataSection of Molecular Pharmacology, Research Innovation and Invention, Dexa Laboratories of Biomolecular Sciences, Dexa Medica, Cikarang, IndonesiaAbstract: DLBS4847 is a standardized bioactive fraction of Curcuma mangga. In this study, we used prostate cancer (PC-3 as the cell line to study the effects of DLBS4847 on prostatic cell viability, as well as related molecular changes associated with the decreased cell number. The observation revealed that DLBS4847 inhibited the growth of PC3 cells through downregulation of the 5α-reductase (5AR pathway. At the transcription level, 5AR1 and androgen-receptor gene expressions were downregulated in a dose-dependent manner. Furthermore, 5AR-1 and dihydrotestosterone expression were also downregulated at the protein level. A microarray study was also performed to see the effects of DLBS4847 on differential gene expressions in prostate cancer 3 cells. Among others, DLBS4847 downregulated genes related to prostate growth and hypertrophy. Our results suggested that DLBS4847 could potentially become an alternative treatment for prostate disorders, such as benign prostatic hyperplasia. In this regard, DLBS4847 exerts its growth inhibition partially through downregulation of the 5AR pathway.Keywords: DLBS4847, Curcuma mangga, 5α-reductase inhibitor, benign prostatic hyperplasia (BPH, prostate cancer

  3. Preclinical targeting of human T-cell malignancies using CD4-specific chimeric antigen receptor (CAR)-engineered T cells.

    Science.gov (United States)

    Pinz, K; Liu, H; Golightly, M; Jares, A; Lan, F; Zieve, G W; Hagag, N; Schuster, M; Firor, A E; Jiang, X; Ma, Y

    2016-03-01

    Peripheral T-cell lymphomas (PTCLs) are aggressive lymphomas with no effective upfront standard treatment and ineffective options in relapsed disease, resulting in poorer clinical outcomes as compared with B-cell lymphomas. The adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) is a promising new approach for treatment of hematological malignancies. However, preclinical reports of targeting T-cell lymphoma with CARs are almost non-existent. Here we have designed a CAR, CD4CAR, which redirects the antigen specificity of CD8+ cytotoxic T cells to CD4-expressing cells. CD4CAR T cells derived from human peripheral blood mononuclear cells and cord blood effectively redirected T-cell specificity against CD4+ cells in vitro. CD4CAR T cells efficiently eliminated a CD4+ leukemic cell line and primary CD4+ PTCL patient samples in co-culture assays. Notably, CD4CAR T cells maintained a central memory stem cell-like phenotype (CD8+CD45RO+CD62L+) under standard culture conditions. Furthermore, in aggressive orthotropic T-cell lymphoma models, CD4CAR T cells efficiently suppressed the growth of lymphoma cells while also significantly prolonging mouse survival. Combined, these studies demonstrate that CD4CAR-expressing CD8+ T cells are efficacious in ablating malignant CD4+ populations, with potential use as a bridge to transplant or stand-alone therapy for the treatment of PTCLs.

  4. IL-4Rα-Associated Antigen Processing by B Cells Promotes Immunity in Nippostrongylus brasiliensis Infection

    Science.gov (United States)

    Hoving, Jennifer C.; Nieuwenhuizen, Natalie; McSorley, Henry J.; Ndlovu, Hlumani; Bobat, Saeeda; Kimberg, Matti; Kirstein, Frank; Cutler, Anthony J.; DeWals, Benjamin; Cunningham, Adam F.; Brombacher, Frank

    2013-01-01

    In this study, B cell function in protective TH2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα−/− mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4+ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88−/− B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4+ T cell-mediated protective immunity against N. brasiliensis infection. PMID:24204255

  5. Enhanced Dendritic Cell-Mediated Antigen-Specific CD4+ T Cell Responses: IFN-Gamma Aids TLR Stimulation

    Directory of Open Access Journals (Sweden)

    Kuo-Ching Sheng

    2013-01-01

    Full Text Available Phenotypic maturation and T cell stimulation are two functional attributes of DCs critical for immune induction. The combination of antigens, including those from cancer, with Toll-like receptor (TLR ligands induces far superior cellular immune responses compared to antigen alone. In this study, IFN-gamma treatment of bone marrow-derived DC, followed by incubation with the TLR2, TLR4, or TLR9 agonists, enhanced DC activation compared to TLR ligation alone. Most notably, the upregulation of CD40 with LPS stimulation and CD86 with CpG stimulation was observed in in vitro cultures. Similarly, IFN-gamma coinjected with TLR ligands was able to promote DC activation in vivo, with DCs migrating from the site of immunization to the popliteal lymph nodes demonstrating increased expression of CD80 and CD86. The heightened DC activation translated to a drastic increase in T cell stimulatory capacity in both antigen independent and antigen dependent fashions. This is the first time that IFN-gamma has been shown to have a combined effect with TLR ligation to enhance DC activation and function. The results demonstrate the novel use of IFN-gamma together with TLR agonists to enhance antigen-specific T cell responses, for applications in the development of enhanced vaccines and drug targets against diseases including cancer.

  6. IL-15 improves the cytotoxicity of cytokine-induced killer cells against leukemia cells by upregulating CD3+CD56+ cells and downregulating regulatory T cells as well as IL-35.

    Science.gov (United States)

    Tao, Qianshan; Chen, Tianping; Tao, Lili; Wang, Huiping; Pan, Ying; Xiong, Shudao; Zhai, Zhimin

    2013-01-01

    Cytokine-induced killer (CIK) cells are usually generated from peripheral blood mononuclear cells with the stimulation of IL-2 in vitro. Unlike the conventional IL-2-stimulated CIK cells (IL-2-CIK cells), we investigated the characteristics and potential mechanism of IL-15-stimulated CIK cells (IL-15-CIK cells) in this study. Compared with IL-2-CIK cells, the percentage of CD3CD56 cells was significantly increased in IL-15-CIK cells, but the expression of regulatory T (Treg) cells and IL-35 was significantly decreased in IL-15-CIK cells. Meanwhile, the in vitro cytotoxicity against human myeloid leukemia cells K562 of IL-15-CIK cells was significantly augmented compared with IL-2-CIK cells. These data suggest that IL-15 may improve the cytotoxicity of CIK cells against leukemia cells by upregulating CD3CD56 cells and downregulating Treg cells and IL-35.

  7. Resveratrol down-regulates survivin and induces apoptosis in human multidrug-resistant SPC-A-1/CDDP cells.

    Science.gov (United States)

    Zhao, Weiguo; Bao, Pengtao; Qi, Haowen; You, Houcheng

    2010-01-01

    We studied the effect of resveratrol treatment on multidrug-resistant human non-small cell lung cancer cells. Human multidrug-resistant SPC-A-1/CDDP cells were treated with resveratrol at a concentration of 25, 50, or 100 microM in in vitro studies and nude mice were implanted with multidrug-resistant SPC-A-1/and fed a special diet that included resveratrol at a dose of either 1 g/kg/day or 3 g/kg/day in in vivo studies. No adverse toxicological effects of resveratrol treatment were observed. The rate of cell proliferation, apoptosis ratio, cell cycle phase distribution, IC50 values of cisplatin, gefitinib, and paclitaxel, implanted tumour volume, and expression of survivin in resveratrol-treated and control mice were then determined. Resveratrol significantly inhibited the proliferation of SPC-A-1/CDDP cells, induced apoptosis, arrested the cell cycle phase between G0-G1 and S phase or at the G2/M phase, decreased the IC50 values of multiple chemotherapeutic drugs, and showed anti-tumour effects in nude mice that had been implanted with SPC-A-1/CDDP cells. In additional, resveratrol affected the proliferation of SPC-A-1/CDDP cells in a dose- and time-dependent manner. Expression of survivin in SPC-A-1/CDDP cells decreased after they were treated with all concentrations of resveratrol and resveratrol was also found to have a dose-dependent effect on survivin expression. Resveratrol can induce apoptosis in multidrug-resistant human NSCLC SPC-A-1/CDDP cells by down-regulating the expression of survivin.

  8. Sinomenine sensitizes multidrug-resistant colon cancer cells (Caco-2 to doxorubicin by downregulation of MDR-1 expression.

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    Full Text Available Chemoresistance in multidrug-resistant (MDR cells over expressing P-glycoprotein (P-gp encoded by the MDR1 gene, is a major obstacle to successful chemotherapy for colorectal cancer. Previous studies have indicated that sinomenine can enhance the absorption of various P-gp substrates. In the present study, we investigated the effect of sinomenine on the chemoresistance in colon cancer cells and explored the underlying mechanism. We developed multidrug-resistant Caco-2 (MDR-Caco-2 cells by exposure of Caco-2 cells to increasing concentrations of doxorubicin. We identified overexpression of COX-2 and MDR-1 genes as well as activation of the NF-κB signal pathway in MDR-Caco-2 cells. Importantly, we found that sinomenine enhances the sensitivity of MDR-Caco-2 cells towards doxorubicin by downregulating MDR-1 and COX-2 expression through inhibition of the NF-κB signaling pathway. These findings provide a new potential strategy for the reversal of P-gp-mediated anticancer drug resistance.

  9. Matrine induces the apoptosis of lung cancer cells through downregulation of inhibitor of apoptosis proteins and the Akt signaling pathway.

    Science.gov (United States)

    Niu, Huiyan; Zhang, Yifei; Wu, Baogang; Zhang, Yi; Jiang, Hongfang; He, Ping

    2014-09-01

    Lung cancer is the leading cause of cancer‑related mortality in humans. The prognosis for advanced lung cancer patients is extremely poor. Current standard care is rather ineffective for prolonging patient life while preserving satisfactory quality of life due to adverse side-effects. Matrine extracted from the traditional Chinese herbal plant Sophora flavescens was shown to induce cancer cell death in vitro. The aim of this study was to investigate the effect of matrine on the proliferation and apoptosis of lung cancer cells and the molecular basis of matrine-induced apoptosis. The results showed that matrine inhibited cell proliferation and induced apoptosis in lung cancer A549 and 95D cells in a dose- and time-dependent manner. The apoptotic effects of matrine on lung cancer cells appeared to act via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K-Akt-mTOR) signaling pathway and downregulation of the expression of the inhibitor of apoptosis protein (IAP) family proteins. Matrine exerts its cancer-killing effect via promoting apoptosis in lung cancer cells and may be a useful adjuvant therapeutic scheme for treating advanced lung cancer patients.

  10. Overexpressed ubiquitin ligase Cullin7 in breast cancer promotes cell proliferation and invasion via down-regulating p53

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hongsheng [Department of Histology and Embryology, Guangdong Medical College, Dongguan 523808, Guangdong (China); Wu, Fenping [The 7th People’s Hospital of Chengdu, Chengdu 610041, Sichuan (China); Wang, Yan [The Second School of Clinical Medicine, Guangdong Medical College, Dongguan 523808, Guangdong (China); Yan, Chong [School of Pharmacy, Guangdong Medical College, Dongguan 523808, Guangdong (China); Su, Wenmei, E-mail: wenmeisutg@126.com [Oncology of Affiliated Hospital Guangdong Medical College, Zhanjiang 524000, Guangdong (China)

    2014-08-08

    Highlights: • Cullin7 is overexpressed in human breast cancer samples. • Cullin7 stimulated proliferation and invasion of breast cancer cells. • Inhibition of p53 contributes to Cullin7-induced proliferation and invasion. - Abstract: Ubiquitin ligase Cullin7 has been identified as an oncogene in some malignant diseases such as choriocarcinoma and neuroblastoma. However, the role of Cullin7 in breast cancer carcinogenesis remains unclear. In this study, we compared Cullin7 protein levels in breast cancer tissues with normal breast tissues and identified significantly higher expression of Cullin7 protein in breast cancer specimens. By overexpressing Cullin7 in breast cancer cells HCC1937, we found that Cullin7 could promote cell growth and invasion in vitro. In contrast, the cell growth and invasion was inhibited by silencing Cullin7 in breast cancer cell BT474. Moreover, we demonstrated that Cullin7 promoted breast cancer cell proliferation and invasion via down-regulating p53 expression. Thus, our study provided evidence that Cullin7 functions as a novel oncogene in breast cancer and may be a potential therapeutic target for breast cancer management.

  11. Galectin-1 is expressed in early-type neural progenitor cells and down-regulates neurogenesis in the adult hippocampus

    Directory of Open Access Journals (Sweden)

    Imaizumi Yoichi

    2011-01-01

    Full Text Available Abstract Background In the adult mammalian brain, neural stem cells (NSCs proliferate in the dentate gyrus (DG of the hippocampus and generate new neurons throughout life. A multimodal protein, Galectin-1, is expressed in neural progenitor cells (NPCs and implicated in the proliferation of the NPCs in the DG. However, little is known about its detailed expression profile in the NPCs and functions in adult neurogenesis in the DG. Results Our immunohistochemical and morphological analysis showed that Galectin-1 was expressed in the type 1 and 2a cells, which are putative NSCs, in the subgranular zone (SGZ of the adult mouse DG. To study Galectin-1's function in adult hippocampal neurogenesis, we made galectin-1 knock-out mice on the C57BL6 background and characterized the effects on neurogenesis. In the SGZ of the galectin-1 knock-out mice, increased numbers of type 1 cells, DCX-positive immature progenitors, and NeuN-positive newborn neurons were observed. Using triple-labeling immunohistochemistry and morphological analyses, we found that the proliferation of the type-1 cells was increased in the SGZ of the galectin-1 knock-out mice, and we propose that this proliferation is the mechanism for the net increase in the adult neurogenesis in these knock-out mice DG. Conclusions Galectin-1 is expressed in the neural stem cells and down-regulates neurogenesis in the adult hippocampus.

  12. miR-193b Modulates Resistance to Doxorubicin in Human Breast Cancer Cells by Downregulating MCL-1

    Directory of Open Access Journals (Sweden)

    Jingpei Long

    2015-01-01

    Full Text Available MicroRNAs (miRNAs family, which is involved in cancer development, proliferation, apoptosis, and drug resistance, is a group of noncoding RNAs that modulate the expression of oncogenes and antioncogenes. Doxorubicin is an active cytotoxic agent for breast cancer treatment, but the acquisition of doxorubicin resistance is a common and critical limitation to cancer therapy. The aim of this study was to investigate whether miR-193b mediated the resistance of breast cancer cells to doxorubicin by targeting myeloid cell leukemia-1 (MCL-1. In this study, we found that miR-193b levels were significantly lower in doxorubicin-resistant MCF-7 (MCF-7/DOXR cells than in the parental MCF-7 cells. We observed that exogenous miR-193b significantly suppressed the ability of MCF-7/DOXR cells to resist doxorubicin. It demonstrated that miR-193b directly targeted MCL-1 3′-UTR (3′-Untranslated Regions. Further studies indicated that miR-193b sensitized MCF-7/DOXR cells to doxorubicin through a mechanism involving the downregulation of MCL-1. Together, our findings provide evidence that the modulation of miR-193b may represent a novel therapeutic target for the treatment of breast cancer.

  13. KCNK5 is Functionally Down-Regulated Upon Long-Term Hypotonicity in Ehrlich Ascites Tumor Cells

    DEFF Research Database (Denmark)

    Kirkegaard, S. S.; Wulff, Tune; Gammeltoft, S.;

    2013-01-01

    Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long-term hypotoni......Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long......-term hypotonicity on expression and function of KCNK5, thus we have investigated the effect of long-term hypotonicity (24h - 48h) on KCNK5 in Ehrlich cells on the mRNA, protein and physiological levels. Methods: Physiological effects of long-term hypotonicity were measured using patch-clamp and Coulter counter...... physiological impairment of KCNK5 in Ehrlich cells after long-term hypotonic stimulation is predominantly due to down-regulation of the KCNK5 protein synthesis.© 2013 S. Karger AG, Basel...

  14. Human leukocyte antigen E contributes to protect tumor cells from lysis by natural killer cells.

    Science.gov (United States)

    Lo Monaco, Elisa; Tremante, Elisa; Cerboni, Cristina; Melucci, Elisa; Sibilio, Leonardo; Zingoni, Alessandra; Nicotra, Maria Rita; Natali, Pier Giorgio; Giacomini, Patrizio

    2011-09-01

    The nonclassic class I human leukocyte antigen E (HLA-E) molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK) cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3) of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D). Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network.

  15. Human Leukocyte Antigen E Contributes to Protect Tumor Cells from Lysis by Natural Killer Cells

    Directory of Open Access Journals (Sweden)

    Elisa Lo Monaco

    2011-09-01

    Full Text Available The nonclassic class I human leukocyte antigen E (HLA-E molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3 of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D. Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network.

  16. Human Leukocyte Antigen E Contributes to Protect Tumor Cells from Lysis by Natural Killer Cells12

    Science.gov (United States)

    Monaco, Elisa Lo; Tremante, Elisa; Cerboni, Cristina; Melucci, Elisa; Sibilio, Leonardo; Zingoni, Alessandra; Nicotra, Maria Rita; Natali, Pier Giorgio; Giacomini, Patrizio

    2011-01-01

    The nonclassic class I human leukocyte antigen E (HLA-E) molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK) cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3) of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D). Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network. PMID:21969815

  17. Detection and manipulation of live antigen-expressing cells using conditionally stable nanobodies

    Science.gov (United States)

    Tang, Jonathan CY; Drokhlyansky, Eugene; Etemad, Behzad; Rudolph, Stephanie; Guo, Binggege; Wang, Sui; Ellis, Emily G; Li, Jonathan Z; Cepko, Constance L

    2016-01-01

    The ability to detect and/or manipulate specific cell populations based upon the presence of intracellular protein epitopes would enable many types of studies and applications. Protein binders such as nanobodies (Nbs) can target untagged proteins (antigens) in the intracellular environment. However, genetically expressed protein binders are stable regardless of antigen expression, complicating their use for applications that require cell-specificity. Here, we created a conditional system in which the stability of an Nb depends upon an antigen of interest. We identified Nb framework mutations that can be used to rapidly create destabilized Nbs. Fusion of destabilized Nbs to various proteins enabled applications in living cells, such as optogenetic control of neural activity in specific cell types in the mouse brain, and detection of HIV-infected human cells by flow cytometry. These approaches are generalizable to other protein binders, and enable the rapid generation of single-polypeptide sensors and effectors active in cells expressing specific intracellular epitopes. DOI: http://dx.doi.org/10.7554/eLife.15312.001 PMID:27205882

  18. Prolonged antigen presentation is required for optimal CD8+ T cell responses against malaria liver stage parasites.

    Directory of Open Access Journals (Sweden)

    Ian A Cockburn

    2010-05-01

    Full Text Available Immunization with irradiated sporozoites is currently the most effective vaccination strategy against liver stages of malaria parasites, yet the mechanisms underpinning the success of this approach are unknown. Here we show that the complete development of protective CD8+ T cell responses requires prolonged antigen presentation. Using TCR transgenic cells specific for the malaria circumsporozoite protein, a leading vaccine candidate, we found that sporozoite antigen persists for over 8 weeks after immunization--a remarkable finding since irradiated sporozoites are incapable of replication and do not differentiate beyond early liver stages. Persisting antigen was detected in lymphoid organs and depends on the presence of CD11c+ cells. Prolonged antigen presentation enhanced the magnitude of the CD8+ T cell response in a number of ways. Firstly, reducing the time primed CD8+ T cells were exposed to antigen in vivo severely reduced the final size of the developing memory population. Secondly, fully developed memory cells expanded in previously immunized mice but not when transferred to naïve animals. Finally, persisting antigen was able to prime naïve cells, including recent thymic emigrants, to become functional effector cells capable of eliminating parasites in the liver. Together these data show that the optimal development of protective CD8+ T cell immunity against malaria liver stages is dependent upon the prolonged presentation of sporozoite-derived antigen.

  19. Antigen-specific cytotoxicity by invariant NKT cells in vivo is CD95/CD178 dependent and is correlated with antigenic potency

    Science.gov (United States)

    Wingender, Gerhard; Krebs, Philippe; Beutler, Bruce; Kronenberg, Mitchell

    2010-01-01

    Invariant NKT (iNKT) cells are a unique subset of T lymphocytes that rapidly carry out effector functions following activation with glycolipid Ags, such as the model Ag α-galactosylceramide (αGalCer). Numerous studies have investigated the mechanisms leading to Th1- and Th2 cytokine production by iNKT cells, and the effects of the copious amounts of cytokines these cells produce. Less is known, however, about the mechanisms of iNKT cell cytotoxicity. Here we investigated the effect of antigen availability and strength, as well as the molecules involved in iNKT cytotoxicity. We demonstrate that the iNKT cell cytotoxicity in vivo correlates directly with the amount of CD1d expressed by the targets as well as the TCR affinity for the target glycolipid Ag. iNKT cells from spleen, liver and thymus were comparable in their cytotoxicity in vitro. Surprisingly, we show that the antigen-specific cytotoxicity of iNKT cells in vivo depended almost exclusively on the interaction of CD95 (Fas) with CD178 (FasL), and that this mechanism can be efficiently utilized for tumor protection. Therefore unlike NK cells, which rely mostly on perforin/granzyme mediated mechanisms, the antigen-specific cytotoxicity of iNKT cells in vivo is largely restricted to the CD95/CD178 pathway. PMID:20660713

  20. Tumor antigen-specific CD4+ T cells in cancer immunity: from antigen identification to tumor prognosis and development of therapeutic strategies.

    Science.gov (United States)

    Protti, M P; De Monte, L; Monte, L D; Di Lullo, G; Lullo, G D

    2014-04-01

    CD4(+) T cells comprise a large fraction of tumor infiltrating lymphocytes and it is now established that they may exert an important role in tumor immune-surveillance. Several CD4(+) T cell subsets [i.e. T helper (Th)1, Th2, T regulatory (Treg), Th17, Th22 and follicular T helper (Tfh)] have been described and differentiation of each subset depends on both the antigen presenting cells responsible for its activation and the cytokine environment present at the site of priming. Tumor antigen-specific CD4(+) T cells with different functional activity have been found in the blood of cancer patients and different CD4(+) T cell subsets have been identified at the tumor site by the expression of specific transcription factors and the profile of secreted cytokines. Importantly, depending on the subset, CD4(+) T cells may exert antitumor versus pro-tumor functions. Here we review the studies that first identified the presence of tumor-specific CD4(+) T cells in cancer patients, the techniques used to identify the tumor antigens recognized, the role of the different CD4(+) T cell subsets in tumor immunity and in cancer prognosis and the development of therapeutic strategies aimed at activating efficient antitumor CD4(+) T cell effectors.

  1. Chimeric Antigen Receptor Therapy for B-cell Malignancies

    Directory of Open Access Journals (Sweden)

    David L Porter, Michael Kalos, Zhaohui Zheng, Bruce Levine, Carl June

    2011-01-01

    Full Text Available We presented data showing that the CART-19 cells expressing the 4-1BB signaling domain can have unprecedented and massive in-vivo expansion, traffic to tumor sites, persist long term in vivo, and induce rapid and potent anti-tumor activity in chemotherapy refractory CLL patients.

  2. Complement-dependent transport of antigen into B cell follicles

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Lukacs-Kornek, Veronika; Kuligowski, Michael P.

    2010-01-01

    an additional novel pathway in which complement C3 and its receptors enhance humoral immunity through delivery of Ag to the B cell compartment. In this review, we discuss this pathway and highlight several novel exceptions recently found with a model influenza vaccine, such as mannose-binding lectin...

  3. Association of Autophagy in the Cell Death Mediated by Dihydrotestosterone in Autoreactive T Cells Independent of Antigenic Stimulation.

    Science.gov (United States)

    Jia, Ting; Anandhan, Annandurai; Massilamany, Chandirasegaran; Rajasekaran, Rajkumar A; Franco, Rodrigo; Reddy, Jay

    2015-12-01

    Gender disparity is well documented in the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with proteolipid protein (PLP) 139-151, in which female, but not male, SJL mice show a chronic relapsing-remitting paralysis. Furthermore, dihydrotestosterone (DHT) has been shown to ameliorate the severity of EAE, but the underlying mechanisms of its protective effects are unclear. Using major histocompatibility complex (MHC) class II dextramers for PLP 139-151, we tested the hypothesis that DHT selectively modulates the expansion and functionalities of