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Signal Transduction in Immune Cells and Protein Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:133-149. [PMID: 33539014 DOI: 10.1007/978-3-030-49844-3_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Immune response relies upon several intracellular signaling events. Among the protein kinases involved in these pathways, members of the protein kinase C (PKC) family are prominent molecules because they have the capacity to acutely and reversibly modulate effector protein functions, controlling both spatial distribution and dynamic properties of the signals. Different PKC isoforms are involved in distinct signaling pathways, with selective functions in a cell-specific manner.In innate system, Toll-like receptor signaling is the main molecular event triggering effector functions. Various isoforms of PKC can be common to different TLRs, while some of them are specific for a certain type of TLR. Protein kinases involvement in innate immune cells are presented within the chapter emphasizing their coordination in many aspects of immune cell function and, as important players in immune regulation.In adaptive immunity T-cell receptor and B-cell receptor signaling are the main intracellular pathways involved in seminal immune specific cellular events. Activation through TCR and BCR can have common intracellular pathways while others can be specific for the type of receptor involved or for the specific function triggered. Various PKC isoforms involvement in TCR and BCR Intracellular signaling will be presented as positive and negative regulators of the immune response events triggered in adaptive immunity.
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Modulating p56Lck in T-Cells by a Chimeric Peptide Comprising Two Functionally Different Motifs of Tip from Herpesvirus saimiri. J Immunol Res 2015; 2015:395371. [PMID: 26539553 PMCID: PMC4619936 DOI: 10.1155/2015/395371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/28/2015] [Accepted: 05/27/2015] [Indexed: 11/18/2022] Open
Abstract
The Lck interacting protein Tip of Herpesvirus saimiri is responsible for T-cell transformation both in vitro and in vivo. Here we designed the chimeric peptide hTip-CSKH, comprising the Lck specific interacting motif CSKH of Tip and its hydrophobic transmembrane sequence (hTip), the latter as a vector targeting lipid rafts. We found that hTip-CSKH can induce a fivefold increase in proliferation of human and Aotus sp. T-cells. Costimulation with PMA did not enhance this proliferation rate, suggesting that hTip-CSKH is sufficient and independent of further PKC stimulation. We also found that human Lck phosphorylation was increased earlier after stimulation when T-cells were incubated previously with hTip-CSKH, supporting a strong signalling and proliferative effect of the chimeric peptide. Additionally, Lck downstream signalling was evident with hTip-CSKH but not with control peptides. Importantly, hTip-CSKH could be identified in heavy lipid rafts membrane fractions, a compartment where important T-cell signalling molecules (LAT, Ras, and Lck) are present during T-cell activation. Interestingly, hTip-CSKH was inhibitory to Jurkat cells, in total agreement with the different signalling pathways and activation requirements of this leukemic cell line. These results provide the basis for the development of new compounds capable of modulating therapeutic targets present in lipid rafts.
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Lim PS, Sutton CR, Rao S. Protein kinase C in the immune system: from signalling to chromatin regulation. Immunology 2015; 146:508-22. [PMID: 26194700 DOI: 10.1111/imm.12510] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/29/2015] [Accepted: 07/15/2015] [Indexed: 12/12/2022] Open
Abstract
Protein kinase C (PKC) form a key family of enzymes involved in signalling pathways that specifically phosphorylates substrates at serine/threonine residues. Phosphorylation by PKC is important in regulating a variety of cellular events such as cell proliferation and the regulation of gene expression. In the immune system, PKCs are involved in regulating signal transduction pathways important for both innate and adaptive immunity, ultimately resulting in the expression of key immune genes. PKCs act as mediators during immune cell signalling through the immunological synapse. PKCs are traditionally known to be cytoplasmic signal transducers and are well embedded in the signalling pathways of cells to mediate the cells' response to a stimulus from the plasma membrane to the nucleus. PKCs are also found to transduce signals within the nucleus, a process that is distinct from the cytoplasmic signalling pathway. There is now growing evidence suggesting that PKC can directly regulate gene expression programmes through a non-traditional role as nuclear kinases. In this review, we will focus on the role of PKCs as key cytoplasmic signal transducers in immune cell signalling, as well as its role in nuclear signal transduction. We will also highlight recent evidence for its newly discovered regulatory role in the nucleus as a chromatin-associated kinase.
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Affiliation(s)
- Pek Siew Lim
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
| | - Christopher Ray Sutton
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
| | - Sudha Rao
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
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Gharagozloo M, Javid EN, Rezaei A, Mousavizadeh K. Silymarin inhibits cell cycle progression and mTOR activity in activated human T cells: therapeutic implications for autoimmune diseases. Basic Clin Pharmacol Toxicol 2012; 112:251-6. [PMID: 23121838 DOI: 10.1111/bcpt.12032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/23/2012] [Indexed: 11/28/2022]
Abstract
Silymarin, a complex flavonolignan from the 'milk thistle' (Silybum marianum) plant, exhibits anticarcinogenic, anti-inflammatory and cytoprotective effects. Several reports have demonstrated immunosuppressive activity of silymarin; however, the molecular mechanisms involved in immunomodulatory activities of silymarin are not fully understood yet. In this study, the effect of silymarin on cell cycle and PI3K/Akt/mTOR signalling pathway of activated T lymphocytes was investigated in vitro. Peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers and activated with anti-CD3 (5 μg/ml) and anti-CD28 (2 μg/ml) monoclonal antibodies. Cells were cultured in Complete RPMI medium with 10, 50 and 100 μM silymarin or dimethyl sulphoxide (DMSO) and incubated for 24-96 hrs. Cell cycle analysis was performed by PI staining and flow cytometry. The effect of silymarin on PI3K/AKT signalling pathway and mTOR activity was determined in activated T cells after 72-hr incubation with silymarin or DMSO. A significant G1 arrest in cell cycle of activated T lymphocytes was found after 96-hr incubation with 100 μM silymarin without causing cell death. Silymarin also significantly inhibited the level of phospho-S6 ribosomal protein and mTOR activity in cell lysates of activated T cells after 72-hr incubation in comparison with DMSO. This study shows that silymarin inhibits cell proliferation through G1 cell cycle arrest and also through the suppression of the mTOR signalling pathway in human activated T lymphocytes in vitro. Characterizing molecular mechanism of such immunomodulatory effects may have a great potential in future practical application of silymarin in transplantation and auoimmunity.
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Affiliation(s)
- Marjan Gharagozloo
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Thakur P, Fomina AF. Density of functional Ca2+ release-activated Ca2+ (CRAC) channels declines after T-cell activation. Channels (Austin) 2011; 5:510-7. [PMID: 22172731 DOI: 10.4161/chan.5.6.18222] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
CRAC channel-mediated Ca(2+) entry plays a crucial role in T lymphocyte activation. Activated T cells display enhanced Ca(2+) signaling compared with resting T cells; this is partially attributed to activation-induced upregulation of CRAC channel expression. Orai and Stim family genes encode CRAC channel structural elements and regulatory proteins, respectively, but studies of their expression in T cells have led to controversial results. We re-examined Orai and Stim gene expression in resting, activated, and Jurkat T cells. Levels of Orai1 transcripts, encoding the human T cell CRAC channel subunit, were not significantly different between resting T and activated T cells. The total amount of all Orai transcripts was 2-fold higher in activated T cells than in resting T cells. Orai1 and total Orai transcript levels were significantly higher in Jurkat T cells than those in resting T cells. Stim expression did not vary significantly among cell types. Maximal whole-cell CRAC current amplitudes were 1.4-fold and 2.3-fold higher in activated and Jurkat T cells, respectively, than in resting T cells. Due to the small size of resting T cells, the surface CRAC channel density was 2.5-fold and 1.6-fold higher in resting T cells than in activated and Jurkat T cells, respectively. Predicted the rates of cytosolic Ca(2+) elevation calculated using the average values of CRAC channel currents and cell volumes showed that < 2-fold increase in the functional CRAC channel expression level cannot account for the enhanced rate of store-operated Ca(2+) entry in activated T cells compared with resting T cells.
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Amirghofran Z, Javidnia K, Bahmani M, Azadmehr A, Esmaeilbeig M. THE EFFECT OF THE METHANOL EXTRACT OFGALIUM MITEON THE CELLULAR IMMUNITY AND ANTIBODY SYNTHESIS. J Immunoassay Immunochem 2011; 32:157-69. [DOI: 10.1080/15321819.2011.552583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Ou CC, Hsiao YM, Wu WJ, Tasy GJ, Ko JL, Lin MY. FIP-fve stimulates interferon-gamma production via modulation of calcium release and PKC-alpha activation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:11008-11013. [PMID: 19919129 DOI: 10.1021/jf902725s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fungal immunomodulatory protein, FIP-fve, has been isolated from Flammulina velutipes, and its immunomodulatory effects are believed to be associated with the enhanced activation of IFN-gamma-releasing Th1 cells. However, the mechanisms of FIP-fve-mediated signal transduction in the regulation of interferon-gamma (IFN-gamma) gene expression in human peripheral blood mononuclear cells (PBMCs) are still poorly understood. Using fluo-3 AM, we found that FIP-fve induces a rapid elevation in calcium concentration. ELISA, RT-PCR and Western blot assays demonstrated significant increases in the production and mRNA expression of IFN-gamma and protein kinase C-alpha (PKC-alpha) activation in activated PBMCs, which were abolished by EGTA, nifedipine and GO6976. In conclusion, Ca2+ release and PKC-alpha activation are required for IFN-gamma production induced by FIP-fve in PBMCs.
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Affiliation(s)
- Chu-Chyn Ou
- School of Nutrition, Chung Shan Medical University, 110, Sec. 1, Chien-kuo N. Road, Taichung 40203, Taiwan
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Chen YC, Chang SC, Wu MH, Chuang KA, Wu JY, Tsai WJ, Kuo YC. Norcantharidin reduced cyclins and cytokines production in human peripheral blood mononuclear cells. Life Sci 2008; 84:218-26. [PMID: 19100750 DOI: 10.1016/j.lfs.2008.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 11/04/2008] [Accepted: 11/27/2008] [Indexed: 12/24/2022]
Abstract
AIMS To evaluate potential agents of therapeutic value in tissue inflammation, we studied norcantharidin (NCTD) and its derivatives for their effects on immune responses of human peripheral blood mononuclear cells (PBMC) in vitro. MAIN METHODS PBMC proliferation was evaluated by tritiated thymidine uptake method. The production and gene expression of cytokines were determined with enzyme immunoassays (EIA) and reverse transcription-polymerase chain reaction (RT-PCR), respectively. KEY FINDINGS Five derivatives from NCTD had no significant effect on cell proliferation in PBMC. NCTD inhibited PBMC proliferation induced by phytohemagglutinin (PHA) with a 50% inhibitory concentration (IC(50)) 42.1+/-2.3 microM. The inhibitory action of NCTD did not involve direct cytotoxicity. To localize the point in the PBMC proliferation where arrest occurred, a set of key regulatory events leading to the cell proliferation, including cell cycle progression, production and gene expression of interleukin-2 (IL-2), IL-4, IL-10, and interferon-gamma (IFN-gamma) and cyclins was examined. Data demonstrated NCTD arrested the cell cycle progression of activated PBMC from the G1 transition to the S phase. The cyclin D3, E, A, and B transcripts and protein production in PHA-treated PBMC was reduced by NCTD. Whereas NCTD exerted no effect on IL-4 and IFN-gamma production, it significantly alleviated the production and mRNA expression of IL-2 and IL-10 in activated PBMC. SIGNIFICANCE The suppressant effects of NCTD on proliferation of PBMC activated by PHA therefore appear to be mediated, at least in part, through inhibition of cyclins and IL-2 production and arrest of cell cycle progression in the cells.
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Affiliation(s)
- Yi-Chun Chen
- Institute of Pharmacology, National Yang-Ming University, Taiwan, ROC
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Tian J, Pabst O, Römermann D, Skubich S, Förster R, Beckmann J, Chen JH, Hoffmann MW. Inactivation of T-cell receptor-mediated integrin activation prolongs allograft survival in ADAP-deficient mice. Transplantation 2007; 84:400-6. [PMID: 17700167 DOI: 10.1097/01.tp.0000269724.06142.92] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Signaling through the T cell receptor (TCR) leads to profound changes in the function and properties of T cells, including integrin activation. Adhesion and degranulation promoting adapter protein (ADAP) is an adapter protein linking T cell receptor stimulation to integrin activation. We aim to clarify how disruption of TCR-mediated integrin activation affects alloreactive immune responses. METHODS In vitro T cell proliferation and the cytokine production was determined. In vivo cytotoxic T lymphocyte (CTL) activity was measured as well. Allogenic skin and heart transplantation was used to test the in vivo role of ADAP in alloimmune responses. Histology and flow cytometry was applied to analyze the graft infiltrating lymphocytes. RESULTS Upon stimulation with allogenic dendritic cells ADAP-deficient T cells displayed impaired proliferative responses compared to wild type (WT) T cells. This was accompanied by significantly decreased production of the cytokine interleukin-2. In contrast, the in vivo CTL activity in ADAP-deficient mice was comparable to that of WT mice. Consistently, we observed a prolongation of fully major histocompatibility complex (MHC)-mismatched heart transplants in ADAP deficient mice. Protection of allogenic heart grafts in ADAP-deficient mice was accompanied by a decrease in the infiltration, proliferation and activation of T cells in the allograft. However, no effect was observed after fully MHC-mismatched skin transplantation. CONCLUSIONS We have shown that although ADAP is dispensable for the rejection of allografts, ADAP function plays an important role for the efficacy of graft rejection. ADAP's main function appears to affect the induction phase of the immune response.
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Affiliation(s)
- Jiong Tian
- Kidney Disease Center, The 1st Affiliated Hospital of Zhejiang University, Zhejiang, China
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10
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Bijian K, Zhang L, Shen SH. Collagen-mediated survival signaling is modulated by CD45 in Jurkat T cells. Mol Immunol 2007; 44:3682-90. [PMID: 17524482 DOI: 10.1016/j.molimm.2007.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 04/03/2007] [Accepted: 04/06/2007] [Indexed: 11/20/2022]
Abstract
T cell activation is a critical step in the development of a proper immune response to infection and inflammation. This dynamic process requires efficient T cell receptor signaling, which in turn is modulated by integrin receptor activation and the actin cytoskeleton. CD45 is a key player in T cell receptor mediated signal transduction. However, its exact role in integrin mediated signaling in T cells remains to be elucidated. The present study addresses the relationship between CD45 and beta1-integrin mediated survival signaling in the human T leukemic cell line Jurkat, in which collagen receptors alpha1 beta1 and alpha2 beta1 integrins are localized. Wild type (WT)-Jurkat T cells treated with collagen demonstrated increased cell proliferation and survival. Monitoring the intracellular signaling pathways activated by collagen in WT-Jurkat cells revealed increased focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK) activation. Moreover, examination of the actin cytoskeleton of WT-Jurkat T cells treated with collagen demonstrated the presence of an organized cortical actin structure, reminiscent of the survival phenotype. This is in contrast to CD45-deficient J45.01 T cells, where collagen treatment failed to enhance cell proliferation/survival and was unable to stimulate FAK and ERK activity. In addition, the actin cytoskeleton of collagen treated J45.01 T cells was disorganized with cortical actin aggregates present throughout. The importance of an organized actin cytoskeleton to proper cell signaling and survival was further demonstrated by the inability of collagen treated WT-Jurkat cells to activate the FAK and ERK survival pathway in the presence of cytochalasin D, a cytoskeleton-disrupting drug. Consistently, addition of the CD45 specific inhibitor abolished collagen-stimulated FAK and ERK activation in WT-Jurkat cells, further depicting CD45 as the key mediator. Furthermore, collagen-mediated T cell signaling alone was able to activate IL-2 gene transcription devoid of concomitant T cell receptor activation. Taken together, these results are the first to demonstrate that CD45 is important in promoting cell survival by modulating integrin-mediated FAK/ERK signaling in Jurkat T cells and is involved in a distinct signal transduction pathway, separate from T cell receptor signaling, influencing T cell immune responses. Hence, this study will help further our knowledge about beta1-integrin mediated signaling in T cells, which may prove to be essential for the regulation of various T cell mediated immune responses.
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Affiliation(s)
- Krikor Bijian
- Mammalian Cell Genetics Group, Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount av., Montreal, Quebec H4P 2R2, Canada
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Liu CP, Kuo YC, Shen CC, Wu MH, Liao JF, Lin YL, Chen CF, Tsai WJ. (S)-Armepavine inhibits human peripheral blood mononuclear cell activation by regulating Itk and PLCγ activation in a PI-3K-dependent manner. J Leukoc Biol 2007; 81:1276-86. [PMID: 17284681 DOI: 10.1189/jlb.0106056] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Chinese herbs are useful edible and medicinal plants for their immune modulatory functions. We have proven that (S)-armepavine (C19H23O3N; MW313) from Nelumbo nucifera inhibits the proliferation of human PBMCs activated with PHA and improves autoimmune diseases in MRL/MpJ-lpr/lpr mice. In the present study, the pharmacological activities of (S)-armepavine were evaluated in PHA-activated PBMCs. The results showed that (S)-armepavine suppressed PHA-induced PBMC proliferation and genes expression of IL-2 and IFN-gamma without direct cytotoxicity. Inhibition of NF-AT and NF-kappaB activation suggested phospholipase Cgamma (PLCgamma)-mediated Ca2+ mobilization and protein kinase C activation were blocked by (S)-armepavine. Phosphorylation of PLCgamma is regulated by lymphocyte-specific kinase (Lck), ZAP-70, and IL-2-inducible T cell kinase (Itk). We found (S)-armepavine inhibited PHA-induced phosphorylation of Itk and PLCgamma efficiently but did not influence Lck or ZAP-70 phosphorylation. In addition, ZAP-70-mediated pathways, such as the association of linker for activation of T cells with PLCgamma and activation of ERK, were also intact in the presence of (S)-armepavine. Finally, reduction of phosphoinositide 3,4,5-trisphosphate formation and Akt phosphorylation suggested that (S)-armepavine inhibited Itk, and PLCgamma phosphorylation might be a result of the influence of PI-3K activation. Addition of exogenous IL-2 or PMA/A23187 rescued PBMC proliferation in the presence of (S)-armepavine. Therefore, we concluded that (S)-armepavine inhibited PHA-induced cell proliferation and cytokine production in a major way by blocking membrane-proximal effectors such as Itk and PLCgamma in a PI-3K-dependent manner.
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Affiliation(s)
- Chih-Peng Liu
- Institute of Pharmacology, National Yang-Ming University, Laboratory of Biochemistry, National Research Institute of Chinese Medicine, No. 155-1, Sec. 2, Li-Nung St., Shih-Pai, 112, Taipei, Taiwan, ROC
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Bunting K, Wang J, Shannon MF. Control of interleukin-2 gene transcription: a paradigm for inducible, tissue-specific gene expression. VITAMINS AND HORMONES 2006; 74:105-45. [PMID: 17027513 DOI: 10.1016/s0083-6729(06)74005-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Interleukin-2 (IL-2) is a key cytokine that controls immune cell function, in particular the adaptive arm of the immune system, through its ability to control the clonal expansion and homeostasis of peripheral T cells. IL-2 is produced almost exclusively by T cells in response to antigenic stimulation and thus provides an excellent example of a cell-specific inducible gene. The mechanisms that control IL-2 gene transcription have been studied in detail for the past 20 years and our current understanding of the nature of the inducible and tissue-specific controls will be discussed.
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Affiliation(s)
- Karen Bunting
- Division of Molecular Bioscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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13
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Wu Z, Kim HP, Xue HH, Liu H, Zhao K, Leonard WJ. Interleukin-21 receptor gene induction in human T cells is mediated by T-cell receptor-induced Sp1 activity. Mol Cell Biol 2005; 25:9741-52. [PMID: 16260592 PMCID: PMC1280258 DOI: 10.1128/mcb.25.22.9741-9752.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Interleukin-21 (IL-21) plays important roles in regulating the immune response. IL-21 receptor (IL-21R) mRNA is expressed at a low level in human resting T cells but is rapidly induced by mitogenic stimulation. We now investigate the basis for IL21R gene regulation in T cells. We found that the -80 to -20 region critically regulates IL-21R promoter activity and corresponds to a major DNase I-hypersensitive site. Electrophoretic mobility shift assays, DNA affinity chromatography followed by mass spectrometry, and chromatin immunoprecipitation assays revealed that Sp1 binds to this region in vitro and in vivo. Moreover, mutation of the Sp1 motif markedly reduced IL-21R promoter activity, and Sp1 small interfering RNAs effectively diminished IL-21R expression in activated T cells. Interestingly, upon T-cell receptor (TCR) stimulation, T cells increased IL-21R expression and Sp1 protein levels while decreasing Sp1 phosphorylation. Moreover, phosphatase inhibitors that increased phosphorylation of Sp1 diminished IL-21R transcription. These data indicate that TCR-induced IL-21R expression is driven by TCR-mediated augmentation of Sp1 protein levels and may partly depend on the dephosphorylation of Sp1.
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MESH Headings
- Amino Acid Motifs
- Base Sequence
- Blotting, Western
- Chromatin Immunoprecipitation
- Chromatography, Affinity
- DNA Restriction Enzymes/pharmacology
- Deoxyribonuclease I/metabolism
- Exons
- Gene Expression Regulation
- Genes, Reporter
- Humans
- Interleukin-21 Receptor alpha Subunit
- Luciferases/metabolism
- Lymphocytes/metabolism
- Mass Spectrometry
- Models, Genetic
- Molecular Sequence Data
- Mutation
- Phosphorylation
- Promoter Regions, Genetic
- Protein Binding
- RNA, Messenger/metabolism
- RNA, Small Interfering/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Interleukin/genetics
- Receptors, Interleukin-21
- Reverse Transcriptase Polymerase Chain Reaction
- Sp1 Transcription Factor/metabolism
- Sp3 Transcription Factor/metabolism
- T-Lymphocytes/metabolism
- Transcription, Genetic
- Transcriptional Activation
- Transfection
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Affiliation(s)
- Zheng Wu
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood InstituteNational Institutes of Health, Building 10, Room 7N252, Bethesda, Maryland 20892-1674, USA
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Abbady AQ, Bronner C, Bathami K, Muller CD, Jeanblanc M, Mathieu E, Klein JP, Candolfi E, Mousli M. TCR pathway involves ICBP90 gene down-regulation via E2F binding sites. Biochem Pharmacol 2005; 70:570-9. [PMID: 15964557 DOI: 10.1016/j.bcp.2005.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 05/10/2005] [Accepted: 05/10/2005] [Indexed: 11/18/2022]
Abstract
Antigen-induced cell death is essential for function, growth and differentiation of T-lymphocytes through legation of the T cell receptor. Since TCR-induced cell death occurs at late G1 checkpoint of the cell cycle and considering that ICBP90 is critical for G1/S transition, we studied the ICBP90 regulation through the TCR pathway in Jurkat cells. ICBP90 expression was strongly decreased after TCR triggering concomitantly to cyclin D3 and topoisomerase IIalpha expression decreases. Cell stimulation with PMA and/or calcium ionophore A23187 down-regulated ICBP90 expression. The decrease of ICBP90 protein and mRNA expressions was accompanied with cell growth arrest. A luciferase reporter assay demonstrated that activation of TCR pathways inhibit ICBP90 gene promoter activity. Three consensus E2F binding sites (called from E2F-a to E2F-c) were identified in the ICBP90 gene promoter and were subjected to mutations. The E2F-a, located in a highly active promoter fragment, shows a strong positive functional activity in proliferating cells. E2F-a and E2F-c binding sites are involved in the TCR-induced down-regulation of ICBP90 gene transcription. Altogether, our data demonstrate that TCR signaling pathways regulate ICBP90 gene expression through pRb/E2F complex. We propose that ICBP90 down-regulation is a key event in G1 arrest preceding T cell death.
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Affiliation(s)
- Abdul-Qader Abbady
- INSERM UMR-S 392, and Laboratoire de Physiopathologie Cellulaire & Moléculaire et Infection, Institut de Parasitolgie et de Pathologie Tropicale, Faculté de Médecine, 3 rue Koeberlé, 67000 Strasbourg, France
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15
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Marth C, Fiegl H, Zeimet AG, Müller-Holzner E, Deibl M, Doppler W, Daxenbichler G. Interferon-gamma expression is an independent prognostic factor in ovarian cancer. Am J Obstet Gynecol 2004; 191:1598-605. [PMID: 15547530 DOI: 10.1016/j.ajog.2004.05.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Epithelial ovarian cancer prognosis is improved by the presence of intratumoral CD3 + T cells, which are known to produce interferon-gamma. We therefore speculated that interferon-gamma expression in ovarian cancer-infiltrating T-lymphocytes might cause better prognosis. PATIENTS AND METHODS Reverse transcriptase polymerase chain reaction was performed to measure the expression of interferon-gamma and other related genes in normal ovaries (n = 19) and in ovarian cancer specimens (n = 99). Median follow-up of patients was 5.8 years. RESULTS Interferon-gamma and CD-3 expression did not significantly differ in normal and malignant tissue. Patients with high levels of interferon-gamma expression had significantly longer progression-free and overall survival. Median time to progression was 10 and 29 months for patients with low and high interferon-gamma expression, respectively ( P = .039). Corresponding survival times were 29 and 44 months ( P < .032). Application of multivariate Cox regression analysis showed interferon-gamma expression to be an independent prognostic factor for progression-free and overall survival. CONCLUSION Elevated interferon-gamma expression correlates with improved clinical outcome in patients with ovarian cancer.
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Affiliation(s)
- Christian Marth
- Department of Obstetrics and Gynecology, Innsbruck Medical University, Innsbruck, Austria.
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16
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Liu CP, Tsai WJ, Lin YL, Liao JF, Chen CF, Kuo YC. The extracts from Nelumbo Nucifera suppress cell cycle progression, cytokine genes expression, and cell proliferation in human peripheral blood mononuclear cells. Life Sci 2004; 75:699-716. [PMID: 15172179 DOI: 10.1016/j.lfs.2004.01.019] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Accepted: 01/27/2004] [Indexed: 11/29/2022]
Abstract
In the hope of identifying agents of therapeutic value in tissue inflammation, we tested ethanolic extracts of six Chinese herbs for their effects on human peripheral blood mononuclear cells (PBMC) proliferation in vitro. The results indicated that the extracts from Nelumbo nucifera Gaertn, used in treatment of tissue inflammation in traditional Chinese medicine, inhibited PBMC proliferation activated with phytohemagglutinin (PHA). By a bioassay-guided fractionation procedure, NN-B-4 identified from N. nucifera ethanolic extracts significantly suppressed activated PBMC proliferation. The inhibitory action of NN-B-4 did not involve direct cytotoxicity. In an attempt to further localize the point in the PBMC proliferation where arrest occurred, a set of key regulatory events leading to the cell proliferation, including cell cycle progression, production and gene expression of interleukin-2 (IL-2), IL-4, IL-10, and interferon-gamma (IFN-gamma) was examined. Cell cycle analysis indicated that NN-B-4 arrested the cell cycle progression of activated PBMC from the G1 transition to the S phase. The cyclin-dependent kinase (cdk) 4 mRNA expression in PBMC stimulated with PHA was reduced by NN-B-4. NN-B-4 suppressed, in activated PBMC, the production and mRNA expression of IL-2, IL-4, IL-10, and IFN-gamma in a dose-dependent fashion. The suppressant effects of NN-B-4 on proliferation of PBMC activated by PHA therefore appear to be mediated, at least in part, through inhibition of early transcripts of PBMC, especially those of important IL-2, IFN-gamma, and cdk4 and arrest of cell cycle progression in the cells.
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Affiliation(s)
- Chih-Peng Liu
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
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17
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Bamberger AM, Jenatschke S, Schulte HM, Ellebrecht I, Beil FU, Bamberger CM. Regulation of the human leukemia inhibitory factor gene by ETS transcription factors. Neuroimmunomodulation 2004; 11:10-9. [PMID: 14557674 DOI: 10.1159/000072964] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Accepted: 01/10/2003] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Leukemia inhibitory factor (LIF) is a pleiotropic cytokine mainly produced by activated T lymphocytes. We previously demonstrated that human Jurkat T lymphoma cells represent a valid model of LIF gene expression. This study was designed to identify regions critical for LIF promoter activation in Jurkat cells. METHODS Luciferase constructs under the control of different portions of the human LIF promoter were transfected into Jurkat cells, and promoter activity was determined by luminometry. Similar experiments were performed with constructs bearing mutations in the putative ETS binding regions in the LIF promoter. RT-PCR, Western blot and gelshift experiments were performed to study expression and DNA binding of ETS factors in lymphoid cells. RESULTS With the exception of the shortest construct not including the putative ETS binding sites, all wildtype LIF promoter constructs were strongly inducible by phorbol ester/ionomycin. In contrast, the mutant constructs were significantly less inducible. Cotransfection of the wild-type constructs with ETS expression vectors resulted in significant enhancement of promoter activity. ets-1 and ets-2 mRNA and protein were shown to be expressed in Jurkat cells. Gelshift experiments revealed that proteins present in nuclear extracts from Jurkat cells specifically bind to both artificial ETS consensus sites and ETS binding sites present in the LIF promoter. CONCLUSIONS We conclude that binding of ETS transcription factors to the ETS binding sites in the human LIF promoter is critical for its inducibility in response to T cell activators. ETS transcription factors thus play an important functional role within the endocrine-immune network.
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Ishikawa J, Ohga K, Yoshino T, Takezawa R, Ichikawa A, Kubota H, Yamada T. A pyrazole derivative, YM-58483, potently inhibits store-operated sustained Ca2+ influx and IL-2 production in T lymphocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:4441-9. [PMID: 12707319 DOI: 10.4049/jimmunol.170.9.4441] [Citation(s) in RCA: 196] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In nonexcitable cells, Ca(2+) entry is mediated predominantly through the store depletion-dependent Ca(2+) channels called store-operated Ca(2+) (SOC) or Ca(2+) release-activated Ca(2+) channels. YM-58483, a pyrazole derivative, inhibited an anti-CD3 mAb-induced sustained Ca(2+) influx in acute T cell leukemia, Jurkat cells. But it did not affect an anti-CD3 mAb-induced transient intracellular Ca(2+) increase in Ca(2+)-free medium, nor anti-CD3 mAb-induced phosphorylation of phospholipase Cgamma1. It was suggested that YM-58483 inhibited Ca(2+) influx through SOC channels without affecting the TCR signal transduction cascade. Furthermore, YM-58483 inhibited thapsigargin-induced sustained Ca(2+) influx with an IC(50) value of 100 nM without affecting membrane potential. YM-58483 inhibited by 30-fold the Ca(2+) influx through SOC channels compared with voltage-operated Ca(2+) channels, while econazole inhibited both SOC channels and voltage-operated Ca(2+) channels with an equivalent range of IC(50) values. YM-58483 potently inhibited IL-2 production and NF-AT-driven promoter activity, but not AP-1-driven promoter activity in Jurkat cells. Moreover, this compound inhibited delayed-type hypersensitivity in mice with an ED(50) of 1.1 mg/kg. Therefore, we concluded that YM-58483 was a novel store-operated Ca(2+) entry blocker and a potent immunomodulator, and could be useful for the treatment of autoimmune diseases and chronic inflammation. Furthermore, YM-58483 would be a candidate for the study of capacitative Ca(2+) entry mechanisms through SOC/CRAC channels and for identification of putative Ca(2+) channel genes.
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Affiliation(s)
- Jun Ishikawa
- Inflammation Research, Pharmacology Laboratories, Institute for Drug Discovery Research, Yamanouchi Pharmaceutical Co., Ltd., Tsukuba-shi, Ibaraki, Japan.
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Zhang L, Conejo-Garcia JR, Katsaros D, Gimotty PA, Massobrio M, Regnani G, Makrigiannakis A, Gray H, Schlienger K, Liebman MN, Rubin SC, Coukos G. Intratumoral T cells, recurrence, and survival in epithelial ovarian cancer. N Engl J Med 2003; 348:203-13. [PMID: 12529460 DOI: 10.1056/nejmoa020177] [Citation(s) in RCA: 2523] [Impact Index Per Article: 120.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Although tumor-infiltrating T cells have been documented in ovarian carcinoma, a clear association with clinical outcome has not been established. METHODS We performed immunohistochemical analysis of 186 frozen specimens from advanced-stage ovarian carcinomas to assess the distribution of tumor-infiltrating T cells and conducted outcome analyses. Molecular analyses were performed in some tumors by real-time polymerase chain reaction. RESULTS CD3+ tumor-infiltrating T cells were detected within tumor-cell islets (intratumoral T cells) in 102 of the 186 tumors (54.8 percent); they were undetectable in 72 tumors (38.7 percent); the remaining 12 tumors (6.5 percent) could not be evaluated. There were significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons). The five-year overall survival rate was 38.0 percent among patients whose tumors contained T cells and 4.5 percent among patients whose tumors contained no T cells in islets. Significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons) were also seen among 74 patients with a complete clinical response after debulking and platinum-based chemotherapy: the five-year overall survival rate was 73.9 percent among patients whose tumors contained T cells and 11.9 percent among patients whose tumors contained no T cells in islets. The presence of intratumoral T cells independently correlated with delayed recurrence or delayed death in multivariate analysis and was associated with increased expression of interferon-gamma, interleukin-2, and lymphocyte-attracting chemokines within the tumor. The absence of intratumoral T cells was associated with increased levels of vascular endothelial growth factor. CONCLUSIONS The presence of intratumoral T cells correlates with improved clinical outcome in advanced ovarian carcinoma.
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Affiliation(s)
- Lin Zhang
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia 19104, USA
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20
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Abstract
Activated T lymphocytes play an important role in autoimmune disease. The process of T-cell activation is therefore of significant importance in understanding the pathogenesis of many rheumatic diseases. This process can be observed from outside the lymphocyte, but we have also gained increased understanding of many of the intracellular events of T-cell activation. This review tries to draw out the most important receptors, pathways, and transcription factors involved in the process.
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Affiliation(s)
- M Aringer
- Division of Rheumatology, Department of Internal Medicine III, University of Vienna.
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21
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Hsu LJ, Lin YS. Roles of I-E molecule and CD28 costimulation in induction of suppression by staphylococcal enterotoxin B in vivo. Cell Immunol 2001; 212:35-43. [PMID: 11716527 DOI: 10.1006/cimm.2001.1841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure to bacterial superantigens leads to the induction of a subsequent state of immune hyporesponsiveness. Using a transwell coculture system, a previous report demonstrated that splenocytes from staphylococcal enterotoxin B (SEB)-injected BALB/c mice secreted soluble mediators to suppress the proliferative response of naive syngeneic splenocytes to SEB stimulation. We show in the present study that, in contrast to the suppressive effect induced by SEB in BALB/c (H-2(d) haplotype), MRL(+/+), and MRL-lpr/lpr (H-2(k)) mice, SEB-primed splenocytes from I-E(-) strains such as B6, B10, A. BY (H-2(b)), and A.SW (H-2(s)) mice failed to inhibit the CD25 expression and the proliferative activity of their syngeneic naive responder splenocytes. Further results revealed that the SEB-primed cells from BALB/c, but not B6, mice inhibited the CD25 expression and proliferation of naive responder cells from either BALB/c or B6 mice, indicating the critical regulatory role of the effector cells. Unlike SEB, staphylococcal enterotoxin A induced profound suppression in both BALB/c and B6 mice. Moreover, the suppressive competence of SEB-primed splenocytes was diminished in CD28-deficient BALB/c mice. Taken together, our results indicate that when SEB is used as a stimulator in vivo, both the I-E molecule and CD28 costimulation are required for the induction of regulatory cells bearing suppressive activity.
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Affiliation(s)
- L J Hsu
- Department of Microbiology and Immunology, National Cheng Kung University Medical College, Tainan, Taiwan, Republic of China
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22
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Boomer JS, Derks RA, Lee GW, DuChateau BK, Gilman-Sachs A, Beaman KD. Regeneration and tolerance factor is expressed during T-lymphocyte activation and plays a role in apoptosis. Hum Immunol 2001; 62:577-88. [PMID: 11390032 DOI: 10.1016/s0198-8859(01)00244-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Regeneration and tolerance factor (RTF) is a protein cloned from the thymus and expressed on B lymphocytes in normal pregnancy, B lymphocytic leukemia lines, and T and B lymphocytes in individuals with HIV infection. Findings, using the Jurkat T-cell model, revealed that RTF is upregulated after activation and anti-RTF antibody-induced apoptosis. In this article anti-RTF antibody-induced apoptosis of both unstimulated and activated T lymphocytes. RTF expression was examined in human PBMC or purified T lymphocytes after their in vitro activation. Kinetic studies indicated maximal RTF cell surface expression on activated T lymphocytes occurred between expression of the early activation antigen CD69 and the IL-2alpha receptor (CD25) by multiparameter flow cytometry. RTF receptor expression correlated with Fas (CD95) and CD25 receptor expression (r2 = 0.6 and 0.5, respectively). RTF surface expression was dependent on the stimuli used to activate T lymphocytes. T lymphocytes obtained maximal RTF expression when activated through the TCR signal complex using anti-CD3epsilon antibody alone when compared with T lymphocytes activated with costimulation provided by anti-CD28 antibody alone or with anti-CD28 and anti-CD3epsilon antibody. RTF is expressed under conditions of both activation and anergy. The RTFs increased concentration on the surface of anergic T cells may protect these cells from apoptosis because increased RTF concentrations inhibited anti-RTF induced apoptosis. These data further characterize the expression of RTF on activated T lymphocytes and the role of anti-RTF antibody in T-lymphocyte apoptosis.
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Affiliation(s)
- J S Boomer
- Clinical Immunology Laboratory, Department of Microbiology/Immunology, Finch University of Health Sciences, The Chicago Medical School, North Chicago, IL 60064, USA
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Bergqvist A, Rice CM. Transcriptional activation of the interleukin-2 promoter by hepatitis C virus core protein. J Virol 2001; 75:772-81. [PMID: 11134290 PMCID: PMC113973 DOI: 10.1128/jvi.75.2.772-781.2001] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2000] [Accepted: 10/02/2000] [Indexed: 02/07/2023] Open
Abstract
Most patients infected with hepatitis C virus (HCV) become chronic carriers. Viruses that efficiently establish persistent infections must have effective ways of evading host defenses. In the case of HCV, little is known about how chronic infections are established or maintained. Besides hepatocytes, several reports suggest that HCV can infect T and B lymphocytes. Since T cells are essential for viral clearance, direct or indirect effects of HCV on T-cell function could influence the outcome of infection. Given that T-cell growth and differentiation require the cytokine interleukin 2 (IL-2), we asked whether HCV might modulate synthesis of IL-2. Portions of the HCV polyprotein were expressed in Jurkat cells under a variety of conditions. We found that the highly conserved HCV core protein, in combination with other stimuli, was able to dramatically activate transcription from the IL-2 promoter. The carboxy-terminal hydrophobic portion of the core protein was required for this activity. Activation was dependent on nuclear factor of activated T cells (NFAT), occurred in cells deficient in the tyrosine kinase p56(lck), and could be blocked by addition of cyclosporin A and by depletion of calcium. These results suggest that the HCV core protein can activate transcription of the IL-2 promoter through the NFAT pathway. This novel activity may have consequences for T-cell development and establishment of persistent infections.
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Affiliation(s)
- A Bergqvist
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA.
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Heller M, Goodlett DR, Watts JD, Aebersold R. A comprehensive characterization of the T-cell antigen receptor complex composition by microcapillary liquid chromatography-tandem mass spectrometry. Electrophoresis 2000; 21:2180-95. [PMID: 10892729 DOI: 10.1002/1522-2683(20000601)21:11<2180::aid-elps2180>3.0.co;2-#] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It has become apparent that many intracellular signaling processes involve the dynamic reorganization of cellular proteins into complex signaling assemblies that have a specific subunit composition, function, and subcellular location. Since the elements of such assemblies interact physically, multiprotein signaling complexes can be isolated and analyzed. Recent technical advances in highly sensitive protein identification by electrospray-tandem mass spectrometry have dramatically increased the sensitivity with which such analyses can be performed. The T-cell antigen receptor (TCR) is an oligomeric transmembrane protein complex that is essential to T-cell recognition and function. The extracellular protein domains are responsible for ligand binding while intracellular domains generate and transduce signals in response to specific receptor-ligand interactions. We used microbore capillary chromatography-tandem mass spectrometry to investigate the composition of the TCR protein complex isolated from resting and activated cells of the murine T-cell line CD11.3. We identified all the previously known subunits of the TCR/CD3 complex as well as proteins previously not known to associate with the TCR. The catalytic activities of some of these proteins could potentially be used to interfere pharmacologically with TCR signaling.
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Affiliation(s)
- M Heller
- Department of Molecular Biotechnology, University of Washington, Seattle, USA.
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