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Müller U, Schaub GA, Mossmann H, Köhler G, Carsetti R, Hölscher C. Immunosuppression in Experimental Chagas Disease Is Mediated by an Alteration of Bone Marrow Stromal Cell Function During the Acute Phase of Infection. Front Immunol 2018; 9:2794. [PMID: 30619242 PMCID: PMC6295583 DOI: 10.3389/fimmu.2018.02794] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/13/2018] [Indexed: 01/29/2023] Open
Abstract
After infection with Trypanosoma cruzi, the etiologic agent of Chagas disease, immunosuppression, and apoptosis of mature lymphocytes contribute to the establishment of the parasite in the host and thereby to persistence and pathology in the chronic stage of infection. In a systemic mouse model of experimental Chagas disease, we have demonstrated a strong depletion of mature B cells in the spleen during the first 2 weeks of infection. Remarkably, the decrease in this cell population commenced already in the bone marrow from infected mice and was a concomitant of an increased apoptosis in pro- and pre-B cell populations. Pro- and pre-B cells in the bone marrow showed a significant reduction accompanied by a functional disturbance of bone marrow-derived stromal cells resulting in diminished levels of IL-7, an essential factor for the development of B cell precursors. Ex vivo, stromal cells isolated from the bone marrow of infected mice had a strikingly impaired capacity to maintain the development of pro- and pre-B cells obtained from uninfected animals. Together, the reduction of an active humoral immune response during acute Chagas disease suggests to be an initial immune evasion mechanism of the parasite to establish persistent infection. Therefore, prevention of B cell depletion by rescuing the stromal cells during this early phase, could give rise to new therapeutic approaches.
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Affiliation(s)
- Uwe Müller
- Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.,Institute of Immunology, Veterinary Medicine, University Leipzig Leipzig, Germany
| | - Günter A Schaub
- Department of Animal Ecology, Evolution, and Biodiversity, Ruhr-Universität-Bochum, Bochum, Germany
| | - Horst Mossmann
- Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany
| | - Gabriele Köhler
- Department of Pathology, University of Freiburg, Freiburg, Germany
| | - Rita Carsetti
- Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany
| | - Christoph Hölscher
- Max Planck Institute for Immunobiology and Epigenetics, Freiburg, Germany.,Infection Immunology, Research Center Borstel, Borstel, Germany
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2
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Liver receptor homolog-1 (NR5a2) regulates CD95/Fas ligand transcription and associated T-cell effector functions. Cell Death Dis 2017; 8:e2745. [PMID: 28406481 PMCID: PMC5477591 DOI: 10.1038/cddis.2017.173] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/16/2017] [Accepted: 03/17/2017] [Indexed: 01/25/2023]
Abstract
CD95/Fas ligand (FasL) is a cell death-promoting member of the tumor necrosis factor family with important functions in the regulation of T-cell homeostasis and cytotoxicity. In T cells, FasL expression is tightly regulated on a transcriptional level involving a complex set of different transcription factors. The orphan nuclear receptor liver receptor homolog-1 (LRH-1/NR5a2) is involved in the regulation of development, lipid metabolism and proliferation and is predominantly expressed in epithelial tissues. However, its expression in T lymphocytes has never been reported so far. Based on in silico analysis, we identified potential LRH-1 binding sites within the FASLG promoter. Here, we report that LRH-1 is expressed in primary and secondary lymphatic tissues, as well as in CD4+ and CD8+ T cells. LRH-1 directly binds to its binding sites in the FASLG promoter, and thereby drives FASLG promoter activity. Mutations in the LRH-1 binding sites reduce FASLG promoter activity. Pharmacological inhibition of LRH-1 decreases activation-induced FasL mRNA expression, as well as FasL-mediated activation-induced T-cell apoptosis and T-cell cytotoxicity. In a mouse model of Concanavalin A-induced and FasL-mediated hepatitis pharmacological inhibition of LRH-1 resulted in decreased hepatic FasL expression and a significant reduction of liver damage. In summary, these data show for the first time LRH-1 expression in T cells, its role in FASLG transcription and the potential of pharmacological inhibition of LRH-1 in the treatment of FasL-mediated immunopathologies.
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3
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van Rensburg IC, Kleynhans L, Keyser A, Walzl G, Loxton AG. B-cells with a FasL expressing regulatory phenotype are induced following successful anti-tuberculosis treatment. IMMUNITY INFLAMMATION AND DISEASE 2016; 5:57-67. [PMID: 28250925 PMCID: PMC5322165 DOI: 10.1002/iid3.140] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 12/19/2022]
Abstract
Introduction Studies show that B‐cells, in addition to producing antibodies and antigen‐presentation, are able to produce cytokines as well. These include regulatory cytokines such as IL‐10 by regulatory B‐cells. Furthermore, a rare regulatory subset of B‐cells have the potential to express FasL, which is a death‐inducing ligand. This subset of B‐cells have a positive role during autoimmune disease, but has not yet been studied during tuberculosis. These FasL‐expressing B‐cells are induced by bacterial LPS and CpG, thus we hypothesized that this phenotype might be induced during tuberculosis as well. Methods B‐cells from participants with TB (at diagnosis and during treatment) and controls were collected, and analyzed by means of real‐time PCR and flow cytometry. In addition to this, BAL was collected from TB participants as well and analyzed by means of MAGPix (multi‐cytokine) technology. Results Gene expression analysis show that FASL transcript levels increase by the end of treatment. Similarly, phenotypic analysis show that there is a higher frequency of FasL‐expressing B‐cells by the end of treatment. Conclusion Collectively, these results indicate that these FasL‐expressing B‐cells are being induced during anti‐TB treatment, and thus may play a positive role. Further studies are required to elucidate this.
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Affiliation(s)
- Ilana C van Rensburg
- Division of Molecular Biology and Human Genetics Faculty of Medicine and Health Sciences SA MRC Centre for TB Research DST/NRF Centre of Excellence for Biomedical Tuberculosis Research Stellenbosch University Cape Town South Africa
| | - Léanie Kleynhans
- Division of Molecular Biology and Human Genetics Faculty of Medicine and Health Sciences SA MRC Centre for TB Research DST/NRF Centre of Excellence for Biomedical Tuberculosis Research Stellenbosch University Cape Town South Africa
| | - Alana Keyser
- Clinical Laboratory Sciences Faculty of Health Sciences University of Cape Town Cape Town South Africa
| | - Gerhard Walzl
- Division of Molecular Biology and Human Genetics Faculty of Medicine and Health Sciences SA MRC Centre for TB Research DST/NRF Centre of Excellence for Biomedical Tuberculosis Research Stellenbosch University Cape Town South Africa
| | - Andre G Loxton
- Division of Molecular Biology and Human Genetics Faculty of Medicine and Health Sciences SA MRC Centre for TB Research DST/NRF Centre of Excellence for Biomedical Tuberculosis Research Stellenbosch University Cape Town South Africa
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4
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Cao K, Wang G, Li W, Zhang L, Wang R, Huang Y, Du L, Jiang J, Wu C, He X, Roberts AI, Li F, Rabson AB, Wang Y, Shi Y. Histone deacetylase inhibitors prevent activation-induced cell death and promote anti-tumor immunity. Oncogene 2015; 34:5960-70. [PMID: 25745993 PMCID: PMC4672172 DOI: 10.1038/onc.2015.46] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 01/24/2015] [Accepted: 01/25/2015] [Indexed: 12/29/2022]
Abstract
The poor efficacy of the in vivo anti-tumor immune response has been partially attributed to ineffective T-cell responses mounted against the tumor. Fas-FasL-dependent activation-induced cell death (AICD) of T cells is believed to be a major contributor to compromised anti-tumor immunity. The molecular mechanisms of AICD are well-investigated, yet the possibility of regulating AICD for cancer therapy remains to be explored. In this study, we show that histone deacetylase inhibitors (HDACIs) can inhibit apoptosis of CD4+ T cells within the tumor, thereby enhancing anti-tumor immune responses and suppressing melanoma growth. This inhibitory effect is specific for AICD through suppressing NFAT1-regulated FasL expression on activated CD4+ T cells. In gld/gld mice with mutation in FasL, the beneficial effect of HDACIs on AICD of infiltrating CD4+ T cells is not seen, confirming the critical role of FasL regulation in the anti-tumor effect of HDACIs. Importantly, we found that the co-administration of HDACIs and anti-CTLA4 could further enhance the infiltration of CD4+ T cells and achieve a synergistic therapeutic effect on tumor. Therefore, our study demonstrates that the modulation of AICD of tumor-infiltrating CD4+ T cells using HDACIs can enhance anti-tumor immune responses, uncovering a novel mechanism underlying the anti-tumor effect of HDACIs.
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Affiliation(s)
- K Cao
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - G Wang
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - W Li
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - L Zhang
- Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.,The First Affiliated Hospital of Soochow University, Institutes for Translational Medicine, Soochow University, Suzhou, China
| | - R Wang
- Uro-Oncology Research, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Y Huang
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - L Du
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - J Jiang
- The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - C Wu
- The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - X He
- The Third Affiliated Hospital of Soochow University, Changzhou, China
| | - A I Roberts
- Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - F Li
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - A B Rabson
- Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Y Wang
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China
| | - Y Shi
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University of Medicine, Shanghai, China.,Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.,The First Affiliated Hospital of Soochow University, Institutes for Translational Medicine, Soochow University, Suzhou, China
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5
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Down regulation of TRAIL and FasL on NK cells by Cyclosporin A in renal transplantation patients. Immunol Lett 2013; 152:1-7. [PMID: 23523711 DOI: 10.1016/j.imlet.2013.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/11/2013] [Accepted: 03/05/2013] [Indexed: 10/27/2022]
Abstract
TNF-related apoptosis-inducing ligand (TRAIL) and FasL can participate in cell mediated cytotoxicity via their death domain-mediated apoptotic signaling in the host-versus-graft disease occurred after renal transplantation. However, the effect of Cyclosporin A (CsA) commonly used as a drug to prevent and to treat renal transplant rejection, on these molecules have not been fully determined. In the present study, we found that with CsA administration, the expression of TRAIL and FasL predominantly on NK cells from renal transplantation patients was increased at day 5 after operation and went down to normal level on day 13. While, the levels of soluble TRAIL (sTRAIL) and sFasL in the serum increased within 25 days and went down to normal level three month later. In addition, we showed that a remarkable increase of TRAIL and FasL expression both on the surface of activated lymphocytes especially on NK cells and in the supernatants generated from mixed lymphocytes culture (MLC). Furthermore, the enhancement of these two molecules was greatly decreased by adding 500 ng/mL CsA at the beginning of MLC. We conclude that CsA may inhibit the transplant rejection partially by down-regulating the expression of TRAIL and FasL on NK cells.
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6
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Nakagawa Y, Shimizu M, Norose Y, Takahashi M, Takahashi H. Induction of rapid apoptosis for class I MHC molecule-restricted CD8+ HIV-1 gp160-specific murine activated CTLs by free antigenic peptide in vivo. Int Immunol 2012; 25:11-24. [DOI: 10.1093/intimm/dxs086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Marín LA, Moya-Quiles MR, Miras M, Minguela A, Bermejo J, Ramírez P, García-Alonso AM, Parrilla P, Alvarez-López MR, Muro M. Evolution of soluble forms of CD86, CD95 and CD95L molecules in liver transplant recipients. Transpl Immunol 2011; 26:94-100. [PMID: 22182632 DOI: 10.1016/j.trim.2011.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/17/2011] [Accepted: 12/05/2011] [Indexed: 11/27/2022]
Abstract
Co-stimulatory factors such as CD86 and apoptotic molecules such as CD95 and CD95L required to start and to turn off the allogenic immune response may also be present as soluble proteins. To determine the role of the soluble forms of CD86 (sCD86), CD95 (sCD95) and CD95L (sCD95L) in the outcome of liver transplants, we analyzed the circulating levels of these molecules in patients subjected to liver transplantation in the pre-operative period and during the first month post-transplantation. Serum samples were obtained from sixty-nine first orthotopic liver transplants (OLT). The patients were classified into acute rejection (AR=24) and not acute rejection (NAR=45), or considering the presence of chronic active hepatitis B or C (VP=30) or other primary liver diseases (VN=39). The levels of sCD86, sCD95 and sCD95L were analyzed by solid phase sandwich enzyme-linked immunoabsorbent assays. Our results first showed that the pre-transplantation serum levels of sCD86 in the AR group were significantly higher than in the NAR group (1007±82U/mL vs. 739±46U/mL, p=0.006), and in the post-transplantation period these levels decreased sharply. Second, the levels of sCD95L and sCD95 in the pre-transplantation period did not point to statistically significant differences between the AR and NAR groups. Considering primary liver disease, the pre-transplantation levels of sCD86 and sCD95L in the VP group were significantly higher than those of the VN group (VP, 977±69U/mL vs. VN, 722±51U/mL, p<0.002, and VP, 482±78pg/mL vs. VN, 221±31pg/mL, p=0.002, respectively). Multivariate analysis revealed that only the pre-transplantation levels of sCD86 were independently associated with the development of episodes of acute rejection (p=0.005, OR=2.1, IC 95%=1.27-3.47). In conclusion, the present work shows that primary liver disease could influence the pre-transplantation levels of sCD86 and sCD95L. High pre-transplantation serum levels of sCD86 could favor the development of episodes of acute rejection.
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Affiliation(s)
- L A Marín
- Immunology Service, University Hospital Virgen de la Arrixaca, Murcia, Spain.
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8
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Weinlich R, Brunner T, Amarante-Mendes GP. Control of death receptor ligand activity by posttranslational modifications. Cell Mol Life Sci 2010; 67:1631-42. [PMID: 20306114 PMCID: PMC11115959 DOI: 10.1007/s00018-010-0289-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 01/20/2010] [Indexed: 01/26/2023]
Abstract
The death receptor ligands are involved in many physiological and pathological processes involving triggering of apoptosis, inflammation, proliferation, and activation. The expression of these molecules is reported to be tightly regulated at the transcriptional level. However, over the last few years, an increasing number of data demonstrated that the control of transcription is only one of the mechanisms that manage the expression of the death receptor ligands. Thus, this review is focused on posttranslational regulation of the three main members of this family, namely FasL, TNF-alpha, and TRAIL. We discuss here the importance of distribution, storage, and degranulation of these molecules, as well as their shedding by proteases on the control of death receptor ligands expression and activity.
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Affiliation(s)
- R Weinlich
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
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9
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Ramaswamy M, Cleland SY, Cruz AC, Siegel RM. Many checkpoints on the road to cell death: regulation of Fas-FasL interactions and Fas signaling in peripheral immune responses. Results Probl Cell Differ 2009; 49:17-47. [PMID: 19132321 DOI: 10.1007/400_2008_24] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Interactions between the TNF-family receptor Fas (CD95) and Fas Ligand (FasL, CD178) can efficiently induce apoptosis and are critical for the maintenance of immunological self-tolerance. FasL is kept under strict control by transcriptional and posttranslational regulation. Surface FasL can be cleaved by metalloproteases, resulting in shed extracellular domains, and FasL can also traffic to secretory lysosomes. Each form of FasL has distinct biological functions. Fas is more ubiquitously expressed, but its apoptosis-inducing function is regulated by a number of mechanisms including submembrane localization, efficiency of receptor signaling complex assembly and activation, and bcl-2 family members in some circumstances. When apoptosis is not induced, Fas-FasL interactions can also trigger a number of activating and proinflammatory signals. Harnessing the apoptosis-inducing potential of Fas for therapy of cancer and autoimmune disease has been actively pursued, and despite a number of unexpected side-effects that result from manipulating Fas-FasL interactions, this remains a worthy goal.
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Affiliation(s)
- Madhu Ramaswamy
- Immunoregulation Unit, Autoimmunity Branch, NIAMS, National Institutes of Health, Bethesda MD 20892, USA
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10
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Kassahn D, Nachbur U, Conus S, Micheau O, Schneider P, Simon HU, Brunner T. Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells. Cell Death Differ 2009; 16:115-24. [PMID: 19079288 DOI: 10.1038/cdd.2008.133] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Fas (CD95/Apo-1) ligand is a potent inducer of apoptosis and one of the major killing effector mechanisms of cytotoxic T cells. Thus, Fas ligand activity has to be tightly regulated, involving various transcriptional and post-transcriptional processes. For example, preformed Fas ligand is stored in secretory lysosomes of activated T cells, and rapidly released by degranulation upon reactivation. In this study, we analyzed the minimal requirements for activation-induced degranulation of Fas ligand. T cell receptor activation can be mimicked by calcium ionophore and phorbol ester. Unexpectedly, we found that stimulation with phorbol ester alone is sufficient to trigger Fas ligand release, whereas calcium ionophore is neither sufficient nor necessary. The relevance of this process was confirmed in primary CD4(+) and CD8(+) T cells and NK cells. Although the activation of protein kinase(s) was absolutely required for Fas ligand degranulation, protein kinase C or A were not involved. Previous reports have shown that preformed Fas ligand co-localizes with other markers of cytolytic granules. We found, however, that the activation-induced degranulation of Fas ligand has distinct requirements and involves different mechanisms than those of the granule markers CD63 and CD107a/Lamp-1. We conclude that activation-induced degranulation of Fas ligand in cytotoxic lymphocytes is differently regulated than other classical cytotoxic granule proteins.
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Affiliation(s)
- D Kassahn
- Division of Immunopathology, Institute of Pathology, University of Bern, Bern, Switzerland
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11
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Zhan Y, Gerondakis S, Coghill E, Bourges D, Xu Y, Brady JL, Lew AM. Glucocorticoid-Induced TNF Receptor Expression by T Cells Is Reciprocally Regulated by NF-κB and NFAT. THE JOURNAL OF IMMUNOLOGY 2008; 181:5405-13. [DOI: 10.4049/jimmunol.181.8.5405] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Charron T, Nili N, Strauss BH. The cell cycle: a critical therapeutic target to prevent vascular proliferative disease. Can J Cardiol 2007; 22 Suppl B:41B-55B. [PMID: 16498512 PMCID: PMC2780832 DOI: 10.1016/s0828-282x(06)70986-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Percutaneous coronary intervention is the preferred revascularization approach for most patients with coronary artery disease. However, this strategy is limited by renarrowing of the vessel by neointimal hyperplasia within the stent lumen (in-stent restenosis). Vascular smooth muscle cell proliferation is a major component in this healing process. This process is mediated by multiple cytokines and growth factors, which share a common pathway in inducing cell proliferation: the cell cycle. The cell cycle is highly regulated by numerous mechanisms ensuring orderly and coordinated cell division. The present review discusses current concepts related to regulation of the cell cycle and new therapeutic options that target aspects of the cell cycle.
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Affiliation(s)
| | | | - Bradley H Strauss
- Correspondence: Dr Bradley H Strauss, St Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B IW8. Telephone 416-864-5913, fax 416-864-5978, e-mail
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Raghavendra PB, Sreenivasan Y, Ramesh GT, Manna SK. Cardiac glycoside induces cell death via FasL by activating calcineurin and NF-AT, but apoptosis initially proceeds through activation of caspases. Apoptosis 2007; 12:307-18. [PMID: 17203245 PMCID: PMC2740376 DOI: 10.1007/s10495-006-0626-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Decrease in caspase activity is a common phenomenon in drug resistance. For effective therapeutic intervention, detection of such agents, which affects other pathway independent of caspases to promote cell death, might be important. Oleandrin, a polyphenolic glycoside induced cell death through activation of caspases in a variety of human tumour cells. In this report we provide evidence that besides caspases activation, oleandrin interacts with plasma membrane, changes fluidity of the membrane, disrupts Na(+)/K(+)-ATPase pump, enhances intracellular free Ca(2+) and thereby activates calcineurin. Calcineurin, in turns, activates nuclear transcription factor NF-AT and its dependent genes such as FasL, which induces cell death as a late response of oleandrin. Cell death at early stages is mediated by caspases where inhibitors partially protected oleandrin-mediated cell death in vector-transfected cells, but almost completely in Bcl-xL-overexpressed cells. Overall, our data suggest that oleandrin might be important therapeutic molecule in case of tumors where cell death pathway occurs due to deregulation of caspase-mediated pathway.
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Affiliation(s)
- Pongali B. Raghavendra
- Laboratory of Immunology, Centre for DNA Fingerprinting & Diagnostics, Nacharam, Hyderabad 500076, India,
| | - Yashin Sreenivasan
- Laboratory of Immunology, Centre for DNA Fingerprinting & Diagnostics, Nacharam, Hyderabad 500076, India,
| | - Govindarajan T. Ramesh
- G. T. Ramesh, Department of Biology, Texas Southern University, Houston, Texas 77004, USA
| | - Sunil K. Manna
- Laboratory of Immunology, Centre for DNA Fingerprinting & Diagnostics, Nacharam, Hyderabad 500076, India,
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Kerstan A, Armbruster N, Leverkus M, Hünig T. Cyclosporin A abolishes CD28-mediated resistance to CD95-induced apoptosis via superinduction of caspase-3. THE JOURNAL OF IMMUNOLOGY 2007; 177:7689-97. [PMID: 17114439 DOI: 10.4049/jimmunol.177.11.7689] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Costimulation of T cells via CD28 promotes both proliferation and resistance to apoptosis. In this study, we show that the immunosuppressive drug cyclosporin A (CsA) fully reverses resistance to CD95-mediated cell death after TCR/CD28 costimulation or superagonistic anti-CD28 mAb stimulation of primary rat lymph node T cells. This effect correlated with a pronounced superinduction of caspase-3 on both mRNA and protein levels, whereas its main antagonist, X chromosome-linked inhibitor of apoptosis, was unaffected by inclusion of CsA. Apoptosis triggered by CD95 cross-linking was characterized by robust caspase-3 activation. Furthermore, CsA sensitization to CD95-mediated apoptosis of CD28-activated T cells did not alter mRNA stability of superinduced caspase-3 mRNA, suggesting a transcriptional regulation of the caspase-3 gene. Addition of Ca(2+) ionophores to TCR/CD28 or superagonistic CD28-stimulated cells reduced caspase-3 levels, further supporting a role for Ca(2+)-dependent signaling pathways in negatively regulating caspase-3. Taken together, these findings suggest that CsA promotes sensitivity to CD95-mediated apoptosis in CD28-stimulated T cells by superinduction of the caspase-3 gene via a mechanism involving suppression of the calcineurin pathway.
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Affiliation(s)
- Andreas Kerstan
- Institute for Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, D-97078 Würzburg, Germany
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15
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van Dieren JM, Kuipers EJ, Samsom JN, Nieuwenhuis EE, van der Woude CJ. Revisiting the immunomodulators tacrolimus, methotrexate, and mycophenolate mofetil: their mechanisms of action and role in the treatment of IBD. Inflamm Bowel Dis 2006; 12:311-27. [PMID: 16633053 DOI: 10.1097/01.mib.0000209787.19952.53] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Inflammatory bowel diseases (IBDs) are thought to result from unopposed immune responses to normal gut flora in a genetically susceptible host. A variety of immunomodulating therapies are applied for the treatment of patients with IBDs. The first-line treatment for IBDs consists of 5-aminosalicylate and/or budesonide. However, these first-line therapies are often not suitable for continuous treatment or do not suffice for the treatment of severe IBD. Recently, efforts have been made to generate novel selective drugs that are more effective and have fewer side effects. Despite promising results, most of these novel drugs are still in a developmental stage and unavailable for clinical application. Yet, another class of established immunomodulators exists that is successful in the treatment of inflammatory bowel diseases. While waiting for emerging novel therapies, the use of these more established drugs should be considered. Furthermore, one of the advantages of using established immunomodulators is the well-documented knowledge on the long-term side effects and on the mechanisms of action. In this review, the authors discuss 3 well-known immunomodulators that are being applied with increased frequency for the treatment of IBD: tacrolimus, methotrexate, and mycophenolate mofetil. These agents have been used for many years as treatment modalities for immunosuppression after organ transplantation, for the treatment of cancer, and for immunomodulation in several other immune-mediated diseases. First, this review discusses the potential targets for immunomodulating therapies in IBDs. Second, the immunomodulating mechanisms and effects of the 3 immunomodulators are discussed in relationship to these treatment targets.
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Affiliation(s)
- Jolanda M van Dieren
- Department of Gastroenterology and Hepatology, Division of Gastroenterology and Nutrition, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
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16
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Nachbur U, Kassahn D, Yousefi S, Legler DF, Brunner T. Posttranscriptional regulation of Fas (CD95) ligand killing activity by lipid rafts. Blood 2006; 107:2790-6. [PMID: 16332972 DOI: 10.1182/blood-2005-07-2744] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AbstractFas (CD95/Apo-1) ligand-mediated apoptosis induction of target cells is one of the major effector mechanisms by which cytotoxic lymphocytes (T cells and natural killer cells) kill their target cells. In T cells, Fas ligand expression is tightly regulated at a transcriptional level through the activation of a distinct set of transcription factors. Increasing evidence, however, supports an important role for posttranscriptional regulation of Fas ligand expression and activity. Lipid rafts are cholesterol- and sphingolipid-rich membrane microdomains, critically involved in the regulation of membrane receptor signaling complexes through the clustering and concentration of signaling molecules. Here, we now provide evidence that Fas ligand is constitutively localized in lipid rafts of FasL transfectants and primary T cells. Importantly, disruption of lipid rafts strongly reduces the apoptosis-inducing activity of Fas ligand. Localization to lipid rafts appears to be predominantly mediated by the characteristic cytoplasmic proline-rich domain of Fas ligand because mutations of this domain result in reduced recruitment to lipid rafts and attenuated Fas ligand killing activity. We conclude that Fas ligand clustering in lipid rafts represents an important control mechanism in the regulation of T cell–mediated cytotoxicity.
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Affiliation(s)
- Ueli Nachbur
- Division of Immunopathology, Institute of Pathology, University of Bern, Murtenstr 31, 3010 Bern, Switzerland
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17
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Wiener Z, Ontsouka EC, Jakob S, Torgler R, Falus A, Mueller C, Brunner T. Synergistic induction of the Fas (CD95) ligand promoter by Max and NFkappaB in human non-small lung cancer cells. Exp Cell Res 2004; 299:227-35. [PMID: 15302589 DOI: 10.1016/j.yexcr.2004.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2003] [Revised: 04/26/2004] [Indexed: 11/28/2022]
Abstract
Fas (CD95/APO-1) ligand is a member of the Tumor Necrosis Factor family and a potent inducer of apoptosis. Fas ligand is expressed in activated T cells and represents a major cytotoxic effector mechanism by which T cells kill their target cells. Activation-induced Fas ligand expression in T cells is under the stringent control of various transcription factors, including nuclear factor kappaB (NFkappaB) and c-Myc/Max. There is accumulating evidence that Fas ligand is also expressed by various non-hematopoietic tumor cells, however, little is known about Fas ligand regulation in tumor cells. In this study, we have analyzed the regulation of the Fas ligand gene promoter induction in two non-small cell lung cancer cell lines, with a major focus on the role of the c-Myc/Max transcription factor. Our results revealed that inhibition of c-Myc/Max did not substantially reduce basal levels of Fas ligand promoter activity, nor did overexpression of c-Myc significantly induce promoter activity. In contrast, we observed that overexpression of Max resulted in a marked increase in basal promoter activity and synergistically enhanced phorbolester- and doxorubicin-induced NFkappaB-mediated Fas ligand promoter activity. These results were confirmed by analyzing endogenous Fas ligand transcription. We conclude that high levels of Max and stress-induced NFkappaB activation may result in elevated expression of Fas ligand in human lung cancer cells and possibly contribute to Fas ligand-associated immune escape mechanisms.
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MESH Headings
- Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
- Basic-Leucine Zipper Transcription Factors
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/immunology
- Carcinoma, Non-Small-Cell Lung/metabolism
- Cell Line, Tumor
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Doxorubicin/pharmacology
- Fas Ligand Protein
- Gene Expression Regulation, Neoplastic/genetics
- Genes, Regulator/genetics
- Humans
- Lung Neoplasms/genetics
- Lung Neoplasms/immunology
- Lung Neoplasms/metabolism
- Membrane Glycoproteins/genetics
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Phorbol Esters/pharmacology
- Promoter Regions, Genetic/genetics
- Proto-Oncogene Proteins c-myc/genetics
- Stress, Physiological/genetics
- Stress, Physiological/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic/genetics
- Tumor Escape/genetics
- Up-Regulation/genetics
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Affiliation(s)
- Zoltan Wiener
- Division of Immunopathology, Institute of Pathology, University of Berne, Berne, Switzerland
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18
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Barreiro R, Luker G, Herndon J, Ferguson TA. Termination of Antigen-Specific Immunity by CD95 Ligand (Fas Ligand) and IL-10. THE JOURNAL OF IMMUNOLOGY 2004; 173:1519-25. [PMID: 15265879 DOI: 10.4049/jimmunol.173.3.1519] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Following elimination of a foreign invader, the immune system must return to its normal quiescent levels. This process requires removal of reactive immune cells when they are no longer needed. We have explored the role of Fas/Fas ligand (FasL) in terminating immunity and demonstrate that mice defective in these proteins have prolonged immune responses. Studies demonstrate that termination of immunity occurs via the interaction of Fas(+) lymphoid cells with FasL(+) nonlymphoid cells at the site of Ag challenge. Our results also show that FasL is absent in quiescent tissue but is rapidly up-regulated during the local immune reaction. This occurs through the production of IL-10. Thus, FasL and IL-10 work in concert to eliminate inflammatory cells and control the duration of an immune response.
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Affiliation(s)
- Ramon Barreiro
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
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19
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Torgler R, Jakob S, Ontsouka E, Nachbur U, Mueller C, Green DR, Brunner T. Regulation of activation-induced Fas (CD95/Apo-1) ligand expression in T cells by the cyclin B1/Cdk1 complex. J Biol Chem 2004; 279:37334-42. [PMID: 15215233 DOI: 10.1074/jbc.m406913200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Fas (CD95/Apo-1) ligand-mediated apoptosis has been recognized as an important mechanism of cell-mediated cytotoxicity and maintenance of immune homeostasis. Chronically activated T cells undergo activation-induced cell death (AICD), which depends on simultaneous Fas and Fas ligand expression. Previous reports have suggested that AICD might be linked to cell cycle progression of T cells and therefore to the expression of cell cycle-related molecules. In particular, cyclin B1 has been implicated in the induction of AICD in T cells. In this study, we have investigated the role of cyclin B1 in AICD and the expression of effector molecules involved in this form of cell death. Our results show that inhibition of cyclin B1 blocks AICD in T cells through specific inhibition of Fas ligand expression but not Fas-induced apoptosis. This effect of cyclin B1 appears to be mediated through the cyclin B1/cyclin-dependent kinase 1 (Cdk1/Cdc2) complex because overexpression of cyclin B1 enhances FasL promoter activity, whereas a dominant-negative version of Cdk1 blocks Fas ligand promoter induction. We provide further evidence that cyclin B1/Cdk1 regulates FasL transcription through the regulation of NFkappaB activation because dominant-negative Cdk1 inhibits activation-induced NFkappaB reporter and Rel A-induced FasL promoter activity. In conclusion, our data support a link between cell cycle progression, activation-induced Fas ligand expression, and apoptosis in T cells.
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Affiliation(s)
- Ralph Torgler
- Division of Immunopathology, Institute of Pathology, University of Bern, 3010 Berne, Switzerland
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20
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Naujokat C, Daniel V, Bauer TM, Sadeghi M, Opelz G. Cell cycle- and activation-dependent regulation of cyclosporin A-induced T cell apoptosis. Biochem Biophys Res Commun 2003; 310:347-54. [PMID: 14521916 DOI: 10.1016/j.bbrc.2003.08.141] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The immunosuppressive agent cyclosporin A (CsA), which interferes with signal transduction pathways leading to cytokine gene transcription in activated T cells, was investigated regarding its ability to induce apoptosis in T cells undergoing cell cycle progression and activation. In Jurkat and peripheral CD4+ T cells, CsA was found to markedly induce apoptosis at the G0 phase of the cell cycle. Susceptibility to CsA-induced apoptosis progressively decreased during cell cycle progression to the S and G2/M phase, and subsequent T cell receptor- and mitogen-mediated activation totally abrogated CsA-induced apoptosis. Because CsA is an inhibitor of the chymotryptic peptidase activity of the proteasome, susceptibility to apoptosis induced by the proteasome inhibitor lactacystin was investigated under the same conditions. A progressive increase of the susceptibility of T cells to lactacystin-induced apoptosis during cell cycle progression and activation was demonstrated. Intracellular protein levels of the cyclin-dependent kinase inhibitor p27(Kip1)decreased from the G0 to G2/M phase and from the cycling to the activation state, but remained unchanged during the induction of apoptosis by CsA and lactacystin, suggesting a role of p27(Kip1)in the regulation of susceptibility to apoptosis during cell cycle progression and activation. Inhibition of CsA- but not lactacytin-induced apoptosis by overexpression of Bcl-2 in Jurkat T cells revealed that CsA and proteasome inhibitors activate different apoptotic pathways, while both CsA- and lactacystin-induced apoptosis were found to be dependent on caspase activation and independent of the FasL/Fas system. The results show that T cells can progressively regulate their susceptibility to apoptosis during cell cycle progression and activation in a stimulus-dependent manner, and suggest that lactacystin, but not CsA, is able to deplete activated T cells by apoptosis, a mechanism deemed necessary for the induction of allograft tolerance.
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Affiliation(s)
- Cord Naujokat
- Department of Transplantation Immunology, Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg, Germany.
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21
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Droin NM, Pinkoski MJ, Dejardin E, Green DR. Egr family members regulate nonlymphoid expression of Fas ligand, TRAIL, and tumor necrosis factor during immune responses. Mol Cell Biol 2003; 23:7638-47. [PMID: 14560009 PMCID: PMC207583 DOI: 10.1128/mcb.23.21.7638-7647.2003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2003] [Revised: 04/25/2003] [Accepted: 07/09/2003] [Indexed: 11/20/2022] Open
Abstract
The Fas ligand (FasL)/Fas pathway is crucial for homeostasis of the immune system and peripheral tolerance. Peripheral lymphocyte deletion involves FasL/Fas in at least two ways: coexpression of both Fas and its ligand on T cells, leading to activation-induced cell death, and expression of FasL by nonlymphoid cells, such as intestinal epithelial cells (IEC), that kill Fas-positive T cells. We demonstrate here that superantigen Staphylococcus enterotoxin B (SEB) induced a dramatic upregulation of FasL, TRAIL, and TNF mRNA expression and function in IEC from BALB/c and C57BL/6 mice. Using adoptive transfer in which CD4(+) T cells from OT-2 T-cell receptor transgenic mice were transferred into recipients, we observed an induction in IEC of FasL, TRAIL, and TNF mRNA after administration of antigen. Specific Egr-binding sites have been identified in the 5' promoter region of the FasL gene, and Egr-1, Egr-2, and Egr-3 mRNA in IEC from mice treated with SEB and from transgenic OT-2 mice after administration of antigen was upregulated. Overexpression of Egr-2 and Egr-3 induced endogenous ligand upregulation that was inhibited by overexpression of Egr-specific inhibitor Nab1. These results support a role for Egr family members in nonlymphoid expression of FasL, TRAIL, and TNF.
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MESH Headings
- Adoptive Transfer
- Animals
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Apoptosis Regulatory Proteins
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Early Growth Response Protein 1
- Early Growth Response Protein 2
- Early Growth Response Protein 3
- Enterotoxins/immunology
- Enterotoxins/metabolism
- Epithelial Cells/cytology
- Epithelial Cells/metabolism
- Fas Ligand Protein
- Gene Expression Regulation
- Humans
- Immediate-Early Proteins/genetics
- Immediate-Early Proteins/metabolism
- Intestinal Mucosa/cytology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- RNA, Messenger/metabolism
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Receptors, TNF-Related Apoptosis-Inducing Ligand
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Type I
- Repressor Proteins/metabolism
- TNF-Related Apoptosis-Inducing Ligand
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- Up-Regulation/physiology
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Affiliation(s)
- Nathalie M Droin
- Division of Cellular Immunology, La Jolla Institute for Allergy and Immunology, San Diego, California 92121, USA
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22
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Wieneke H, Dirsch O, Sawitowski T, Gu YL, Brauer H, Dahmen U, Fischer A, Wnendt S, Erbel R. Synergistic effects of a novel nanoporous stent coating and tacrolimus on intima proliferation in rabbits. Catheter Cardiovasc Interv 2003; 60:399-407. [PMID: 14571494 DOI: 10.1002/ccd.10664] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To overcome the problem of in-stent restenosis, the concept of local delivery of antiproliferative or immunosuppressive drugs has been introduced into interventional cardiology. Local drug delivery can be achieved by drug-eluting stents coated with polymer surfaces used for controlled drug release. However, several polymer coatings have shown an induction of inflammatory response and increased neointima formation. In the present study, the effect of a new inorganic ceramic nanoporous aluminum oxide (Al(2)O(3)) coating on neointima proliferation and its suitability as a carrier for the immunosuppressive drug tacrolimus have been investigated. 316 L stainless steel coronary stents were coated with a 500 nm thin nanoporous aluminum oxide layer. This ceramic nanolayer was used as a carrier for tacrolimus. Bare stents (n = 6), ceramic coated stents (n = 6), and ceramic coated stents loaded with 60 (n = 7) and 120 mug (n = 6) tacrolimus were implanted in the common carotid artery of New Zealand rabbits. The ceramic coating caused no significant reduction of neointimal thickness after 28 days. Loading the ceramic stents with tacrolimus led to a significant reduction of neointima thickness by 52% for 60 mug (P = 0.047) and 56% for 120 mug (P = 0.036) as compared to the bare stents. The ceramic coating alone as well as in combination with tacrolimus led to a reduced infiltration of lymphocytes and macrophages in the intima in response to stent implantation. Ceramic coating of coronary stents with a nanoporous layer of aluminum oxide in combination with tacrolimus resulted in a significant reduction in neointima formation and inflammatory response. The synergistic effects of the ceramic coating and tacrolimus suggest that this new approach may have a high potential to translate into clinical benefit.
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MESH Headings
- Animals
- Blood Vessel Prosthesis Implantation
- Carotid Artery, Common/pathology
- Carotid Artery, Common/surgery
- Carotid Artery, Common/ultrastructure
- Ceramics/metabolism
- Ceramics/pharmacology
- Ceramics/therapeutic use
- Coated Materials, Biocompatible/metabolism
- Coated Materials, Biocompatible/pharmacology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Synergism
- Equipment Design/instrumentation
- Female
- Graft Occlusion, Vascular/prevention & control
- Immunosuppressive Agents/blood
- Immunosuppressive Agents/pharmacology
- Male
- Microscopy, Electron
- Models, Cardiovascular
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/pathology
- Myocytes, Smooth Muscle/ultrastructure
- Rabbits
- Stents
- Tacrolimus/blood
- Tacrolimus/pharmacology
- Tunica Intima/drug effects
- Tunica Intima/pathology
- Tunica Intima/ultrastructure
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23
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Crist SA, Griffith TS, Ratliff TL. Structure/function analysis of the murine CD95L promoter reveals the identification of a novel transcriptional repressor and functional CD28 response element. J Biol Chem 2003; 278:35950-8. [PMID: 12855690 DOI: 10.1074/jbc.m306220200] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD28 costimulation, an important second signal for antigen-mediated T cell activation, is known to enhance expression of several genes important for the regulation of CD4+ T cell effector function including interleukin-2 and CD154. Previous studies demonstrate CD28-mediated enhancement of the transcription and expression of Fas ligand (CD95L) in T cell lines, suggesting a regulatory link between CD28 and CD95L expression. These results served as the basis for structure/function analysis of the CD95L promoter to elucidate the mechanism for CD28-mediated enhancement of CD95L. In this report, we describe a novel response element, located at -210 to -201 bp upstream of the transcription start site, that confers CD28 responsiveness to the CD95L gene. This response element is homologous to the CD28 response element (CD28RE) previously identified in the IL-2 promoter and bears structural similarities to a newly identified CD28RE in the CD154 promoter. We further demonstrate that CD28-mediated enhancement of promoter activity correlates with enhanced expression of CD95L mRNA, cell surface expression of CD95L protein, and increased apoptosis of CD95+ target cells. These results demonstrate a direct transcriptional regulatory role for CD28 in CD95L-mediated functional activity in CD4+ T cells. Mutational analysis of the CD95L promoter also reveals a novel transcriptional repressor element located approximately 60 bp 5' of the CD28RE. The repressor element bears sequence homology to an activator protein-1 element, constitutively binds c-Fos but not c-Jun, and is activation-independent.
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Affiliation(s)
- Scott A Crist
- Department of Urology and the Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, Iowa 52242, USA
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24
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Ryeom S, Greenwald RJ, Sharpe AH, McKeon F. The threshold pattern of calcineurin-dependent gene expression is altered by loss of the endogenous inhibitor calcipressin. Nat Immunol 2003; 4:874-81. [PMID: 12925851 DOI: 10.1038/ni966] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2003] [Accepted: 07/16/2003] [Indexed: 01/29/2023]
Abstract
Calcineurin links calcium signaling to transcriptional responses in the immune, nervous and cardiovascular systems. To determine the function of the calcipressins, a family of putative calcineurin inhibitors, we assessed the calcineurin-dependent process of T cell activation in mice engineered to lack the gene encoding calcipressin 1 (Csp1). Csp1 regulated calcineurin in vivo, and genes triggered in an immune response had unique transactivation thresholds for T cell receptor stimulation. In the absence of Csp1, the apparent transactivation thresholds for all these genes were shifted because of enhanced calcineurin activity. This unbridled calcineurin activity drove Fas ligand expression, which normally requires high T cell receptor stimulation and results in the premature death of T helper type 1 cells. Thus, calcipressins modulate the pattern of calcineurin-dependent transcription, and may influence calcineurin activity beyond calcium to integrate a broad array of signals into the cellular response.
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Affiliation(s)
- Sandra Ryeom
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA
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25
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Abstract
A properly functioning immune system is dependent on programmed cell death at virtually every stage of lymphocyte development and activity. This review addresses the phenomenon of activation-induced cell death (AICD) in T lymphocytes, in which activation through the T-cell receptor results in apoptosis. AICD can occur in a cell-autonomous manner and is influenced by the nature of the initial T-cell activation events. It plays essential roles in both central and peripheral deletion events involved in tolerance and homeostasis, although it is likely that different forms of AICD proceed via different mechanisms. For example, while AICD in peripheral T cells is often caused by the induction of expression of the death ligand, Fas ligand (CD95 ligand, FasL), it does not appear to be involved in AICD in thymocytes. This and other mechanisms of AICD are discussed. One emerging model that may complement other forms of AICD involves the inducible expression of FasL by nonlymphoid tissues in response to activated T lymphocytes. Induction of nonlymphoid FasL in this manner may serve as a sensing mechanism for immune cell infiltration, which contributes to peripheral deletion.
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Affiliation(s)
- Douglas R Green
- La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
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26
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Itescu S, John R. Interactions between the recipient immune system and the left ventricular assist device surface: immunological and clinical implications. Ann Thorac Surg 2003; 75:S58-65. [PMID: 12820736 DOI: 10.1016/s0003-4975(03)00480-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The unquestionable clinical success of left ventricular assist device (LVAD) implantation has, nevertheless, been accompanied by complications arising from interactions between the implanted biomaterial and the host immune system. The aberrant state of monocyte and T-cell activation resulting from these host/device interactions is accompanied by two parallel processes: (1) selective loss of Th1 cytokine producing CD4 T-cells through activation-induced cell death; and (2) unopposed activation of Th2 cytokine producing CD4 T-cells resulting in B-cell hyperreactivity and dysregulated immunoglobulin synthesis through Th2 cytokines and heightened CD40 ligand-CD40 interactions. The net results of these events is that, on the one hand, the LVAD recipient develops progressive defects in cellular immunity and is at increased risk of serious infection, and, on the other hand, is more likely to develop allosensitization, posing a significant risk to successful transplant outcome. Intravenous immunoglobulin therapy is an effective and safe modality for sensitized LVAD recipients awaiting cardiac transplantation, reducing serum anti-human lymphoicyte antigen (HLA) alloreactivity and shortening the duration to transplantation. The therapeutic and safety profile of intravenous immunoglobulin would appear to be superior to plasmapheresis. Immunosuppression incorporating intravenous cyclophosphamide before and after transplantation is safe and highly effective in sensitized LVAD recipients of cardiac transplantation. When used after transplantation as part of triple immunosuppressive regimens, cyclophosphamide is superior to mycophenolate mofetil in reducing episodes of allograft rejection in these patients. Because these immune dysfunctions appear to be related to the effects of excessive biomaterial-associated T-cell activation, future efforts will need to be directed at either altering the physical properties of the materials interacting with the host circulation or pharmacological intervention aimed more selectively at inhibiting T-cell activation.
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Affiliation(s)
- Silviu Itescu
- Department of Surgery, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA.
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27
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Itescu S, Schuster M, Burke E, Ankersmit J, Kocher A, Deng M, John R, Lietz K. Immunobiologic consequences of assist devices. Cardiol Clin 2003; 21:119-33, ix-x. [PMID: 12790051 DOI: 10.1016/s0733-8651(02)00135-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The aberrant state of monocyte and T-cell activation resulting from these host-device interaction is accompanied by two parallel processes: (1) selective loss of Th1 cytokine-producing CD4 T cells through activation-induced cell death, and (2) unopposed activation of Th2 cytokine-producing CD4 T cells resulting in B-cell hyperreactivity and dysregulated immunoglobulin synthesis via Th2 cytokines and heightened CD40 ligand-CD40 interactions. The net result of these events is that on one hand the VAD recipient develops progressive defects in cellular immunity and is at increased risk of serious infection, and on the other hand the VAD recipient is more likely to develop allosensitization, posing a significant risk to successful transplant outcome.
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Affiliation(s)
- Silviu Itescu
- College of Physicians and Surgeons of Columbia University, 622 West 168th Street, New York, NY 10032, USA.
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28
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Solomon JC, Sharma K, Wei LX, Fujita T, Shi YF. A novel role for sphingolipid intermediates in activation-induced cell death in T cells. Cell Death Differ 2003; 10:193-202. [PMID: 12700647 DOI: 10.1038/sj.cdd.4401136] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Activation-induced cell death (AICD), a process mediated by CD95 and CD95 ligand (CD95L), plays a critical role in regulating homeostasis of the immune system. Although the role of sphingolipids such as ceramides has been suggested to participate in CD95-mediated apoptosis, the exact role of these molecules in this process remains controversial. We employed myriocin, a specific inhibitor of serine palmitoyl-CoA transferase that mediates the first commitment step in sphingolipid synthesis. We found that myriocin could effectively block AICD in T-cell hybridomas and T-cell blasts. However, fumonisin B1, an inhibitor of the final step of ceramide synthesis, or inhibitors of sphingomyelinases did not prevent AICD. Furthermore, ceramide analogues, such as C2 and C6, could not reverse the inhibitory effect of myriocin. Interestingly, sphinganine, an intermediate of ceramide synthesis, completely reversed the inhibitory effect of myriocin, indicating a critical role of sphinganine. Myriocin did not modulate the expression of CD95 or CD95L, instead, it interfered with the early steps of CD95-mediated caspase activation. Therefore, we have uncovered a novel mechanism by which sphingolipid intermediates regulate CD95-mediated apoptosis.
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Affiliation(s)
- J C Solomon
- Department of Immunology, American Red Cross, Rockville, MD 20855, USA
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29
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Acosta Rodriguez EV, Zuñiga E, Montes CL, Gruppi A. Interleukin-4 biases differentiation of B cells from Trypanosoma cruzi-infected mice and restrains their fratricide: role of Fas ligand down-regulation and MHC class II-transactivator up-regulation. J Leukoc Biol 2003; 73:127-36. [PMID: 12525570 DOI: 10.1189/jlb.0702353] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In the present work, we demonstrate that interleukin (IL)-4 is able to rescue B cells from Trypanosoma cruzi-infected mice, counteracting the strong apoptotic signals that these cells received in vivo. We have observed that IL-4 restrains the apoptosis of immunoglobulin (Ig)M(+) and IgG(+) B cells from infected and normal mice without inducing them to proliferate. In addition, IL-4 does not modify the quantity or quality of the antibodies secreted by B cells from infected mice, as it blocks their terminal differentiation to plasma cells and favors memory pathway. It is interesting that the protective effect of IL-4 over B cells from infected mice is mediated, at least partly, by the down-regulation of Fas ligand (FasL) expression, which leads to interference in the apoptosis executed by these B cells through the Fas/FasL death pathway. Accordingly, a marked up-regulation of the "FasL gene repressor" class II transactivator was observed, suggesting that this would be one mechanism underlying the IL-4-mediated FasL down-regulation.
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Affiliation(s)
- E V Acosta Rodriguez
- Inmunología, Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, Haya de la Torre Medina Allende, Cordoba (5000), Argentina
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30
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Ducoroy P, Micheau O, Perruche S, Dubrez-Daloz L, de Fornel D, Dutartre P, Saas P, Solary E. LF 15-0195 immunosuppressive agent enhances activation-induced T-cell death by facilitating caspase-8 and caspase-10 activation at the DISC level. Blood 2003; 101:194-201. [PMID: 12393594 DOI: 10.1182/blood-2002-02-0603] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The deoxyspergualin derivative LF 15-0195 has demonstrated some efficacy in animal models of autoimmune and graft-versus-host diseases and is currently tested in clinics. The molecular mechanisms of LF 15-0195 immunosuppressive activity remained unknown. We show that exposure to LF 15-0195 sensitizes Jurkat T cells to apoptosis induced by an agonistic anti-CD95 antibody (CH11 clone) and by the cytokine TNF-related apoptosis-inducing ligand. LF 15-0195 does not demonstrate any significant effect on the postmitochondrial activation of caspases, nor does it modify overall expression of CD95, Fas-associated death domain, and procaspase-8. The compound facilitates the recruitment of these molecules to the death-inducing signaling complex (DISC) and enhances caspase-8 and -10 activation, thus increasing cytochrome c and direct IAP binding with low pI (DIABLO)/Smac mitochondrial release. LF 15-0195 also sensitizes Jurkat T cells to CD3-mediated apoptosis, an in vitro model for activation-induced T-cell death (AICD). LF 15-0195-mediated sensitization to AICD was further confirmed in human peripheral T cells exposed to anti-CD3 antibodies, then cultured in the presence of interleukin-2. In these cells, LF 15-0195 increased apoptosis triggered by either anti-CD95 antibodies or CD3 restimulation, whereas no effect was observed on "passive apoptosis." Finally, in bone marrow recipient mice, LF 15-0195 enhanced allogeneic donor T-cell death, which required a functional CD95 pathway. These results suggest that LF 15-0195 sensitizes T cells to AICD by increasing caspase activation at the DISC level in response to CD95 engagement. This original mechanism, together with LF 15-0195 efficacy in various disease models, makes this compound a promising immunosuppressive drug.
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Affiliation(s)
- Patrick Ducoroy
- Institut National de la Santé et de la Recherche Médicale (INSERM) U517, IFR 100, Faculties of Medicine and Pharmacy, Dijon, France
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31
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Selleri C, Maciejewski JP, Catalano L, Ricci P, Andretta C, Luciano L, Rotoli B. Effects of cyclosporine on hematopoietic and immune functions in patients with hypoplastic myelodysplasia: in vitro and in vivo studies. Cancer 2002; 95:1911-22. [PMID: 12404285 DOI: 10.1002/cncr.10915] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Immunosuppression may benefit some patients with hypoplastic myelodysplasia (HMDS) and refractory anemia (RA), but its mechanism of action is still obscure. METHODS Using flow cytometry, we studied Fas-receptor (Fas-R), Fas-ligand (Fas-L), and interferon-gamma (IFN-gamma) expression in CD34(+) cells and lymphocytes obtained from 11 HMDS and 20 RA patients. In colony assays and long-term cultures, the effects of Fas triggering, IFN-gamma blockade, or cyclosporine(CsA) on the growth of hematopoietic progenitors (colony-forming cells [CFC]) were determined. The effects of CsA at daily doses of 1-3 mg/kg for at least 3 months in HMDS patients were also studied. RESULTS In basal conditions, committed and immature progenitor cells were found decreased in myelodysplastic (MDS) patients. No significant differences between HMDS and RA patients were detected. IFN-gamma-expressing CD4(+) cells were significantly increased in HMDS patients, whereas intracytoplasmic Fas-L expression was only borderline elevated in CD3(+) MDS cells. Increased numbers of CD34(+) cells expressing Fas-R were found in HMDS and RA patients. CFC and secondary CFC showed higher susceptibility to Fas-L-mediated inhibition and the blockade of IFN-gamma improved marrow primary, but not secondary, CFC growth. CsA added in vitro to patient's lymphocytes significantly decreased the number of IFN-gamma-expressing CD4(+) cells, but not Fas-L production. These effects were associated with increased colony formation. Similar to IFN-gammablockade, production of secondary CFC was not enhanced by CsA. Administration of CsA to patients resulted in prolonged partial hematologic improvement in 8 of 11 HMDS patients. CONCLUSIONS Increased frequency of IFN-gamma producing CD4(+) cells supports the involvement of lymphocyte-mediated suppression of hematopoiesis in the development of cytopenia in MDS patients. The ability of CsA to decrease in vitro IFN-gamma production may improve hematopoietic function, explaining the beneficial effect of this agent in HMDS patients.
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Affiliation(s)
- Carmine Selleri
- Division of Hematology, Federico II University of Naples, Italy.
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32
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Ferguson TA, Herndon J, Elzey B, Griffith TS, Schoenberger S, Green DR. Uptake of apoptotic antigen-coupled cells by lymphoid dendritic cells and cross-priming of CD8(+) T cells produce active immune unresponsiveness. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:5589-95. [PMID: 12023355 DOI: 10.4049/jimmunol.168.11.5589] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The induction of immunologic unresponsiveness by i.v. administration of Ag-coupled lymphoid cells has been studied extensively, but the mechanisms remain unclear. We have further explored this model by examining the role of Fas/Fas ligand (FasL)-mediated apoptosis. Using i.v. injection of trinitrophenyl-coupled splenocytes (TNP-spl) as tolerogen, we found that Fas signaling for apoptosis in the spleen cells delivered by FasL in the recipient is the critical event. The requirement for Fas and FasL was overcome by prior induction of apoptosis in TNP-spl, making the tolerogen 100 times more potent. Prevention of apoptosis by a caspase inhibitor blocks tolerance. Interestingly, while blocking CD40/CD40 ligand interaction does not prevent tolerance induction, an agonist anti-CD40 Ab turns tolerogenic TNP-spl into an immunizing Ag. Studies further showed that tolerance is induced through cross-presentation of Ag in a class I MHC-dependent manner by CD8(+)CD11c(+) lymphoid-derived dendritic cells to regulatory T cells. The results provide a mechanism for a well-established method of inducing immunologic unresponsiveness.
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Affiliation(s)
- Thomas A Ferguson
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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33
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Yang Y, Dong B, Mittelstadt PR, Xiao H, Ashwell JD. HIV Tat binds Egr proteins and enhances Egr-dependent transactivation of the Fas ligand promoter. J Biol Chem 2002; 277:19482-7. [PMID: 11909874 DOI: 10.1074/jbc.m201687200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HIV Tat can enhance activation-induced up-regulation of Fas ligand (FasL), which may contribute to T cell apoptosis in human immune deficiency virus (HIV)-infected individuals. We have assessed functional and physical interactions between Tat and the Egr family of transcription factors (Egr-1, -2, and -3), the latter two of which are major participants in activation-induced FasL up-regulation. Here we report that whereas Tat itself has no effect on the FasL promoter, it binds to Egr-2 and -3 and synergizes with them to superinduce expression of a FasL promoter-driven reporter. A Tat molecule containing a single amino acid substitution that results in the loss of transactivation activity for the HIV long terminal repeat still binds Egr-3 but can no longer enhance Egr-mediated transactivation of the FasL promoter. Furthermore, the mutated Tat acts as a dominant negative inhibitor, blocking the superinduction of FasL caused by wild type Tat. Because Tat is present in virus-infected cells and in the serum of HIV-infected individuals, these results suggest that increased expression of FasL in these circumstances may result from the cooperative activities of activation-induced Egrs and Tat.
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Affiliation(s)
- Yili Yang
- Laboratory of Immune Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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34
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Strauss G, Osen W, Debatin KM. Induction of apoptosis and modulation of activation and effector function in T cells by immunosuppressive drugs. Clin Exp Immunol 2002; 128:255-66. [PMID: 11985515 PMCID: PMC1906394 DOI: 10.1046/j.1365-2249.2002.01777.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunosuppressive drugs (ISD) are used for the prevention and treatment of graft rejection, graft-versus-host-disease (GVHD) and autoimmune disorders. The precise mechanisms by which ISD interfere with T cell activation and effector function or delete antigen-specific T cells are defined only partially. We analysed commonly used ISD such as dexamethasone (DEX), mycophenolic acid (MPA), FK506, cyclosporin A (CsA), rapamycin (RAP), methotrexate (MTX) and cyclophosphamide (CP) for apoptosis-induction and modulation of activation and effector function in human peripheral T cells, cytotoxic T cell lines (CTL) and Jurkat T cells. Of all drugs tested only CP and MTX prevented antigen-specific proliferation of T cells and decreased cytotoxicity of alloantigen specific CTL lines by direct induction of apoptosis. MTX and CP also slightly increased activation-induced cell death (AICD) and CD95-sensitivity. In contrast, all other drugs tested did not induce T cell apoptosis, increase CD95-sensitivity or AICD. CsA and FK506 even prevented AICD by down-modulation of CD95L. DEX, MPA, CsA, FK506 and RAP inhibited activation of naive T cells, but were not able to block proliferation of activated T cells nor decrease cytotoxic capacity of CTL lines. These results show that ISD can be classified according to their action on apoptosis-induction and inhibition of proliferation and would favour a rational combination therapy to delete existing reactive T cells and prevent further T cell activation.
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Affiliation(s)
- G Strauss
- University Children's Hospital, Ulm, Germany
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35
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Miller AT, Berg LJ. Defective Fas ligand expression and activation-induced cell death in the absence of IL-2-inducible T cell kinase. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:2163-72. [PMID: 11859102 DOI: 10.4049/jimmunol.168.5.2163] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The Tec family tyrosine kinase, IL-2-inducible T cell kinase (Itk), plays an important role in TCR signaling. Studies of T cells from Itk-deficient mice have demonstrated that Itk is critical for the activation of phospholipase-Cgamma1, leading to calcium mobilization in response to TCR stimulation. This biochemical defect results in reduced IL-2 production by Itk-deficient T cells. To further characterize the downstream effects of the Itk deficiency, we crossed Itk-/- mice to a TCR-transgenic line and examined T cell responses to stimulation by peptide plus APC. These studies show that Itk is required for maximal activation of early growth responses 2 and 3 and Fas ligand transcription after TCR stimulation. These transcriptional defects lead to reduced activation-induced cell death of stimulated Itk-/- T cells, both in vitro and in vivo. Together these studies define an important role for Itk in TCR signaling, leading to cytokine gene expression and activation-induced cell death.
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Affiliation(s)
- Andrew T Miller
- Department of Pathology, Program in Immunology and Virology, University of Massachusetts Medical Center, 55 Lake Avenue North, Worcester, MA 01655, USA
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36
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Wasem C, Frutschi C, Arnold D, Vallan C, Lin T, Green DR, Mueller C, Brunner T. Accumulation and activation-induced release of preformed Fas (CD95) ligand during the pathogenesis of experimental graft-versus-host disease. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2936-41. [PMID: 11509642 DOI: 10.4049/jimmunol.167.5.2936] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fas (CD95/APO-1) ligand (FasL)-mediated cytotoxicity has been implicated in tissue destruction in a variety of diseases, including acute graft-vs-host disease (GVHD). In this study, we have analyzed FasL expression and regulation during the course of experimental murine acute GVHD. Although activation-induced FasL-mediated cytotoxicity in control T cells was sensitive to the immunosuppressant cyclosporin A, we observed that functional FasL expression of GVHD T cells became increasingly cyclosporin A unresponsive. This was found to be the result of a massive in vivo accumulation and intracellular storage of FasL protein and its release in a transcription- and protein synthesis-independent manner. Immunohistochemistry analysis of FasL expression in situ revealed accumulation of FasL-expressing cells in the spleen, the liver, and small intestine, with a typical cytoplasmic and granular expression pattern. Thus, we conclude that the release of preformed FasL by infiltrating donor T cells may contribute to recipient tissue damage during the pathogenesis of acute GVHD.
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Affiliation(s)
- C Wasem
- Division of Immunopathology, Institute of Pathology, University of Bern, Bern, Switzerland
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37
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Gan YH, Lui SSN, Malkovsky M. Differential Susceptibility of Naïve and Activated Human γδ T Cells to Activation-Induced Cell Death by T-Cell Receptor Cross-Linking. Mol Med 2001. [DOI: 10.1007/bf03401870] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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38
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Brunner T, Arnold D, Wasem C, Herren S, Frutschi C. Regulation of cell death and survival in intestinal intraepithelial lymphocytes. Cell Death Differ 2001; 8:706-14. [PMID: 11464215 DOI: 10.1038/sj.cdd.4400854] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2000] [Revised: 01/31/2001] [Accepted: 02/07/2001] [Indexed: 11/09/2022] Open
Abstract
Intraepithelial lymphocytes (IEL) of the small murine bowel represent a unique population of mostly CD8(+) T lymphocytes that reside within the epithelial cell layer of the intestinal mucosa. The close interaction with epithelial cells appears to be crucial for IEL survival since isolation and ex vivo culture induces massive apoptosis in this lymphocyte population. Here, we provide evidence that this form of IEL cell death may be mediated at least in part by endogenously produced glucocorticoids since adrenalectomy or treatment of mice with a glucocorticoid receptor antagonist significantly enhanced ex vivo survival of IEL. We further demonstrate that ex vivo activation of IEL induces upregulation of anti-apoptotic gene products, compensates for the lack of survival cytokines and rescues from apoptotic cell death. Thus, similar to thymocytes and T cell hybridomas, IEL survival may be regulated by the antagonistic action of TCR activation and glucocorticoids.
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Affiliation(s)
- T Brunner
- Division of Immunopathology, Institute of Pathology, University of Bern, Murtenstrasse 31, 3010 Bern, Switzerland.
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39
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Hashimoto Y, Matsuoka N, Kawakami A, Tsuboi M, Nakashima T, Eguchi K, Tomioka T, Kanematsu T. Novel immunosuppressive effect of FK506 by augmentation of T cell apoptosis. Clin Exp Immunol 2001; 125:19-24. [PMID: 11472421 PMCID: PMC1906112 DOI: 10.1046/j.1365-2249.2001.01586.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have recently reported the accumulation of oligoclonal activated T cells in the spontaneously developed autoimmune pancreatitis in aly/aly mouse. In this study, we examined the effects of FK506 in this mouse model in preventing autoimmune pancreatitis and investigated its action on calcium signalling apoptosis of alymphoplasia (aly) lymphocytes in vitro. Mice were treated with FK506 from 8 to 25 weeks of age. At the age of 15 weeks, minimal mononuclear cell infiltration was observed in the pancreas in both the FK506 treated group and the control group. Furthermore, a marked cell infiltration associated with destruction of acini and partial fatty changes were observed in 25-week-old control mice. In contrast, FK506 treated mice showed almost no tissue destruction or mononuclear cell infiltration at the age of 25 weeks. Furthermore, at 15 weeks of age, most mononuclear cells in FK506-treated mice were TUNEL positive, whereas only a few were positive in control mice. This augmentation of T cell apoptosis by FK506 was confirmed using naive splenocytes activated by PMA and ionomycin in vitro. Finally, a suppressive effect of FK506 on Bcl-2 production but not on Bax production was confirmed by Western blotting. This unique effect of FK506 on the augmentation of T cell apoptosis is probably one of the mechanisms explaining its beneficial effect on aly autoimmune pancreatitis.
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Affiliation(s)
- Y Hashimoto
- Department of Surgery II, Nagasaki University School of Medicine, Nagasaki City, Nagasaki, Japan
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40
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Dzialo-Hatton R, Milbrandt J, Hockett RD, Weaver CT. Differential expression of Fas ligand in Th1 and Th2 cells is regulated by early growth response gene and NF-AT family members. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:4534-42. [PMID: 11254710 DOI: 10.4049/jimmunol.166.7.4534] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Inducible expression of Fas ligand (CD95 ligand) by activated T cells and the resulting apoptosis of CD95-bearing cells is a critical component of peripheral T cell homeostasis and cytotoxic effector mechanisms. Transcriptional control of the expression of Fas ligand has been attributed to a number of factors, including early growth response gene 2 (Egr2), Egr3, Sp1, and NF-AT, although a direct contribution of NF-AT is controversial. The present study confirms a role for Egr factors and indicates that NF-AT is essential for optimal expression of murine Fas ligand through a direct interaction with an NF-AT consensus element. The role of these factors was further defined by studying the differential expression of Fas ligand in Th1 and Th2 lines derived from DO11.10 TCR transgenic mice. EMSA analyses of a composite Egr/NF-AT site showed recruitment of Sp1 to this site in Th2 cells, but not in Th1 cells. Furthermore, gel-shift analyses demonstrated the binding of Egr1, 2, and 3 in Th2 cells and Egr1 and 2, but not Egr3 in Th1 cells at a known Egr site. Northern analysis corroborated the lack of Egr3 in Th1 cells. Differential usage of these transcription factors by Th1 and Th2 cells suggests a potential mechanism underlying the differential expression of Fas ligand by distinct T cell lineages.
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Affiliation(s)
- R Dzialo-Hatton
- Department of Pathology, University of Alabama, Birmingham, AL 35294, USA
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41
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Wang R, Zhang L, Zhang X, Moreno J, Luo X, Tondravi M, Shi Y. Differential regulation of the expression of CD95 ligand, receptor activator of nuclear factor-kappa B ligand (RANKL), TNF-related apoptosis-inducing ligand (TRAIL), and TNF-alpha during T cell activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1983-90. [PMID: 11160247 DOI: 10.4049/jimmunol.166.3.1983] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Members of TNF superfamily are characterized by their ability to inflict apoptosis upon binding to their cognate receptors in a homotrimeric manner. These proteins are expressed on different cell types under various conditions. However, the mechanisms governing the expression of these molecules remain elusive. We have found that the TCR signal can elicit the expression of receptor activator of NF-kappaB ligand (RANKL), TNF-alpha, CD95L, and TNF-related apoptosis inducing ligand (TRAIL) in T cell hybridoma A1.1 cells, thus allowing us to examine the expression pattern of these molecules under precisely the same conditions. We have previously reported that CD95L expression requires both protein kinase C (PKC) translocation and Ca2+ mobilization and is inhibited by cyclosporin A, and dexamethasone. We demonstrate now that activation-induced expression of RANKL is mediated by Ca2+ mobilization. PKC activation does not induce RANKL expression nor does it synergize with the Ca2+ signal. Activation-induced RANKL expression is blocked by cyclosporin A, but not by dexamethasone. The expression of TNF, in contrast, is mediated by PKC, but not by Ca2+. TNF-alpha expression is not inhibited by cyclosporin A, but is sensitive to dexamethasone. A1.1 cells constitutively express TRAIL at low levels. Stimulation with anti-CD3 leads to an initial reduction and subsequent increase in TRAIL expression. TRAIL induction is not inhibited by cyclosporin A, but highly sensitive to dexamethasone. Therefore, expression of the TNF superfamily genes is regulated by distinct signals. Detailed understanding of the regulatory mechanisms could provide crucial information concerning the role of these molecules in the modulation of the immune system.
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Affiliation(s)
- R Wang
- Department of Immunology and Tissue Biology, Jerome H. Holland Laboratory, American Red Cross, Rockville, MD 20855, USA
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42
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Delgado M, Ganea D. Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit expression of Fas ligand in activated T lymphocytes by regulating c-Myc, NF-kappa B, NF-AT, and early growth factors 2/3. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1028-40. [PMID: 11145682 DOI: 10.4049/jimmunol.166.2.1028] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activation-induced cell death in T cells, a major mechanism for limiting an ongoing immune response, is initiated by Ag reengagement and mediated through Fas/Fas ligand interactions. Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP), two multifunctional neuropeptides, modulate innate and adaptive immunity. We reported previously that VIP/PACAP protect T cells from activation-induced cell death through down-regulation of Fas ligand (FasL). In this study, we investigate the molecular mechanisms involved in the protective effect of VIP and PACAP. VIP/PACAP reduce in a dose-dependent manner anti-CD3-induced apoptosis in 2B4.11 T cell hybridomas. The protective effect is mediated through the specific type 2 VIP receptor, and the cAMP/protein kinase A pathway. A functional study demonstrates that VIP/PACAP inhibit activation-induced FasL expression. VIP/PACAP inhibit the expression and/or DNA-binding activity of several transcriptional factors involved in FasL expression, i.e., c-myc, NF-kappaB, NF-ATp, and early growth factors (Egr) 2/3. The inhibition of NF-kappaB binding is due to the stabilization of I-kappaB (inhibitory protein that dissociates from NF-kappaB), through the inhibition of I-kappaB kinase alpha activity. Subsequently, p65 nuclear translocation is significantly reduced. The inhibition in NF-ATp binding results from a calcineurin-independent reduction in NF-ATp nuclear translocation. VIP/PACAP inhibit the expression of Egr2 and 3, but not of Egr1. The effects on the transcriptional factors are mediated through type 2 VIP receptor with cAMP as secondary messenger.
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Affiliation(s)
- M Delgado
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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43
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Sharma K, Wang RX, Zhang LY, Yin DL, Luo XY, Solomon JC, Jiang RF, Markos K, Davidson W, Scott DW, Shi YF. Death the Fas way: regulation and pathophysiology of CD95 and its ligand. Pharmacol Ther 2000; 88:333-47. [PMID: 11337030 DOI: 10.1016/s0163-7258(00)00096-6] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Apoptotic cell death mediated by the members of the tumor necrosis factor receptor family is an essential process involved in the regulation of cellular homeostasis during development, differentiation, and pathophysiological conditions. Among the cell death receptors comprising the tumor necrosis factor receptor superfamily, CD95/APO-1 (Fas) is the best characterized. The specific interaction of Fas with its cognate ligand, Fas ligand (FasL), elicits the activation of a death-inducing caspase (cysteine aspartic acid proteases) cascade, occurring in a transcription-independent manner. Caspase activation executes the apoptosis process by cleaving various intracellular substrates, leading to genomic DNA fragmentation, cell membrane blebbing, and the exposure of phagocytosis signaling molecules on the cell surface. Recent studies have shown that the Fas/FasL pathway plays an important role in regulating the life and death of the immune system through activation-induced cell death. In addition, these molecules have been implicated in aging, human immunodeficiency virus infection, drug abuse, stress, and cancer development. In this review, we will focus on the mechanisms that regulate Fas and FasL expression, and how their deregulation leads to diseases.
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Affiliation(s)
- K Sharma
- Department of Immunology, Holland Laboratory, American Red Cross, 15601 Crabbs Branch Way, Rockville, MD 20855, USA
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44
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Odaka C, Mizuochi T. Angiotensin-converting enzyme inhibitor captopril prevents activation-induced apoptosis by interfering with T cell activation signals. Clin Exp Immunol 2000; 121:515-22. [PMID: 10971519 PMCID: PMC1905724 DOI: 10.1046/j.1365-2249.2000.01323.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Captopril is an orally active inhibitor of angiotensin-converting enzyme (ACE) which is widely used as an anti-hypertensive agent. In addition to its ability to reduce blood pressure, captopril has a number of other biological activities. Recently the drug was shown to inhibit Fas-induced apoptosis in human activated peripheral T cells and human lung epithelial cells. In this study, we investigated whether captopril blocks activation-induced apoptosis in murine T cell hybridomas, and found that captopril inhibited IL-2 synthesis and apoptotic cell death upon activation with anti-CD3 antibody. In addition, captopril inhibited an inducible caspase-3-like activity during activation-induced apoptosis. On the other hand, captopril did not interfere with Fas signalling, since anti-Fas antibody-induced apoptosis in Fas+ Jurkat cells was unaffected by the drug. Furthermore, we examined whether captopril blocks activation-induced apoptosis by interfering with expression of Fas, Fas ligand (FasL), or both on T cell hybridomas. FasL expression on activated T cells was significantly inhibited by captopril, whereas up-expression of Fas was partially inhibited, as assessed by cell surface staining. Taking all data together, we conclude that captopril prevents activation-induced apoptosis in T cell hybridomas by interfering with T cell activation signals. Captopril has been reported to induce systemic lupus erythematosus syndrome, and our findings may be useful for elucidating the mechanism of captopril-induced autoimmunity.
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Affiliation(s)
- C Odaka
- Department of Bacterial and Blood Products, National Institute of Infectious Diseases, Tokyo, Japan.
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45
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Abstract
The increasing use of implanted biomaterial devices has made it evident that no material is biologically inert. As a result of direct contact with elements of the blood circulation, such as during hemodialysis or after left ventricular assist device (LVAD) implantation, significant changes in systemic immunologic and thrombostatic functions occur. The clinical success of LVAD implantation has, nevertheless, been accompanied by complications arising from an aberrant state of monocyte and T-cell activation, leading to heightened susceptibility of circulating CD4 T cells to undergo activation-induced cell death; this results in progressive defects in cellular immunity and an increased risk of serious infection. Because of the increased state of T-cell activation and the selective loss of Th1 cytokine producing CD4 T cells, LVAD recipients also develop B-cell hyperreactivity and dysregulated immunoglobulin syntheses by unopposed production of Th2 cytokines and increased CD40 Ligand-CD40 interactions. LVADs are currently being evaluated as a permanent therapy for end-stage heart failure. Because these immune dysfunctions appear to be related to the effects of excessive biomaterial associated T-cell activation, future efforts will need to be directed at either altering the physical properties of the materials interacting with the host circulation or pharmacological intervention aimed at inhibiting T-cell activation.
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Affiliation(s)
- S Itescu
- Department of Surgery, Columbia-Presbyterian Medical Center, New York, NY 10032, USA
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46
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Pan S, Tsuruta R, Masuda ES, Imamura R, Bazan F, Arai K, Arai N, Miyatake S. NFATz: a novel rel similarity domain containing protein. Biochem Biophys Res Commun 2000; 272:765-76. [PMID: 10860829 DOI: 10.1006/bbrc.2000.2831] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nuclear Factor of Activated T cell (NFAT) is a family of transcription factors that are important for the coordinate expression of various cytokines and immunoregulatory cell surface molecules in T cells and other types of cells in the immune system. In addition, analysis of gene disrupted mice revealed that some members of NFAT family are important for the development of myocardium, myocardial hypertrophy, and mesenchymal stem cells. NFAT family proteins have two conserved domains, the NFAT Homology Domain (NHD) and the Rel Similarity Domain (RSD). The RSD is DNA binding and AP-1 interacting domain which has structural similarity to the Rel Homology Region, the DNA binding domain of Rel family proteins. The NHD is a regulatory domain required for the Ca regulated translocation of NFAT. We report here the isolation and initial characterization of a novel RSD containing protein designated NFATz. NFATz has a RSD but no NHD. NFATz protein is localized in the nucleus without Ca signal. There is no detectable binding to a typical NFAT site even in the presence of AP-1, and it is not capable of activating transcription through the NFAT site. The chromosomal location determined by FISH revealed that NFATz and NFATx genes are in the same region.
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Affiliation(s)
- S Pan
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan
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47
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Norian LA, Latinis KM, Eliason SL, Lyson K, Yang C, Ratliff T, Koretzky GA. The regulation of CD95 (Fas) ligand expression in primary T cells: induction of promoter activation in CD95LP-Luc transgenic mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:4471-80. [PMID: 10779747 DOI: 10.4049/jimmunol.164.9.4471] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The interaction between CD95 (Fas) and CD95L (Fas ligand) initiates apoptosis in a variety of cell types. Although the regulation of CD95L expression on activated T cells is an area of intense study, knowledge related to the induction of CD95L promoter activity in primary T cells is lacking. In this report we describe the generation of a novel transgenic mouse strain, CD95LP-Luc, in which murine CD95L promoter sequence controls the expression of a luciferase reporter gene. We use these mice to illustrate several important findings related to transcriptional regulation of CD95L in primary T cells. We demonstrate that maximal CD95L promoter activity occurs only after prolonged T cell stimulation and requires costimulation through CD28. We provide evidence that thymocytes express CD95L/luciferase after strong TCR ligation and that inducible CD95L promoter activation is present, but unequal, in both Th1 and Th2 effector cells. We also illustrate that while agonist peptide presentation by APCs generates robust proliferation during a primary T cell response, the same stimulus induces only modest CD95L promoter activity. These results suggest alternate explanations for the well-characterized delay in CD95-mediated activation-induced cell death following initial ligation of the TCR.
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Affiliation(s)
- L A Norian
- Interdisciplinary Graduate Program in Immunology, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
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48
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Popović P, Colić M, Vucević D, Gasić S, Pavicić L. Comparison of signaling pathways involved in apoptosis of a thymocyte hybridoma triggered by a rat thymic medullary epithelial cell line, dexamethasone or T-cell receptor cross-linking. Immunol Lett 2000; 72:83-91. [PMID: 10841942 DOI: 10.1016/s0165-2478(00)00165-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Using an in vitro co-culture assay we found that a rat medullary thymic epithelial cell (TEC) line (TE-R2.5) induces apoptosis of the BWRT8 thymocyte hybridoma (TH) (CD4(hi)CD8(low) alphabetaTCR(hi)). TH apoptosis induced by this TEC line was predominantly mediated by direct cell-cell contacts and was potentiated by cross-linking of the T cell receptor (TCR) by R73 monoclonal antibody (mAb). Dexamethasone (Dx) also triggered TH apoptosis but inhibited death of these cells induced by TE-R2.5 cells or immobilized R73 mAb. The TEC-induced apoptosis was independent of the LFA-1/ICAM-1 interaction but partly depended on a novel 29 kDa molecule expressed on TE-R2.5 cells. All three types of TH apoptosis were followed by the cleavage of poly-(ADP-ribose)-polymerase and were blocked by a caspase inhibitor Z-Val-Ala-Asp(OMe)-CH(2)F.PKC stimulation by phorbol myristate acetate interfered with the TH apoptosis induced by TE-R2.5 and Dx, but did not modulate the effect of R73 mAb. On the contrary, inhibition of calcineurin with cyclosporine A did not influence the apoptosis induced by TE-R2.5 and Dx, but completely prevented the R73-triggered TH cell death. The TE-R2.5-mediated BWRT8 apoptosis was suppressed by Na-orthovanadate, an inhibitor of protein tyrosine phosphatases (PTP) as well as by genistein, a protein tyrosine kinase (PTK) inhibitor, while both compounds potentiated the effect of Dx. Blocking PTP, but not PTK decreased the proapoptotic effect of R73 mAb. These results, including those using a BWRT8 subclone (BWRT8-MDP.2) which is resistant to TCR-triggered apoptosis, but sensitive to apoptosis stimulated by TE-R2.5 and Dx, indicate that TE-R2.5-induced TH apoptosis in our model is different from apoptosis in other TEC co-culture models, published so far.
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Affiliation(s)
- P Popović
- Institue of Medical Research, Military Medical Academy, Crnotravska 17, 11002, Belgrade, Yugoslavia
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Brunner T, Kasibhatla S, Pinkoski MJ, Frutschi C, Yoo NJ, Echeverri F, Mahboubi A, Green DR. Expression of Fas ligand in activated T cells is regulated by c-Myc. J Biol Chem 2000; 275:9767-72. [PMID: 10734130 DOI: 10.1074/jbc.275.13.9767] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcription factor c-Myc is important for the control of cell cycle progression, neoplasia, and apoptotic cell death. c-Myc dimerizes with its partner Max to form an active transcription factor complex. Little is known, however, about the transcriptional targets of c-Myc and their roles in c-Myc-induced cell death. Here we demonstrate that T cell activation-induced expression of Fas ligand (FasL, CD95-L, APO-1-L), which can induce apoptotic cell death in many different cell types, is regulated by c-Myc. Down-modulation of c-Myc protein via antisense oligonucleotides blocked activation-induced FasL mRNA and protein expression and functional FasL expression in activated T cells and T cell lines. Further, FasL promoter activity in T cells is driven by overexpression of c-Myc and inhibited by expression of dominant-negative mutants of c-Myc and Max. Our findings indicate that c-Myc controls apoptotic cell death in T cells through regulation of FasL expression.
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Affiliation(s)
- T Brunner
- Division of Immunopathology, Institute for Pathology, University of Berne, 3010 Berne, Switzerland
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50
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Lin T, Genestier L, Pinkoski MJ, Castro A, Nicholas S, Mogil R, Paris F, Fuks Z, Schuchman EH, Kolesnick RN, Green DR. Role of acidic sphingomyelinase in Fas/CD95-mediated cell death. J Biol Chem 2000; 275:8657-63. [PMID: 10722706 DOI: 10.1074/jbc.275.12.8657] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Engagement of the Fas receptor has been reported to induce ceramide generation via activation of acidic sphingomyelinase (aSMase). However, the role of aSMase in Fas-mediated cell death is controversial. Using genetically engineered mice deficient in the aSMase gene (aSMase(-/-)), we found that thymocytes, concanavalin A-activated T cells, and lipopolysaccharide-activated B cells derived from both aSMase(-/-) and aSMase(+/+) mice were equally sensitive to Fas-mediated cell death, triggered by either anti-Fas antibody or Fas ligand in vitro. Similarly, activation-induced apoptosis of T lymphocytes was unaffected by the status of aSMase, and aSMase(-/-) mice failed to show immunological symptoms seen in animals with defects in Fas function. In vivo, intravenous injection of 3 microg/25 g mouse body weight of anti-Fas Jo2 antibody into aSMase(-/-) mice failed to affect hepatocyte apoptosis or mortality, whereas massive hepatocyte apoptosis and animal death occurred in wild type littermates. Animals heterozygous for aSMase deficiency were also significantly protected. Susceptibility of aSMase(-/-) mice to anti-Fas antibody was demonstrated with higher antibody doses (>/=4 microg/25 g mouse). These data indicate a role for aSMase in Fas-mediated cell death in some but not all tissues.
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Affiliation(s)
- T Lin
- Department of Cellular Immunology, La Jolla Institute for Allergy and Immunology, San Diego, California 92121, USA
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