scholarly journals A Point Mutation of Tyr-759 in Interleukin 6 Family Cytokine Receptor Subunit gp130 Causes Autoimmune Arthritis

2002 ◽  
Vol 196 (7) ◽  
pp. 979-990 ◽  
Author(s):  
Toru Atsumi ◽  
Katsuhiko Ishihara ◽  
Daisuke Kamimura ◽  
Hideto Ikushima ◽  
Takuya Ohtani ◽  
...  
Keyword(s):  
T Cells ◽  
Point Mutation ◽  
Fas Ligand ◽  
Tyrosine Phosphatase ◽  
Disease Onset ◽  
Cytokine Receptor ◽  
Joint Disease ◽  
Clonal Deletion ◽  
Activated T Cells ◽  
Autoantibody Production

We generated a mouse line in which the src homology 2 domain–bearing protein tyrosine phosphatase (SHP)-2 binding site of gp130, tyrosine 759, was mutated to phenylalanine (gp130F759/F759). The gp130F759/F759 mice developed rheumatoid arthritis (RA)-like joint disease. The disease was accompanied by autoantibody production and accumulated memory/activated T cells and myeloid cells. Before the disease onset, the T cells were hyperresponsive and thymic selection and peripheral clonal deletion were impaired. The inhibitory effect of IL-6 on Fas ligand expression during activation-induced cell death (AICD) was augmented in gp130F759/F759 T cells in a manner dependent on the tyrosine residues of gp130 required for signal transducer and activator of transcription 3 activation. Finally, we showed that disease development was dependent on lymphocytes. These results provide evidence that a point mutation of a cytokine receptor has the potential to induce autoimmune disease.

scholarly journals Fas ligand mediates activation-induced cell death in human T lymphocytes.

1995 ◽  
Vol 181 (1) ◽  
pp. 71-77 ◽  
Author(s):  
M R Alderson ◽  
T W Tough ◽  
T Davis-Smith ◽  
S Braddy ◽  
B Falk ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Fas Ligand ◽  
Significant Proportion ◽  
Cell Receptor ◽  
Target Cells ◽  
Activated T Cells ◽  
Activation Induced Cell Death ◽  
Fas L

A significant proportion of previously activated human T cells undergo apoptosis when triggered through the CD3/T cell receptor complex, a process termed activation-induced cell death (AICD). Ligation of Fas on activated T cells by either Fas antibodies or recombinant human Fas-ligand (Fas-L) also results in cytolysis. We demonstrate that these two pathways of apoptosis are causally related. Stimulation of previously activated T cells resulted in the expression of Fas-L mRNA and lysis of Fas-positive target cells. Fas-L antagonists inhibited AICD of T cell clones and staphylococcus enterotoxin B (SEB)-specific T cell lines. The data indicate AICD in previously stimulated T cells is mediated by Fas/Fas-L interactions.

scholarly journals Induction of Fas (Apo-1, CD95)-Mediated Apoptosis of Activated Lymphocytes by Polyclonal Antithymocyte Globulins

Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2360-2368 ◽  
Author(s):  
Laurent Genestier ◽  
Sylvie Fournel ◽  
Monique Flacher ◽  
Olga Assossou ◽  
Jean-Pierre Revillard ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Fas Ligand ◽  
Mononuclear Cells ◽  
Resting Cells ◽  
Activated T Cells ◽  
Peripheral Blood Mononuclear ◽  
Gene And Protein Expression ◽  
Fas L ◽  
Induced Apoptosis

Polyclonal horse antilymphocyte and rabbit antithymocyte globulins (ATGs) are currently used in severe aplastic anemia and for the treatment of organ allograft acute rejection and graft-versus-host disease. ATG treatment induces a major depletion of peripheral blood lymphocytes, which contributes to its overall immunosuppressive effects. Several mechanisms that may account for lymphocyte lysis were investigated in vitro. At high concentrations (.1 to 1 mg/mL) ATGs activate the human classic complement pathway and induce lysis of both resting and phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells. At low, submitogenic, concentration ATGs induce antibody-dependent cell cytotoxicity of PHA-activated cells, but not resting cells. They also trigger surface Fas (Apo-1, CD95) expression in naive T cells and Fas-ligand gene and protein expression in both naive and primed T cells, resulting in Fas/Fas-L interaction-mediated cell death. ATG-induced apoptosis and Fas-L expression were not observed with an ATG preparation lacking CD2 and CD3 antibodies. Susceptibility to ATG-induced apoptosis was restricted to activated cells, dependent on IL-2, and prevented by Cyclosporin A, FK506, and rapamycin. The data suggest that low doses of ATGs could be clinically evaluated in treatments aiming at the selective deletion of in vivo activated T cells in order to avoid massive lymphocyte depletion and subsequent immunodeficiency.

scholarly journals SHP-1 Acts as a Key Regulator of Alloresponses by Modulating LFA-1-Mediated Adhesion in Primary Murine T Cells

2016 ◽  
Vol 36 (24) ◽  
pp. 3113-3127 ◽  
Author(s):  
Martin G. Sauer ◽  
Jessica Herbst ◽  
Ulf Diekmann ◽  
Christopher E. Rudd ◽  
Christian Kardinal
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Phosphatase ◽  
Activated T Cells ◽  
Sirna Knockdown ◽  
Antigen Presenting ◽  
Pharmaceutical Agents ◽  
Interfering Rna ◽  
Clinical Potential

The clinical potential of transplantation is often reduced by T cell-mediated alloresponses that cause graft rejection or graft-versus-host disease. Integrin-mediated adhesion between alloreactive T cells and antigen-presenting cells is essential for allorejection. The identity of the signaling events needed for the activation of integrins such as LFA-1 is poorly understood. Here, we identified a novel role of the protein tyrosine phosphatase SHP-1 in the regulation of murine LFA-1-mediated adhesion in an allograft setting. Upon alloactivation, SHP-1 activity is reduced, resulting in an increase in LFA-1 adhesion compared to that for syngeneically activated T cells. The importance of these differential activation properties was further indicated by small interfering RNA (siRNA) knockdown of SHP-1 in syngeneically and allogeneically stimulated T cells. Mechanistically, SHP-1 modulated the binding of SLP-76 to ADAP by dephosphorylation of the YDGI tyrosine motif of ADAP, a known docking site for the Src family kinase Fyn. This novel key role of SHP-1 in the regulation of LFA-1-mediated adhesion may provide a new insight into T cell-mediated alloresponses and may pave the way to the development of new immunosuppressive pharmaceutical agents.

Activated T Cells, but Not Lung Tumor Cells, Express Fas Ligand

2014 ◽  
Vol 97 (1) ◽  
pp. 379-380 ◽  
Author(s):  
Heriberto Prado-Garcia ◽  
Susana Romero-Garcia ◽  
Jose Sullivan Lopez-Gonzalez
Keyword(s):  
T Cells ◽  
Tumor Cells ◽  
Fas Ligand ◽  
Lung Tumor ◽  
Activated T Cells

scholarly journals A subclass of dendritic cells kills CD4 T cells via Fas/Fas-ligand-induced apoptosis.

1996 ◽  
Vol 183 (4) ◽  
pp. 1789-1796 ◽  
Author(s):  
G Süss ◽  
K Shortman
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd4 T Cells ◽  
Fas Ligand ◽  
Activated T Cells ◽  
T Cell Apoptosis ◽  
Peripheral T Cells ◽  
Surface Staining ◽  
Induced Apoptosis ◽  
Antigen Presenting

Dendritic cells (DC), the most efficient antigen-presenting cells, are well equipped for activation of naive CD4+ T cells by their expression of high levels of major histocompatibility complex and costimulator molecules. We now demonstrate that some DC are equally well equipped for killing these same T cells. Murine splenic DC consist of both conventional CD8alpha- DC and a major population of CD8alpha+ DC. Whereas CD8- DC induce a vigorous proliferative response in CD4 T cells, CD8+ DC induce a lesser response that is associated with marked T cell apoptosis. By using various mixtures of T cells and DC from Fas-mutant lpr/lpr mice and Fas-ligand (FasL) mutant gld/gld mice, we show this death is due to interaction of Fas on activated T cells with FasL on CD8+ DC. Furthermore, we show by direct surface staining that CD8+ DC, but not CD8- DC, express FasL at high levels. These findings indicate that FasL+ CD8+ DC are a specialized subgroup of DC with a role in the regulation of the response of primary peripheral T cells.

Reciprocal Regulation of DSCR1 (Down Syndrome Critical Region 1) Expression and NFAT (Nuclear Factor of Activated T Cells) Activation in Megakaryocytes.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2204-2204
Author(s):  
Satu Kyttaelae ◽  
Ivonne Habermann ◽  
Martin Bornhaeuser ◽  
Gerhard Ehninger ◽  
Alexander Kiani
Keyword(s):  
T Cells ◽  
Down Syndrome ◽  
Critical Region ◽  
Fas Ligand ◽  
Nuclear Translocation ◽  
Specific Inhibitor ◽  
Chromosome 21 ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Retroviral Transduction

Abstract NFAT (Nuclear Factor of Activated T cells) is a family of calcium-induced, calcineurin-dependent transcription factors, well characterized as central regulators of inducible gene expression in T lymphocytes but now known to function also in several other cell types in various adaptation and differentiation processes. Activation of NFAT by the phosphatase calcineurin is counteracted by several inhibitory kinases and can be completely blocked by the immunosuppressant Cyclosporin A. The Down syndrome critical region 1 (DSCR1; also termed CSP1, MCIP1 or RCAN1) gene belongs to the calcipressin family of endogenous calcineurin inhibitors and is expressed in several isoforms, one of which (isoform C, coded by exons 4–7) has been described to be a transcriptional target for NFAT in striated muscle, endothelial, and neural cells. The DSCR1 gene is located within the Down syndrome critical region of human chromosome 21 and is, together with 200–300 other genes, overexpressed about 1.5-fold in patients with Down syndrome (DS). Previously, dysregulation of NFAT signaling by overexpression of DSCR1 has been implicated in causing various of the pathophysiological features observed in DS patients. Children with DS also suffer from an about 500-fold increased incidence of acute megakaryocytic leukemia; the respective roles of NFAT or DSCR1 in megakaryocytes of either normal individuals or those with DS, however, has not yet been established. Here we show that DSCR1 is upregulated during megakaryocytic differentiation in a lineage-specific manner, and in mature megakaryocytes is further strongly induced by calcineurin stimulation. DSCR1 expression in megakaryocytes is regulated by NFAT, since overexpression of NFATc2 enhances, while overexpression of the specific inhibitor of NFAT activation, VIVIT, suppresses expression of the gene. We further demonstrate that DSCR1 does not only represent an NFAT target in megakaryocytes, but itself acts an inhibitor of NFAT signaling in these cells. Overexpression of DSCR1 in CMK cells as well as in primary megakaryocytes by retroviral transduction profoundly suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFATc2, as well as transactivation of an NFAT-dependent promoter construct. Finally, overexpression of DSCR1 in megakaryocytes markedly downregulated both the constitutive and induced expression of Fas Ligand, a pro-apoptotic gene recently established as a NFAT target in megakaryocytes. Together, these results suggest that DSCR1 acts as an NFAT-induced NFAT inhibitor in megakaryocytes and, when overexpressed, interferes with the expression of NFAT-dependent megakaryocytic genes.

Cytokine Induced Killer Cells Can Kill Target through Antigen/TCR Dependent and Independent Mechanisms: New Clinical Perspectives of Utilisation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3024-3024
Author(s):  
Alice Pievani ◽  
Gianmaria Borleri ◽  
Camilla Belussi ◽  
Alessandro Rambaldi ◽  
Josee Golay ◽  
...  
Keyword(s):  
T Cells ◽  
Target Cell ◽  
Fas Ligand ◽  
Conflicts Of Interest ◽  
Leukaemic Cell ◽  
Similar Data ◽  
Antigen Specificity ◽  
Activated T Cells ◽  
Cik Cells

Abstract Abstract 3024 Poster Board II-1000 Cytokine induced killer (CIK) cells cultures can easily be obtained by stimulating PBMCs with monoclonal antibody anti-CD3 OKT3, IFNgamma and IL2. After 3-4 weeks at least 3 separate populations are present in the culture: CD3+/CD56-/CD8+ precursors (40.5 ± 19.9%), CD3-CD56+ NK cells (2.5 ± 1.5%) and CD3+/CD56+/CD8+ CIK cells (56.9 ± 21%) which show a T EMRA phenotype (Franceschetti et al., Exp Hematol. 37, 616-628, 2009). CIK cultures are currently used in allogeneic or autologous settings as potential anti-neoplastic effectors for adoptive transfer clinical approaches. We have further characterised the mechanism of target cell recognition and role of activating receptors and of lytic mediators in the cytotoxicity of purified CD3+/CD56+/CD8+ CIK cells. We have observed that CIK cells can kill targets through at least two distinct mechanisms: the first TCR-dependent and antigen-specific and the second non TCR-dependent. Indeed, upon TCR/CD3 crosslinking in CIK cells we observe ERK-1/2 phosphorylation, IFNgamma production (mean 32.6% of positive cells by intracellular staining) and TNFalpha production (mean 19.6%). CD3 ligation by OKT3 results in a significant increase over time in the percentage of CIK cells undergoing degranulation evaluated as CD107a positive cells (respectively 15.5 ± 2.2% at 60', 24.4 ± 1% at 120', 32,9 ± 8.7% at 180' and 34.2 ± 11.1% at 240'). CD3 ligation on CIK cells can induce cytotoxicity in a reverse Ab-dependent killing assay. Addition of OKT3 enhances also the cytotoxicity of CIK cells against K562 leukaemic target (from 16 ± 5% to 50 ± 4 %, E:T 10:1; p<0.001). The TCR/CD3 mediated activation is blocked by pre-treatment with cyclosporine A, confirming the role of calcium-regulated phosphatase calcineurin in the CD3-linked degranulation pathway. Interestingly, CIK cells retain functional activity as antigen-specific memory T cells. Indeed in case of CIK cultures obtained from CMV-seropositive donors, CMV-specific CD3+/CD56+ CIK cells can be generated. CMV-specific CIK cells immunopurified by HLA-peptide tetramers are able to specifically recognise and kill autologous but not allogeneic PHA-blasts pulsed with pp65495-503 but not with irrelevant peptide (average lysis 63 ± 8%, E:T 10:1) and to produce IFNgamma following antigenic stimulation (26.4 ± 7%). Similar data are obtained with EBV-specific T cells. Moreover, CIK cells also show non-MHC-restricted cytotoxicity against numerous leukemic target cell lines. The same CMV-specific purified CIK population shows to posses non MHC-restricted cytotoxic properties against several leukemic targets (average lysis 44 ± 8%, E:T 10:1). NKG2D, described as receptor that can trigger TCR-independent cytotoxicity in activated T cells, is expressed on all CIK cells (mean 99%, MFI 251). Although we can show that NKG2D is functional in these cells since cross-linking with anti-NKG2D mAb leads to ERK phophorylation, blocking of this receptor with mAb does not affect the cytolysis of leukaemic targets. NKG2D crosslinking in CIK cells is not sufficient to induce granule esocytosis and INFgamma or TNFalpha production. No correlation is found between expression and surface density of NKG2D ligands on leukaemic cell targets and their susceptibility to CIK-mediated lysis. Unrestricted CIK-mediated cytotoxicity occurs in the absence of measurable degranulation, is not affected by cyclosporin A, but is inhibited by 70% in presence of brefeldin A, a surface upregulation of glycopolypeptide molecules inhibitor, suggesting a role for Fas-ligand family molecules. CIK cells indeed express TNFalpha (mean 16%, MFI 56), FasL (mean 34%, MFI 34) and TRAIL (mean 37%, MFI 49). The role of this death ligands in leukaemic cell killing is currently under investigation. These data clearly show that CD3+/CD56+/CD8+ CIK cells are activated T EMRA cells which have retained their TCR/CD3 complex usage and their antigen specificity but have acquired unrestricted anti-leukaemic activity. The identification of the molecules involved in this killing is still under investigation. These data open up the possibility of multiple clinical use of CIK cultures, including anti-leukaemic and anti-infective usage particularly in immunodeficient patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals SHP-2 activates signaling of the nuclear factor of activated T cells to promote skeletal muscle growth

2006 ◽  
Vol 175 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Mara Fornaro ◽  
Peter M. Burch ◽  
Wentian Yang ◽  
Lei Zhang ◽  
Claire E. Hamilton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
T Cells ◽  
Intracellular Signaling ◽  
Tyrosine Phosphatase ◽  
Muscle Growth ◽  
Interleukin 4 ◽  
Type I ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Skeletal Muscle Growth

The formation of multinucleated myofibers is essential for the growth of skeletal muscle. The nuclear factor of activated T cells (NFAT) promotes skeletal muscle growth. How NFAT responds to changes in extracellular cues to regulate skeletal muscle growth remains to be fully defined. In this study, we demonstrate that mice containing a skeletal muscle–specific deletion of the tyrosine phosphatase SHP-2 (muscle creatine kinase [MCK]–SHP-2 null) exhibited a reduction in both myofiber size and type I slow myofiber number. We found that interleukin-4, an NFAT-regulated cytokine known to stimulate myofiber growth, was reduced in its expression in skeletal muscles of MCK–SHP-2–null mice. When SHP-2 was deleted during the differentiation of primary myoblasts, NFAT transcriptional activity and myotube multinucleation were impaired. Finally, SHP-2 coupled myotube multinucleation to an integrin-dependent pathway and activated NFAT by stimulating c-Src. Thus, SHP-2 transduces extracellular matrix stimuli to intracellular signaling pathways to promote skeletal muscle growth.

Glucocorticoids inhibit activation-induced cell death (AICD) via direct DNA-dependent repression of the CD95 ligand gene by a glucocorticoid receptor dimer

Blood ◽  
2005 ◽  
Vol 106 (2) ◽  
pp. 617-625 ◽  
Author(s):  
Sven Baumann ◽  
Anja Dostert ◽  
Natalia Novac ◽  
Anton Bauer ◽  
Wolfgang Schmid ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Glucocorticoid Receptor ◽  
Fas Ligand ◽  
Regulatory Elements ◽  
Activated T Cells ◽  
Activation Induced Cell Death

Abstract Glucocorticoids (GCs) play an important role in the regulation of peripheral T-cell survival. Their molecular mechanism of action and the question of whether they have the ability to inhibit apoptosis in vivo, however, are not fully elucidated. Signal transduction through the glucocorticoid receptor (GR) is complex and involves different pathways. Therefore, we used mice with T-cell-specific inactivation of the GR as well as mice with a function-selective mutation in the GR to determine the signaling mechanism. Evidence is presented for a functional role of direct binding of the GR to 2 negative glucocorticoid regulatory elements (nGREs) in the CD95 (APO-1/Fas) ligand (L) promoter. Binding of GRs to these nGREs reduces activation-induced CD95L expression in T cells. These in vitro results are fully supported by data obtained in vivo. Administration of GCs to mice leads to inhibition of activation-induced cell death (AICD). Thus, GC-mediated inhibition of CD95L expression of activated T cells might contribute to the anti-inflammatory function of steroid drugs. (Blood. 2005;106:617-625)

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