scholarly journals Activation of Nuclear Factor of Activated T Cells by Human T-Lymphotropic Virus Type 1 Accessory Protein p12I

2002 ◽  
Vol 76 (7) ◽  
pp. 3493-3501 ◽  
Author(s):  
Björn Albrecht ◽  
Celine D. D'Souza ◽  
Wei Ding ◽  
Susheela Tridandapani ◽  
K. Mark Coggeshall ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Persistent Infection ◽  
Lymphocyte Activation ◽  
Accessory Protein ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
T Lymphotropic Virus ◽  
Calcium Dependent

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1) is the agent of an aggressive malignancy of CD4+ T lymphocytes, called adult T-cell lymphoma/leukemia, and is associated with numerous immune-mediated diseases. To establish infection, HTLV-1 must activate targeted T cells during early stages of infection. We recently demonstrated that the HTLV-1 accessory protein p12I is critical for persistent infection in vivo and for viral infectivity in quiescent primary lymphocytes, suggesting a role for p12I in lymphocyte activation. To test whether p12I modulates signaling pathways required for T-lymphocyte activation, we examined AP-1-, NF-κB-, and nuclear factor of activated T cells (NFAT)-driven reporter gene activity in p12I-expressing Jurkat T cells compared to vector-transfected control cells. HTLV-1 p12I specifically induced NFAT-mediated transcription approximately 20-fold in synergy with the Ras/mitogen-activated protein kinase pathway, but did not influence AP-1- or NF-κB-dependent gene expression. Inhibition of calcium-dependent signals by cyclosporin A, BAPTA-AM [glycine, N,N′-1,2-ethanediylbis(oxy-2,1-phenylene)-bis-N-2-(acetyloxy)methoxy-2-oxoethyl]-[bis(acetyloxy)methyl ester], and a dominant negative mutant of NFAT2 abolished the p12I-mediated activation of NFAT-dependent transcription. In contrast, inhibition of phospholipase C-γ and LAT (linker for activation of T cells) did not affect p12I-induced NFAT activity. Importantly, p12I functionally substituted for thapsigargin, which selectively depletes intracellular calcium stores. Our data are the first to demonstrate a role for HTLV-1 p12I in calcium-dependent activation of NFAT-mediated transcription in lymphoid cells. We propose a novel mechanism by which HTLV-1, a virus associated with lymphoproliferative disease, dysregulates common T-cell activation pathways critical for the virus to establish persistent infection.

scholarly journals Human T-Cell Lymphotropic Virus Type 1 p12I Expression Increases Cytoplasmic Calcium To Enhance the Activation of Nuclear Factor of Activated T Cells

2002 ◽  
Vol 76 (20) ◽  
pp. 10374-10382 ◽  
Author(s):  
Wei Ding ◽  
Björn Albrecht ◽  
Robert E. Kelley ◽  
Natarajan Muthusamy ◽  
Seung-Jae Kim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Calcium Release ◽  
Nuclear Factor ◽  
Cytoplasmic Calcium ◽  
Activated T Cells ◽  
Human T Cell ◽  
Nfat Activation

ABSTRACT Human T-cell lymphotropic virus type 1 (HTLV-1) establishes persistent infection and is associated with lymphoproliferative or neurodegenerative diseases. As a complex retrovirus, HTLV-1 contains typical structural and enzymatic genes, as well as regulatory and accessory genes encoded in the pX region. The early events necessary for HTLV-1 to establish infection in lymphocytes, its primary target cells, remain unresolved. Recent studies have demonstrated the importance of regulatory and accessory gene products in determining this virus-host interaction. Among these, pX open reading frame I, which encodes two proteins, p12I and p27I, is required for establishing persistent infection in vivo and for infection in quiescent primary lymphocytes. In addition, p12I localizes in the endoplasmic reticulum (ER) and cis-Golgi apparatus and associates with a calcium binding protein, calreticulin. We recently reported that p12I expression induces the calcium-responsive T-cell transcription factor, nuclear factor of activated T cells (NFAT), in the presence of phorbol ester activation. Based on these studies, we hypothesize that p12I may modulate calcium release from the ER. Here, we report that p12I expression increases basal cytoplasmic calcium and concurrently diminishes calcium available for release from the ER stores. Overexpression of calreticulin, a calcium buffer protein, blocked p12I-mediated NFAT activation independently of its ability to bind p12I. Chemical inhibition studies using inhibitors of inositol 1,4,5-triphosphate receptor and calcium release-activated calcium channels suggest that inositol 1,4,5-triphosphate receptor in the ER membrane and calcium release-activated calcium channels in the plasma membrane contribute to p12I-mediated NFAT activation. Collectively, our results are the first to demonstrate the role of p12I in elevating cytoplasmic calcium, an antecedent to T-cell activation, and further support the important role of this accessory protein in the early events of HTLV-1 infection.

scholarly journals Signals from OX40 regulate nuclear factor of activated T cells c1 and T cell helper 2 lineage commitment

2006 ◽  
Vol 103 (10) ◽  
pp. 3740-3745 ◽  
Author(s):  
T. So ◽  
J. Song ◽  
K. Sugie ◽  
A. Altman ◽  
M. Croft
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lineage Commitment ◽  
Nuclear Factor ◽  
Activated T Cells

scholarly journals The Activated Type 1–Polarized Cd8+ T Cell Population Isolated from an Effector Site Contains Cells with Flexible Cytokine Profiles

1999 ◽  
Vol 190 (8) ◽  
pp. 1081-1092 ◽  
Author(s):  
Anthony G. Doyle ◽  
Kathy Buttigieg ◽  
Penny Groves ◽  
Barbara J. Johnson ◽  
Anne Kelso
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
Expression Profiles ◽  
Lung Parenchyma ◽  
Activated T Cells ◽  
Cytokine Genes ◽  
Effector Site

The capacity of activated T cells to alter their cytokine expression profiles after migration into an effector site has not previously been defined. We addressed this issue by paired daughter analysis of a type 1–polarized CD8+ effector T cell population freshly isolated from lung parenchyma of influenza virus–infected mice. Single T cells were activated to divide in vitro; individual daughter cells were then micromanipulated into secondary cultures with and without added IL-4 to assess their potential to express type 2 cytokine genes. The resultant subclones were analyzed for type 1 and 2 cytokine mRNAs at day 6–7. When the most activated (CD44highCD11ahigh) CD8+ subpopulation from infected lung was compared with naive or resting (CD44lowCD11alow) CD8+ cells from infected lung and from normal lymph nodes (LNs), both clonogenicity and plasticity of the cytokine response were highest in the LN population and lowest in the activated lung population, correlating inversely with effector function. Multipotential cells were nevertheless detected among clonogenic CD44highCD11ahigh lung cells at 30–50% of the frequency in normal LNs. The data indicate that activated CD8+ T cells can retain the ability to proliferate and express new cytokine genes in response to local stimuli after recruitment to an effector site.

scholarly journals A Conserved Calcineurin-binding Motif in Human T Lymphotropic Virus Type 1 p12IFunctions to Modulate Nuclear Factor of Activated T Cell Activation

2003 ◽  
Vol 278 (18) ◽  
pp. 15550-15557 ◽  
Author(s):  
Seung-jae Kim ◽  
Wei Ding ◽  
Björn Albrecht ◽  
Patrick L. Green ◽  
Michael D. Lairmore
Keyword(s):  
T Cell ◽  
Virus Type ◽  
T Cell Activation ◽  
Cell Activation ◽  
Binding Motif ◽  
Nuclear Factor ◽  
T Lymphotropic Virus ◽  
Activated T Cell

PKCθ-regulated signalling in health and disease

2014 ◽  
Vol 42 (6) ◽  
pp. 1484-1489 ◽  
Author(s):  
Pulak R. Nath ◽  
Noah Isakov
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Immunological Synapse ◽  
Cell Types ◽  
Cell Receptor ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Health And Disease

Protein kinase Cθ (PKCθ) is a key enzyme in T-lymphocytes where it plays an important role in signal transduction downstream of the activated T-cell receptor (TCR) and the CD28 co-stimulatory receptor. Antigenic stimulation of T-cells triggers PKCθ translocation to the centre of the immunological synapse (IS) at the contact site between antigen-specific T-cells and antigen-presenting cells (APCs). The IS-residing PKCθ phosphorylates and activates effector molecules that transduce signals into distinct subcellular compartments and activate the transcription factors, nuclear factor κB (NF-κB), nuclear factor of activated T-cells (NFAT) and activating protein 1 (AP-1), which are essential for the induction of T-cell-mediated responses. Besides its major biological role in T-cells, PKCθ is expressed in several additional cell types and is involved in a variety of distinct physiological and pathological phenomena. For example, PKCθ is expressed at high levels in platelets where it regulates signal transduction from distinct surface receptors, and is required for optimal platelet activation and aggregation, as well as haemostasis. In addition, PKCθ is involved in physiological processes regulating insulin resistance and susceptibility to obesity, and is expressed at high levels in gastrointestinal stromal tumours (GISTs), although the functional importance of PKCθ in these processes and cell types is not fully clear. The present article briefly reviews selected topics relevant to the biological roles of PKCθ in health and disease.

scholarly journals Possible origin of adult T-cell leukemia/lymphoma cells from human T lymphotropic virus type-1-infected regulatory T cells

2005 ◽  
Vol 96 (8) ◽  
pp. 527-533 ◽  
Author(s):  
Tomoko Kohno ◽  
Yasuaki Yamada ◽  
Norihiko Akamatsu ◽  
Simeru Kamihira ◽  
Yoshitaka Imaizumi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Virus Type ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Lymphoma Cells ◽  
T Lymphotropic Virus ◽  
Adult T Cell Leukemia

scholarly journals Nuclear Factor of Activated T Cells Regulates Neutrophil Recruitment, Systemic Inflammation, and T-Cell Dysfunction in Abdominal Sepsis

2014 ◽  
Vol 82 (8) ◽  
pp. 3275-3288 ◽  
Author(s):  
Su Zhang ◽  
Lingtao Luo ◽  
Yongzhi Wang ◽  
Maria F. Gomez ◽  
Henrik Thorlacius
Keyword(s):  
T Cells ◽  
T Cell ◽  
Systemic Inflammation ◽  
Abdominal Sepsis ◽  
Neutrophil Recruitment ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

ABSTRACTThe signaling mechanisms regulating neutrophil recruitment, systemic inflammation, and T-cell dysfunction in polymicrobial sepsis are not clear. This study explored the potential involvement of the calcium/calcineurin-dependent transcription factor, nuclear factor of activated T cells (NFAT), in abdominal sepsis. Cecal ligation and puncture (CLP) triggered NFAT-dependent transcriptional activity in the lung, spleen, liver, and aorta in NFAT-luciferase reporter mice. Treatment with the NFAT inhibitor A-285222 prior to CLP completely prevented sepsis-induced NFAT activation in all these organs. Inhibition of NFAT activity reduced sepsis-induced formation of CXCL1, CXCL2, and CXCL5 chemokines and edema as well as neutrophil infiltration in the lung. Notably, NFAT inhibition efficiently reduced the CLP-evoked increases in HMBG1, interleukin 6 (IL-6), and CXCL5 levels in plasma. Moreover, administration of A-285222 restored sepsis-induced T-cell dysfunction, as evidenced by markedly decreased apoptosis and restored proliferative capacity of CD4 T cells. Along these lines, treatment with A-285222 restored gamma interferon (IFN-γ) and IL-4 levels in the spleen, which were markedly reduced in septic mice. CLP-induced formation of regulatory T cells (CD4+CD25+Foxp3+) in the spleen was also abolished in A-285222-treated animals. All together, these novel findings suggest that NFAT is a powerful regulator of pathological inflammation and T-cell immune dysfunction in abdominal sepsis. Thus, our data suggest that NFAT signaling might be a useful target to protect against respiratory failure and immunosuppression in patients with sepsis.

scholarly journals Identification of cis-acting regulatory elements controlling interleukin-4 gene expression in T cells: roles for NF-Y and NF-ATc.

1993 ◽  
Vol 13 (8) ◽  
pp. 4793-4805 ◽  
Author(s):  
S J Szabo ◽  
J S Gold ◽  
T L Murphy ◽  
K M Murphy
Keyword(s):  
T Cells ◽  
T Cell ◽  
Promoter Activity ◽  
Regulatory Elements ◽  
Interleukin 4 ◽  
Specific Factor ◽  
Gene Promoters ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Cis Acting

Activity of the murine interleukin-4 (IL-4) promoter was localized to several cis-acting elements present within the first 300 bp from the transcriptional initiation site. Five repeated elements, P0 to P4, that share the common consensus ATTTTCCNNT were located between -40 and -250, and each was shown to interact with the T-cell-specific factor NF(P). These distinct P sites appear functionally interchangeable and cooperatively confer cyclosporin A-sensitive and ionomycin-inducible promoter activity. NF(P) may be closely related to the cytoplasmic component of NF-AT (nuclear factor of activated T cells), a T-cell-specific factor essential for IL-2 gene transcription, as judged from indistinguishable molecular weights and protease fragmentation patterns of UV-photolabeled factors. Also, we identified an element in the IL-4 promoter with homology to the Y box common to all major histocompatibility complex class II gene promoters. Our data show that the IL-4 promoter Y box -114CTGATTGG-107 significantly enhances overall promoter activity, since point mutations within this element diminish promoter activity by 85%. The factor binding this region is indistinguishable from the cloned nuclear factor NF-Y, as judged from interactions with specific anti-NF-Y monoclonal and polyclonal antibodies. Last, we point out the presence of two sites that share sequence identity to the OAP region of the ARRE-1 site within the IL-2 promoter (K. S. Ullman, W. M. Flanagan, C. A. Edwards, and G. R. Crabtree, Science 254:558-562, 1991). These regions, -85GTGTAATA-78 and -245GTGTAATT-238, reside adjacent to the NF(P) binding sites P1 and P4 and bind a distinct nuclear factor.

Clinical significance of CD70 expression on T cells in human T-lymphotropic virus type-1 carriers and adult T cell leukemia/ lymphoma patients

2015 ◽  
Vol 57 (3) ◽  
pp. 685-691
Author(s):  
Izumi Masamoto ◽  
Makoto Yoshimitsu ◽  
Ayako Kuroki ◽  
Sawako Horai ◽  
Chibueze Chioma Ezinne ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Clinical Significance ◽  
Virus Type ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
T Lymphotropic Virus ◽  
Adult T Cell Leukemia

scholarly journals Crucial Role for Nuclear Factor of Activated T Cells in T Cell Receptor-mediated Regulation of Human Interleukin-17

2004 ◽  
Vol 279 (50) ◽  
pp. 52762-52771 ◽  
Author(s):  
Xikui K. Liu ◽  
Xin Lin ◽  
Sarah L. Gaffen
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Promoter Activity ◽  
Cell Receptor ◽  
Cross Linking ◽  
Supporting Evidence ◽  
Nuclear Factor ◽  
Tcr Signaling ◽  
Activated T Cells

The biological activities of the inflammatory cytokine interleukin (IL)-17 have been widely studied. However, comparatively little is known about how IL-17 expression is controlled. Here, we examined the basis for transcriptional regulation of the human IL-17 gene. IL-17 secretion was induced in peripheral blood mononuclear cells following anti-CD3 cross-linking to activate the T cell receptor (TCR), and costimulatory signaling through CD28 strongly enhanced CD3-induced IL-17 production. To definecis-acting elements important for IL-17 gene regulation, we cloned 1.25 kb of genomic sequence upstream of the transcriptional start site. This putative promoter was active in Jurkat T cells following CD3 and CD28 cross-linking, and its activity was inhibited by cyclosporin A and MAPK inhibitors. The promoter was also active in Hut102 T cells, which we have shown to secrete IL-17 constitutively. Overexpression of nuclear factor of activated T cells (NFAT) or Ras enhanced IL-17 promoter activity, and studies in Jurkat lines deficient in specific TCR signaling pathways provided supporting evidence for a role for NFAT. To delineate the IL-17 minimal promoter, we created a series of 5′ truncations and identified a region between -232 and -159 that was sufficient for inducible promoter activity. Interestingly, two NFAT sites were located within this region, which bound to NFATc1 and NFATc2 in nuclear extracts from Hut102 and Jurkat cells. Moreover, mutations of these sites dramatically reduced both specific DNA binding and reporter gene activity, and chromatin immunoprecipitation assays showed occupancy of NFAT at this regionin vivo. Together, these data show that NFAT is the crucial sensor of TCR signaling in the IL-17 promoter.

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