A central role for Fos in human B- and T-cell NFAT (nuclear factor of activated T cells): an acidic region is required for in vitro assembly

1994 ◽  
Vol 14 (10) ◽  
pp. 6886-6895
Author(s):  
N R Yaseen ◽  
J Park ◽  
T Kerppola ◽  
T Curran ◽  
S Sharma
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Cell ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Nuclear Extracts ◽  
In Vitro Reconstitution ◽  
Direct Binding ◽  
Acidic Region

Nuclear factor of activated T cells (NFAT) is a multicomponent transcription factor that contains Fos and Jun family proteins in addition to a constitutively expressed factor(s). It is important for the production of interleukin 2 (IL-2) by T cells and is also expressed in B cells. Here we show that NFAT complexes in B- and T-cell nuclear extracts can be supershifted prominently with Fos antibodies and to a variable extent with Jun family protein antibodies. Fos and Jun proteins appear to participate in NFAT complexes as heterodimers, since efficient in vitro reconstitution of NFAT in unstimulated B- or T-cell nuclear extracts required both Fos and Jun. Using Fos and Jun deletion derivatives, we found that an acidic Fos region (amino acids 118 to 138), outside the DNA binding and dimerization domains, was necessary for the in vitro reconstitution of the NFAT complex in both B- and T-lymphocyte extracts although it was not required for binding to an AP-1 site. Fos-Jun heterodimers exhibited low-affinity direct binding to the NFAT site in the absence of nuclear extracts. This binding also required the Fos acidic region, amino acids 118 to 138. Mutating a variant AP-1 site in the NFAT oligonucleotide abolished both direct binding of Fos-Jun heterodimers and in vitro reconstitution of NFAT. These results demonstrate a central role of Fos in NFAT complex formation in both B and T lymphocytes and show that NFAT assembly involves direct binding of Fos-Jun heterodimers to a variant AP-1 site within the human NFAT recognition site.

scholarly journals A central role for Fos in human B- and T-cell NFAT (nuclear factor of activated T cells): an acidic region is required for in vitro assembly.

1994 ◽  
Vol 14 (10) ◽  
pp. 6886-6895 ◽  
Author(s):  
N R Yaseen ◽  
J Park ◽  
T Kerppola ◽  
T Curran ◽  
S Sharma
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Cell ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Nuclear Extracts ◽  
In Vitro Reconstitution ◽  
Direct Binding ◽  
Acidic Region

Nuclear factor of activated T cells (NFAT) is a multicomponent transcription factor that contains Fos and Jun family proteins in addition to a constitutively expressed factor(s). It is important for the production of interleukin 2 (IL-2) by T cells and is also expressed in B cells. Here we show that NFAT complexes in B- and T-cell nuclear extracts can be supershifted prominently with Fos antibodies and to a variable extent with Jun family protein antibodies. Fos and Jun proteins appear to participate in NFAT complexes as heterodimers, since efficient in vitro reconstitution of NFAT in unstimulated B- or T-cell nuclear extracts required both Fos and Jun. Using Fos and Jun deletion derivatives, we found that an acidic Fos region (amino acids 118 to 138), outside the DNA binding and dimerization domains, was necessary for the in vitro reconstitution of the NFAT complex in both B- and T-lymphocyte extracts although it was not required for binding to an AP-1 site. Fos-Jun heterodimers exhibited low-affinity direct binding to the NFAT site in the absence of nuclear extracts. This binding also required the Fos acidic region, amino acids 118 to 138. Mutating a variant AP-1 site in the NFAT oligonucleotide abolished both direct binding of Fos-Jun heterodimers and in vitro reconstitution of NFAT. These results demonstrate a central role of Fos in NFAT complex formation in both B and T lymphocytes and show that NFAT assembly involves direct binding of Fos-Jun heterodimers to a variant AP-1 site within the human NFAT recognition site.

Nuclear Factor of Activated T Cells (NFAT) Is Involved in the Depolarization-Induced Activation of Growth Hormone-Releasing Hormone Gene Transcription in Vitro

2004 ◽  
Vol 18 (12) ◽  
pp. 3011-3019 ◽  
Author(s):  
Masato Asai ◽  
Yasumasa Iwasaki ◽  
Masanori Yoshida ◽  
Noriko Mutsuga-Nakayama ◽  
Hiroshi Arima ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Site Directed Mutagenesis ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
High Potassium ◽  
Direct Binding

Abstract GHRH plays a pivotal role in the regulation of both synthesis and secretion of GH in the anterior pituitary. In this study, we examined the molecular mechanism of depolarization-induced GHRH gene transcription using the hypothalamus cell line, Gsh+/+, revealing the involvement of the transcription factor called nuclear factor of activated T cells (NFAT). GHRH, NFAT1, NFAT4, and related genes were endogenously expressed in Gsh+/+ cells and the rat arcuate nucleus, where NFAT1 and GHRH were colocalized. Cellular excitation with high potassium potently stimulated endogenous GHRH gene 5′-promoter activity as well as the NFAT-mediated gene transcription, the former being further enhanced by coexpression of NFAT. On the other hand, cyclosporin A (a calcineurin-NFAT inhibitor) or EGTA (a calcium chelator) significantly blocked the depolarization-induced GHRH gene transcription. EMSA and site-directed mutagenesis experiments showed the direct binding of NFAT at five sites of the GHRH promoter, among which the relative importance of three distal sites (−417/−403, −402/−387, −317/−301) was suggested. Finally, elimination of all five sites completely abolished the NFAT-induced GHRH gene up-regulation. Altogether, our results suggest that the transcription factor NFAT is involved in the depolarization-induced transcriptional activation of GHRH gene in the neuronal cells.

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

Activation of nuclear factor of activated T cells 5 in the peritoneal membrane of uremic patients

2015 ◽  
Vol 308 (11) ◽  
pp. F1247-F1258 ◽  
Author(s):  
Daniel Kitterer ◽  
Joerg Latus ◽  
Christoph Ulmer ◽  
Peter Fritz ◽  
Dagmar Biegger ◽  
...  
Keyword(s):  
T Cells ◽  
Mrna Expression ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Significant Difference ◽  
Ccl2 Mrna ◽  
Uremic Patients ◽  
High Concentrations

Peritoneal inflammation and fibrosis are responses to the uremic milieu and exposure to hyperosmolar dialysis fluids in patients on peritoneal dialysis. Cells respond to high osmolarity via the transcription factor nuclear factor of activated T cells (NFAT5). In the present study, the response of human peritoneal fibroblasts to glucose was analyzed in vitro. Expression levels of NFAT5 and chemokine (C-C motif) ligand (CCL2) mRNA were quantified in peritoneal biopsies of five nonuremic control patients, five uremic patients before PD (pPD), and eight patients on PD (oPD) using real-time PCR. Biopsies from 5 control patients, 25 pPD patients, and 25 oPD patients were investigated using immunohistochemistry to detect the expression of NFAT5, CCL2, NF-κB p50, NF-κB p65, and CD68. High glucose concentrations led to an early, dose-dependent induction of NFAT5 mRNA in human peritoneal fibroblasts. CCL2 mRNA expression was upregulated by high concentrations of glucose after 6 h, but, most notably, a concentration-dependent induction of CCL2 was present after 96 h. In human peritoneal biopsies, NFAT5 mRNA levels were increased in uremic patients compared with nonuremic control patients. No significant difference was found between the pPD group and oPD group. CCL2 mRNA expression was higher in the oPD group. Immunohistochemistry analysis was consistent with the results of mRNA analysis. CD68-positive cells were significantly increased in the oPD group. In conclusion, uremia results in NFAT5 induction, which might promote early changes of the peritoneum. Upregulation of NFAT5 in PD patients is associated with NFκB induction, potentially resulting in the recruitment of macrophages.

scholarly journals Venetoclax enhances T cell-mediated anti-leukemic activity by increasing ROS production

Blood ◽  
2021 ◽  
Author(s):  
JongBok Lee ◽  
Dilshad H. Khan ◽  
Rose Hurren ◽  
Mingjing Xu ◽  
Yoosu Na ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mechanism Of Action ◽  
Adoptive Cell Therapy ◽  
Complete Response ◽  
Ros Generation ◽  
Activated T Cells ◽  
Treatment Naïve

Venetoclax, a Bcl-2 inhibitor, in combination with the hypomethylating agent, Azacytidine, achieves complete response with or without count recovery in approximately 70% of treatment-naïve elderly patients unfit for conventional intensive chemotherapy. However, the mechanism of action of this drug combination is not fully understood. We discovered that Venetoclax directly activated T cells to increase their cytotoxicity against AML in vitro and in vivo. Venetoclax enhanced T cell effector function by increasing ROS generation through inhibition of respiratory chain supercomplexes formation. In addition, Azacytidine induced a viral-mimicry response in AML cells by activating the STING/cGAS pathway, thereby rendering the AML cells more susceptible to T-cell mediated cytotoxicity. Similar findings were seen in patients treated with Venetoclax as this treatment increased ROS generation and activated T cells. Collectively, this study demonstrates a new immune mediated mechanism of action for Venetoclax and Azacytidine in the treatment of AML and highlights a potential combination of Venetoclax and adoptive cell therapy for patients with AML.

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.

T cell-T cell activation in multiple sclerosis

1997 ◽  
Vol 3 (4) ◽  
pp. 238-242 ◽  
Author(s):  
JW Lindsey ◽  
RH Kerman ◽  
JS Wolinsky
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Viral Infections ◽  
Activated T Cells ◽  
In Vitro Proliferation

Activated T cells are able to stimulate proliferation in resting T cells through an antigen non-specific mechanism. The in vivo usefulness of this T cell-T cell activation is unclear, but it may serve to amplify immune responses. T cell-T cell activation could be involved in the well-documented occurrence of multiple sclerosis (MS) exacerbations following viral infections. Excessive activation via this pathway could also be a factor in the etiology of MS. We tested the hypothesis that excessive T cell-T cell activation occurs in MS patients using in vitro proliferation assays comparing T cells from MS patients to T cells from controls. When tested as responder cells, T cells from MS patients proliferated slightly less after stimulation with previously activated cells than T cells from controls. When tested as stimulator cells, activated cells from MS patients stimulated slightly more non-specific proliferation than activated cells from controls. Neither of these differences were statistically significant We conclude that T cell proliferation in response to activated T cells is similar in MS and controls.

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 Production and characterization of a bispecific IgG capable of inducing T-cell-mediated lysis of malignant B cells

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3343-3349 ◽  
Author(s):  
BK Link ◽  
GJ Weiner
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Hybridoma Cells ◽  
Activated T Cells ◽  
Human B Cells ◽  
B Cell Malignancy ◽  
Cell Malignancy

Abstract Bispecific monoclonal antibodies (bsabs) recognizing both CD3 and a tumor antigen can redirect T-cell-mediated cytotoxicity toward cells bearing that antigen. Such bsabs have been shown to be more effective than monospecific monoclonal antibodies (MoAbs) at preventing tumor growth in animal models of B-cell malignancy. The current studies describe the production and preliminary evaluation of a bsab designed to induce the lysis of malignant human B cells by human T cells. The bsab was obtained from a hybrid-hybridoma cell line produced by fusing OKT3-secreting hybridoma cells with hybridoma cells that secrete 1D10. 1D10 is an MoAb that recognizes an antigen found on a majority of malignant human B cells that has not been detected to a significant degree on normal resting or activated lymphocytes. High performance liquid chromatography (HPLC) was used to separate bsab from monospecific antibodies that were also present in the hybrid-hybridoma antibody product. The bsab was then evaluated in vitro for its ability to induce lysis of malignant B cells by activated T cells. The bsab consistently induced extensive lysis in vitro of 1D10 (+) cells, including both cell lines and cells obtained from patients with a variety of B-cell malignancies. No such effect was seen with activated T cells alone or activated T cells with monospecific antibody. No increased lysis was seen with 1D10 (-) cell lines. The bsab also mediated lysis of malignant B cells by autologous T cells. We conclude bsab containing an OKT3 arm and a 1D10 arm can induce T-cell-mediated lysis in a manner that is both potent and specific. This supports further evaluation of this bsab as a potential immunotherapy of B-cell malignancy.

scholarly journals SBF-1 inhibits contact hypersensitivity in mice through down-regulation of T-cell-mediated responses

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Wei Chen ◽  
Xianying Fang ◽  
Yuan Gao ◽  
Ke Shi ◽  
Lijun Sun ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Contact Hypersensitivity ◽  
Immunosuppressive Activity ◽  
Con A ◽  
Activated T Cells ◽  
Picryl Chloride

Abstract Background T lymphocytes play an important role in contact hypersensitivity. This study aims to explore the immunosuppressive activity of SBF-1, an analog of saponin OSW-1, against T lymphocytes in vitro and in vivo. Methods Proliferation of T lymphocytes from lymph nodes of mice was determined by MTT assay. Flow cytometry analysis was performed to assess T cell activation and apoptosis. Levels of cytokines were determined by PCR and ELISA. BALB/c mice were sensitized and challenged with picryl chloride and thickness of left and right ears were measured. Results SBF-1 effectively inhibited T lymphocytes proliferation induced by concanavalin A (Con A) or anti-CD3 plus anti-CD28 at a very low dose (10 nM) but exhibited little toxicity in non-activated T lymphocytes at concentrations up to 10 μM. In addition, SBF-1 inhibited the expression of CD25 and CD69, as well as he phosphorylation of AKT in Con A-activated T cells. SBF-1 also induced apoptosis of activated T cells. In addition, SBF-1 also downregulated the induction of the T cell cytokines, IL-2 and IFN-γ in a dose-dependent manner. Furthermore, SBF-1 significantly suppressed ear swelling and inflammation in a mouse model of picryl chloride-induced contact hypersensitivity. Conclusions Our findings suggest that SBF-1 has an unique immunosuppressive activity both in vitro and in vivo mainly through inhibiting T cell proliferation and activation. Its mechanism appears to be related to the blockage of AKT signaling pathway.

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