scholarly journals BCL11B Upregulates the Expression of NF-κB in T Cells Stimulated with SEA

2021 ◽  
Author(s):  
Yuhui Yan ◽  
Senlin Wang ◽  
Chen Lin
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
T Cell ◽  
Protein Expression ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Jurkat Cells ◽  
Cell Leukaemia ◽  
Normal Peripheral Blood ◽  
Gene And Protein Expression

Abstract BackgroundNF-κB is one of the most important inflammatory mediators in the tumour microenvironment promotes inflammation-induced cancer. Many studies report that NF-κB is activated in many kinds of leukaemia, so that some researchers by inhibiting NF-κB to treat leukaemia. The overexpression of BCL11B has been primarily reported in T cell malignancies. Some studies have reported that BCL11B is a potential transcriptional repressor which has several splice isoforms. MiR-21-5p promotes cell proliferation by targeting BCL11B in Thp-1 human monocytes. Both NF-κB and BCL11B transcription factors are related to inflammation and leukaemia. Whether there is correlation between NF-κB and BCL11B transcription factors? If BCL11B is a potential important transcription factor in treatment of T lymphocyte leukaemia? In this study, we stimulated Jurkat cells and normal peripheral blood T cells with staphylococcal enterotoxin A(SEA), and we detected the expression of both the BCL11B and NF-κB genes and their respective proteins at different stimulation times. Then, the BCL11B gene was suppressed by BCL11B-siRNA and detected at another stimulation time. ResultsWe found that the mRNA expression of BCL11B and NF-κB increased in two kinds of T cell lines over time which stimulated by SEA or PMA+IO. A similar result was confirmed for BCL11B and NF-κB protein expression. While the expression of the NF-κB protein did not increase on equal conditions in the BCL11B-knockdown group. ConclusionOur result suggested that the gene and protein expression levels of both BCL11B and NF-κB were related, and BCL11B regulates NF-κB expression in Jukat cells and healthy human peripheral blood through the TCR signalling pathway. This study reveals that BCL11B can be used as a new therapeutic target for chronic inflammation and T cell leukaemia pathogenesis.

scholarly journals Cytoplasmic expression of the CD3 antigen as a diagnostic marker for immature T-cell malignancies

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 603-612
Author(s):  
JJ van Dongen ◽  
GW Krissansen ◽  
IL Wolvers-Tettero ◽  
WM Comans-Bitter ◽  
HJ Adriaansen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Peripheral Blood ◽  
Diagnostic Marker ◽  
Surface Membrane ◽  
Cell Lineage ◽  
Normal Peripheral Blood ◽  
Thymus Cell ◽  
T Cell Malignancies

The expression of cytoplasmic CD3 (CyCD3) was analyzed in 45 leukemias, five thymus cell samples, five peripheral blood (PB) samples, and ten cell lines. All T cell acute lymphoblastic leukemias (T-ALL) that did not express surface membrane CD3 (SmCD3) appeared to express CyCD3. Furthermore, the majority of SmCD3+ T-ALL also expressed CyCD3. Analogous results were obtained with thymus cell samples in that about 95% of the thymocytes expressed CyCD3 whereas 60% to 75% of the thymocytes also expressed SmCD3. In normal peripheral blood only prominent SmCD3 expression was found. These data indicate that immature T cells express CyCD3 only, that the combined expression of CyCD3 and SmCD3 is characteristic for intermediate differentiation stages, and that mature T cells express prominent SmCD3. All (precursor) B cell leukemias, acute myeloid leukemias, and non-T cell lines tested did not express CyCD3. On the basis of these data, we conclude that CyCD3 expression is restricted to the T cell lineage and can be used as a diagnostic marker for immature SmCD3- T cell malignancies. Therefore, we evaluated which fixative is optimal for CyCD3 staining, and we determined by immunofluorescence staining and Western blotting which anti-CD3 monoclonal antibody (MoAb) can be used for the detection of CyCD3. In our opinion, acid ethanol was the best fixative for the cytocentrifuge preparations. Furthermore, we demonstrated that CyCD3 can be easily detected by use of MoAbs raised against denaturated CD3 chains such as those of the SP series (SP-6, SP-10, SP-64, and SP-78). In addition we tested 22 anti-CD3 MoAbs of the Oxford CD3 panel that were raised against native SmCD3, and it appeared that only four (UCHT1, VIT-3b, G19–41 and SK7/Leu-4) of them were able to detect CyCD3. In Western blot analysis all four MoAbs recognized the CD3- epsilon chain only.

AB0268 HUMAN T-CELL LEUKAEMIA VIRUS TYPE 1 MAY INVALIDATE T-SPOT.TB RESULTS AMONG RHEUMATOID ARTHRITIS PATIENTS: A RETROSPECTIVE OBSERVATIONAL STUDY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1432.1-1433
Author(s):  
K. Umekita ◽  
Y. Hashiba ◽  
R. Kudou ◽  
S. Miyauchi ◽  
M. Kimura ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Virus Type ◽  
Peripheral Blood ◽  
Medical Records ◽  
Cell Leukaemia ◽  
Leukaemia Virus ◽  
Human T Cell ◽  
Ifn Γ

Background:In clinical rheumatology, interferon-γ release assays (IGRAs) have been reported as a useful diagnostic test for latent tuberculosis infection (LTBI) before beginning the administration of biologics such as anti-TNF therapies (1). CD4-positive T cells are the main target in Human T-cell leukaemia virus type 1 (HTLV-1) infection. Several reports suggest that the reaction of tuberculin skin test (TST) is attenuated in HTLV-1-positive individuals compared with that in HTLV-1-negative individuals (2). However, it remains unclear whether IGRAs are reliable for detecting TB infection among HTLV-1-positive RA patients.Objectives:The present study aimed to investigate the usefulness of the T-SPOT.TBassay in HTLV-1-positive RA patients. In addition, the association between the existence of IFN-γ producing T cells and HTLV-1 proviral loads (PVLs) in HTLV-1-positive RA patients was analysed on the basis of the T-SPOT.TBassay results.Methods:We reviewed the medical records of 75 HTLV-1-negative and 29 HTLV-1-positive RA patients were suspected cases of LTBI and evaluated using the T-SPOT.TBassay as a clinical practice from April 2012 to July 2019. The results of T-SPOT.TBwere collected from medical records, retrospectively. Peripheral blood samples were obtained from HTLV-1-positive RA patients for the analysis of HTLV-1 PVLs values. The study protocol was approved by the research ethics committees of our hospitals.Results:Approximately 55% of the HTLV-1-positive RA patients showed invalid results for the T-SPOT.TBassay (p < 0.0001); the cause of invalid results was a spot-forming count of >10 spots in the negative controls of the T-SPOT.TBassay among HTLV-1-positive RA patients. Among HTLV-1-positive RA patients, HTLV-1 PVL values were significantly higher in 16 patients who showed invalid results than in 13 patients who did not (p = 0.003). There were no between-group differences in female patient ratio, age, RA disease activity and therapeutic regimens. IFN-γ producing cells were detected in the peripheral blood of HTLV-1-positive RA patients without stimulation with TB-specific antigens.Conclusion:The incidence of invalid results for the T-SPOT.TBassay has been reported to be as low as 0.6% (3). The results of this assay for screening of LTBI in HTLV-1-positive RA patients should be interpreted with caution. Furthermore, our results show that an increase in IFN-γ producing T cell numbers due to HTLV-1 infection in RA patients may affect the pathogenesis of RA.References:[1]Iannone, F., et al.J. Rheumatol. Suppl.91, 41-46 (2014).[2]Tachibana, N., et al.Int. J. Cancer42, 829-831 (1988).[3]Rego, K., et al.Tuberculosis (Edinb.)108, 178-185 (2018).Acknowledgments:We would like to thank Dr Yuki Hashikura and Ms Yuki Kaseda of the University of Miyazaki for their technical support in this work. We would also like to acknowledge Ms Yumiko Kai at the Institute of Rheumatology, Zenjinkai Shimin-no-Mori Hospital, for her help in data management.A part this work was supported by a grant from the Practical Research Project for Rare/Intractable Diseases of the Japan Agency for Medical Research and Development (Grant No. JP19ek0109356), a Health and Labor Sciences Research Grant on Rare and Intractable Diseases from the Ministry of Health, Labor and Welfare of Japan (Grant No. 19FC1007), and a Grant-in-Aid for Clinical Research from Miyazaki University Hospital.Disclosure of Interests:Kunihiko Umekita Paid instructor for: Astellas Pharma Inc. Chugai Pharma Inc. Tanabe-Mitsubishi Pharma Inc., Speakers bureau: Bristol-Myers Squibb, Yayoi Hashiba: None declared, Risa Kudou: None declared, Shunichi Miyauchi: None declared, Masatoshi Kimura: None declared, Motohiro Matsuda: None declared, Chihiro Iwao: None declared, Yumi Kariya: None declared, Takeshi Kawaguchi: None declared, Katoko Takajo: None declared, Koushou Iwao: None declared, Yuuki Rikitake: None declared, Ichiro Takajo: None declared, Toshihiko Hidaka Paid instructor for: Astellas Pharma Inc. Chugai Pharma Inc. Tanabe-Mitsubishi Pharma Inc., Speakers bureau: Astellas Pharma Inc. Chugai Pharma Inc. Tanabe-Mitsubishi Pharma Inc., Akihiko Okayama: None declared

Effect of CD28 signal transduction on c-Rel in human peripheral blood T cells

1994 ◽  
Vol 14 (12) ◽  
pp. 7933-7942
Author(s):  
R G Bryan ◽  
Y Li ◽  
J H Lai ◽  
M Van ◽  
N R Rice ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Nuclear Translocation ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Cd28 Costimulation

Optimal T-cell activation requires both an antigen-specific signal delivered through the T-cell receptor and a costimulatory signal which can be delivered through the CD28 molecule. CD28 costimulation induces the expression of multiple lymphokines, including interleukin 2 (IL-2). Because the c-Rel transcription factor bound to and activated the CD28 response element within the IL-2 promoter, we focused our study on the mechanism of CD28-mediated regulation of c-Rel in human peripheral blood T cells. We showed that CD28 costimulation accelerated the kinetics of nuclear translocation of c-Rel (and its phosphorylated form), p50 (NFKB1), and p65 (RelA). The enhanced nuclear translocation of c-Rel correlated with the stimulation of Il-2 production and T-cell proliferation by several distinct anti-CD28 monoclonal antibodies. This is explained at least in part by the long-term downregulation of I kappa B alpha following CD28 signalling as opposed to phorbol myristate acetate alone. Furthermore, we showed that the c-Rel-containing CD28-responsive complex is enhanced by, but not specific to, CD28 costimulation. Our results indicate that c-Rel is one of the transcription factors targeted by CD28 signalling.

Age-related increase of frequency of a new, phenotypically distinct subpopulation of human peripheral blood T cells expressing lowered levels of CD4

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 1100-1107 ◽  
Author(s):  
Ewa Bryl ◽  
Magdalena Gazda ◽  
Jerzy Foerster ◽  
Jacek M. Witkowski
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
The Elderly ◽  
Cell Subpopulation ◽  
Cell Phenotype ◽  
Receptor Complexes ◽  
Age Related

Aging is associated with modifications of T-cell phenotype and function, leading to impaired activation in response to both new and recall antigens. It is not known if T-cell activation results in elimination of a number of the CD4 molecules from the cell surface, as is the case with CD3/T-cell receptor complexes, or how aging influences the process. The T cells of young and elderly donors with reduced expression of CD4 were examined to see whether these cells exhibit other phenotypic features suggesting their active state. It was found that T lymphocytes expressing CD4 can be divided into 2 semidiscrete subpopulations: the major (CD4+) population, in which the level of expression of CD4 is constant and high, and a minor population (CD4lo), in which the expression of CD4 can be up to an order of magnitude lower than on the CD4+ cells. The proportion of CD4locells is age dependent and highly variable in the apparently healthy human population, with the expression of CD4 ranging from around 10% of all peripheral blood lymphocytes in the young to more than 30% in the elderly. Lowered expression of CD4 is correlated with a reduced expression of CD3, as well as with a decreased amount of CD28 and CD95Fas. Activation of CD4lo cells is suggested by their expression of CD25 and increased amounts of HLA-DR. Phenotypic characteristics of the CD4lo T-cell subpopulation suggest that it might be formed by (perhaps chronically) activated, temporarily apoptosis-resistant cells, possibly accumulating in the elderly.

scholarly journals Direct demonstration of the clonogenic potential of every human peripheral blood T cell. Clonal analysis of HLA-DR expression and cytolytic activity.

1983 ◽  
Vol 157 (2) ◽  
pp. 743-754 ◽  
Author(s):  
A Moretta ◽  
G Pantaleo ◽  
L Moretta ◽  
J C Cerottini ◽  
M C Mingari
Keyword(s):  
T Cells ◽  
T Cell ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Cell Populations ◽  
Target Cells ◽  
Flow Cytofluorometry ◽  
Hla Dr ◽  
Clonogenic Potential ◽  
Precursor Frequency

In an attempt to determine the clonogenic properties of human peripheral blood T cells, we have developed a limiting dilution microculture system using phytohemagglutinin (PHA) as T cell activator and supernatant from PHA-stimulated spleen cultures as a source of T cell growth factors. The frequencies of cells capable of extensive proliferation under these culture conditions were 0.52-0.73, 0.98-1.11, and less than 0.02 in peripheral blood mononuclear, E-rosette-positive, and E-rosette-negative cell populations, respectively. The clonogenic potential of virtually all T cells was confirmed in experiments using single cells isolated by micromanipulation. Clone size ranged between 5 and 30 X 10(4) cells on day 14 of culture. The same microculture system was used to determine the precursor frequency of all cytolytic T lymphocytes (CTL-P). As assessed by a lectin-dependent 51Cr release assay, the CTL-P frequency in purified T cell populations ranged between 0.30 and 0.34. In comparison, the precursor frequency of T cells capable of lysing K562 target cells was ranging between 0.14 and 0.16. Parallel analysis of individual clonal cultures for both lytic activities showed that 50% of the clones exhibiting lectin-dependent lysis were also active against K562 target cells. All of the proliferating clones expressed HLA-DR antigens, although to a varying degree as assessed by flow cytofluorometry. Given the high cloning efficiency of this culture system, it appears now possible to determine the precursor frequencies of the various classes of functional cells in T cell populations.

Lysophosphatidic acid enhances interleukin-13 gene expression and promoter activity in T cells

2006 ◽  
Vol 290 (1) ◽  
pp. L66-L74 ◽  
Author(s):  
Joshua Rubenfeld ◽  
Jia Guo ◽  
Nitat Sookrung ◽  
Rongbing Chen ◽  
Wanpen Chaicumpa ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Lysophosphatidic Acid ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Regulatory Elements ◽  
Jurkat Cells

Lysophosphatidic acid (LPA) is a membrane-derived lysophospholipid with wide-ranging effects on multiple lung cells including airway epithelial and smooth muscle cells. LPA can augment migration and cytokine synthesis in lymphocytes, but its potential effects on Th2 cytokines have not been well studied. We examined the effects of physiological concentrations of LPA on IL-13 gene expression in human T cells. The Jurkat T cell line and human peripheral blood CD4+ T cells were incubated with LPA alone or with 1) pharmacological agonists of different signaling pathways, or 2) antibodies directed against the T cell receptor complex and costimulatory molecules. Luciferase-based reporter constructs driven by different lengths of the human IL-13 promoter were transfected by electroporation in Jurkat cells treated with and without LPA. The effects of LPA on IL-13 mRNA stability were examined using actinomycin D to halt ongoing transcription. Expression of mRNA encoding LPA2and LPP-1 increased with T cell activation. LPA augmented IL-13 secretion under conditions of submaximal T cell activation. This was observed using pharmacological agonists activating intracellular calcium-, PKC-, and cAMP-dependent signaling pathways, as well as antibodies directed against CD3 and CD28. LPA only slightly prolonged IL-13 mRNA half-life in submaximally stimulated Jurkat cells. In contrast, LPA significantly enhanced transcriptional activation of the IL-13 promoter via regulatory elements contained within proximal 312 bp. The effects of LPA on IL-13 promoter activation appeared to be distinct from those mediated by GATA-3. LPA can augment IL-13 gene expression in T cells, especially under conditions of submaximal activation.

DAP10 Costimulates Chimeric Receptor-Mediated T Cell Responses to Tumor Antigen.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3052-3052
Author(s):  
Bianca Altvater ◽  
Sibylle Pscherer ◽  
Heribert Juergens ◽  
Claudia Rossig
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Adoptive Immunotherapy ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Cytokine Secretion ◽  
Immunotherapy Of Cancer

Abstract Chimeric receptors (chRecs) combining extracellular recognition domains with the T cell receptor ζ an redirect the cellular immune response of primary T-cells to tumor cells. T cell activation by chRec induces efficient cytokine release and cytotoxicity, however, it fails to mediate proliferative responses, limiting the usefulness of chRec-gene-modified T cells for adoptive immunotherapy of cancer. Inclusion of a CD28 costimulatory signaling component in the chRec endodomain enhances antigen-specific proliferation. Whereas the signal mediated by ligation of CD28 is of crucial importance for the activation of resting CD4+ T cells, further molecules with costimulatory functions have contributory roles. NKG2D is a stimulatory receptor that was first identified in NK cells, but is also expressed in cytotoxic T cells and positively modulates CD8+ T cell immune responses. We hypothesized that inclusion of the NKG2D-associated signaling domain DAP10 would enhance the capacity of chRecs to induce tumor-specific activation and proliferation of in vitro expanded effector T cells. Based on a GD2-specific scFv, we generated chRecs containing either the DAP10 signaling chain alone (14.G2a-DAP10) or combined with TCRζ 14.G2a-DAP10ζ), and expressed them in nonspecifically activated human peripheral blood T cells of three individual donors by retroviral gene transfer. As controls, T cells were transduced with 14.G2a-ζ and -CD28ζ chRec. High chRec surface expression was obtained with all four constructs (55±11%, ζ; 85±3, CD28ζ; 68±5%, DAP10; 78±1%; DAP10ζ). Immunophenotypes were dominated by a CD3+CD8+ population in all cell cultures. Whereas DAP10 alone failed to mediate specific tumor cell lysis, 51Cr release assays revealed efficient and comparable lysis of GD2+ tumor targets by T cells transduced with all ζ-containing constructs, with 49±8% (ζ), 52±7% (CD28ζ), and 52±18% (DAP10ζ) cytolysis at an effector-to-target ratio of 40:1. Intracellular cytokine secretion by chRec+ T cells was induced in response to tumor targets by 14.G2a-ζ (up to 37% IFN-γ secreting cells), CD28ζ, and DAPζ (both up to 22%), but not by DAP10 alone (0,2%). Weekly stimulation with tumor cells for 6 weeks induced only limited expansion of T cells transduced with 14.G2a-ζ (7–45fold) or with 14.G2a-DAP10 (14–26-fold). Adding CD28 or DAP10 domains significantly enhanced expansion by a comparable degree (270–483-fold and 126–436-fold, respectively). Thus, while neither CD28 nor DAP10 enhances antigen-specific cytokine secretion and cytolysis, DAP10 signaling can completely replace CD28 signaling in costimulating antigen-specific proliferation of peripheral blood T cells. DAP10-containing chRec may be a powerful new tool for adoptive immunotherapy of cancer.

Lipopolysaccharide(LPS)-Induction of the HTLV-1 LTR in Monocytes

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2167-2167
Author(s):  
Junichi Tsukada ◽  
Takehiro Higashi ◽  
Atsushi Iwashige ◽  
Takefumi Katsuragi ◽  
Naho Nomura ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Transcription Factors ◽  
T Cell ◽  
Transgenic Mouse ◽  
Promoter Activity ◽  
Viral Proteins ◽  
Jurkat Cells ◽  
Structural Proteins ◽  
Cytokine Gene Expression

Abstract Abstract 2167 The human leukemia virus type 1 (HTLV-1) gene expression is regulated by the viral proteins and various cellular transcription factors. HTLV-1 genome encodes not only structural proteins, but also non-structural proteins such as Tax, a transcriptional activator for STAT5 p12I, and HTLV-1 bZIP factor (HBZ) encoded by the minus strand of the viral genome. The functional analysis of the viral proteins such as Tax has shed light on the pathogenesis of adult T cell leukemia/lymphoma (ATL). Expression of Tax is enhanced by T-cell activation stimuli such as phorbol ester (PMA), phytohemagglutinin (PHA) or sodium butyrate in chronically HTLV-1-infected CD4+T-cells. Transgenic mouse studies with Tax expression under the control of the granzyme B promoter or the proximal Lck promoter showed that disease progression is associated with infiltration of activated T- and inflammatory cells, and dysregulated inflammatory cytokine production. More recently, a transgenic mouse model with Tax expression regulated by the LTR (LTR-Tax) showed that LTR-Tax CD4 positive T-cells are hyper-proliferative and hyper-responsive to immune stimulation and strongly produce Th1-, Th2- and Th17-associated cytokines. In addition, HTLV-1 infection causes inflammatory disease of the central nerve system, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as ATL. Aberrant cytokine gene expression is the hallmark of HTLV-1-associated diseases. HTLV-1 infection is widely distributed among mammalian cells. We previously demonstrated that Tax transactivates the promoter of human proIL-1β gene (IL1B) gene through association with two transcription factors, NF-IL6 (C/EBPβ) and Spi-1 (PU.1) in monocytes. Tax synergized with lipopolysaccharide (LPS) to induce IL1B promoter activity. Spi-1 is an Ets family protein restricted in expression to monocytes/myelocytes, B cells, mast cells and erythrocyte stem cells, while NF-IL6 is widely expressed. LPS, a component of the gram-negative bacterial cell wall involved in the activation of monocytes, binds to TLR4, leading to activation of TRAF6, IRAK and MyD88. We now extend these studies to elucidate roles of LPS and Tax on HTLV-1 LTR promoter regulation in monocytes. When HTLV-1 LTR reporter was transfected into THP-1 monocytic cells, LPS dose-dependently induced HTLV-1 LTR. The mid-LTR of the HTLV-1 gene possesses three potential Ets binding elements centered on a GGAA motif (PuB1, pets and PuB2). Elf-1 has been shown to be the predominant protein binding to the HTLV-1 Ets sites in Jurkat and peripheral blood T-cells. In the present study, mutation of the Ets sites, especially pets and PuB2 caused significant inhibition of LPS-induced LTR activity in THP-1 cells. EMSA studies using THP-1 nuclear extracts showed binding of Spi-1 to the HTLV-1 Ets sites in THP-1 cells. Anti-Spi-1 Ab, but not anti-Elf-1 Ab or anti-ets-1 Ab supershifted the complex generated by THP-1 nuclear extract and HTLV-1 LTR Ets site. However, when migration pattern of the complex was compared with recombinant Spi-1 in vitro translated in a reticulocyte lysate system, the THP-1 complex migrated slower than recombinant Spi-1 protein. In this regard, anti-IRF-8 Ab further recognized the slow complex. Several reports recently showed that IRF-8 functions as a heterodimeric complex with spi-1 for expression of relevant genes. On the other hand, when Tax expression vector was cotransfected into THP-1 cells along with HTLV-1 LTR reporter, Tax synergized with LPS to activate LTR. Spi-1 protein has three independent transcriptional activation domains (TAD); a TBP binding region, a Q domain, and a PEST region. GST pull-down studies using GST-Tax and 35S-labeled recombinant Spi-1 revealed that mutant Spi-1 lacking the TADs still retains the ability to interact with Tax. In contrast to THP-1 cells, Jurkat T-cells showed only a marginal increase in IL1B promoter activity following Tax expression. Mutations of the Spi-1 binding site in the IL1B promoter did not affect Tax-induced activity in Jurkat cells. Any factors did not bind to the IL1B Spi-1 site in Jurkat cells. Thus, our data suggest that LPS cooperates with Tax to activate the viral and various cellular genes in HTLV-1-infected monocytes. Spi-1 is a key player in the monocyte-specific gene regulation in HTLV-1 infection. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Activation of hypoxia-inducible factor 1 in human T-cell leukaemia virus type 1-infected cell lines and primary adult T-cell leukaemia cells

2007 ◽  
Vol 406 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Mariko Tomita ◽  
Gregg L. Semenza ◽  
Canine Michiels ◽  
Takehiro Matsuda ◽  
Jun-Nosuke Uchihara ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Protein Expression ◽  
Cell Lines ◽  
Transcriptional Activity ◽  
Cell Leukaemia ◽  
Leukaemia Virus ◽  
Human T Cell ◽  
T Cell Lines

HTLV-1 (human T-cell leukaemia virus type 1) is the causative agent for ATL (adult T-cell leukaemia). HTLV-1 Tax can activate the PI3K (phosphoinositide 3-kinase)/Akt signalling pathway, which is responsible for survival of HTLV-1-infected T-cells. HIFs (hypoxia-inducible factors) are transcriptional regulators that play a central role in the response to hypoxia. Overexpression of HIF-1α in many cancers is associated with a poor response to treatment and increased patient mortality. Our objectives in the present study were to investigate whether HIF-1 was activated in HTLV-1-infected T-cells and to elucidate the molecular mechanisms of HIF-1 activation by focusing on the PI3K/Akt signalling pathway. We detected a potent pathway that activated HIF-1 in the HTLV-1-infected T-cells under a normal oxygen concentration. Enhanced HIF-1α protein expression and HIF-1 DNA-binding activity were exhibited in HTLV-1-infected T-cell lines. Knockdown of HIF-1α by siRNA (small interfering RNA) suppressed the growth and VEGF (vascular endothelial growth factor) expression of the HTLV-1-infected T-cell line. HIF-1 protein accumulation and transcriptional activity were enhanced by Tax, which was inhibited by dominant-negative Akt. Importantly, mutant forms of Tax that are defective in activation of the PI3K/Akt pathway failed to induce HIF-1 transcriptional activity. The PI3K inhibitor LY294002 suppressed HIF-1α protein expression, HIF-1 DNA-binding and HIF-1 transcriptional activity in HTLV-1-infected T-cell lines. In primary ATL cells, HIF-1α protein levels were strongly correlated with levels of phosphorylated Akt. The results of the present study suggest that PI3K/Akt activation induced by Tax leads to activation of HIF-1. As HIF-1 plays a major role in tumour progression, it may represent a molecular target for the development of novel ATL therapeutics.

scholarly journals Recombinant human interferon-inducible protein 10 is a chemoattractant for human monocytes and T lymphocytes and promotes T cell adhesion to endothelial cells.

1993 ◽  
Vol 177 (6) ◽  
pp. 1809-1814 ◽  
Author(s):  
D D Taub ◽  
A R Lloyd ◽  
K Conlon ◽  
J M Wang ◽  
J R Ortaldo ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Biological Activity ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
T Cell ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Inducible Protein ◽  
Interferon Inducible Protein

The human cytokine interferon-inducible protein 10 (IP-10) is a small glycoprotein secreted by activated T cells, monocytes, endothelial cells, and keratinocytes, and is structurally related to a family of chemotactic cytokines called chemokines. Although this protein is present in sites of delayed-type hypersensitivity reactions and lepromatous leprosy lesions, the biological activity of IP-10 remains unknown. We report here that recombinant human IP-10 stimulated significant in vitro chemotaxis of human peripheral blood monocytes but not neutrophils. Recombinant human IP-10 also stimulated chemotaxis of stimulated, but not unstimulated, human peripheral blood T lymphocytes. Phenotypic analysis of the stimulated T cell population responsive to IP-10 demonstrated that stimulated CD4+ and CD29+ T cells migrated in response to IP-10. This resembles the biological activity of the previously described T cell chemoattractant RANTES. Using an endothelial cell adhesion assay, we demonstrated that stimulated T cells pretreated with optimal doses of IP-10 exhibited a greatly enhanced ability to bind to an interleukin 1-treated endothelial cell monolayer. These results demonstrate that the IP-10 gene encodes for an inflammatory mediator that specifically stimulates the directional migration of T cells and monocytes as well as potentiates T cell adhesion to endothelium.

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