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Khan AUH, Ali AK, Marr B, Jo D, Ahmadvand S, Fong-McMaster C, Almutairi SM, Wang L, Sad S, Harper ME, Lee SH. The TNFα/TNFR2 axis mediates natural killer cell proliferation by promoting aerobic glycolysis. Cell Mol Immunol 2023; 20:1140-1155. [PMID: 37553427 PMCID: PMC10541863 DOI: 10.1038/s41423-023-01071-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 06/29/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023] Open
Abstract
Natural killer (NK) cells are predominant innate lymphocytes that initiate the early immune response during infection. NK cells undergo a metabolic switch to fuel augmented proliferation and activation following infection. Tumor necrosis factor-alpha (TNFα) is a well-known inflammatory cytokine that enhances NK cell function; however, the mechanism underlying NK cell proliferation in response to TNFα is not well established. Here, we demonstrated that upon infection/inflammation, NK cells upregulate the expression of TNF receptor 2 (TNFR2), which is associated with increased proliferation, metabolic activity, and effector function. Notably, IL-18 can induce TNFR2 expression in NK cells, augmenting their sensitivity toward TNFα. Mechanistically, TNFα-TNFR2 signaling upregulates the expression of CD25 (IL-2Rα) and nutrient transporters in NK cells, leading to a metabolic switch toward aerobic glycolysis. Transcriptomic analysis revealed significantly reduced expression levels of genes involved in cellular metabolism and proliferation in NK cells from TNFR2 KO mice. Accordingly, our data affirmed that genetic ablation of TNFR2 curtails CD25 upregulation and TNFα-induced glycolysis, leading to impaired NK cell proliferation and antiviral function during MCMV infection in vivo. Collectively, our results delineate the crucial role of the TNFα-TNFR2 axis in NK cell proliferation, glycolysis, and effector function.
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Affiliation(s)
- Abrar Ul Haq Khan
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- The University of Ottawa Centre for Infection, Immunity, and Inflammation, Ottawa, ON, Canada
| | - Alaa Kassim Ali
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bryan Marr
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Donghyeon Jo
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Simin Ahmadvand
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Claire Fong-McMaster
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Saeedah Musaed Almutairi
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Botany and Microbiology Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Lisheng Wang
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- The University of Ottawa Centre for Infection, Immunity, and Inflammation, Ottawa, ON, Canada
| | - Subash Sad
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- The University of Ottawa Centre for Infection, Immunity, and Inflammation, Ottawa, ON, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- The University of Ottawa Centre for Infection, Immunity, and Inflammation, Ottawa, ON, Canada
| | - Seung-Hwan Lee
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
- The University of Ottawa Centre for Infection, Immunity, and Inflammation, Ottawa, ON, Canada.
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El-Deeb NM, Yassin AM, Al-Madboly LA, El-Hawiet A. A novel purified Lactobacillus acidophilus 20079 exopolysaccharide, LA-EPS-20079, molecularly regulates both apoptotic and NF-κB inflammatory pathways in human colon cancer. Microb Cell Fact 2018; 17:29. [PMID: 29466981 PMCID: PMC5820793 DOI: 10.1186/s12934-018-0877-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/12/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The direct link between inflammatory bowel diseases and colorectal cancer is well documented. Previous studies have reported that some lactic acid bacterial strains could inhibit colon cancer progression however; the exact molecules involved have not yet been identified. So, in the current study, we illustrated the tumor suppressive effects of the newly identified Lactobacillus acidophilus DSMZ 20079 cell-free pentasaccharide against colon cancer cells. The chemical structure of the purified pentasaccharide was investigated by MALDI-TOF mass spectrum, 1D and 2D Nuclear Magnetic Resonance (NMR). The anticancer potentiality of the purified pentasaccharide against both Human colon cancer (CaCo-2) and Human breast cancer (MCF7) cell lines with its safety usage pattern were evaluated using cytotoxicity, annexin V quantification and BrdU incorporation assays. Also, the immunomodulatory effects of the identified compound were quantified on both LPS-induced PBMC cell model and cancer cells with monitoring the immunophenotyping of T and dendritic cell surface marker. At molecular level, the alteration in gene expression of both inflammatory and apoptotic pathways were quantified upon pentasaccharide-cellular treatment by RTqPCR. RESULTS The obtained data of the spectroscopic analysis, confirmed the structure of the newly extracted pentasaccharide; (LA-EPS-20079) to be: α-D-Glc (1→2)][α-L-Fuc(1→4)] α-D-GlcA(1→2) α-D-GlcA(1→2) α-D-GlcA. This pentasaccharide, recorded safe dose on normal mammalian cells ranged from 2 to 5 mg/ml with cancer cells selectivity index, ranged of 1.96-51.3. Upon CaCo-2 cell treatment with the non-toxic dose of LA-EPS-20079, the inhibition percentage in CaCo-2 cellular viability, reached 80.65 with an increase in the ratio of the apoptotic cells in sub-G0/G1 cell cycle phase. Also, this pentasaccharide showed potentialities to up-regulate the expression of IKbα, P53 and TGF genes. CONCLUSION The anticancer potentialities of LA-EPS-20079 oligosaccharides against human colon cancer represented through its regulatory effects on both apoptotic and NF-κB inflammatory pathways.
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Affiliation(s)
- Nehal M El-Deeb
- Biopharmacetical Product Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, 21934, Alexandria, Egypt.
| | - Abdelrahman M Yassin
- Biopharmacetical Product Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, 21934, Alexandria, Egypt
| | - Lamiaa A Al-Madboly
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Tanta University, Tanta, 31527, Egypt.
| | - Amr El-Hawiet
- Department of Pharmacognosy, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
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Ahn G, Bing SJ, Kang SM, Lee WW, Lee SH, Matsuda H, Tanaka A, Cho IH, Jeon YJ, Jee Y. The JNk/NFkappaB pathway is required to activate murine lymphocytes induced by a sulfated polysaccharide from Ecklonia cava. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1830:2820-9. [PMID: 23262141 DOI: 10.1016/j.bbagen.2012.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 11/21/2012] [Accepted: 12/10/2012] [Indexed: 12/22/2022]
Abstract
BACKGROUND The proven immunomodulatory and immune system activating properties of Ecklonia cava (E. cava) have been attributed to its plentiful polysaccharide content. Therefore, we investigated whether the sulfated polysaccharide (SP) of E. cava specifically activates the protein kinases (MAPKs) and nuclear factor-kappaB (NFkappaB) to incite immune responses. METHODS To assess immune responsiveness, lymphocytes were isolated from spleens of ICR mice and cultured with SP and its inhibitors. Assays included 3H-thymidine incorporation, flow cytometry, real time polymerase chain reaction (rtPCR), enzyme linked immunosorbent assay (ELISA), intracellular cytokine assay. Western blot, and electrophoretic mobility shift assay (EMSA). RESULTS SP dose-dependently increased the proliferation of lymphocytes without cytotoxicity. In particular, SP markedly enhanced the proliferation and differentiation of CD3+ mature T cells and CD45R/B220+ pan B cells. Additionally, SP increased the expression and/or production of IL-2, IgG(1a), and IgG(2b) compared to that in untreated cells. The subsequent application of JNK (SP600125), NFkappaB (PDTC), and serine protease (TPCK) inhibitors significantly inhibited the proliferation and IL-2 production of SP-treated lymphocytes as well as the phosphorylation of JNK and IkappaB, the activation of nuclear NFkappaB p65, and binding of NFkappaB p65 DNA. Moreover, co-application of both JNK and NFkappaB inhibitors completely blocked the proliferation of lymphocytes even in the presence of SP. CONCLUSION These results suggest that SP induced T and B cell responses via both JNK and NFkappaB pathways. GENERAL SIGNIFICANCE The effect of SP on splenic lymphocyte activation was assayed here for the first time and indicated the underlying functional mechanism.
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Affiliation(s)
- Ginnae Ahn
- Laboratory of Comparative Animal Medicine, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
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4
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Ahn G, Park E, Lee WW, Hyun JW, Lee KW, Shin T, Jeon YJ, Jee Y. Enzymatic extract from Ecklonia cava induces the activation of lymphocytes by IL-2 production through the classical NF-κB pathway. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2011; 13:66-73. [PMID: 20480199 DOI: 10.1007/s10126-010-9270-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 01/03/2010] [Indexed: 05/29/2023]
Abstract
Activated nuclear factor-kappa B (NF-κB), a well-known transcription factor, leads to the development, differentiation, and proliferation of T and B lymphocytes and the secretion of cytokines by the classical pathway. We have examined here whether an enzymatic extract (ECK) from the brown seaweed, Alariaceae Laminariales Ecklonia cava may contribute to activating lymphocytes through the NF-κB pathway for participation in immune responses. In our study, ECK dose-dependently enhanced the proliferation of lymphocytes. ECK significantly increased the phosphorylation of inhibitors of κB at 0.25 and 0.5 h of exposure, followed by its gradual decrease. In addition, NF-κB p65 was gradually activated, and its binding to nuclear deoxyribonucleic acid was observed from 0.25 h after stimulation (up to 0.5 h). Further experiments showed that the application of N-p-tosyl-L: -phenylalanine chloromethyl ketone, an NF-κB inhibitor, significantly blocked ECK-induced lymphocyte's proliferation and the interleukin (IL)-2 productions. Accordingly, our results suggest that ECK increases the production of IL-2 through the activation of NF-κB then induces the proliferation of lymphocytes with the coordinated stimulation of IL-2.
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Affiliation(s)
- Ginnae Ahn
- Department of Marine Life Science, Jeju National University, Jeju, 690-756, Republic of Korea
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McCracken SA, Hadfield K, Rahimi Z, Gallery ED, Morris JM. NF-kappaB-regulated suppression of T-bet in T cells represses Th1 immune responses in pregnancy. Eur J Immunol 2007; 37:1386-96. [PMID: 17407192 DOI: 10.1002/eji.200636322] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The molecular mechanisms that suppress Th1 immune responses in pregnancy are unknown. We assessed the expression of the Th1 cytokine transcription factor T-bet. We isolated PBMC and T cells from non-pregnant and pregnant women and demonstrated that T-bet is specifically down-regulated in pregnancy under basal and stimulated conditions. Low levels of T-bet protein were detected in the nuclear fraction of unstimulated PBMC from non-pregnant, but not pregnant women. Nuclear levels of T-bet increased in response to PMA/ionomycin in PBMC from non-pregnant, but not pregnant women. T-bet expression was greater in whole cell lysates of stimulated CD3(+) T cells from non-pregnant relative to pregnant women. NF-kappaB is specifically down-regulated in T cells in pregnant women, resulting in suppressed expression of Th1 cytokines IL-2, IFN-gamma and TNF-alpha. In this study, down-regulation of NF-kappaB also resulted in diminished expression of T-bet. PMA induces NF-kappaB translocation, T-bet expression and IL-2, IFN-gamma and TNF-alpha production. Conversely, pre-incubation with SN50, and NF-kappaB oligodeoxyribonucleotide decoys suppressed PMA-induced NF-kappaB translocation and gene transcription, respectively, resulting in diminished T-bet expression and Th1 cytokine production. Therefore, maintenance of the cytokine environment for pregnancy success is mediated via strict regulation of Th1 immune responses, more specifically through control of NF-kappaB and T-bet transcription.
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Affiliation(s)
- Sharon A McCracken
- Perinatal Research Group, Kolling Institute of Medical Research, University of Sydney, St Leonards, Australia.
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Kim HP, Imbert J, Leonard WJ. Both integrated and differential regulation of components of the IL-2/IL-2 receptor system. Cytokine Growth Factor Rev 2006; 17:349-66. [PMID: 16911870 DOI: 10.1016/j.cytogfr.2006.07.003] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Interleukin-2 was discovered in 1976 as a T-cell growth factor. It was the first type I cytokine cloned and the first for which a receptor component was cloned. Its importance includes its multiple actions, therapeutic potential, and lessons for receptor biology, with three components differentially combining to form high, intermediate, and low-affinity receptors. IL-2Ralpha and IL-2Rbeta, respectively, are markers for double-negative thymocytes and regulatory T-cells versus memory cells. gamma(c), which is shared by six cytokines, is mutated in patients with X-linked severe-combined immunodeficiency. We now cover an under-reviewed area-the regulation of genes encoding IL-2 and IL-2R components, with an effort to integrate/explain this knowledge.
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Affiliation(s)
- Hyoung Pyo Kim
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1674, United States.
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Ishimaru N, Kishimoto H, Hayashi Y, Sprent J. Regulation of naive T cell function by the NF-kappaB2 pathway. Nat Immunol 2006; 7:763-72. [PMID: 16732290 DOI: 10.1038/ni1351] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Accepted: 04/26/2006] [Indexed: 11/08/2022]
Abstract
T cell activation involves the orchestration of several signaling pathways, including that of the 'classical' transcription factor NF-kappaB components NF-kappaB1-RelA. The function of the 'nonclassical' NF-kappaB2-RelB pathway is less clear, although T cells lacking components of this pathway have activation defects. Here we show that mice deficient in NF-kappaB-inducing kinase have a complex phenotype consisting of immunosuppression mediated by CD25(-)Foxp3(-) memory CD4(+) cells and, in the absence of those cells, hyper-responsive naive CD4(+) T cells, which caused autoimmune lesions after adoptive transfer into hosts deficient in recombination-activating genes. Biochemical studies indicated involvement of a cell-intrinsic mechanism in which NF-kappaB2 (p100) limits nuclear translocation of NF-kappaB1-RelA and thereby functions as a regulatory 'brake' for the activation of naive T cells.
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Podolin PL, Callahan JF, Bolognese BJ, Li YH, Carlson K, Davis TG, Mellor GW, Evans C, Roshak AK. Attenuation of murine collagen-induced arthritis by a novel, potent, selective small molecule inhibitor of IkappaB Kinase 2, TPCA-1 (2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide), occurs via reduction of proinflammatory cytokines and antigen-induced T cell Proliferation. J Pharmacol Exp Ther 2004; 312:373-81. [PMID: 15316093 DOI: 10.1124/jpet.104.074484] [Citation(s) in RCA: 229] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Demonstration that IkappaB kinase 2 (IKK-2) plays a pivotal role in the nuclear factor-kappaB-regulated production of proinflammatory molecules by stimuli such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 suggests that inhibition of IKK-2 may be beneficial in the treatment of rheumatoid arthritis. In the present study, we demonstrate that a novel, potent (IC(50) = 17.9 nM), and selective inhibitor of human IKK-2, 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1), inhibits lipopolysaccharide-induced human monocyte production of TNF-alpha, IL-6, and IL-8 with an IC(50) = 170 to 320 nM. Prophylactic administration of TPCA-1 at 3, 10, or 20 mg/kg, i.p., b.i.d., resulted in a dose-dependent reduction in the severity of murine collagen-induced arthritis (CIA). The significantly reduced disease severity and delay of disease onset resulting from administration of TPCA-1 at 10 mg/kg, i.p., b.i.d. were comparable to the effects of the antirheumatic drug, etanercept, when administered prophylactically at 4 mg/kg, i.p., every other day. Nuclear localization of p65, as well as levels of IL-1beta, IL-6, TNF-alpha, and interferon-gamma, were significantly reduced in the paw tissue of TPCA-1- and etanercept-treated mice. In addition, administration of TPCA-1 in vivo resulted in significantly decreased collagen-induced T cell proliferation ex vivo. Therapeutic administration of TPCA-1 at 20 mg/kg, but not at 3 or 10 mg/kg, i.p., b.i.d., significantly reduced the severity of CIA, as did etanercept administration at 12.5 mg/kg, i.p., every other day. These results suggest that reduction of proinflammatory mediators and inhibition of antigen-induced T cell proliferation are mechanisms underlying the attenuation of CIA by the IKK-2 inhibitor, TPCA-1.
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Affiliation(s)
- Patricia L Podolin
- Respiratory and Inflammation Center of Excellence for Drug Discovery, GlaxoSmithKline, King of Prussia, PA 19406, USA.
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Rodríguez CI, Gironès N, Fresno M. Cha, a basic helix-loop-helix transcription factor involved in the regulation of upstream stimulatory factor activity. J Biol Chem 2003; 278:43135-45. [PMID: 12923186 DOI: 10.1074/jbc.m300053200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report here the characterization of Cha, a transcription factor of the basic helix-loop-helix (bHLH) family. The basic region of Cha shares DNA-interacting amino acids with members of class C bHLH transcription factors. In addition, the HLH region of Cha presents a Myc-type dimerization domain signature required for heterodimer formation between members of this class. Cha protein and mRNA were ubiquitously expressed in many human tissues. Electrophoretic mobility shift assays showed that Cha and upstream stimulatory factor (USF)-1 formed a complex that specifically bound to E-box DNA elements. Moreover, pull-down and co-immunoprecipitation experiments showed an interaction between Cha and USF-1. Cha did not bind to E-box DNA elements and required USF-1 for protein-DNA complex formation. Moreover, Cha inhibited USF-1-stimulated transcription of CD2 (a USF-1-dependent gene) and E-box promoter reporter plasmids. Chromatin immunoprecipitation assays showed that Cha occupied the CD2 promoter in resting, but not in mitogen-stimulated, T cells. Finally, Cha mRNA and protein expression were high in resting T cells and absent in mitogen-activated T cells and inversely correlated with CD2 expression. Contrarily, overexpression of Cha in T cells significantly reduced CD2 expression. In summary, our results indicated that Cha is a new bHLH transcription factor that negatively regulates USF-dependent transcription.
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Affiliation(s)
- Clara I Rodríguez
- Centro de Biología Molecular, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049, Spain
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Punzón C, Alcaide A, Fresno M. In vitro anti-inflammatory activity of Phlebodium decumanum. Modulation of tumor necrosis factor and soluble TNF receptors. Int Immunopharmacol 2003; 3:1293-9. [PMID: 12890427 DOI: 10.1016/s1567-5769(03)00117-6] [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: 10/27/2022]
Abstract
The immunomodulatory activity of a standardized water soluble fraction of the fern Phlebodium decumanum (EXPLY-37) previously shown to have "in vivo" anti-inflammatory activity was analyzed "in vitro". This extract inhibited tumor necrosis factor (TNF) production by macrophages activated with lipopolysaccharide (LPS) or LPS plus interferon (IFN)-gamma. In contrast, nitric oxide (NO) and interleukin (IL)-1beta production were not affected in the same cultures, whereas IL-6 production was partially inhibited. More interestingly, EXPLY-37 increased the release of soluble TNF-receptor 2 (sTNFR2) and of IL-1R antagonist (IL-1Ra) but not of sTNFR1, by activated macrophages. EXPLY-37 had no effect on T lymphocyte activation, measured as proliferation as well as expression of early and late cell surface antigens CD69, CD25 (IL-2R-alpha) and CD71 (transferrin receptor) at the cell membrane. At the molecular level, EXPLY-37 did not inhibit the activation of the nuclear factor kappa B (NF-kappaB) transcription factor by TNF. In summary, EXPLY-37 has two anti-inflammatory activities "in vitro": it decreases TNF production and increases IL-1Ra and sTNFR2, which may be able to neutralize IL-1 and TNF activity, respectively.
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MESH Headings
- Adjuvants, Immunologic/isolation & purification
- Adjuvants, Immunologic/pharmacology
- Adult
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/isolation & purification
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Cell Line/drug effects
- Cell Line/metabolism
- Drug Evaluation, Preclinical
- HeLa Cells/drug effects
- HeLa Cells/metabolism
- Humans
- Interleukin 1 Receptor Antagonist Protein
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/metabolism
- Lipopolysaccharides/pharmacology
- Lymphocyte Activation/drug effects
- Macrophages/drug effects
- Macrophages/metabolism
- Mice
- NF-kappa B/metabolism
- Plant Extracts/isolation & purification
- Plant Extracts/pharmacology
- Plants, Medicinal/chemistry
- Polypodiaceae/chemistry
- Receptors, Tumor Necrosis Factor/biosynthesis
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type II
- Sialoglycoproteins/biosynthesis
- Sialoglycoproteins/genetics
- T-Lymphocytes/drug effects
- Transcription, Genetic/drug effects
- Tumor Necrosis Factor-alpha/metabolism
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Affiliation(s)
- Carmen Punzón
- Centro de Biología Molecular "Severo Ochoa", CSIC-UAM Universidad Autónoma de Madrid, Canto Blanco, E-28049 Madrid, Spain
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11
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Asai T, Nakatani T, Tamada S, Kuwabara N, Yamanaka S, Tashiro K, Nakao T, Komiya T, Okamura M, Kim S, Iwao H, Miura K. Activation of transcription factors AP-1 and NF-kappaB in chronic cyclosporine A nephrotoxicity: role in beneficial effects of magnesium supplementation. Transplantation 2003; 75:1040-4. [PMID: 12698095 DOI: 10.1097/01.tp.0000057242.96219.af] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND It has been shown that the transcription factors activator protein (AP)-1 and nuclear factor (NF)-kappaB play a pivotal role in various renal diseases. We aimed to study their activations in chronic cyclosporine A (CsA) nephrotoxicity and evaluate the effect of magnesium (Mg) supplementation and blockade of the renin-angiotensin system (RAS), which are known to ameliorate CsA nephrotoxicity, on these transcription factors. METHODS CsA (15 mg/kg/day) was administered subcutaneously daily to rats maintained on a low-sodium diet for 7, 14, and 28 days. DNA-binding activities of AP-1 and NF-kappaB in renal cortex were determined by electrophoretic mobility shift assay. RESULTS DNA-binding activity of AP-1 and NF-kappaB started to increase at day 14 and further elevated at day 28 by CsA treatment. These activations were markedly attenuated when rats were maintained on a high-Mg diet. In contrast, angiotensin-converting enzyme inhibitor (ACEI) had no effect on CsA-induced AP-1 activation. CsA-induced activation of NF-kappaB was suppressed by ACEI at day 14, whereas such effect could not be observed at day 28. CONCLUSIONS Renal cortical AP-1 and NF-kappaB DNA binding were activated in chronic CsA nephrotoxicity. These activations were induced largely by means of RAS-independent mechanisms. It is suggested that prevention of CsA-induced DNA-binding activation of these transcription factors is at least in part responsible for the beneficial effects of Mg supplementation on CsA nephrotoxicity.
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Affiliation(s)
- Toshihiro Asai
- Department of Urology, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno, Osaka 545-8585, Japan
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12
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San-Antonio B, Iñiguez MA, Fresno M. Protein kinase Czeta phosphorylates nuclear factor of activated T cells and regulates its transactivating activity. J Biol Chem 2002; 277:27073-80. [PMID: 12021260 DOI: 10.1074/jbc.m106983200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Although several isoforms of protein kinase C (PKC) have been implicated in T lymphocyte activation events, little is known about their mode of action. To address the role of PKCzeta in T cell activation, we have generated Jurkat T cell transfectants expressing either the wild type (J-PKCzeta) or "kinase-dead" mutant (J-PKCzeta(mut)) versions of this protein. Expression of PKCzeta but not PKCzeta(mut) increased transcriptional activation mediated by the NF-kappaB or nuclear factor of activated T cells (NFAT). PKCzeta cooperates with calcium ionophore and with NFAT1 or NFAT2 proteins to enhance transcriptional activation of a NFAT reporter construct. However, neither NFAT nuclear translocation nor DNA binding were in J-PKCzeta cells. Our results show that PKCzeta enhanced transcriptional activity mediated by Gal4-NFAT1 fusion proteins containing the N-terminal transactivation domain of human NFAT1. Interestingly, PKCzeta synergizes with calcineurin to induce transcriptional activation driven by the NFAT1 transactivation domain. Co-precipitation experiments showed physical interaction between PKCzeta and NFAT1 or NFAT2 isoforms. Even more, PKCzeta was able to phosphorylate recombinant glutathione S-transferase-NFAT1 (1-385) protein. These data reveal a new role of PKCzeta in T cells through the control of NFAT function by modulating the activity of its transactivation domain.
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Affiliation(s)
- Belén San-Antonio
- Centro de Biologia Molecular, Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
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Vockerodt M, Tesch H, Kube D. Epstein-Barr virus latent membrane protein-1 activates CD25 expression in lymphoma cells involving the NFkappaB pathway. Genes Immun 2001; 2:433-41. [PMID: 11781710 DOI: 10.1038/sj.gene.6363803] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Epstein-Barr virus (EBV) is associated with several human malignancies including Burkitt's lymphoma (BL), Hodgkin's disease (HD) and nasopharyngeal carcinoma. A variety of cytokines and receptors have been described to be activated by EBV. Here we show that the IL-2 receptor (IL-2R) alpha-chain, which is weakly expressed on normal resting lymphoid cells, is activated by EBV. Comparison of EBV-negative BL cell lines and their EBV convertants showed an enhanced CD25 expression in EBV-positive BL cells. Transient expression of the oncogenic virus protein latent membrane protein-1 (LMP1) in L428 Hodgkin's lymphoma cells and in Burkitt's lymphoma cells (BL2, BL41, BL30) cells leads to enhanced CD25 expression. Both C-terminal activating regions (CTARs) of LMP1 are involved in CD25 activation. Inhibition of LMP1-mediated NFkappaB enhancement by a constitutive repressive form of IkappaB-alpha resulted in decreased CD25 surface expression, indicating that NFkappaB is involved in CD25 gene regulation. Furthermore, LMP1-mediated CD25 activation was associated with enhanced levels of the soluble form of CD25 (sCD25) in L428 Hodgkin's lymphoma cells but not in BL cells. LMP1 associated enhanced expression of membrane CD25 and soluble CD25 may have immunomodulatory functions and could be involved in biology of EBV-associated diseases.
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Affiliation(s)
- M Vockerodt
- Klinik für Innere Medizin I, Zentrum für Molekulare Medizin der Universität zu Köln, D-50924 Köln, Germany.
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14
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Lee M, Yang KH. 2-Acetylaminofluorene suppresses immune response through the inhibition of nuclear factor-kappaB activation during the early stage of B cell development. Toxicol Lett 2000; 114:173-80. [PMID: 10713482 DOI: 10.1016/s0378-4274(99)00294-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
2-Acetylaminofluorene (AAF), an arylamide carcinogen, has been known to inhibit humoral and cell-mediated immune response by lipopolysaccharide (LPS). In the current study we demonstrate that AAF induced the down-regulation of protein kinase C (PKC) that is a key enzyme in the pathways leading to LPS-induced B-cell proliferation, while having no inhibitory effect on intracellular cAMP in spleen cells. Additionally, to identify the mechanism of action of AAF during B-cell development, we determined the effects of AAF on LPS-induced nuclear factor-kappaB (NF-kappaB) activation in 70Z/3 murine pre-B cells, CH12 murine mature B cells and S194 murine plasmacytoma cells. LPS-induced NF-kappaB activation, which is dependent on PKC, was inhibited by pretreatment with AAF for 2 h in the nuclei of 70Z/3 murine pre-B cells by detection of NF-kappaB specific DNA-protein binding. Conversely, AAF barely inhibited the constitutive NF-kappaB binding activity in mature B-cells, S194 and CH12. To confirm the effect of AAF on NF-kappaB activation, a chloramphenicol acetyl transferase (CAT) expression vector containing multiple copies of the NF-kappaB element (pCAT(kappaB)(3)) was transiently transfected into 70Z/3 or S194 cells, and assessed for inducible CAT activity. AAF treatment of 70Z/3 cells resulted in a significant inhibition of CAT activity induced by LPS. However, AAF exhibited no inhibitory effect on constitutive CAT activity in mature B cells, S194, indicating that AAF no longer has suppressive effects on the immune response in differentiated B cells. Taken together, these results suggest that AAF may act to suppress immune response by blocking the activation of PKC and nuclear expression of NF-kappaB at the early stage of B cell development.
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Affiliation(s)
- M Lee
- Cell Cycle and Signal Transduction Research Unit, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusong, Taejon, South Korea.
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15
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Haas E, Grell M, Wajant H, Scheurich P. Continuous autotropic signaling by membrane-expressed tumor necrosis factor. J Biol Chem 1999; 274:18107-12. [PMID: 10364265 DOI: 10.1074/jbc.274.25.18107] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor necrosis factor (TNF) exists in two bioactive forms, the membrane-integrated form and the proteolytically derived soluble cytokine. Cells that produce TNF are often responsive to TNF, allowing autocrine/juxtacrine feedback loops. However, whether the membrane form of TNF is involved in such regulatory circuits is unclear. Here we demonstrate that HeLa cells, expressing a permanently membrane-integrated mutant form of TNF, constitutively express TNF.TNF receptor complexes at their cell surface. These cells show a permanent activation of the transcription factor NF-kappaB, exert constitutive p38 mitogen-activated protein kinase activity, and produce high amounts of interleukin-6. In parallel, transmembrane TNF-expressing HeLa cells display high sensitivity to cycloheximide or interferon-gamma, similar to untransfected cells treated with these agents in combination with sTNF. Moreover, cycloheximide-induced apoptosis in transmembrane TNF transfectants can be blocked by the caspase inhibitor zVAD-fmk and does not necessarily need cell to cell contact, indicating a critical role of constitutive autotropic signaling of TNF.TNF receptor complexes. These data demonstrate that autotropic signaling loops of membrane TNF can exist, which may be of importance for cells that express both TNF and TNF receptors, such as T lymphocytes, macrophages, and endothelial cells.
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Affiliation(s)
- E Haas
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
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16
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Tchou-Wong KM, Tanabe O, Chi C, Yie TA, Rom WN. Activation of NF-kappaB in Mycobacterium tuberculosis- induced interleukin-2 receptor expression in mononuclear phagocytes. Am J Respir Crit Care Med 1999; 159:1323-9. [PMID: 10194184 DOI: 10.1164/ajrccm.159.4.9710105] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Soluble interleukin-2 receptor-alpha (IL-2Ralpha) has been reported to be increased in the sera of patients with advanced tuberculosis, and levels decline after therapy in accordance with improvement of radiologic findings. We investigated expression of the IL-2Ralpha in bronchoalveolar lavage (BAL) cells in active pulmonary tuberculosis, and evaluated the mechanism Mycobacterium tuberculosis induces in the IL-2Ralpha using the THP-1 mononuclear phagocyte cell line. We found IL-2Ralpha expression to be increased in BAL cells from involved sites of active pulmonary tuberculosis. Expression of the alpha-chain of IL-2Ralpha on peripheral blood monocytes (PBM) was induced by M. tuberculosis by flow cytometry evaluation. Northern analysis demonstrated increased IL-2Ralpha gene expression after stimulation with M. tuberculosis which was further induced by interferon-gamma (IFN-gamma). The IL-2Ralpha promoter containing the nuclear factor kappa B (NF-kappaB) site was transcriptionally induced by M. tuberculosis and this NF-kappaB site could confer inducibility to a heterologous herpes thymidine kinase (TK) promoter by M. tuberculosis. Electrophoretic mobility shift assays (EMSAs) revealed specific binding of nuclear protein to the NF-kappaB site upon induction with M. tuberculosis. Using antibodies against the p50 and p65 subunits of NF-kappaB in EMSAs, the involvement of both p50 and p65 proteins was further demonstrated. Functional expression of the IL-2Ralpha on mononuclear phagocytes in M. tuberculosis infection may play an important immunomodulatory role in the host response.
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Affiliation(s)
- K M Tchou-Wong
- Division of Pulmonary and Critical Care Medicine, Departments of Medicine, Microbiology, and Environmental Medicine, New York University Medical Center, New York, New York, USA
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17
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Ponnappan U, Zhong M, Trebilcock GU. Decreased proteasome-mediated degradation in T cells from the elderly: A role in immune senescence. Cell Immunol 1999; 192:167-74. [PMID: 10087185 DOI: 10.1006/cimm.1998.1418] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Induction of NFkappaB is a highly regulated process requiring phosphorylation, ubiquitination, and proteasome-mediated degradation of the cytosolic inhibitor IkappaBalpha. Analyses of the regulation of IkappaBalpha in TNF-alpha-treated T lymphocytes from young and elderly donors revealed severely compromised degradation of IkappaBalpha in T cells from the elderly. Examination of activation-induced phosphorylation and ubiquitination of IkappaBalpha did not demonstrate any significant age-related alterations. However, examination of proteasome activity in these T cells using fluorogenic peptide assays revealed a significant age-related decline in chymotryptic activity. These results suggest that a decline in proteasome activity results in a failure to fully degrade IkappaBalpha in the elderly. This failure to degrade IkappaBalpha may underlie both the observed decrease in NFkappaB induction and the IL-2 receptor expression in TNF-treated T cells during aging. Thus, decreased proteasome-mediated degradation may be central to immune dysfunction that accompanies aging.
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Affiliation(s)
- U Ponnappan
- Department of Geriatrics, GRECC, University of Arkansas for Medical Sciences, John C. McClellan Memorial Hospital, 4300 W. 7th Street, Little Rock, Arkansas 72205, USA
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18
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Laín de Lera T, Folgueira L, Martín AG, Dargemont C, Pedraza MA, Bermejo M, Bonay P, Fresno M, Alcami J. Expression of IkappaBalpha in the nucleus of human peripheral blood T lymphocytes. Oncogene 1999; 18:1581-8. [PMID: 10102628 DOI: 10.1038/sj.onc.1202455] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
According to current models the inhibitory capacity of I(kappa)B(alpha) would be mediated through the retention of Rel/NF-kappaB proteins in the cytosol. However, I(kappa)B(alpha) has also been detected in the nucleus of cell lines and when overexpressed by transient transfection. To gain better insight into the potential role of nuclear I(kappa)B(alpha) in a physiological context we have analysed its presence in the nucleus of human peripheral blood T lymphocytes (PBL). We demonstrate the nuclear localization of I(kappa)B(alpha) in PBL by different techniques: Western blot, indirect immunofluorescence and electron microscopy. Low levels of nuclear I(kappa)B(alpha) were detected in resting cells whereas a superinduction was obtained after PMA activation. The nuclear pool of I(kappa)B(alpha) showed a higher stability than cytosolic I(kappa)B(alpha) and was partially independent of the resynthesis of the protein. Unexpectedly, the presence of nuclear I(kappa)B(alpha) did not inhibit NF-kappaB binding to DNA and this phenomenon was not due to the presence of IkappaBbeta at the nuclear level. Immunoprecipitation experiments failed to demonstrate an association between nuclear I(kappa)B(alpha) and NF-kappaB proteins. Our results demonstrate that in resting and PMA-activated human PBL, I(kappa)B(alpha) is present in the nucleus in an apparently inactive form unable to disrupt NF-kappaB binding from DNA.
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Affiliation(s)
- T Laín de Lera
- Servicio de Microbiología, Centro de Investigación, Hospital 12 de Octubre, Madrid, Spain
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19
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Liu B, Whisler RL. Transcriptional activation and redox regulation of the tumor necrosis factor-alpha promoter in human T cells: role of the CRE/kappa3 promoter region. J Interferon Cytokine Res 1998; 18:999-1007. [PMID: 9858322 DOI: 10.1089/jir.1998.18.999] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aberrancies in T cell expression of tumor necrosis factor-alpha (TNF-alpha) are frequently observed in inflammatory states characterized by oxidative stress due to excessive generation of hydrogen peroxide (H2O2) and other reactive oxygen species (ROS). In this study, we examined the possible effects of oxidative stress on the expression of TNF-alpha protein and transcriptional activation of the TNF-alpha promoter in human T cells. Results show that exposure of resting T cells to micromolar concentrations of H2O2 did not induce TNF-alpha protein production or transcriptional activation of the TNF-alpha promoter. However, oxidative signals resulted in a dose-dependent suppression of TNF-alpha protein production and transcriptional activation in T cells stimulated with the lectin phytohemagglutinin (PHA) and phorbol myristate acetate (PMA). Optimal suppression of TNF-alpha promoter activity was observed when cells were exposed to oxidative stress during early T cell activation, and other experiments demonstrated that the transactivation responses of the TNF-alpha promoter were quite susceptible to inhibition by both oxidative and reducing changes in cellular redox. Furthermore, reporter gene assays with 5' deletion mutants of the TNF-alpha promoter showed that the CRE/kappa3 composite site played a major role in activation of the TNF-alpha promoter by dual stimulatory signals and suppression of the TNF-alpha promoter by oxidative signals. Thus, T cell expression of TNF-alpha at the protein and transcriptional levels is highly regulated by changes in cellular redox, and the CRE/kappa3 composite site is important for both activation and redox regulation of the TNF-alpha promoter.
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Affiliation(s)
- B Liu
- Department of Medical Biochemistry, The William H. Davis Medical Research Center, The Ohio State University, Columbus 43210-1228, USA
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20
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Nakazato Y, Hayashida T, Kanno Y, Sasamura H, Okada H, Suzuki H, Saruta T. Interleukin (IL)-1 and IL-4 synergistically stimulate NF-IL6 activity and IL-6 production in human mesangial cells. Kidney Int 1998; 54:71-9. [PMID: 9648065 DOI: 10.1046/j.1523-1755.1998.00967.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND While interleukin (IL)-4 inhibits pro-inflammatory cytokine expression by human monocytes, we have observed that it potentiates IL-6 production by IL-1-activated human mesangial cells (MC). To study the mechanism of this cell-type specific interaction between IL-1 and IL-4 in MC, we examined the effect of both cytokines on the activities of nuclear factor kappa B (NF-kappa B) and nuclear IL-6 NL-IL 6), transcription factors that are essential for IL-6 gene expression. METHODS We evaluated IL-6 synthesis, mRNA expression, and mRNA stability by ELISA, Northern analysis, and the actinomycin D method, respectively. Activities of NF-kappa B and NF-IL 6 were analyzed by gel shift assay. RESULTS IL-4 augmented the IL-1 stimulated IL-6 mRNA levels by about threefold without altering mRNA stability. IL-1 treatment rapidly induced the binding activity of NF-kappa B. In contrast, IL-4 did not affect basal and IL-1-induced NF-kappa B activities. Both IL-1 and IL-4 stimulated NF-IL6 activity as early as 30 minutes after treatment. When MC were treated with both cytokines together, marked activation of NF-IL6 was observed at five hours. CONCLUSIONS These results suggest that simultaneous activation of NF-kappa B and NF-IL6 is essential for IL-6 gene expression and that IL-1 and IL-4 cooperatively stimulate MC IL-6 production through their synergistic activation of NF-IL6.
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Affiliation(s)
- Y Nakazato
- Department of Internal Medicine, School of Medicine, Keio University, Saitama, Japan
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21
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Pyatt DW, Stillman WS, Irons RD. Hydroquinone, a reactive metabolite of benzene, inhibits NF-kappa B in primary human CD4+ T lymphocytes. Toxicol Appl Pharmacol 1998; 149:178-84. [PMID: 9571986 DOI: 10.1006/taap.1998.8369] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hydroquinone (HQ), a reactive metabolite of benzene, is present in cigarette smoke and is known to inhibit mitogen-stimulated activation of both T and B lymphocytes. Despite extensive study, the underlying mechanism for HQ's immunotoxicity is not clear. NF-kappa B is a transcription factor known to regulate the expression of a number of genes critical for normal T cell activation. We therefore hypothesized that NF-kappa B might be involved in HQ-induced immunosuppression. In this study, we demonstrate that 1 microM HQ inhibits tumor necrosis factor alpha induced activation of NF-kappa B in primary human CD4+ T cells. This inhibition is not accompanied by a loss in viability, and HQ-treated T cells maintain other active signaling pathways throughout the exposure duration. Additionally, the inhibition of NF-kappa B is reversible as HQ-treated T cells regain normal functioning after 72 h in culture. HQ does not appear to alter NF-kappa B directly as preincubation of nuclear extracts with HQ does not diminish activity of this protein. We further demonstrate that 1 microM HQ inhibits intracellular IL-2 production in T cells stimulated with phorbol ester but does not alter surface expression of CD25 (the alpha-subunit of the IL-2 receptor). These data suggest that NF-kappa B may be an important molecular mediator of HQ's (and benzene's) immunotoxicity.
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Affiliation(s)
- D W Pyatt
- Molecular Toxicology and Environmental Health Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver 80262, USA
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22
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Jolly CA, McMurray DN, Chapkin RS. Effect of dietary n-3 fatty acids on interleukin-2 and interleukin-2 receptor alpha expression in activated murine lymphocytes. Prostaglandins Leukot Essent Fatty Acids 1998; 58:289-93. [PMID: 9654402 DOI: 10.1016/s0952-3278(98)90038-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) suppress interleukin-2 (IL-2) secretion and impair T-lymphocyte proliferation. To determine the mechanism of action, mice were fed diets containing either safflower oil (control diet enriched in linoleic acid, 18:2n-6), EPA, DHA or arachidonic acid (20:4n-6). Splenic lymphocytes were isolated and concanavalin A-induced kinetics of IL-2 and IL-2 receptor alpha mRNA expression were determined by relative competitive-PCR. EPA and DHA did not affect IL-2 mRNA expression but suppressed IL-2 receptor alpha mRNA levels. These data show, for the first time, the selective effects of dietary EPA and DHA on T-lymphocyte gene expression.
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Affiliation(s)
- C A Jolly
- Faculty of Nutrition and Molecular and Cell Biology Group, Texas A&M University, College Station 77843-2471, USA
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23
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Díaz-Guerra MJ, Velasco M, Martín-Sanz P, Boscá L. Evidence for common mechanisms in the transcriptional control of type II nitric oxide synthase in isolated hepatocytes. Requirement of NF-kappaB activation after stimulation with bacterial cell wall products and phorbol esters. J Biol Chem 1996; 271:30114-20. [PMID: 8939960 DOI: 10.1074/jbc.271.47.30114] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Incubation of primary cultures of rat hepatocytes with lipopolysaccharide (LPS), S-[2,3-bis(palmitoyloxy)-(2-R, S)-propyl]-N-palmitoyl-(R)-Cys-Ser-Lys4 (TPP), a synthetic lipopeptide present in bacterial cell wall lipoproteins, or with phorbol 12,13-dibutyrate (PDBu) induced an increase in nitric oxide synthesis through the expression of type II nitric oxide synthase (iNOS). Transfection of hepatocytes with a HindII fragment corresponding to the promoter region of the murine iNOS gene (from nucleotide -1588 to +165) resulted in the expression of the reporter gene when cells were stimulated with these factors. The transcription factors activated by these stimuli involved an increase in the nuclear content of proteins that bind to kappaB, AP-1, GAS, and SIE sequences. Inhibition of NF-kappaB activation with pyrrolidine dithiocarbamate eliminated the expression of iNOS in hepatocytes stimulated with LPS, TPP, or PDBu. In addition to this, transfection of hepatocytes with promoter mutants in which a sequential 2-base pair change within the kappaB sites was introduced (position -971 to -961 and -85 to -75, respectively), resulted in approximately 17 and 35%, respectively, of the activity of the naive promoter. Simultaneous mutation of both kappaB sites abolished the promoter activity. Analysis of the proteins involved in kappaB binding showed the presence of p50/p65 dimers in the nuclei of activated cells at the time that an important decrease of IkappaB-alpha was observed soon after cell stimulation with LPS, TPP, or PDBu. However, only LPS was able to decrease the amount of IkappaB-beta. These results suggest that LPS, TPP, and PDBu, although activating different signal transduction pathways, use a common mechanism mediating iNOS expression in cultured hepatocytes.
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Affiliation(s)
- M J Díaz-Guerra
- Instituto de Bioquímica (CSIC-UCM), Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
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24
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Lee M, Kim HM, Yang KH. Down-regulation of protein kinase C in murine splenocytes: a potential mechanism for 2-acetylaminofluorene-mediated immunosuppression. Cancer Lett 1996; 101:53-7. [PMID: 8625282 DOI: 10.1016/0304-3835(96)04113-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
2-Acetylaminofluorene (AAF), an arylamide carcinogen, inhibited in a dose dependent manner mouse spleen cell proliferation in response to lipopolysaccharide (LPS). The objective of the present studies was to investigate the effects of AAF on protein kinase C (PKC) activation, an enzyme required for LPS-induced splenocytes proliferation. After treatment with 50 microM AAF for 18 h, PKC activity in the cytosolic fraction decreases by 50% from the control level, and splenocytes lost 30% of total PKC activity. Furthermore, as determined by the electrophoretic mobility shift assay, AAF inhibited the binding activity of the transcription factor complex, NF-KB, whose LPS-mediated induction is dependent on PKC activation in murine splenocytes. These results strongly suggest that LPS-mediated signaling in spleen cells is interrupted by AAF early in the signal transduction pathway, at a point proximal to the activation of PKC.
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Affiliation(s)
- M Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Kuson-dong Yusong-gu Taejon, Korea
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25
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O'Connell MA, Cleere R, Long A, O'Neill LA, Kelleher D. Cellular proliferation and activation of NF kappa B are induced by autocrine production of tumor necrosis factor alpha in the human T lymphoma line HuT 78. J Biol Chem 1995; 270:7399-404. [PMID: 7706285 DOI: 10.1074/jbc.270.13.7399] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tumor necrosis factor (TNF) is a pleiotropic cytokine which has both cytotoxic and proliferative effects. HuT 78, a T-cell line derived from a Sezary lymphoma, is resistant to the cytotoxic effects of TNF, suggesting that TNF may be a growth factor for this cell line. The aim of this study was to determine whether autocrine TNF production could function as a growth factor for HuT 78. Resting HuT 78 and K-4 cells, a protein kinase C-beta-deficient clone of HuT 78, both produced significant amounts of TNF compared with Jurkat cells. Thymidine incorporation by HuT 78 and K-4 cells was inhibited by 90.5 and 73.2%, respectively, with addition of a neutralizing monoclonal antibody to TNF alpha, suggesting that TNF is an autocrine growth factor for these cells. HuT 78 and K-4 cells also expressed high levels of constitutively active NF kappa B, unlike Jurkat cells, which expressed high levels only upon activation with TNF or phorbol 12-myristate 13-acetate. p50 was the major component in the NF kappa B complexes in HuT 78 and K-4 cells. Anti-TNF alpha antibody dramatically decreased levels of NF kappa B in both HuT 78 and K-4 cells. As the TNF gene has an NF kappa B binding motif, an autocrine loop involving TNF induction of NF kappa B is therefore likely in these cells. These findings in a neoplastic T-cell line suggest that therapy directed against TNF could be effective in a subset of T-cell lymphomas.
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Affiliation(s)
- M A O'Connell
- Department of Clinical Medicine, Trinity College, Dublin, Ireland
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