751
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Wang Y, Ko BCB, Yang JY, Lam TTL, Jiang Z, Zhang J, Chung SK, Chung SSM. Transgenic mice expressing dominant-negative osmotic-response element-binding protein (OREBP) in lens exhibit fiber cell elongation defect associated with increased DNA breaks. J Biol Chem 2005; 280:19986-91. [PMID: 15774462 DOI: 10.1074/jbc.m501689200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Osmotic-response element-binding protein (OREBP), also known as TonEBP or NFAT5, is thought to be responsible for the induction of osmolyte-accumulating genes when cells are under hypertonic stress. Recent studies suggest that OREBP also plays a role in water reabsorption in the kidney, T-cell proliferation, and embryonic development. We developed transgenic mice that express the dominant-negative OREBP (OREBPdn) specifically in the lens because our earlier studies showed that it is particularly sensitive to osmotic stress. The transgenic mice developed nuclear cataract soon after birth, suggesting defects in lens development. The developing transgenic lenses showed incomplete elongation of fiber cells and formation of vacuoles. This is accompanied by evidence of DNA strand breaks, activation of p53, and induction of checkpoint kinase, suggesting that the developing fiber cells lacking OREBP are in a similar physiological state as cells experiencing hypertonic stress. These results indicate that OREBP-mediated accumulation of osmolytes is essential during elongation of the lens fiber cells.
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Affiliation(s)
- Yu Wang
- Department of Chemistry, The University of Hong Kong, China.
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752
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Abstract
We previously reported evidence that patients with periodontitis have serum antibodies to oral Gram positive bacteria that are cross-reactive with epithelial antigens. In the present report cross-reactive epithelial antigens including CD24, lactate dehydrogenase A [LDM-A], antioxidant protein 2 [AOP 2] and nuclear factor of activated T cells 5 [NFAT 5], were identified by screening a cDNA expression library with pooled patient sera. Titres of antibodies to CD24 peptide correlated negatively with indices of periodontal disease severity. Strong expression of CD24 in the reactive periodontal epithelium and inflamed gingival attachment contrasted with low to undetectable expression in the external gingival epithelium. In periodontitis, a local action of these auto-reactive antibodies could modulate the regulatory potential associated with expression of CD24 in this epithelium.
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Affiliation(s)
- P Ye
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, NSW, Australia
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753
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Abstract
Increasing evidence shows a crucial role of the Ca2+/ calcineurin-mediated activation of the nuclear factor of activated T cells (NFAT) in the regulation of a variety of processes in nonimmune cells. Here we provide evidence that NFATc1 and NFATc2 are expressed in human colon carcinoma cell lines. These proteins are translocated from the cytoplasm to the nucleus upon treatment with a combination of phorbol 12-myristate 13-acetate plus the calcium ionophore A23187. Subsequent to translocation to the nucleus, NFATc1 and NFATc2 were able to bind to a NFAT response element in the DNA, regulating transcriptional activation of genes containing a NFAT-responsive element such as cyclooxygenase-2 (COX-2). COX-2 expression and prostaglandin E2 (PGE2) production were induced upon pharmacological stimuli leading to NFAT activation and blunted by inhibition of calcineurin phosphatase with cyclosporin A or tacrolimus (FK506). Expression of NFAT wild type protein or the active catalytic subunit of calcineurin transactivates COX-2 promoter activity, whereas a dominant negative mutant of NFAT inhibited COX-2 induction in colon carcinoma cell lines. Furthermore, mutation or deletion of NFAT binding sites in the human COX-2 promoter greatly diminished its induction by phorbol 12-myristate 13-acetate/calcium ionophore A23187. These findings demonstrate the presence and activation of NFAT in human colon carcinoma cells, with important implications in the regulation of genes involved in the transformed phenotype as COX-2.
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Affiliation(s)
- Javier Duque
- Centro de Biología Molecular Severo Ochoa, Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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754
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Abstract
The ZAP-70 tyrosine kinase has been described more than ten years ago. Its key role in thymocytes development and mature T lymphocytes activation has been illustrated by the characterization of several human immunodeficiencies presenting with mutations in the zap-70 gene resulting in the absence of ZAP-70 expression. More recently, it has been shown that deregulation of ZAP-70 activity can induce autoimmune diseases. Finally, ZAP-70 expression has been shown in some B chronic lymphocytic leukaemia and correlated with bad prognosis of the disease. The diversity of pathologies associated with deregulation of ZAP-70 demonstrates its key role in immune responses. Research aiming at deciphering the different signalling pathways regulated by ZAP-70 will not only shed some lights on these pathologies, but will also help finding new pharmacological tools, targeting ZAP-70, designed to induce immunosuppression or tolerance.
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Affiliation(s)
- Claire Hivroz
- Inserm U.365, Institut Curie, Section Recherche, 26, rue d'Ulm, 75248 Paris Cedex 05, France.
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755
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Alfonso-Jaume MA, Mahimkar R, Lovett DH. Co-operative interactions between NFAT (nuclear factor of activated T cells) c1 and the zinc finger transcription factors Sp1/Sp3 and Egr-1 regulate MT1-MMP (membrane type 1 matrix metalloproteinase) transcription by glomerular mesangial cells. Biochem J 2004; 380:735-47. [PMID: 14979875 PMCID: PMC1224202 DOI: 10.1042/bj20031281] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 02/06/2004] [Accepted: 02/23/2004] [Indexed: 01/17/2023]
Abstract
The transition of normally quiescent glomerular MCs (mesangial cells) to a highly proliferative phenotype with characteristics of myofibroblasts is a process commonly observed in inflammatory diseases affecting the renal glomerulus, the ultimate result of which is glomerulosclerosis. Generation of proteolytically active MMP (matrix metalloproteinase)-2 by the membrane-associated membrane type 1 (MT1)-MMP is responsible for the transition of mesangial cells to the myofibroblast phenotype [Turck, Pollock, Lee, Marti and Lovett (1996) J. Biol. Chem. 271, 15074-15083]. In the present study, we show that the expression of MT1-MMP within the context of MCs is mediated by three discrete cis -acting elements: a proximal non-canonical Sp1 site that preferentially binds Sp1; an overlapping Sp1/Egr-1-binding site that preferentially binds Egr-1; and a more distal binding site for the NFAT (nuclear factor of activated T cells) that binds the NFAT c1 isoform present in MC nuclear extracts. Transfection with an NFAT c1 expression plasmid, or activation of calcineurin with a calcium ionophore, yielded major increases in NFAT c1 nuclear DNA-binding activity, MT1-MMP transcription and protein synthesis, which were additive with the lower levels of transactivation provided by the proximal Sp1 and the overlapping Sp1/Egr-1 sites. Specific binding of NFAT c1 to the MT1-MMP promoter was confirmed by chromatin immunoprecipitation studies, while MT1-MMP expression was suppressed by treatment with the calcineurin inhibitor, cyclosporin A. These studies are the first demonstration that a specific NFAT isoform enhances transcription of an MMP (MT1-MMP) that plays a major role in the proteolytic events that are a dominant feature of acute glomerular inflammation. Suppression of MT1-MMP by commonly used calcineurin inhibitors may play a role in the development of renal fibrosis following renal transplantation.
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Affiliation(s)
- Maria Alejandra Alfonso-Jaume
- The Department of Medicine, San Francisco VAMC/University of California, 111J Medical Service, 4150 Clement Street, San Francisco, CA 94121, USA
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756
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Liu Z, Dronadula N, Rao GN. A Novel Role for Nuclear Factor of Activated T Cells in Receptor Tyrosine Kinase and G Protein-coupled Receptor Agonist-induced Vascular Smooth Muscle Cell Motility. J Biol Chem 2004; 279:41218-26. [PMID: 15272006 DOI: 10.1074/jbc.m406917200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In addition to their role in cytokine gene regulation in T cells, nuclear factors of activated T cells (NFATs) have been shown to be involved in cardiac development and hypertrophy. We have reported previously that NFATs play an important role in the regulation of vascular smooth muscle cell (VSMC) proliferation by receptor tyrosine kinase (RTK) and G protein-coupled receptor (GPCR) agonists, platelet-derived growth factor-BB (PDGF-BB) and thrombin, respectively. To understand the role of NFATs in vascular disease and development, we have now studied the role of these transcriptional factors in VSMC motility. PDGF-BB and thrombin induced VSMC motility in a dose-dependent manner. Blockade of NFAT activation resulted in substantial reduction in PDGF-BB- and thrombin-induced VSMC motility. PDGF-BB and thrombin also induced interleukin-6 (IL-6) expression in NFAT-dependent manner. Furthermore, IL-6 dose-dependently caused VSMC motility. A neutralizing anti-rat IL-6 antibody inhibited VSMC motility induced by IL-6, PDGF-BB, and thrombin. In addition, exogenous addition of IL-6 rescued both PDGF-BB- and thrombin-induced VSMC motility from inhibition by the blockade of NFAT activation. Together, these results for the first time demonstrate that NFATs mediate both RTK and GPCR agonist-induced VSMC motility via induction of expression of IL-6.
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Affiliation(s)
- Zhimin Liu
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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757
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Zaichuk TA, Shroff EH, Emmanuel R, Filleur S, Nelius T, Volpert OV. Nuclear factor of activated T cells balances angiogenesis activation and inhibition. ACTA ACUST UNITED AC 2004; 199:1513-22. [PMID: 15184502 PMCID: PMC2211785 DOI: 10.1084/jem.20040474] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
It has been demonstrated that vascular endothelial cell growth factor (VEGF) induction of angiogenesis requires activation of the nuclear factor of activated T cells (NFAT). We show that NFATc2 is also activated by basic fibroblast growth factor and blocked by the inhibitor of angiogenesis pigment epithelial–derived factor (PEDF). This suggests a pivotal role for this transcription factor as a convergence point between stimulatory and inhibitory signals in the regulation of angiogenesis. We identified c-Jun NH2-terminal kinases (JNKs) as essential upstream regulators of NFAT activity in angiogenesis. We distinguished JNK-2 as responsible for NFATc2 cytoplasmic retention by PEDF and JNK-1 and JNK-2 as mediators of PEDF-driven NFAT nuclear export. We identified a novel NFAT target, caspase-8 inhibitor cellular Fas-associated death domain–like interleukin 1β–converting enzyme inhibitory protein (c-FLIP), whose expression was coregulated by VEGF and PEDF. Chromatin immunoprecipitation showed VEGF-dependent increase of NFATc2 binding to the c-FLIP promoter in vivo, which was attenuated by PEDF. We propose that one possible mechanism of concerted angiogenesis regulation by activators and inhibitors may be modulation of the endothelial cell apoptosis via c-FLIP controlled by NFAT and its upstream regulator JNK.
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Affiliation(s)
- Tetiana A Zaichuk
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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758
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Abstract
Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.
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Affiliation(s)
- Martyn A French
- Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital and School of Surgery and Pathology, University of Western Australia, Perth, Australia.
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759
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Steinberg M, Adjali O, Swainson L, Merida P, Di Bartolo V, Pelletier L, Taylor N, Noraz N. T-cell receptor–induced phosphorylation of the ζ chain is efficiently promoted by ZAP-70 but not Syk. Blood 2004; 104:760-7. [PMID: 15059847 DOI: 10.1182/blood-2003-12-4314] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractEngagement of the T-cell receptor (TCR) results in the activation of Lck/Fyn and ZAP-70/Syk tyrosine kinases. Lck-mediated tyrosine phosphorylation of signaling motifs (ITAMs) in the CD3-ζ subunits of the TCR is an initial step in the transduction of signaling cascades. However, ζ phosphorylation is also promoted by ZAP-70, as TCR-induced ζ phosphorylation is defective in ZAP-70–deficient T cells. We show that this defect is corrected by stable expression of ZAP-70, but not Syk, in primary and transformed T cells. Indeed, these proteins are differentially coupled to the TCR with a 5- to 10-fold higher association of ZAP-70 with ζ as compared to Syk. Low-level Syk-ζ binding is associated with significantly less Lck coupled to the TCR. Moreover, diminished coupling of Lck to ζ correlates with a poor phosphorylation of the positive regulatory tyr352 residue of Syk. Thus, recruitment of Lck into the TCR complex with subsequent ζ chain phosphorylation is promoted by ZAP-70 but not Syk. Importantly, the presence of ZAP-70 positively regulates the TCR-induced tyrosine phosphorylation of Syk. The interplay between Syk and ZAP-70 in thymocytes, certain T cells, and B-chronic lymphocytic leukemia cells, in which they are coexpressed, will therefore modulate the amplitude of antigen-mediated receptor signaling.
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Affiliation(s)
- Marcos Steinberg
- Institut de Génétique Moléculaire de Montpellier, Centre National de la Recherche Scientifique Unité de Recherches 5535/Institut Fédératife de Recherche, F-34293 Montpellier 5, France
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760
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Holzmann K, Kohlhammer H, Schwaenen C, Wessendorf S, Kestler HA, Schwoerer A, Rau B, Radlwimmer B, Döhner H, Lichter P, Gress T, Bentz M. Genomic DNA-chip hybridization reveals a higher incidence of genomic amplifications in pancreatic cancer than conventional comparative genomic hybridization and leads to the identification of novel candidate genes. Cancer Res 2004; 64:4428-33. [PMID: 15231651 DOI: 10.1158/0008-5472.can-04-0431] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Genomic analyses aimed at the detection of high-level DNA amplifications were performed on 13 widely used pancreatic cancer cell lines and 6 pancreatic tumor specimens. For these analyses, array-based comparative genomic hybridization (Matrix-CGH) onto dedicated microarrays was used. In comparison with chromosomal CGH (eight amplifications), a >3-fold number of DNA amplifications was detected (n = 29). The most frequent amplifications mapped to 7p12.3 (three pancreatic cancer cell lines and three pancreatic tumor specimens), 8q24 (four pancreatic cancer cell lines and one pancreatic tumor specimen), 11q13 (three pancreatic cancer cell lines and three pancreatic tumor specimens), and 20q13 (four pancreatic cancer cell lines and three pancreatic tumor specimens). Genes contained in the consensus regions were MYC (8q24), EGFR (7p12.3), and FGF3 (11q13). In six of seven pancreatic cancer cell lines and pancreatic tumor specimens with 20q13 amplifications, the novel candidate gene NFAT C2, which plays a role in the activation of cytokines, was amplified. Other amplifications also affected genes for which a pathogenetic role in pancreatic carcinoma has not been described, such as BCL10 and BCL6, two members of the BCL family. A subset of amplified genes was checked for overexpression by means of real-time PCR, revealing the highest expression levels for BCL6 and BCL10. Thus, Matrix-CGH allows the detection of a high number of amplifications, resulting in the identification of novel candidate genes in pancreatic cancer.
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761
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Abstract
Human chymase is known to function as a chemoattractant for human leukocytes. To investigate the mechanism of the chymase-induced cell migration, change in intracellular calcium concentration ([Ca(2+)]i) was examined in human polymorphonuclear (PMN) cells using Fluo-3 as a fluorescent Ca(2+) indicator. Treatment of PMN cells with human chymase caused [Ca(2+)]i elevation in a concentration-dependent manner. Depletion of extracellular Ca(2+) from the medium partially attenuated the chymase-induced [Ca(2+)]i increase, showing that both Ca(2+) influx and Ca(2+) release from internal stores might be involved in the [Ca(2+)]i response. Pretreatment of the cells with pertussis toxin completely blocked the chymase-induced [Ca(2+)]i signal, suggesting an involvement of G protein in the chymase-mediated [Ca(2+)]i elevation. The data in the present study raise the possibility that the chymase-induced cell migration is mediated by the [Ca(2+)]i elevation, which might be caused by stimulation of a G-protein-coupled receptor such as protease-activated receptors (PARs).
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Affiliation(s)
- Kayo Saito
- Suntory Biomedical Research Limited, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, 618-8503, Osaka, Japan
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762
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Chung J, Yoon SO, Lipscomb EA, Mercurio AM. The Met receptor and alpha 6 beta 4 integrin can function independently to promote carcinoma invasion. J Biol Chem 2004; 279:32287-93. [PMID: 15161909 DOI: 10.1074/jbc.m403809200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It has been proposed that a constitutive, physical association of the Met receptor and the alpha(6)beta(4) integrin exists on the surface of invasive carcinoma cells and that hepatocyte growth factor (HGF)-mediated invasion is dependent on alpha(6)beta(4) (Trusolino, L., Bertotti, A., and Comoglio, P. M. (2001) Cell 107, 643-654). The potential significance of these results prompted us to re-examine this hypothesis. Using three different carcinoma cell lines that express both Met and alpha(6)beta(4), we were unable to detect the constitutive association of these receptors by co-immunoprecipitation. Moreover, carcinoma cells that lacked expression of alpha(6)beta(4) exhibited Met-dependent invasion toward HGF, and increasing Met expression by viral infection of these cells enhanced invasion without inducing alpha(6)beta(4) expression. Although expression of alpha(6)beta(4) in such cells enhanced their invasion to HGF, it also enhanced their ability to invade toward other chemoattractants such as lysophosphatidic acid, and this latter invasion was not inhibited by a function-blocking Met antibody. Finally, depletion of beta(4) by RNA interference in invasive carcinoma cells that express both receptors reduced the ability of these cells to invade toward HGF by approximately 25%, but it did not abrogate their invasion. These data argue that the invasive function of Met can be independent of alpha(6)beta(4) and that alpha(6)beta(4) has a generic influence on the invasion of carcinoma cells that is not specific to Met.
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Affiliation(s)
- Jun Chung
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
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763
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Ayers M, Symmans WF, Stec J, Damokosh AI, Clark E, Hess K, Lecocke M, Metivier J, Booser D, Ibrahim N, Valero V, Royce M, Arun B, Whitman G, Ross J, Sneige N, Hortobagyi GN, Pusztai L. Gene expression profiles predict complete pathologic response to neoadjuvant paclitaxel and fluorouracil, doxorubicin, and cyclophosphamide chemotherapy in breast cancer. J Clin Oncol 2004; 22:2284-93. [PMID: 15136595 DOI: 10.1200/jco.2004.05.166] [Citation(s) in RCA: 427] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The goal of this study was to examine the feasibility of developing a multigene predictor of pathologic complete response (pCR) to sequential weekly paclitaxel and fluorouracil + doxorubicin + cyclophosphamide (T/FAC) neoadjuvant chemotherapy regimen for breast cancer. PATIENTS AND METHODS All patients underwent one-time pretreatment fine-needle aspiration to obtain RNA from the cancer for transcriptional profiling using cDNA arrays containing 30721 human sequence clones. Analysis was performed after profiling, and 42 patients' clinical results were available, 24 of which were used for predictive marker discovery; 18 patients' results were used as an independent validation set. RESULTS Thirty-one percent of patients had pCR (six discovery and seven validation), defined as disappearance of all invasive cancer in the breast after completion of chemotherapy. We could identify no single marker that was sufficiently associated with pCR to be used as an individual predictor. A multigene model with 74 markers (P <or=.09) was built using data from the discovery samples and tested on the validation samples. Overall, a 78% (14 of 18) predictive accuracy was observed, with a 100% (three of three) positive predictive value for pCR, a 73% (11 of 15) negative predictive value, a sensitivity of 43% (three of seven), and a specificity of 100% (11 of 11). The expected response rate to T/FAC neoadjuvant therapy in unselected patients is 28%. CONCLUSION Our results suggest that transcriptional profiling has the potential to identify a gene expression pattern in breast cancer that may lead to clinically useful predictors of pCR to T/FAC neoadjuvant therapy.
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Affiliation(s)
- M Ayers
- Millennium Pharmaceuticals Inc, Cambridge, MA, USA
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764
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Ofotokun I, Buch KP, Lee EY, Hoven A. Pulmonary Mycobacterium avium Complex Infection in HIV-Infected Patient After Immune Reconstitution With Highly Active Antiretroviral Therapy. Infectious Diseases in Clinical Practice 2004; 12:171-3. [DOI: 10.1097/01.idc.0000129849.26885.8c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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765
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Fosmire SP, Dickerson EB, Scott AM, Bianco SR, Pettengill MJ, Meylemans H, Padilla M, Frazer-Abel AA, Akhtar N, Getzy DM, Wojcieszyn J, Breen M, Helfand SC, Modiano JF. Canine malignant hemangiosarcoma as a model of primitive angiogenic endothelium. J Transl Med 2004; 84:562-72. [PMID: 15064773 DOI: 10.1038/labinvest.3700080] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Hemangiosarcoma (HSA) is a common untreatable cancer of dogs that resembles human angiosarcoma. Detailed studies of these diseases have been historically hindered by the paucity of suitable reagents. Here, we show that expression of CD117 (c-Kit) can distinguish primitive (malignant) from mature (benign) proliferative endothelial lesions, and we describe eight independent cell lines derived from canine HSA explants. Endothelial origin was confirmed by sustained expression of surface CD105 (endoglin), CD146 (MUC18), and CD51/CD61 (alpha(v)beta(3) integrin). The cell lines showed anchorage-independent growth and were motile and invasive when cultured on a basement membrane matrix. They required endothelial growth factors for growth and survival, and they could be induced to form tubular structures resembling blood vessels when cultured under low calcium conditions. The formation of vessel-like structures was blocked by nicotine, and restored by FK506, suggesting that 'nuclear factor of activated T cells' activity prevents differentiation of these cells. In summary, these cell lines represent a unique and novel resource to improve our understanding of endothelial cell biology in general and canine HSA in particular.
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Affiliation(s)
- Susan P Fosmire
- AMC Cancer Research Center and Integrated Department of Immunology, University of Colorado Health Sciences Center, Denver, 80214, USA
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766
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Abstract
The pathogenesis of Peyronie's disease (induratio penis plastica) is unclear, but immune phenomena appear likely to be involved. Two cases are presented where the condition developed in temporal association with a virological response to highly active antiretroviral therapy (HAART) in men with HIV infection. It is suggested that this may represent another manifestation of immune restoration disease.
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Affiliation(s)
- G D Rogers
- Health in Human Diversity Unit, Department of General Practice, University of Adelaide, Adelaide, SA 5005, Australia.
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767
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López-Rodríguez C, Antos CL, Shelton JM, Richardson JA, Lin F, Novobrantseva TI, Bronson RT, Igarashi P, Rao A, Olson EN. Loss of NFAT5 results in renal atrophy and lack of tonicity-responsive gene expression. Proc Natl Acad Sci U S A 2004; 101:2392-7. [PMID: 14983020 PMCID: PMC356961 DOI: 10.1073/pnas.0308703100] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The transcription factor NFAT5/TonEBP, a member of the NFAT/Rel family of transcription factors, has been implicated in diverse cellular responses, including the response to osmotic stress, integrin-dependent cell migration, T cell activation, and the Ras pathway in Drosophila. To clarify the in vivo role of NFAT5, we generated NFAT5-null mice. Homozygous mutants were genetically underrepresented after embryonic day 14.5. Surviving mice manifested a progressive and profound atrophy of the kidney medulla with impaired activation of several osmoprotective genes, including those encoding aldose reductase, Na+/Cl--coupled betaine/gamma-aminobutyric acid transporter, and the Na+/myo-inositol cotransporter. The aldose reductase gene is controlled by a tonicity-responsive enhancer, which was refractory to hypertonic stress in fibroblasts lacking NFAT5, establishing this enhancer as a direct transcriptional target of NFAT5. Our findings demonstrate a central role for NFAT5 as a tonicity-responsive transcription factor required for kidney homeostasis and function.
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Affiliation(s)
- Cristina López-Rodríguez
- Department of Pathology, Harvard Medical School and Center for Blood Research, Institute for Biomedical Research, 200 Longwood Avenue, Boston MA 02115, USA
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768
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Ramírez A, Faupel J, Goebel I, Stiller A, Beyer S, Stöckle C, Hasan C, Bode U, Kornak U, Kubisch C. Identification of a novel mutation in the coding region of the grey-lethal geneOSTM1in human malignant infantile osteopetrosis. Hum Mutat 2004; 23:471-6. [PMID: 15108279 DOI: 10.1002/humu.20028] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Autosomal recessive malignant infantile osteopetrosis (ARO) is characterized by severe osteosclerosis, pathologic fractures, hepatosplenomegaly, and pancytopenia. The pathophysiological basis is inadequate bone resorption due to osteoclast dysfunction. In the majority of cases, mutations in either of two human genes cause this fatal disorder: TCIRG1, encoding a subunit of the osteoclast H(+)-ATPase, and the voltage-gated chloride channel gene CLCN7. We excluded both genes in a small inbred family with malignant infantile osteopetrosis and undertook linkage analysis of several candidate loci that are involved in murine osteopetrosis. A region spanning more than 20 cM between the markers D6S1717 and D6S1608 on chromosome 6q21 was found to be homozygous in the affected child. This locus is syntenic to the genomic region harboring the gene for the osteopetrotic mutant mouse grey-lethal (gl). Recently, mutations in a novel gene of unknown function were described in the grey-lethal mouse and in one human patient. Mutation screening of the grey-lethal gene (OSTM1), revealed a homozygous 2-bp deletion in exon 2 (c.415_416delAG) in the affected child. No mutations could be found in six independent ARO patients who had tested negative for mutations in TCIRG1 and CLCN7. In summary, we describe the identification of a novel mutation in the coding sequence of the human grey-lethal gene, which is the second OSTM1 mutation found in human ARO, confirming the involvement of this gene in the pathogenesis of this severe bone disease.
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769
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Wang H, Fu W, Im JH, Zhou Z, Santoro SA, Iyer V, DiPersio CM, Yu QC, Quaranta V, Al-Mehdi A, Muschel RJ. Tumor cell alpha3beta1 integrin and vascular laminin-5 mediate pulmonary arrest and metastasis. J Cell Biol 2004; 164:935-41. [PMID: 15024036 PMCID: PMC2172296 DOI: 10.1083/jcb.200309112] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 02/10/2004] [Indexed: 11/22/2022] Open
Abstract
Arrest of circulating tumor cells in distant organs is required for hematogenous metastasis, but the tumor cell surface molecules responsible have not been identified. Here, we show that the tumor cell alpha3beta1 integrin makes an important contribution to arrest in the lung and to early colony formation. These analyses indicated that pulmonary arrest does not occur merely due to size restriction, and raised the question of how the tumor cell alpha3beta1 integrin contacts its best-defined ligand, laminin (LN)-5, a basement membrane (BM) component. Further analyses revealed that LN-5 is available to the tumor cell in preexisting patches of exposed BM in the pulmonary vasculature. The early arrest of tumor cells in the pulmonary vasculature through interaction of alpha3beta1 integrin with LN-5 in exposed BM provides both a molecular and a structural basis for cell arrest during pulmonary metastasis.
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Affiliation(s)
- Hui Wang
- Dept. of Pathology, Rm. 916D ARC, Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA
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770
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Yamaguchi K, Itoh K, Ohnishi N, Itoh Y, Baum C, Tsuji T, Nagao T, Higashitsuji H, Okanoue T, Fujita J. Engineered long terminal repeats of retroviral vectors enhance transgene expression in hepatocytes in vitro and in vivo. Mol Ther 2004; 8:796-803. [PMID: 14599813 DOI: 10.1016/j.ymthe.2003.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To analyze the important elements for retroviral expression in hepatocytes, cis-acting elements in the U3 region of the long terminal repeat (LTR) of the polycythemic strain of spleen focus-forming virus (SFFVp) were analyzed in a hepatocellular carcinoma cell line. Two cis-acting elements located within the upstream region of the direct repeat, which positively regulated retroviral expression, were identified. Transcription factors NFAT5 and Sp1, which are ubiquitously expressed in a variety of tissues, bound to these elements. To increase specificity without lowering the potency of retroviral expression in hepatocytes, these elements were replaced by a sequence derived from the hepatitis B virus enhancer II region. Novel vectors, SF-Hep3 and SF-Hep5 (SFFVp-based vector for hepatocytes 3 and 5), were developed with these engineered LTRs. The engineered LTRs of these vectors enhanced the retroviral expression only in hepatocellular carcinoma cell lines in vitro. These vectors also increased transgene expression 4- to 9-fold or 3.5- to 5-fold in comparison with a Moloney murine leukemia virus-based vector or a vector containing the wild-type LTR of SFFVp, respectively, in murine hepatocytes in vivo.
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Affiliation(s)
- Kanji Yamaguchi
- Department of Clinical Molecular Biology, Faculty of Medicine, Kyoto University, 606-8507, Kyoto, Japan
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771
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Escher R, Jones A, Hagos F, Carmichael C, Horwitz M, Olopade OI, Scott HS. Chromosome band 16q22-linked familial AML: Exclusion of candidate genes, and possible disease risk modification byNQO1 polymorphisms. Genes Chromosomes Cancer 2004; 41:278-82. [PMID: 15334552 DOI: 10.1002/gcc.20084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Analyses of chromosomal translocation and inversion breakpoints in sporadic acute myeloid leukemias have identified many transcription factors as playing a role in leukemogenesis. Studies of families with a Mendelian predisposition to hematological malignancies have identified the gene coding for the transcription factor RUNX1 as a leukemia-predisposing gene involved in the first steps of leukemogenesis. Using two families, another autosomal dominant familial leukemia locus was linked to chromosome band 16q22 where the CBFB gene maps. Although CBFB forms a core-binding factor transcriptional complex with RUNX1, previous analyses have excluded the CBFB gene as the leukemia-predisposing gene in these families. In the current study, we performed an extended molecular analysis in these families of the four other transcription factor genes in the 16q22 critical region as well as of two other genes with a known association with leukemia. Several previously undescribed but nonpathogenic sequence variants were identified. We demonstrated that the transcription factors E2F4, CTCF, NFATC3, and NFAT5, and the genes coding for NAD(P)H:quinone oxido-reductase 1 (NQO1) and for E-cadherin are not responsible for the leukemia susceptibility in these families. The presence of NQO1 polymorphisms may suggest a role for this gene in disease risk modification in these families.
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Affiliation(s)
- Robert Escher
- Genetics and Bioinformatics Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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772
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Berger P, Lepidi H, Drogoul-Vey MP, Poizot-Martin I, Drancourt M. Mycobacterium avium brain abscess at the initiation of highly active antiretroviral therapy. Eur J Clin Microbiol Infect Dis 2003; 23:142-4. [PMID: 14689317 DOI: 10.1007/s10096-003-1070-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- P Berger
- Unité des Rickettsies CNRS UMR 6020, IFR 48, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille Cédex 05, France
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773
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Lipscomb EA, Dugan AS, Rabinovitz I, Mercurio AM. Use of RNA interference to inhibit integrin (alpha6beta4)-mediated invasion and migration of breast carcinoma cells. Clin Exp Metastasis 2003; 20:569-76. [PMID: 14598892 DOI: 10.1023/a:1025819521707] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The application of small interfering RNA (siRNA) oligonucleotides to silence gene expression has profound implications for the intervention of human diseases including cancer. Using this technique, we explored the possibility that the alpha6beta4 integrin, a laminin adhesion receptor with a recognized role in the invasive phenotype of many carcinomas, represents a potential therapeutic target to inhibit the migration and invasion of carcinoma cells. We found that siRNA oligonucleotides targeted to either subunit of the alpha6beta4 integrin reduced cell surface expression of this integrin and resulted in decreased invasion of MDA-MB-231 breast carcinoma cells. Interestingly, reduced alpha6beta4 expression also promoted decreased migration on non-laminin substrata indicating that this integrin can function in a ligand-independent manner. In addition, the absence of beta4 expression in these cells augmented the formation of alpha6beta1 heterodimers and increased adhesion to laminin-1. Taken together, these results substantiate the importance of the alpha6beta4 integrin in invasion and migration that has been demonstrated previously by expression of the beta4 subunit in beta4-deficient cell lines and by function blocking antibodies. Furthermore, these data suggest that the utilization of siRNA oligonucleotides to reduce the expression of the alpha6beta4 integrin may be a useful approach to prevent carcinoma cell progression.
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Affiliation(s)
- Elizabeth A Lipscomb
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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774
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Abstract
Tonicity-responsive enhancer binding protein (TonEBP), also known as NFAT5, belongs to the Rel family of transcriptional activators. In the kidney medulla and thymus, TonEBP plays a major role in protecting renal cells and T cells from the deleterious effects of ambient hypertonicity. TonEBP is stimulated by hypertonicity via several pathways: increased expression of protein, nuclear translocation, and increased transactivation. In this study, we identified five domains of TonEBP involved in transactivation. The two conserved glutamine repeats were not involved in transactivation. There were three activation domains that could stimulate transcription independently. In addition, there were two modulation domains that potentiated the activity of the activation domains. One of the activation domains is unique to a splice isoform that is more active than others, indicating that alternative splicing can affect the activity of TonEBP. Another activation domain and one of the modulation domains were stimulated by hypertonicity. All the five domains acted in synergy in every combination. Although overall phosphorylation of TonEBP increased in response to hypertonicity, phosphorylation of the activation and modulation domains did not increase in isolation. In sum, TonEBP possesses far more elaborate domains involved in transactivation compared with other Rel proteins.
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Affiliation(s)
- Sang Do Lee
- Department of Medicine, University of Maryland, Baltimore, Maryland 21201, USA
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775
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Zhang Z, Ferraris JD, Brooks HL, Brisc I, Burg MB. Expression of osmotic stress-related genes in tissues of normal and hyposmotic rats. Am J Physiol Renal Physiol 2003; 285:F688-93. [PMID: 12824075 DOI: 10.1152/ajprenal.00028.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
TonEBP is a transcription factor that, when activated by hypertonicity, increases transcription of genes, including those involved in organic osmolyte accumulation. Surprisingly, it is expressed in virtually all tissues, including many never normally exposed to hypertonicity. We measured TonEBP mRNA (real-time PCR) and protein (Western blot analysis) in tissues of control (plasma osmolality 294 +/- 1 mosmol/kgH2O) and hyposmotic (dDAVP infusion plus water loading for 3 days, 241 +/- 2 mosmol/kgH2O) rats to test whether the ubiquitous expression of TonEBP mRNA is osmotically regulated around the normal plasma osmolality. TonEBP protein is reduced by hyposmolality in thymus and liver, but not in brain, and is not detected in heart and skeletal muscle. TonEBP mRNA decreases in brain and liver but is unchanged in other tissues. There are no general changes in mRNA of TonEBP-mediated genes: aldose reductase (AR) does not change in any tissue, betaine transporter (BGT1) decreases only in liver, taurine transporter (TauT) only in brain and thymus, and inositol transporter (SMIT) only in skeletal muscle and liver. Heat shock protein (Hsp)70-1 and Hsp70-2 mRNA increase greatly in most tissues, which cannot be attributed to decreased TonEBP activity. The conclusions are as follows: 1) TonEBP protein or mRNA expression is reduced by hyposmolality in thymus, liver, and brain. 2) TonEBP protein and mRNA expression are differentially regulated in some tissues. 3) Although AR, SMIT, BGT1, and TauT are regulated by TonEBP in renal medullary cells, other sources of regulation may predominate in other tissues. 4) TonEBP abundance and activity are regulated by factors other than tonicity in some tissues.
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Affiliation(s)
- Zheng Zhang
- Laboratory of Kidney and Electrolyte Metabolism, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA.
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776
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Affiliation(s)
- Patrick G Hogan
- The Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA
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777
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Abstract
CD4 is a coreceptor on T helper (Th) cells that interacts with MHC class II molecules (MHCII). The mechanisms mediating the effects of CD4 on responses by T helper cells to stimulation of the antigen-specific T cell receptor (TCR) are still poorly understood. Here, we demonstrate T cell costimulation via CD4 signalling independent of T cell receptor-mediated signals. Incubation of T helper cells with peptide mimetics of the CD4-binding region on the MHC class II beta2 domain caused intracellular calcium mobilization in the absence of antigen or other T cell receptor stimuli. Engagement of CD4 by peptide mimetics or wild-type MHC class II, but not by mutant MHC class II molecules incapable of engaging CD4, inhibited the T cell receptor-mediated increase in cyclic AMP (cAMP) concentrations in T helper cells. CD4-mediated signals activated cyclic AMP phosphodiesterases (PDEs) and inhibited adenylyl cyclase. Full activation and clonal expansion of antigen-stimulated T helper cells required the CD4-mediated regulation of cyclic AMP. Our results suggest a costimulatory mechanism of CD4 function that acts on the second messengers, calcium and cyclic AMP.
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Affiliation(s)
- Wenhong Zhou
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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778
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Abstract
HIV infection results in formidable immune dysfunction, widely affecting the immune system, but typified by T lymphopenia. This dysfunction includes a perturbed immune response to several persistent viruses that have a propensity to cause tumors. Effective control of HIV replication by highly active antiretroviral therapy (HAART) results in regeneration of the damaged immune system, and recent advances have allowed this immune reconstitution to be better defined. This article describes the immunodeficiency caused by HIV and the response of the immune system to HAART, with specific reference to the immune response to cancers associated with HIV infection.
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Affiliation(s)
- Paul Robertson
- AIDS Research Center, Massachusetts General Hospital, Harvard Medical School 149, 13th Street, Room 5212, Boston, MA 02109, USA
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779
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Abstract
NFAT5/TonEBP, the most recently described member of the rel/NFkappaB/NFAT family of signal-dependent transcription factors, is activated by extracellular hypertonicity-a cellular stress of particular and perhaps unique physiologic relevance to cells of the renal medulla. Accumulating evidence suggests that NFAT5/TonEBP also functions in vivo under isotonic conditions as part of a ubiquitous regulatory mechanism that senses and adjusts available intracellular volume during cell growth to establish an intracellular environment appropriate for optimal cell proliferation.
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Affiliation(s)
- Steffan N Ho
- Department of Pathology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0644, USA.
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780
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Abstract
The calcineurin/nuclear factor of activated T cells (NFAT) signaling pathway is best known for its role in T lymphocyte activation. However, it has become increasingly apparent that this signaling pathway is also involved in the regulation of cell growth and development in a wide variety of different tissues and cell types. Here we have investigated the effects of sustained NFATc1 signaling on the growth and differentiation of the murine 3T3-L1 preadipocyte cell line. Remarkably, we find that expression of a constitutively active NFATc1 mutant (caNFATc1) in these immortalized cells inhibits their differentiation into mature adipocytes and causes them to adopt a transformed cell phenotype, including loss of contact-mediated growth inhibition, reduced serum growth requirements, protection from growth factor withdrawal-induced apoptosis, and formation of colonies in semisolid media. Furthermore, we find that caNFATc1-expressing cells acquire growth factor autonomy and are able to proliferate even in the complete absence of serum. We provide evidence that this growth factor independence is caused by the NFATc1-dependent production of a soluble heat-labile autocrine factor that is capable of promoting the growth and survival of wild type 3T3-L1 cells as well as potently inhibiting their differentiation into mature adipocytes. Finally, we demonstrate that cells expressing caNFATc1 form tumors in nude mice. Taken together, these results indicate that deregulated NFATc1 activity is able to induce the immortalized 3T3-L1 preadipocyte cell line to acquire the well established hallmarks of cellular transformation and thereby provide direct evidence for the oncogenic potential of the NFATc1 transcription factor.
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Affiliation(s)
- Joel W Neal
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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781
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Bommireddy R, Saxena V, Ormsby I, Yin M, Boivin GP, Babcock GF, Singh RR, Doetschman T. TGF-beta 1 regulates lymphocyte homeostasis by preventing activation and subsequent apoptosis of peripheral lymphocytes. J Immunol 2003; 170:4612-22. [PMID: 12707339 DOI: 10.4049/jimmunol.170.9.4612] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TGF-beta1 plays an important role in the maintenance of immune homeostasis and self-tolerance. To determine the mechanism by which TGF-beta1 prevents autoimmunity we have analyzed T cell activation in splenic lymphocytes from TGF-beta1-deficient mice. Here we demonstrate that unlike wild-type splenic lymphocytes, those from Tgfb1(-/-) mice are hyporesponsive to receptor-mediated mitogenic stimulation, as evidenced by diminished proliferation and reduced IL-2 production. However, they have elevated levels of IFN-gamma and eventually undergo apoptosis. Receptor-independent stimulation of Tgfb1(-/-) T cells by PMA plus ionomycin induces IL-2 production and mitogenic response, and it rescues them from anergy. Tgfb1(-/-) T cells display decreased CD3 expression; increased expression of the activation markers LFA-1, CD69, and CD122; and increased cell size, all of which indicate prior activation. Consistently, mutant CD4(+) T cells have elevated intracellular Ca(2+) levels. However, upon subsequent stimulation in vitro, increases in Ca(2+) levels are less than those in wild-type cells. This is also consistent with the anergic phenotype. Together, these results demonstrate that the ex vivo proliferative hyporesponsiveness of Tgfb1(-/-) splenic lymphocytes is due to prior in vivo activation of T cells resulting from deregulated intracellular Ca(2+) levels.
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Affiliation(s)
- Ramireddy Bommireddy
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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782
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Kohler JJ, Tuttle DL, Coberley CR, Sleasman JW, Goodenow MM. Human immunodeficiency virus type 1 (HIV-1) induces activation of multiple STATs in CD4+ cells of lymphocyte or monocyte/macrophage lineages. J Leukoc Biol 2003; 73:407-16. [PMID: 12629155 DOI: 10.1189/jlb.0702358] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) impacts the activation state of multiple lineages of hematopoietic cells. Chronic HIV-1 infection among individuals with progressive disease can be associated with increased levels of activated signal transducers and activators of transcription (STATs) in peripheral blood mononuclear cells. To investigate interactions between HIV-1 and CD4(+) cells, activated, phosphorylated STAT proteins in nuclear extracts from lymphocytic and promonocytic cell lines as well as primary monocyte-derived macrophages were measured. Levels of activated STATs increased six- to tenfold in HUT78 and U937 cells within 2 h following exposure to virions. The response to virus was dose-dependent, but kinetics of activation was delayed relative to interleukin-2 or interferon-gamma. Activation of STAT1, STAT3, and STAT5 occurred with diverse viral envelope proteins, independent of coreceptor use or viral replication. Envelope-deficient virions had no effect on STAT activation. Monoclonal antibody engagement of CD4 identified a novel role for CD4 as a mediator in the activation of multiple STATs. Results provide a model for HIV-1 pathogenesis in infected and noninfected hematopoietic cells.
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Affiliation(s)
- James J Kohler
- Department of Pathology, Immunology, and Laboratory Medicine, Division of Immunology and Infectious Diseases, College of Medicine, University of Florida, Gainesville 32610, USA
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783
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Abstract
Although they were used initially as non-specific immunosuppressants in transplantation, CD3-specific monoclonal antibodies have elicited renewed interest owing to their capacity to induce immune tolerance. In mouse models of autoimmune diabetes, CD3-specific antibodies induce stable disease remission by restoring tolerance to pancreatic beta-cells. This phenomenon was extended recently to the clinic--preservation of beta-cell function in recently diagnosed patients with diabetes was achieved by short-term administration of a CD3-specific antibody. CD3-specific antibodies arrest ongoing disease by rapidly clearing pathogenic T cells from the target. Subsequently, they promote long-term T-cell-mediated active tolerance. Recent data indicate that transforming growth factor-beta-dependent CD4+CD25+ regulatory T cells might have a central role in this effect.
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Affiliation(s)
- Lucienne Chatenoud
- Centre de l'Association Claude Bernard sur les Maladies Autoimmunes and Hôpital Necker Enfants Malades IRNEM, 161 Rue de Sèvres, 75015 Paris, France.
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784
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Scimeca JC, Quincey D, Parrinello H, Romatet D, Grosgeorge J, Gaudray P, Philip N, Fischer A, Carle GF. Novel mutations in the TCIRG1 gene encoding the a3 subunit of the vacuolar proton pump in patients affected by infantile malignant osteopetrosis. Hum Mutat 2003; 21:151-7. [PMID: 12552563 DOI: 10.1002/humu.10165] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fifty percent of the infantile malignant osteopetrosis (IMO) cases reported in the literature present mutations in the TCIRG1 gene encoding the 116-kDa osteoclast specific subunit of the vacuolar proton ATPase (ATP6I). In this study, we identified four novel mutations in a series of six IMO patients. All of these mutations correspond to single nucleotide changes and affect splice acceptor or donor sites, resulting in aberrant transcription products. We report also a missense mutation, G405R, previously described in several Costa Rican patients. This independent finding suggests that the highly conserved residue at amino acid 405 plays a critical role in the a3 subunit function. Finally, the results of this study were used to provide a prenatal diagnosis to one of the families.
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MESH Headings
- Chromosomes, Human, Pair 11/genetics
- Female
- Genes, Recessive/genetics
- Genetic Markers/genetics
- Genotype
- Haplotypes/genetics
- Humans
- Infant
- Infant, Newborn
- Infant, Newborn, Diseases/diagnosis
- Infant, Newborn, Diseases/genetics
- Infant, Newborn, Diseases/mortality
- Male
- Mutation/genetics
- Organ Specificity/genetics
- Osteoclasts/classification
- Osteoclasts/metabolism
- Osteopetrosis/diagnosis
- Osteopetrosis/genetics
- Osteopetrosis/mortality
- Pedigree
- Prenatal Diagnosis
- Protein Subunits/genetics
- Vacuolar Proton-Translocating ATPases/genetics
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Affiliation(s)
- Jean-Claude Scimeca
- Instabilité et Altérations des Génomes, UMR6549 CNRS/UNSA, Faculté de Médecine de l'Université de Nice-Sophia Antipolis, Nice, France
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785
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Abstract
TonEBP is a transcriptional activator that is expressed throughout development in many tissues and cell types. In the kidney medulla, TonEBP appears to be an important local regulator of differentiation by virtue of stimulating several genes. To study the function of TonEBP, two small interfering RNA (siRNA) duplexes were developed that reduced TonEBP expression effectively via RNA interference. The silencing lasted only 3 d after introduction of the TonEBP-siRNA's. As expected, TonEBP-driven reporter gene expression and expression of the sodium/myo-inositol cotransproter (SMIT), aldose reductase (AR) and heat shock protein 70 (HSP70) mRNA were significantly decreased in cells where TonEBP expression was silenced. These data provide direct evidence that the SMIT, AR, and HSP70 genes are targets of TonEBP, although the potential role of other proteins, such as accessory proteins, cannot be excluded. The TonEBP-siRNA is an effective tool that should prove useful in the investigation of loss-of-function relationship in cells.
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Affiliation(s)
- Ki Young Na
- Division of Nephrology, Johns Hopkins University, Baltimore, Maryland, USA
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786
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Ferraris JD, Persaud P, Williams CK, Chen Y, Burg MB. cAMP-independent role of PKA in tonicity-induced transactivation of tonicity-responsive enhancer/ osmotic response element-binding protein. Proc Natl Acad Sci U S A 2002; 99:16800-5. [PMID: 12482947 PMCID: PMC139224 DOI: 10.1073/pnas.222659799] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Hypertonicity-induced increase in activity of the transcription factor tonicity-responsive enhancer/osmotic response element-binding protein (TonEBP/OREBP) protects renal cells by increasing transcription of genes, including those involved in increased accumulation of organic osmolytes. We previously showed that hypertonicity increases transactivating activity of TonEBP/OREBP. Assay with a binary GAL4 transactivation system showed that the 984 C-terminal amino acids of TonEBP/OREBP (amino acids 548-1531) contain a tonicity-dependent transactivation domain (TAD). Also, amino acids 548-1531 undergo tonicity-dependent phosphorylation, and some inhibitors of protein kinases reduce the tonicity-dependent transactivation. In the present studies we examined the role of protein kinase A (PKA). RESULTS (i) An inhibitor of PKA (H89) reduces tonicity-dependent increases in transactivation, ORE/TonE reporter activity, and induction of aldose reductase and betaine transporter mRNAs. (ii) Overexpression of the catalytic subunit of PKA (PKAc) increases transactivation activity of amino acids 548-1531 and activity of an ORE/TonE reporter. The increases are much greater under isotonic than under hypertonic conditions. (iii) A dominant-negative PKAc reduces activity of an ORE/TonE reporter. (iv) PKAc activity increases with tonicity but cAMP does not. (v) TonEBP/OREBP and PKAc coimmunoprecipitate. (vi) amino acids 872-1271, including N- and C-terminal polyglutamine stretches, demonstrate tonicity-dependent transactivation, albeit less than amino acids 548-1531, and a similar role for PKA. CONCLUSIONS (i) PKA plays an important role in TonEBP/OREBP activation of tonicity-dependent gene expression; (ii) PKA activation of TonEBP/OREBP appears to be cAMP-independent; and (iii) amino acids 872-1271 are sufficient for tonicity-dependent transactivation of TonEBP/OREBP.
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Affiliation(s)
- Joan D Ferraris
- Laboratory of Kidney and Electrolyte Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
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787
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Bernard F, Jaleco S, Dardalhon V, Steinberg M, Yssel H, Noraz N, Taylor N, Kinet S. Ex vivo isolation protocols differentially affect the phenotype of human CD4+ T cells. J Immunol Methods 2002; 271:99-106. [PMID: 12445733 DOI: 10.1016/s0022-1759(02)00412-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Leukemic T cell lines have facilitated signal transduction studies but their physiological relevance is restricted. The use of primary T lymphocytes overcomes this limitation but it has long been speculated that methodological aspects of blood collection and the isolation procedure modify the phenotype of the cell. Here we demonstrate that several characteristics of human peripheral T cells are affected by the selection conditions. A significantly higher induction of the chemokine receptor CXCR4 was observed on CD4+ lymphocytes isolated by sheep red blood cell (SRBC) rosetting and CD4 MicroBeads as compared with positively selected CD4+ cells where the antibody/bead complex was immediately detached. These latter cells expressed CXCR4 at levels equivalent to that observed on CD4+ lymphocytes obtained by negative antibody-mediated selection. Furthermore, CD4+ cells isolated by SRBC rosetting and CD4 MicroBeads formed aggregates upon in vitro culture. CD4+ lymphocytes obtained by SRBC rosetting as well as those isolated following positive selection demonstrated basal phosphorylation of the extracellular signal-regulated kinase (ERK)-2. Altogether these data suggest that certain discrepancies concerning signal transduction in primary human T cells can be attributed to the selection conditions. Thus, it is essential to establish the parameters influenced by the isolation protocol in order to fully interpret T cell responses to antigens, chemokines, and cytokines.
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Affiliation(s)
- Frédéric Bernard
- Institut de Génétique Moléculaire de Montpellier, UMR 5535/IFR 22, 1919 Route de Mende, F34293 Montpellier, Cedex 5, France.
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788
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Almeida CAM, Price P, French MAH. Immune activation in patients infected with HIV type 1 and maintaining suppression of viral replication by highly active antiretroviral therapy. AIDS Res Hum Retroviruses 2002; 18:1351-5. [PMID: 12487806 DOI: 10.1089/088922202320935429] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Immune activation associated with HIV infection declines after highly active antiretroviral therapy (HAART), but may persist or recur in some patients. It is not clear whether this reflects a resurgence of HIV replication or another cause of immune activation, such as inflammatory reactions to opportunistic pathogens (immune restoration disease [IRD]). Here, we studied plasma and cellular immune activation markers in adult HIV-1 patients who had received HAART for >12 months and maintained plasma HIV RNA levels of <400 copies/ml for >6 months. Plasma interleukin 1 receptor antagonist and tumor necrosis factor receptor I levels were similar in patients and HIV-negative control subjects, but the highest levels occurred mainly in patients with a history of IRD. In contrast, expression of HLA-DR and CD38 on monocytes and of HLA-DR on CD8(+) T cells was higher in patients than in control subjects. Thus, cellular markers of immune activation are abnormal in some patients with a good virological response to HAART, and abnormalities of plasma immune activation markers correlate with a history of IRD.
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Affiliation(s)
- Coral-Ann M Almeida
- Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital, WA 6001, Australia
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789
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Price P, Morahan G, Huang D, Stone E, Cheong KYM, Castley A, Rodgers M, McIntyre MQ, Abraham LJ, French MA. Polymorphisms in cytokine genes define subpopulations of HIV-1 patients who experienced immune restoration diseases. AIDS 2002; 16:2043-7. [PMID: 12370503 DOI: 10.1097/00002030-200210180-00009] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To further elucidate the immunopathogenesis of immune restoration diseases (IRD) in HIV patients responding to antiretroviral therapy and determine whether IRD associated with different opportunistic pathogens involve distinct immunopathological mechanisms. DESIGN DNA samples from patients with a range of IRD were typed for polymorphic loci in genes encoding immune-mediators. METHODS PCR-restriction fragment length polymorphism assays were used to type loci in the and genes. Alleles of a microsatellite in the CD30 promoter were determined by capillary electrophoresis. RESULTS Only 8% of patients with IRD associated with a herpesvirus infection carried IL12B-3'UTR*2, compared with 42-54% of patients with other or no IRD. Patients with IRD arising from mycobacterial infection rarely carried IL6-174*C (36% versus 61-71%) and never carried TNFA-308*2 (0% versus 23-52%). TNFA-308*2 was carried by 52% of patients who experienced IRD associated with a herpesvirus infection, as several patients with exacerbations of cytomegalovirus retinitis carried this as part of a HLA-A2,B44 haplotype. Polymorphisms in and showed no distinct patterns. CONCLUSIONS Distinct cytokine-mediated mechanisms contribute to IRD initiated by herpesvirus and mycobacterial infections.
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Affiliation(s)
- Patricia Price
- Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital, Australia
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790
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Dumont C, Blanchard N, Di Bartolo V, Lezot N, Dufour E, Jauliac S, Hivroz C. TCR/CD3 down-modulation and zeta degradation are regulated by ZAP-70. J Immunol 2002; 169:1705-12. [PMID: 12165490 DOI: 10.4049/jimmunol.169.4.1705] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TCR down-modulation following binding to MHC/peptide complexes is considered to be instrumental for T cell activation because it allows serial triggering of receptors and the desensitization of stimulated cells. We studied CD3/TCR down-modulation and zeta degradation in T cells from two ZAP-70-immunodeficient patients. We show that, at high occupancy of the TCR, down-modulation of the CD3/TCR is comparable whether T cells express or do not express ZAP-70. However, if TCR occupancy was low, we found that CD3/TCR was down-regulated to a lesser extent in ZAP-70-negative than in ZAP-70-positive T cells. We studied CD3/TCR down-modulation in P116 (a ZAP-70-negative Jurkat cell-derived clone) and in P116 transfected with genes encoding the wild-type or a kinase-dead form of ZAP-70. Down-modulation of the TCR at high occupancy did not require ZAP-70, whereas at low TCR occupancy down-modulation was markedly reduced in the absence of ZAP-70 and in cells expressing a dead kinase mutant of ZAP-70. Thus, the presence of ZAP-70 alone is not sufficient for down-modulation; the kinase activity of this molecule is also required. The degradation of zeta induced by TCR triggering is also severely impaired in T cells from ZAP-70-deficient patients, P116 cells, and P116 cells expressing a kinase-dead form of ZAP-70. This defect in TCR-induced zeta degradation is observed at low and high levels of TCR occupancy. Our results identify ZAP-70, a tyrosine kinase known to be crucial for T cell activation, as a key player in TCR down-modulation and zeta degradation.
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Affiliation(s)
- Céline Dumont
- Institut National de la Santé et de la Recherche Médicale, Unité 520, Institut Curie, Institut Pasteur, Paris, France
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791
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Harding S, Lipp P, Alexander DR. A therapeutic CD4 monoclonal antibody inhibits TCR-zeta chain phosphorylation, zeta-associated protein of 70-kDa Tyr319 phosphorylation, and TCR internalization in primary human T cells. J Immunol 2002; 169:230-8. [PMID: 12077249 DOI: 10.4049/jimmunol.169.1.230] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The molecular mechanisms mediating the inhibitory effects of a humanized CD4 mAb YHB.46 on primary human CD4(+) T cells were investigated. Preincubation of T cells with soluble YHB.46 caused a general inhibition of TCR-stimulated protein tyrosine phosphorylation events, including a reduction in phosphorylation of p95(vav), linker for activation of T cells, and Src homology 2 domain-containing leukocyte protein of 76-kDa signaling molecules. A marked reduction in activation of the Ras/mitogen-activated protein kinase pathway was also observed. Examination of the earliest initiation events of TCR signal transduction showed that YHB.46 inhibited TCR-zeta chain phosphorylation together with recruitment and tyrosine phosphorylation of the zeta-associated protein of 70-kDa tyrosine kinase, particularly at Tyr(319), as well as reduced recruitment of p56(lck) to the TCR-zeta and zeta-associated protein of 70-kDa complex. These inhibitory events were associated with inhibition of TCR endocytosis. Our results show that the YHB.46 mAb is a powerful inhibitor of the early initiating events of TCR signal transduction.
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Affiliation(s)
- Susanne Harding
- Laboratories of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, United Kingdom
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792
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Abstract
The author hopes to convince the reader that the data presented argue for a stage during the development of IDDM when beta-cell destruction can be counteracted and tolerance to beta cells restored, provided the immune aggression is arrested. This argument constitutes a solid rationale for immunointervention in established IDDM, especially by using potent agents such as CD3. The future for the application of monoclonal antibodies not only in autoimmunity but also in transplantation is exiting. With the development of humanized monoclonal antibodies, therapeutic uses for them are likely to expand. Enormous progress has been made in the last 15 years, and it is likely that before a similar time period has elapsed, monoclonal antibodies will have become standard tools that will dispense the need for long-term immunosuppression and its inherent dangers in various clinical arenas.
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793
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Abstract
It is well established that non-depleting anti-CD4 monoclonal antibodies (mAb) have potent immunomodulatory properties in vivo and as such can induce a profound state of tolerance. Receptor blockade, CD4 modulation, or the transmission of a negative signal have all been proposed to explain their effects, however their precise mechanism of action, particularly at the level of cellular signaling, remains obscure. Experiments were thus carried out to examine the underlying mechanisms of action of two non-depleting anti-mouse CD4 mAb, YTS177 and KT6, which differ in their ability to modulate CD4 expression. The effects of the mAb were examined on CD4(+) T cells derived from D0.11.10 TCR transgenic mice. Functional studies revealed that both mAb could effectively block antigen-driven proliferation and IL-2 production but had only modest effects at higher peptide doses. Importantly, mAb pre-treatment of T cells stimulated by sub-optimal peptide seemed to induce an anergy-like state making them unresponsive to subsequent re-stimulation. Analysis of intracellular signaling demonstrated that certain key upstream events such as the phosphorylation of Zap-70 and LAT were also blocked by mAb pretreatment which may be due to interference with stable T cell-APC conjugate formation.
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Affiliation(s)
- Zoltán Fehérvári
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, GB
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794
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Abstract
Previously, we have demonstrated age-associated alterations in transmembrane signaling. One of the most reproducible alterations found in the immune response with aging is the decrease of lymphocyte proliferation on stimulation with various different mitogens. Here, we confirm that proliferative responses to stimulation with phytohaemagglutin (PHA), recombinant human IL-2, or anti-CD3 monoclonal antibody are all greater in the young (20-25 years) than old (60-87 years) population. We attempted to modulate the proliferative response using various agents acting at different levels of transmembrane signaling (pertussis toxin, cholera toxin, isoproterenol, PMA, Ca ionophore A23187), as well as at the level of the lymphocyte plasma membrane (methyl-beta-cyclodextrin, MBCD), or by using antioxidant vitamins (Vitamin E or C). None of these agents was able to restore effectively the proliferative response of lymphocytes from the aged to the level of young subjects. Even the combination of A23187 and PMA acting directly on calcium metabolism and protein kinase C activity was insufficient to restore the decreased mitogenic capacity of T cells from elderly subjects. Cyclodextrin, which decreases the cholesterol content of the membrane, increased the proliferative response of lymphocytes of elderly subjects, but not to the level of the young. Vitamin E had a very strong inhibitory effect on lymphocyte stimulation in both the age groups, except in combination with MBCD in T cells of the elderly, while Vitamin C had no significant modulatory effect. MAPK ERK and p38 activation was found to be decreased with aging in T cells after anti-CD3 mAb stimulation. Vitamin E but not Vitamin C strongly inhibited MAPK ERK or p38 activation. The direct activation of certain molecules or the modulation of the cholesterol content of the membrane seems to be effective immunomodulatory interventions with aging.
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Affiliation(s)
- Nadine Douziech
- Centre de Recherche en Gérontologie et Gériatrie, Institut Universitaire de Gériatrie de Sherbrooke, 1036 rue Belvedère sud, Sherbrooke, Quebec, Canada J1H 4C4
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795
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Bès C, Briant-Longuet L, Cerruti M, De Berardinis P, Devauchelle G, Devaux C, Granier C, Chardès T, DeBerardinis P. Efficient CD4 binding and immunosuppressive properties of the 13B8.2 monoclonal antibody are displayed by its CDR-H1-derived peptide CB1. FEBS Lett 2001; 508:67-74. [PMID: 11707270 DOI: 10.1016/s0014-5793(01)03036-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A systematic exploration of the V(H)2/V(kappa)12-13 variable domains of the anti-CD4 monoclonal antibody (mAb) 13B8.2 was performed by the Spot method to screen for paratope-derived peptides (PDPs) demonstrating CD4 binding ability. Nine peptides, named CB1 to CB9, were identified, synthesized in a cyclic and soluble form and tested for binding to recombinant soluble CD4. Among them, CB1, CB2 and CB8 showed high anti-CD4 activity. Competition studies for CD4 binding indicated that PDPs CB1, CB8, and the parental mAb 13B8.2 recognized the same complementarity determining region (CDR)3-like loop region. PDP CB1 was shown to mimic the biological properties of 13B8.2 mAb in two independent cellular assays, demonstrating inhibitory activities in the micromolar range on antigen presentation and human immunodeficiency virus promoter activation. Our results indicate that the bioactive CDR-H1 PDP CB1 has retained a significant part of the parental 13B8.2 mAb properties and might be a lead for the design of anti-CD4 peptidomimetics of clinical interest.
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Affiliation(s)
- C Bès
- CNRS-UMR 5094, Faculté de Pharmacie, Institut de Biotechnologie et Pharmacologie, 15 avenue Charles Flahault, 34060 Montpellier Cedex 2, France
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796
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Gilbert C, Barabé F, Rollet-Labelle E, Bourgoin SG, McColl SR, Damaj BB, Naccache PH. Evidence for a role for SAM68 in the responses of human neutrophils to ligation of CD32 and to monosodium urate crystals. J Immunol 2001; 166:4664-71. [PMID: 11254726 DOI: 10.4049/jimmunol.166.7.4664] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
SAM68 (Src-associated in mitosis 68 kDa) is a member of the signal transduction of activator RNA novel gene family coding for proteins postulated to be involved in signal transduction and activation of RNA. It has been implicated through its phosphorylation status in the control of the transition from the G(1) to the S phases during mitosis. However, the implication and role of SAM68 in nonproliferative cells are unknown. The present study was initiated to examine the role of SAM68 in the phagocytic responses of the terminally differentiated human neutrophils. The results obtained show that SAM68 is present in human neutrophils and that it is tyrosine phosphorylated in response to stimulation by monosodium urate crystals or by ligation of CD32. Stimulation of neutrophils by these agonists decreases the association of SAM68 with Sepharose-conjugated poly-U beads. Additionally, the amount of immunoprecipitable SAM68 was modulated differentially after stimulation by monosodium urate crystals or by CD32 engagement indicating that the posttranslational modifications and/or protein associations of SAM68 induced by these two agonists differed. The results of this study provide evidence for an involvement of SAM68 in signal transduction by phagocytic agonists in human neutrophils and indicate that SAM68 may play a role in linking the early events of signal transduction to the posttranscriptional modulation of RNA.
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Affiliation(s)
- C Gilbert
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier de l'Universite Laval, Ste-Foy, Québec, Canada
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797
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Affiliation(s)
- L Briant
- Laboratoire Infections Rétrovirales et Signalisation Cellulaire, CNRS EP 2104, Montpellier, France
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798
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Bostik P, Mayne AE, Villinger F, Greenberg KP, Powell JD, Ansari AA. Relative resistance in the development of T cell anergy in CD4+ T cells from simian immunodeficiency virus disease-resistant sooty mangabeys. J Immunol 2001; 166:506-16. [PMID: 11123330 DOI: 10.4049/jimmunol.166.1.506] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Despite high viral loads, T cells from sooty mangabey (SM) monkeys that are naturally infected with SIV but remain clinically asymptomatic, proliferate and demonstrate normal Ag-specific memory recall CD4(+) T cell responses. In contrast, CD4(+) T cells from rhesus macaques (RM) experimentally infected with SIV lose Ag-specific memory recall responses and develop immunological anergy. To elucidate the mechanisms for these distinct outcomes of lentiviral infection, highly enriched alloreactive CD4(+) T cells from humans, RM, and SM were anergized by TCR-only stimulation (signal 1 alone) and subsequently challenged with anti-CD3/anti-CD28 Abs (signals 1 + 2). Whereas alloreactive CD4(+)T cells from humans and RM became anergized, surprisingly, CD4(+) T cells from SM showed marked proliferation and IL-2 synthesis after restimulation. This resistance to undergo anergy was not secondary to a global deficiency in anergy induction of CD4(+) T cells from SM since incubation of CD4(+) T cells with anti-CD3 alone in the presence of rapamycin readily induced anergy in these cells. The resistance to undergo anergy was reasoned to be due to the ability of CD4(+) T cells from SM to synthesize IL-2 when incubated with anti-CD3 alone. Analysis of phosphorylated kinases involved in T cell activation showed that the activation of CD4(+) T cells by signal 1 in SM elicited a pattern of response that required both signals 1 + 2 in humans and RM. This function of CD4(+) T cells from SM may contribute to the resistance of this species to SIV-induced disease.
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Affiliation(s)
- P Bostik
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
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799
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Abstract
Due to the limited efficacy of the current antiretroviral drug regimens in completely eradicating HIV and reconstituting the immune system, AIDS research is turning toward immune-based therapy to complement highly active antiretroviral therapy. Here we review potential mechanisms of protective cellular immunity and current HIV-specific immune-based strategies and discuss the rationale for novel hypothetical immunologic approaches for modulation of host antiviral immunity. One of the mechanisms by which the immune system exerts antiviral effects is via leukocyte generation of anti-HIV factors. Recent observations in this area of research suggest that non-HIV antigens can stimulate the in vitro production of anti-HIV activity by leukocytes from healthy uninfected individuals and HIV-infected patients. These findings may provide insights for the design of novel therapeutic or prophylactic approaches, which might contribute to modulating immune system control of HIV infection.
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Affiliation(s)
- L A Pinto
- Experimental Immunology Branch, National Institutes of Health, Bethesda, Maryland, 20892, USA
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800
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Semba I, Ishigami T, Sugihara K, Kitano M. Higher osteoclastic demineralization and highly mineralized cement lines with osteocalcin deposition in a mandibular cortical bone of autosomal dominant osteopetrosis type II: ultrastructural and undecalcified histological investigations. Bone 2000; 27:389-95. [PMID: 10962350 DOI: 10.1016/s8756-3282(00)00330-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this study we report on histological and ultrastructural investigations of the mandibular cortical bone in a case of autosomal dominant osteopetrosis type II complicated by mandibular osteomyelitis. Histologically, there was a marked increase in the number and size of osteoclasts on the inner bone surface. An undecalcified preparation showed a pair of deeply stained (highly demineralized) and stain-phobic (highly mineralized) layers on the bone surface just beneath the osteoclasts. The layers were incorporated into the bone matrix during the remodeling process as thickened cement lines. A contact microradiogram of the cortical bone revealed highly mineralized layers at the cement lines, which were closely correlated with immunohistochemical evidence of deposition of osteocalcin at the thickened cement lines. Ultrastructural examination showed that the osteoclasts had a typical clear zone, but they were deficient in ruffled border formation and had numerous lysosomal vacuoles containing dense substances. An electron-dense amorphous material layer was present on the bone surface just beneath the osteoclasts as well as at the cement lines. The layer was partly composed of a short fibrillar material, and it partially revealed the lamellar structure. Consequently, an osteoclastic malfunction might be primarily involved in the process of bone matrix resorption rather than demineralization, resulting in higher demineralization and abnormal material deposition on the bone surface and at the cement lines. Furthermore, evidence of active osteoclastic bone resorption with a brush border formation at the bone involved in the inflammatory lesion in this case suggests that the osteoclastic malfunction is influenced and recovered by a microenvironment such as inflammatory cytokines.
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Affiliation(s)
- I Semba
- Department of Oral Pathology, Kagoshima University Dental School, Kagoshima, Japan.
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