1001
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Rayner SA, King WJ, Comer RM, Isaacs JD, Hale G, George AJ, Larkin DF. Local bioactive tumour necrosis factor (TNF) in corneal allotransplantation. Clin Exp Immunol 2000; 122:109-16. [PMID: 11012626 PMCID: PMC1905741 DOI: 10.1046/j.1365-2249.2000.01339.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The aim of this study was to examine the kinetic profile of bioactive TNF levels in aqueous humour of rabbit eyes undergoing corneal allograft rejection and to investigate the effect of locally blocking TNF activity after corneal transplantation. In a rabbit corneal transplantation, endothelial allograft rejection was identified and correlated with increase in central graft thickness. Samples of aqueous humour obtained on alternate days following transplantation were tested for TNF mRNA and bioactive TNF protein. To investigate the effect of locally blocking TNF activity in allograft recipients, the fusion protein TNFR-Ig was administered by injections into the anterior chamber after transplantation. Pulsatile increases in levels of this cytokine were found in 14 of 15 allograft recipients. Peaks of TNF bioactivity preceded by varying intervals the observed onset of rejection in allograft recipients. TNF levels were not elevated in aqueous humour from corneal autograft recipient controls or in serum of allografted animals. mRNA levels were elevated before onset of and during clinically observed allograft rejection. In three of seven animals receiving TNFR-Ig injections on alternate days from day 8 to day 16 post-transplant, clear prolongation of corneal allograft survival was demonstrated. Bioactive TNF is present in aqueous humour following rabbit corneal allotransplantation. Rather than correlating directly with endothelial rejection onset, pulsatile peak levels of TNF precede and follow the observed onset of endothelial rejection. Blockade of TNF activity prolongs corneal allograft survival in some animals, indicating that this cytokine may be a suitable target in local therapy of corneal allograft rejection.
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Affiliation(s)
- S A Rayner
- Department of Immunology, Division of Medicine, Imperial College School of Medicine, Hammersmith Hospital, London
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1002
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Xavier KA, Eder PS, Giordano T. RNA as a drug target: methods for biophysical characterization and screening. Trends Biotechnol 2000; 18:349-56. [PMID: 10899816 DOI: 10.1016/s0167-7799(00)01464-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
RNA folds into complex structures that can interact specifically with effector proteins. These interactions are essential for various biological functions. In order to discover small molecules that can affect important RNA-protein complexes, a thorough analysis of the thermodynamics and kinetics of RNA-protein binding is required. This can facilitate the formulation of high-throughput screening strategies and the development of structure-activity relationships for compound leads. In addition to traditional methods, such as filter binding, gel mobility shift assay and various fluorescence techniques, newer methods such as surface plasmon resonance and mass spectrometry are being used for the study of RNA-protein interactions.
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Affiliation(s)
- K A Xavier
- Message Pharmaceuticals, Malvern, PA 19355, USA.
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1003
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Piecyk M, Wax S, Beck AR, Kedersha N, Gupta M, Maritim B, Chen S, Gueydan C, Kruys V, Streuli M, Anderson P. TIA-1 is a translational silencer that selectively regulates the expression of TNF-alpha. EMBO J 2000; 19:4154-63. [PMID: 10921895 PMCID: PMC306595 DOI: 10.1093/emboj/19.15.4154] [Citation(s) in RCA: 408] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
TIA-1 and TIAR are related proteins that bind to an AU-rich element (ARE) in the 3' untranslated region of tumor necrosis factor alpha (TNF-alpha) transcripts. To determine the functional significance of this interaction, we used homologous recombination to produce mutant mice lacking TIA-1. Although lipopolysaccharide (LPS)-stimulated macrophages derived from wild-type and TIA-1(-/-) mice express similar amounts of TNF-alpha transcripts, macrophages lacking TIA-1 produce significantly more TNF-alpha protein than wild-type controls. The half-life of TNF-alpha transcripts is similar in wild-type and TIA-1(-/-) macrophages, indicating that TIA-1 does not regulate transcript stability. Rather, the absence of TIA-1 significantly increases the proportion of TNF-alpha transcripts that associate with polysomes, suggesting that TIA-1 normally functions as a translational silencer. TIA-1 does not appear to regulate the production of interleukin 1 beta, granulocyte-macrophage colony-stimulating factor or interferon gamma, indicating that its effects are, at least partially, transcript specific. Mice lacking TIA-1 are hypersensitive to the toxic effects of LPS, indicating that this translational control pathway may regulate the organismal response to microbial stress.
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Affiliation(s)
- M Piecyk
- Division of Rheumatology and Immunology, Brigham and Women's Hospital, Smith 652, One Jimmy Fund Way, Boston, MA 02115, USA
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1004
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Abstract
TNF-alpha is a proinflammatory cytokine that has been implicated in the severity of different immune-regulated diseases including autoimmune diseases and transplantation. The gene for TNF-alpha is located within the MHC region on chromosome 6p21.3. This is a highly polymorphic region, and the TNF-alpha itself contains a large number of polymorphisms. Some of these polymorphisms form extended haplotypes with the HLA class I and II alleles. TNF polymorphisms have been investigated in different diseases and most often whenever there is an HLA association with the disease (for example IDDM and RA) association(s) with TNF polymorphisms has been described. There are many studies on the function of the TNF polymorphisms showing the influence of the different alleles on the in vitro and in vivo levels of TNF production. However, recent studies in animal models suggest that not only polymorphisms within the TNF cluster are important in the regulation of TNF production but also the receptors as well (TNF R). This suggests that investigating polymorphisms within the TNF cluster and TNF receptors will be important in understanding the role of TNF regulation in a given disease.
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Affiliation(s)
- A H Hajeer
- School of Epidemiological Sciences and School of Biological Sciences, University of Manchester M13 9PT, United Kingdom
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1005
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Kitani A, Fuss IJ, Nakamura K, Schwartz OM, Usui T, Strober W. Treatment of experimental (Trinitrobenzene sulfonic acid) colitis by intranasal administration of transforming growth factor (TGF)-beta1 plasmid: TGF-beta1-mediated suppression of T helper cell type 1 response occurs by interleukin (IL)-10 induction and IL-12 receptor beta2 chain downregulation. J Exp Med 2000; 192:41-52. [PMID: 10880525 PMCID: PMC1887715 DOI: 10.1084/jem.192.1.41] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In this study, we show that a single intranasal dose of a plasmid encoding active transforming growth factor beta1 (pCMV-TGF-beta1) prevents the development of T helper cell type 1 (Th1)-mediated experimental colitis induced by the haptenating reagent, 2,4, 6-trinitrobenzene sulfonic acid (TNBS). In addition, such plasmid administration abrogates TNBS colitis after it has been established, whereas, in contrast, intraperitoneal administration of rTGF-beta1 protein does not have this effect. Intranasal pCMV-TGF-beta1 administration leads to the expression of TGF-beta1 mRNA in the intestinal lamina propria and spleen for 2 wk, as well as the appearance of TGF-beta1-producing T cells and macrophages in these tissues, and is not associated with the appearances of fibrosis. These cells cause marked suppression of interleukin (IL)-12 and interferon (IFN)-gamma production and enhancement of IL-10 production; in addition, they inhibit IL-12 receptor beta2 (IL-12Rbeta2) chain expression. Coadministration of anti-IL-10 at the time of pCMV-TGF-beta1 administration prevents the enhancement of IL-10 production and reverses the suppression of IL-12 but not IFN-gamma secretion. However, anti-IL-10 leads to increased tumor necrosis factor alpha production, especially in established colitis. Taken together, these studies show that TGF-beta1 inhibition of a Th1-mediated colitis is due to: (a) suppression of IL-12 secretion by IL-10 induction and (b) inhibition of IL-12 signaling via downregulation of IL-12Rbeta2 chain expression. In addition, TGF-beta1 may also have an inhibitory effect on IFN-gamma transcription.
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Affiliation(s)
- Atsushi Kitani
- Mucosal Immunity Section, Laboratory of Clinical Investigation
| | - Ivan J. Fuss
- Mucosal Immunity Section, Laboratory of Clinical Investigation
| | | | - Owen M. Schwartz
- Biological Imaging Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Takashi Usui
- Mucosal Immunity Section, Laboratory of Clinical Investigation
| | - Warren Strober
- Mucosal Immunity Section, Laboratory of Clinical Investigation
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1006
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Arseneau KO, Pizarro TT, Cominelli F. Discovering the cause of inflammatory bowel disease: lessons from animal models. Curr Opin Gastroenterol 2000; 16:310-7. [PMID: 17031094 DOI: 10.1097/00001574-200007000-00004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The precise cause of inflammatory bowel disease remains unclear. Relevant animal models are important tools for studying the underlying mechanisms of inflammation and disease pathogenesis. The purpose of this review is to summarize the various types of animal models available for use in inflammatory bowel disease research and to illustrate how these models have contributed to a better understanding of the etiopathogenesis of inflammatory bowel disease, particularly focusing on papers published during calendar year 1999. Studies using appropriate animal models have provided important discoveries in this field of investigation. These include determination of the key role that pathogenic and regulatory T cells, proinflammatory and immunoregulatory cytokines, indigenous bacterial flora, and putative predisposing genes play in the disease process. The availability of new animal models that closely resemble the human disease is expected to allow further characterization of the initiating event(s) in inflammatory bowel disease and lead to a possible cure for this devastating disease.
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Affiliation(s)
- K O Arseneau
- Division of Gastroenterology and Hepatology and Digestive Health Research Center, University of Virginia Health System, Charlottesville, Virginia 22906, USA
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1007
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Abstract
Recent advances in the drug treatment of inflammatory bowel disease (IBD) have paralleled our understanding of the pathophysiology of ulcerative colitis and Crohn's disease. Several proinflammatory and immune-regulatory cytokines are upregulated in the mucosa of patients with IBD, and differences and similarities in the cytokine profiles of ulcerative colitis and Crohn's disease have been elucidated. Several clinical trials involving a chimeric anti-TNF-alpha (tumor necrosis factor-alpha) antibody have shown marked clinical benefit in the majority of patients with Crohn's disease, verifying the importance of TNF-alpha in the pathogenesis of Crohn's disease. In preliminary studies, treatment with recombinant human interleukin-10 has been beneficial in Crohn's disease but not in ulcerative colitis. Future treatment of IBD may include combination or sequential cytokine and anticytokine administration in defined groups of patients based on their mucosal cytokine profiles.
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Affiliation(s)
- K A Papadakis
- Division of Gastroenterology, Cedars-Sinai Medical Center, University of California, Los Angeles 90048, USA
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1008
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Iyer S, Kontoyiannis D, Chevrier D, Woo J, Mori N, Cornejo M, Kollias G, Buelow R. Inhibition of tumor necrosis factor mRNA translation by a rationally designed immunomodulatory peptide. J Biol Chem 2000; 275:17051-7. [PMID: 10748117 DOI: 10.1074/jbc.m909219199] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Based on sequences of immunomodulatory peptides derived from the heavy chain of HLA Class I, novel immunomodulatory peptides with increased potency were developed by computer-aided rational design. Allotrap 1258 was characterized in detail and shown to inhibit cell-mediated immune responses in vitro and in vivo. Immunomodulatory activity was associated with the capability of the peptides to modulate heme oxygenase (HO) activity. In this study we analyzed the effect of Allotrap 1258 on cytokine expression. Allotrap 1258 inhibited concanavalin A- and lipopolysaccharide-induced human and mouse tumor necrosis factor (TNF) production in vitro and in vivo but had no effect on interleukin (IL)-1, IL-2, IL-4, IL-6, or IL-10 expression. Experiments with HO-1/KO and iNOS/KO mice showed that Allotrap 1258-mediated inhibition of TNF was independent of HO-1 and iNOS. Quantitation of TNF protein expression and mRNA steady state levels demonstrated that Allotrap 1258-mediated inhibition occurred at the translational level. Deletion of the AU-rich element in the 3'-untranslated region (UTR) of TNF mRNA, a region known to be involved in TNF mRNA translation, had minimal effect on Allotrap 1258-mediated inhibition. However, replacement of the TNF 3'-UTR with the human globin 3'-UTR rendered the peptide inactive. This demonstrates that besides AU-rich elements, other sequences in the 3'-UTR of TNF mRNA are involved in translational control of TNF expression. Such sequences are necessary for Allotrap 1258-mediated inhibition of TNF production.
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Affiliation(s)
- S Iyer
- SangStat, The Transplant Company, Fremont, California 94555 and the Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens 11521, Greece.
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1009
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Conne B, Stutz A, Vassalli JD. The 3' untranslated region of messenger RNA: A molecular 'hotspot' for pathology? Nat Med 2000; 6:637-41. [PMID: 10835679 DOI: 10.1038/76211] [Citation(s) in RCA: 411] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The role of the 3' untranslated region in posttranscriptional regulation of mRNA expression is being elucidated. Here we describe diseases arising from anomalies in this region, that affect the expression of one or more genes.
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Affiliation(s)
- B Conne
- Department of MorphologyFaculty of Medicine University of Geneva CMU, 1211 Geneva 4, Switzerland.
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1010
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Pizarro TT, Arseneau KO, Cominelli F. Lessons from genetically engineered animal models XI. Novel mouse models to study pathogenic mechanisms of Crohn's disease. Am J Physiol Gastrointest Liver Physiol 2000; 278:G665-9. [PMID: 10801257 DOI: 10.1152/ajpgi.2000.278.5.g665] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Crohn's Disease (CD) affects more than 500,000 individuals in the United States and represents the second most common chronic inflammatory disorder after rheumatoid arthritis. Although major advances have been made in defining the basic mechanisms underlying chronic intestinal inflammation, the precise etiopathogenesis of CD remains unknown. We have recently characterized two novel mouse models of enteritis that express a CD-like phenotype, namely the TNF DeltaARE model of tumor necrosis factor (TNF) overexpression and the SAMP1/Yit model of spontaneous ileitis. The unique feature of these models is that they closely resemble CD for location and histopathology. These genetically manipulated new models of intestinal inflammation offer a powerful tool to investigate potential causes of human disease and may allow the development of novel disease-modifying therapeutic modalities for the treatment of CD.
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Affiliation(s)
- T T Pizarro
- Division of Gastroenterology and Hepatology and Digestive Health Research Center, University of Virginia Health System, Charlottesville, Virginia 22906, USA
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1011
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Hommes DW, van Deventer SJ. Anti- and proinflammatory cytokines in the pathogenesis of tissue damage in Crohn's disease. Curr Opin Clin Nutr Metab Care 2000; 3:191-5. [PMID: 10871234 DOI: 10.1097/00075197-200005000-00005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Crohn's disease is a chronic inflammatory bowel disease of unknown origin. The understanding of the pathogenesis of inflammatory bowel diseases has been greatly advanced by manipulations of the immune system in mice using targeted disruptions of genes that encode specific anti- and proinflammatory cytokines, as well as T-cell subsets. The outcome of these experiments has implicated CD4+ lymphocytes and certain proinflammatory cytokines (tumour necrosis factor-alpha, interleukin-12) as playing a central role in the pathogenesis of mucosal inflammation in Crohn's disease. The present review focuses on these recent important immunological observations, and discusses several newly developed therapeutic strategies that are based either on blocking proinflammatory cytokines or on the administration of anti-inflammatory cytokines.
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Affiliation(s)
- D W Hommes
- Laboratory for Experimental Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
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1012
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Lee JC, Kumar S, Griswold DE, Underwood DC, Votta BJ, Adams JL. Inhibition of p38 MAP kinase as a therapeutic strategy. IMMUNOPHARMACOLOGY 2000; 47:185-201. [PMID: 10878289 DOI: 10.1016/s0162-3109(00)00206-x] [Citation(s) in RCA: 350] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Since the discovery of p38 MAP kinase in 1994, our understanding of its biology has progressed dramatically. The key advances include (1) identification of p38 MAP kinase homologs and protein kinases that act upstream and downstream from p38 MAP kinase, (2) identification of interesting and potentially important substrates, (3) elucidation of the role of p38 MAP kinase in cellular processes and (4) the establishment of the mechanism by which the pyridinylimidazole p38 MAP kinase inhibitors inhibit enzyme activity. It is now known that there are four members of the p38 MAP kinase family. They differ in their tissue distribution, regulation of kinase activation and subsequent phosphorylation of downstream substrates. They also differ in terms of their sensitivities toward the p38 MAP kinase inhibitors. The best-studied isoform is p38 alpha, whose activation has been observed in many hematopoietic and non-hematopoietic cell types upon treatment with appropriate stimuli. The pyridinylimidazole compounds, exemplified by SB 203580, were originally prepared as inflammatory cytokine synthesis inhibitors that subsequently were found to be selective inhibitors of p38 MAP kinase. SB 203580 inhibits the catalytic activity of p38 MAP kinase by competitive binding in the ATP pocket. X-ray crystallographic studies of the target enzyme complexed with inhibitor reinforce the observations made from site-directed mutagenesis studies, thereby providing a molecular basis for understanding the kinase selectivity of these inhibitors. The p38 MAP kinase inhibitors are efficacious in several disease models, including inflammation, arthritis and other joint diseases, septic shock, and myocardial injury. In all cases, p38 activation in key cell types correlated with disease initiation and progression. Treatment with p38 MAP kinase inhibitors attenuated both p38 activation and disease severity. Structurally diverse p38 MAP kinase inhibitors have been tested extensively in preclinical studies.
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Affiliation(s)
- J C Lee
- SmithKline Beecham Pharmaceuticals, 709 Swedeland Road, King of Prussia, PA 19406, USA.
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1013
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Huang S, New L, Pan Z, Han J, Nemerow GR. Urokinase plasminogen activator/urokinase-specific surface receptor expression and matrix invasion by breast cancer cells requires constitutive p38alpha mitogen-activated protein kinase activity. J Biol Chem 2000; 275:12266-72. [PMID: 10766865 DOI: 10.1074/jbc.275.16.12266] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Overexpression of urokinase plasminogen activator (uPA) and its receptor (uPAR) has been well documented in a wide variety of tumor cells. In breast cancer, expression of uPA/uPAR is essential for tumor cell invasion and metastasis. However, the mechanism responsible for uPA/uPAR expression in cancer cells remains unclear. In the studies reported here, we show that endogenous p38 MAPK activity correlates well with breast carcinoma cell invasiveness. Treatment of highly invasive BT549 cells with a specific p38 MAPK inhibitor SB203580 diminished both uPA/uPAR mRNA and protein expression and abrogated the ability of these cells to invade matrigel, suggesting that p38 MAPK signaling pathway is involved in the regulation of uPA/uPAR expression and breast cancer cell invasion. We also demonstrated that SB203580-induced reduction in uPA/uPAR mRNA expression resulted from the de- stabilization of uPA and uPAR mRNA. Finally, by selectively inhibiting p38alpha or p38beta MAPK isoforms, we demonstrate that p38alpha, rather than p38beta, MAPK activity is essential for uPA/uPAR expression. These studies suggest that p38alpha MAPK signaling pathway is important for the maintenance of breast cancer invasive phenotype by promoting the stabilities of uPA and uPAR mRNA.
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Affiliation(s)
- S Huang
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
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1014
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Di Noia JM, D'Orso I, Sánchez DO, Frasch AC. AU-rich elements in the 3'-untranslated region of a new mucin-type gene family of Trypanosoma cruzi confers mRNA instability and modulates translation efficiency. J Biol Chem 2000; 275:10218-27. [PMID: 10744707 DOI: 10.1074/jbc.275.14.10218] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma cruzi has a complex mucin gene family of 500 members with hypervariable regions expressed preferentially in vertebrate associated stages of the parasite. In this work, a novel mucin-type gene family is reported, composed of two groups of genes organized in independent tandems and having very short open reading frames. The structures of deduced proteins share the N and C termini but differ in central regions. One group has repeats with the consensus Lys-Asn-Thr(7)-Ser-Thr(3)-Ser(Ser/Lys)-Ala-Pro and the other a Thr-rich sequence of the type Asp-Gln-Thr(17-20)-Asn-Ala-Pro-Ala-Lys-Asp-Thr(5-7)-Asn-Ala-Pro-Ala-L ys. In both cases, expected mature core proteins are around 7 kDa. Both groups, named L and S, respectively, differ in the structure of genomic loci and mRNA, with differential blocks in the 3'-untranslated region. The highest mRNA level for S and L groups are in the epimastigote stage but they show distinct developmentally regulated patterns. Transcripts are short lived and their steady-state abundance is regulated post-transcriptionally with increased mRNA stability in insect stage epimastigote. AU-rich sequences, similar to ARE motives known to cause mRNA instability in higher eukaryotes, are present in the 3'-untranslated region of the transcripts. In transfection experiments this sequence is shown to be functional for the L group destabilizing its mRNA in a stage-specific manner. Furthermore, an effect of this AU-rich region on translation efficiency is shown. To our knowledge, this is the first time that a functional ARE sequence-dependent post-transcriptional regulation mechanism is reported in a lower eukaryote.
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Affiliation(s)
- J M Di Noia
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de General San Martín, C.C. 30, 1650 San Martín, Pcia. de Buenos Aires, Argentina
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1015
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Oberholzer A, Oberholzer C, Moldawer LL. Cytokine signaling--regulation of the immune response in normal and critically ill states. Crit Care Med 2000; 28:N3-12. [PMID: 10807312 DOI: 10.1097/00003246-200004001-00002] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cytokines are produced during the activation of innate and acquired immunity, and are the principal means for intercellular communication of a microbial invasion. Cytokines serve to initiate the inflammatory response and to define the magnitude and the nature of the acquired immune response. The response of critically ill patients to their injury and/or invading pathogens is dependent, in large part, on the pattern of cytokines which are produced. The immunologic response of critically ill patients can vary from a strongly proinflammatory response, characterized by increased production of tumor necrosis factor-alpha, interleukin (IL)-1, interferon (IFN)-gamma, and IL-12 to one predominantly of anergy, characterized by increased production of T(H)2 cytokines, like IL-10 and to IL-4. Therapeutic efforts to modify the host immune response in critical illness will require a more thorough understanding of the cytokine milieu and the factors that determine their production.
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Affiliation(s)
- A Oberholzer
- Department of Surgery, University of Florida College of Medicine, Gainesville 32610, USA
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1016
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Clark A. Post-transcriptional regulation of pro-inflammatory gene expression. ARTHRITIS RESEARCH 2000; 2:172-4. [PMID: 11094425 PMCID: PMC129998 DOI: 10.1186/ar83] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2000] [Accepted: 03/09/2000] [Indexed: 11/25/2022]
Abstract
The cytokine tumour necrosis factor (TNF)alpha is a vital mediator of the innate immune response, and a pleiotropic regulator of cellular function. Its involvement in rheumatoid arthritis is illustrated by the clinical benefits of TNF alpha blockade. Post-transcriptional regulation (the control of mRNA stability and translation) appears to play a critical role in the regulation of TNF alpha expression by mitogen activated protein kinase signal transduction pathways and by anti-inflammatory agents. The aim of this article is to review some recent advances in our understanding of these processes, and to speculate on mechanisms of regulation of TNF alpha and other pro-inflammatory genes.
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Affiliation(s)
- A Clark
- Kennedy Institute of Rheumatology, Imperial College School of Medicine, London, UK.
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1017
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Mueller C, Corazza N, Trachsel-Løseth S, Eugster HP, Bühler-Jungo M, Brunner T, Imboden MA. Noncleavable transmembrane mouse tumor necrosis factor-alpha (TNFalpha) mediates effects distinct from those of wild-type TNFalpha in vitro and in vivo. J Biol Chem 1999; 274:38112-8. [PMID: 10608881 DOI: 10.1074/jbc.274.53.38112] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor necrosis factor-alpha (TNFalpha) exists in two biologically active forms, a 26-kDa transmembrane form and a proteolytically cleaved and secreted form. We sequentially inactivated all three known cleavage sites of mouse TNFalpha by mutating the corresponding DNA sequences. A murine T cell hybridoma transfected with the nonsecretable mutant TNFalpha efficiently lysed L929 target cells in a cell contact-dependent manner and induced expression of vascular cell adhesion molecule-1 on mouse endothelioma cells. A genomic mouse TNFalpha clone encoding this mutant was subsequently introduced as a transgene into TNFalpha(-/-) lymphotoxin-alpha(-/-) mice. The 3' AU-rich regulatory elements of the TNF locus were maintained in the transgene to assure adequate gene regulation. Transmembrane TNFalpha transgenic mice were fully protected from endotoxic shock, and no TNFalpha bioactivity was detectable in the serum after stimulation with lipopolysaccharide. Activated CD4 T cells from these animals, however, lysed L929 cells in a cell contact-dependent way. After administration of lipopolysaccharide, transmembrane TNFalpha transgenic mice produced significantly higher levels of interleukin-12 than wild-type mice or TNF-deficient mice. This indicates that transmembrane TNFalpha may greatly affect the course of a cellular immune responses in vivo and exerts quantitatively and qualitatively distinct functions from secreted TNFalpha in vitro and in vivo.
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Affiliation(s)
- C Mueller
- Department of Pathology, Division of Immunopathology, University of Bern, Murtenstrasse 31, CH 3010 Bern, Switzerland.
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1018
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Yan F, Polk DB. Aminosalicylic acid inhibits IkappaB kinase alpha phosphorylation of IkappaBalpha in mouse intestinal epithelial cells. J Biol Chem 1999; 274:36631-6. [PMID: 10593965 DOI: 10.1074/jbc.274.51.36631] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Tumor necrosis factor alpha (TNFalpha)-stimulated nuclear factor (NF) kappaB activation plays a key role in the pathogenesis of inflammatory bowel disease (IBD). Phosphorylation of NFkappaB inhibitory protein (IkappaB) leading to its degradation and NFkappaB activation, is regulated by the multimeric IkappaB kinase complex, including IKKalpha and IKKbeta. We recently reported that 5-aminosalicylic acid (5-ASA) inhibits TNFalpha-regulated IkappaB degradation and NFkappaB activation. To determine the mechanism of 5-ASA inhibition of IkappaB degradation, we studied young adult mouse colon (YAMC) cells by immunodetection and in vitro kinase assays. We show 5-ASA inhibits TNFalpha-stimulated phosphorylation of IkappaBalpha in intact YAMC cells. Phosphorylation of a glutathione S-transferase-IkappaBalpha fusion protein by cellular extracts or immunoprecipitated IKKalpha isolated from cells treated with TNFalpha is inhibited by 5-ASA. Recombinant IKKalpha and IKKbeta autophosphorylation and their phosphorylation of glutathione S-transferase-IkappaBalpha are inhibited by 5-ASA. However, IKKalpha serine phosphorylation by its upstream kinase in either intact cells or cellular extracts is not blocked by 5-ASA. Surprisingly, immunodepletion of cellular extracts suggests IKKalpha is predominantly responsible for IkappaBalpha phosphorylation in intestinal epithelial cells. In summary, 5-ASA inhibits TNFalpha-stimulated IKKalpha kinase activity toward IkappaBalpha in intestinal epithelial cells. These findings suggest a novel role for 5-ASA in the management of IBD by disrupting TNFalpha activation of NFkappaB.
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Affiliation(s)
- F Yan
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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1019
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Clark A. Post-transcriptional regulation of TNF gene expression in vivo. Arthritis Res Ther 1999. [DOI: 10.1186/ar-1999-66730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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1020
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Papadakis KA, Targan SR. Serologic testing in inflammatory bowel disease: its value in indeterminate colitis. Curr Gastroenterol Rep 1999; 1:482-5. [PMID: 10980990 DOI: 10.1007/s11894-999-0007-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Serologic testing in inflammatory bowel disease provides a unique tool to classify these diseases into more homogeneous groups. Serum markers can also be used to identify common antigenic triggers and specific defects in mucosal immune regulation and cytokine imbalance in different parts of the gastrointestinal tract. ANCA (antineutrophil cytoplasmic antibodies) and ASCA (anti-Saccharomyces cerevisiae antibodies), the most extensively studied serologic markers, have been used to classify ulcerative colitis and Crohn's disease into such groups with certain phenotypic characteristics and responses to treatment. Similar studies have been initiated in indeterminate colitis, and these results will help in the future to define the immunopathogenesis, prognosis, and response to certain treatments in patients with this type of disease.
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Affiliation(s)
- K A Papadakis
- *Inflammatory Bowel Disease Center, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, D-4062, Los Angeles, CA 90048, USA
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1021
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Cho J. Genetic aspects of inflammatory bowel disease: how far have we come, and where are we heading? Curr Gastroenterol Rep 1999; 1:491-5. [PMID: 10980992 DOI: 10.1007/s11894-999-0009-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Crohn"s disease and ulcerative colitis are related complex genetic disorders, with gene-gene and gene-environment interactions that are critical to their pathogenesis. Multiple genetic loci have been implicated through genome-wide searches. Of these, a locus on Crohn"s disease has been definitively established in the pericentromeric region of chromosome 16. Multiple candidate gene studies have been forwarded, and functionally significant variants in immune-associated genes will provide additional insight. Characterization of the genetic variation responsible for causing inflammatory bowel disease will result in development of novel therapeutic approaches as well as in tailoring of specific therapies to individual patients based on their specific molecular pathogenesis.
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Affiliation(s)
- J Cho
- Emma Getz Inflammatory Bowel Disease Research Center, Department of Medicine, Gastroenterology Section, The University of Chicago, 5841 South Maryland Avenue, G705, MC 6084, Chicago, IL 60637-1521, USA
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1022
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Joe B, Griffiths MM, Remmers EF, Wilder RL. Animal models of rheumatoid arthritis and related inflammation. Curr Rheumatol Rep 1999; 1:139-48. [PMID: 11123028 DOI: 10.1007/s11926-999-0011-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The major, extensively studied, experimentally-induced rat and mouse models of arthritis with features resembling rheumatoid arthritis are reviewed here. Etiopathogenetic studies that were recently published are emphasized. In summary, multiple triggering stimuli can induce disease in genetically-prone strains of inbred rats and mice. Multiple genetic loci, including both MHC and non-MHC, regulate disease expression in these animals. By comparison with other models of autoimmune disease, clustering of regulatory loci within and among species is increasingly becoming evident. At the cellular level, both innate and acquired immune systems are involved in the disease manifestations. At the molecular level, unbalanced chronic production of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1, IL-6 and IL-12, as opposed to IL-4 and IL-10, is correlated with arthritis disease susceptibility and severity.
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Affiliation(s)
- B Joe
- Inflammatory Joint Diseases Section, Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institute of Health, Building 10, Room 9N240, 9000 Rockville Pike, Bethesda, MD 20892, USA
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1023
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Blumberg RS, Saubermann LJ, Strober W. Animal models of mucosal inflammation and their relation to human inflammatory bowel disease. Curr Opin Immunol 1999; 11:648-56. [PMID: 10631550 DOI: 10.1016/s0952-7915(99)00032-1] [Citation(s) in RCA: 343] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Animal models of inflammatory bowel disease (IBD) have been useful in the identification of those immune responses uniquely involved in IBD pathogenesis and in defining the important roles of environmental influences, such as normal luminal bacterial flora and the genetic composition of the host, in modifying IBD-associated inflammation. Recent studies have focused particular attention on CD4+ T cells which produce excessive quantities either of Th1 cytokines (IFN-gamma and TNF) directed by IL-12 or of a Th2 cytokine (IL-4), relative to the production of suppressive cytokines such as IL-10 and transforming growth factor beta. Such insights will be extremely beneficial in the development of novel approaches to the control of IBD-type inflammation, such as the use of anticytokine therapies and gene therapy, and finally, in the identification of the genetic abnormalities and the antigens driving the inflammation that underlies the human disease.
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Affiliation(s)
- R S Blumberg
- Gastroenterology Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
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1024
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Procyk KJ, Rippo MR, Testi R, Hoffmann F, Parker PJ, Baccarini M. Distinct Mechanisms Target Stress and Extracellular Signal-Activated Kinase 1 and Jun N-Terminal Kinase During Infection of Macrophages with Salmonella. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.9.4924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The interaction between bacteria and macrophages is central to the outcome of Salmonella infections. Salmonella can escape killing by these phagocytes and survive and multiply within them, giving rise to chronic infections. Cytokines produced by infected macrophages are involved in the early gastrointestinal pathology of the infection as well as in the induction and maintenance of the immune response against the invaders. Jun N-terminal kinases (JNK) are activated by inflammatory stimuli and play a role in cytokine production. We have investigated the signaling routes leading to JNK activation in Salmonella-infected macrophages and have discovered that they differ radically from the mechanisms operating in epithelial cells. In particular, activation of the JNK kinase stress and extracellular-activated kinase 1 (SEK1) and of JNK in macrophages occurs independently of actin rearrangements and of the GTPases Cdc42 and Rac, essential mediators in other cells. Activation of JNK is effected by a novel pathway comprising tyrosine kinase(s), phosphoinositide 3-kinase and, likely, atypical protein kinase C ζ. SEK1 is stimulated by a distinct mechanism involving phosphatidylcholine-phospholipase C and acidic sphingomyelinase. Dominant-negative SEK1 can block JNK activation by LPS, but not by Salmonella. These data demonstrate that SEK1 and JNK are activated independently in Salmonella-infected macrophages and offer experimental support for the concept that incoming signals can direct the selective coupling of downstream pathways to elicit highly specific responses. Inhibitors of stress kinase pathways are receiving increasing attention as potential anti-inflammatory drugs. The precise reconstruction of stimulus-specific pathways will be instrumental in predicting/evaluating the effects of the inhibitors on a given pathological condition.
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Affiliation(s)
- Katarzyna J. Procyk
- *Department of Cell and Microbiology, Institute of Microbiology and Genetics, Vienna Biocenter, Vienna, Austria
| | - Maria Rita Rippo
- †Department of Experimental Medicine and Biochemical Sciences, University of Rome “Tor Vergata,” Rome, Italy
| | - Roberto Testi
- †Department of Experimental Medicine and Biochemical Sciences, University of Rome “Tor Vergata,” Rome, Italy
| | - Fred Hoffmann
- ‡Institut für Pharmakologie und Toxikologie, Freiburg, Germany; and
| | - Peter J. Parker
- §Protein Phosphorylation Lab, Imperial Cancer Research Fund, London United Kingdom
| | - Manuela Baccarini
- *Department of Cell and Microbiology, Institute of Microbiology and Genetics, Vienna Biocenter, Vienna, Austria
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1025
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MacDonald TT, Bajaj-Elliott M, Pender SL. T cells orchestrate intestinal mucosal shape and integrity. IMMUNOLOGY TODAY 1999; 20:505-10. [PMID: 10529778 DOI: 10.1016/s0167-5699(99)01536-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- T T MacDonald
- Dept of Paediatric Gastroenterology, St Bartholomews and the Royal London School of Medicine and Dentistry, St Bartholomews Hospital, London, UK EC1A 7BE.
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1026
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van den Berg WB, Joosten LA, Kollias G, van De Loo FA. Role of tumour necrosis factor alpha in experimental arthritis: separate activity of interleukin 1beta in chronicity and cartilage destruction. Ann Rheum Dis 1999; 58 Suppl 1:I40-8. [PMID: 10577972 PMCID: PMC1766568 DOI: 10.1136/ard.58.2008.i40] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Chronic arthritis is characterised by persistent joint inflammation and concomitant joint destruction. Using murine arthritis models and neutralising antibodies as well as cytokine specific knockout conditions, it was found that tumour necrosis factor alpha (TNFalpha) is important in early joint swelling. Membrane bound TNFalpha is sufficient to drive this aspect of inflammation as well as the acute cellular infiltrate in the synovial tissue. Interleukin 1 (IL1) is not necessarily a dominant cytokine in early joint swelling, but has a pivotal role in sustained cellular infiltration and erosive cartilage damage. TNFalpha independent IL1 production is a prominent feature in murine arthritis models. These observations provide evidence for potential uncoupling of joint inflammation and erosive changes, implying that both cytokines need to be targeted to achieve optimal treatment.
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Affiliation(s)
- W B van den Berg
- Department of Rheumatology, University Hospital Nijmegen, the Netherlands
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1027
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Kollias G, Douni E, Kassiotis G, Kontoyiannis D. The function of tumour necrosis factor and receptors in models of multi-organ inflammation, rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease. Ann Rheum Dis 1999; 58 Suppl 1:I32-9. [PMID: 10577971 PMCID: PMC1766575 DOI: 10.1136/ard.58.2008.i32] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is now good evidence to demonstrate that aberrations in tumour necrosis factor (TNF) production in vivo may be either pathogenic or protective and several plausible mechanisms may explain these contrasting activities. According to the classic pro-inflammatory scenario, failure to regulate the production of TNF at a site of immunological injury may lead to chronic activation of innate immune cells and to chronic inflammatory responses, which may consequently lead to organ specific inflammatory pathology and tissue damage. However, more cryptic functions of this molecule may be considered to play a significant part in the development of TNF mediated pathologies. Direct interference of TNF with the differentiation, proliferation or death of specific pathogenic cell targets may be an alternative mechanism for disease initiation or progression. In addition to these activities, there is now considerable evidence to suggest that TNF may also directly promote or down regulate the adaptive immune response. A more complete understanding of the temporal and spatial context of TNF/TNF receptor (TNF-R) function and of the molecular and cellular pathways leading to the development of TNF/TNF-R mediated pathologies is necessary to fully comprehend relevant mechanisms of disease induction and progression in humans. In this paper, the potential pathogenic mechanisms exerted by TNF and receptors in models of multi-organ inflammation, rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease are discussed. Elucidating the nature and level of contribution of these mechanisms in chronic inflammation and autoimmunity may lead to better regulatory and therapeutic applications.
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Affiliation(s)
- G Kollias
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, 127 Vas Sofias Avenue, Athens 115 21, Greece
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1028
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Affiliation(s)
- F Balkwill
- Head, Biological Therapy Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, UK
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1029
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Ruuls SR, Sedgwick JD. Unlinking tumor necrosis factor biology from the major histocompatibility complex: lessons from human genetics and animal models. Am J Hum Genet 1999; 65:294-301. [PMID: 10417271 PMCID: PMC1377927 DOI: 10.1086/302517] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- S R Ruuls
- DNAX Research Institute, Palo Alto, CA 94304-1104, USA
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1030
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Abstract
A new pathway leading to arthritis has been revealed by the discovery that antibodies specific for a ubiquitously expressed antigen are able to transfer a severe arthritic phenotype in mice. This new model will be useful for further analyses of the different pathways involved in rheumatoid arthritis.
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Affiliation(s)
- R Holmdahl
- Lund University, Section for Medical Inflammation Research, Sölvegatan 19, 22362, Lund, Sweden.
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1031
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Kollias G, Douni E, Kassiotis G, Kontoyiannis D. On the role of tumor necrosis factor and receptors in models of multiorgan failure, rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease. Immunol Rev 1999; 169:175-94. [PMID: 10450517 DOI: 10.1111/j.1600-065x.1999.tb01315.x] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The specific role of the tumor necrosis factor (TNF)/TNF receptor (TNFR) system in disease pathogenesis still remains an unresolved puzzle. Recent studies in transgenic and knockout animals, where the pathogenic influence of genetically perturbed TNF expression has been evaluated, indicate that several pathways of TNF/TNFR action may contribute independently or in concert to initiate, promote or downregulate disease pathogenesis. Evidently, organ-specific inflammatory or autoimmune pathology may ensue due to sustained activation by TNF of innate immune cells and inflammatory responses, which may consequently lead to tissue damage and to organ-specific chronic pathology. However, more cryptic functions of this molecule may be considered to play a significant part in the development of TNF-mediated pathologies. Direct interference of TNF with the differentiation, proliferation or death of specific pathogenic cell targets may be an alternative mechanism for disease initiation or progression. In addition to these activities, there is now considerable evidence to suggest that TNF may also directly promote or downregulate the adaptive immune response. It is therefore evident that no general scenario may adequately describe the role of TNF in disease pathogenesis. In this article, we aim to place these diverse functions of TNF/TNFRs into context with the development of specific pathology in murine models of multiorgan failure, rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease.
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Affiliation(s)
- G Kollias
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, Athens, Greece.
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1032
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