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Mack U, Migliori GB, Sester M, Rieder HL, Ehlers S, Goletti D, Bossink A, Magdorf K, Holscher C, Kampmann B, Arend SM, Detjen A, Bothamley G, Zellweger JP, Milburn H, Diel R, Ravn P, Cobelens F, Cardona PJ, Kan B, Solovic I, Duarte R, Cirillo DM. LTBI: latent tuberculosis infection or lasting immune responses to M. tuberculosis? A TBNET consensus statement. Eur Respir J 2009; 33:956-73. [DOI: 10.1183/09031936.00120908] [Citation(s) in RCA: 365] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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27
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Neumann J, Endermann T, Ehlers S, Reiling N. Inverse relationship of TLR/NF-κB signalling and the Wnt/β-catenin pathway during inflammation: Deciphering the role of Frizzled1 in M. tuberculosis infection. Cell Commun Signal 2009. [PMCID: PMC4291751 DOI: 10.1186/1478-811x-7-s1-a52] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Hecke F, Steinwede K, Mühlradt PF, Pabst R, Ehlers S, Dorsch M, Maus U, Tschernig T. Tuberkulose im Tiermodell: Einfluss von MALP-2 auf eine Infektion mit M. bovis BCG. Pneumologie 2009. [DOI: 10.1055/s-0029-1202444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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29
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Scharn N, Ballmaier M, Reinhardt K, Ehlers S, Zimmermann M, Welte K, Reinhardt D, Germeshausen M. CSF3Rmutations in paediatric acute myeloid leukaemia. Br J Haematol 2009; 144:140-2. [DOI: 10.1111/j.1365-2141.2008.07440.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Sommer C, Häuser W, Berliner M, Brückle W, Ehlers S, Mönkemöller K, Moradi B, Petzke F, Uçeyler N, Wörz R, Winter E, Nutzinger DO. [Pharmacological treatment of fibromyalgia syndrome]. Schmerz 2008; 22:313-23. [PMID: 18458958 DOI: 10.1007/s00482-008-0676-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND An interdisciplinary guideline for the treatment of fibromyalgia syndrome (FMS) and chronic widespread pain (CWP) was developed in cooperation with ten German medical and psychological associations and two patients' self-help organizations. METHODS Using the Cochrane Collaboration Reviews (1993-12/2006), Medline (1980-2006), PsychInfo (1966-12/2006), and Scopus (1980-12/ 2006) a systematic literature search was performed, which included all randomised controlled trials (RCT) evaluating multicomponent therapy in FMS and CWP. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine. The strength of recommendation was graded according to the German program for disease management guidelines. Consensus was achieved using a multi-step nominal group procedure. RESULTS The short-term use of amitriptyline is strongly recommended (grade A) and the short-term use of fluoxetine und duloxetine is recommended (grade B). CONCLUSIONS The recommendations regarding pharmacological treatment of FMS are limited by the short duration of the RCT, the lack of follow-ups and absence of cost-effectiveness studies.
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Hölscher C, Hölscher A, Schreiber T, Rückerl D, Adams P, Woodland D, McKenzie A, Brombacher F, Iwakura Y, Ehlers S, Lange C. The tuberculin skin test in mice mainly depends on interferon-gamma-producing CD4+ T- lymphocytes. Pneumologie 2008. [DOI: 10.1055/s-2008-1074418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Aly S, Laskay T, Mages J, Malzan A, Lang R, Ehlers S. Interferon-gamma-dependent mechanisms of mycobacteria-induced pulmonary immunopathology: the role of angiostasis and CXCR3-targeted chemokines for granuloma necrosis. J Pathol 2007; 212:295-305. [PMID: 17534845 DOI: 10.1002/path.2185] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Accepted: 03/30/2007] [Indexed: 11/11/2022]
Abstract
The mechanisms leading to granuloma caseation, a hallmark of tuberculosis (TB) in humans, are poorly understood. Lung histopathology of C57BL/6 (WT) mice 16 weeks after aerosol infection with Mycobacterium avium strain TMC724 is uniquely characterized by centrally necrotizing granulomas, strongly resembling human TB lesions. However, IFN-gamma-deficient (GKO) and IFN-gamma-receptor-deficient (GRKO) mice did not develop granuloma necrosis following M. avium infection. Comparison of differentially expressed genes in infected WT and GKO lungs by DNA microarray and RNase protection assays revealed that the angiostatic chemokines CXCL9-11 were significantly reduced in GKO mice. In contrast, angiogenic mediators such as angiopoietin and vascular endothelial growth factor, and angiogenic chemokines such as CXCL2, CCL3, and CCL4, remained unchanged or were expressed at higher levels than in infected WT mice, suggesting impaired neovascularization of the granuloma as a possible mechanism for caseation in WT mice. Granuloma vascularization was significantly decreased in central, but not peripheral, areas of granulomas of infected WT compared to GKO mice. In contrast to GRKO mice, WT mice showed signs of severe hypoxia in cells immediately surrounding the necrotic core of granulomas as measured immunohistochemically with a reagent detecting pimonidazole adducts. To test the hypothesis that CXCR3, the common receptor for the angiostatic chemokines CXCL9-11, is involved in granuloma caseation, histomorphology was assessed in M. avium-infected mice deficient for CXCR3 (CXCR3-KO). 16 weeks after infection, these mice developed caseating granulomas similar to WT mice. We conclude that IFN-gamma causes a dysbalance between angiostatic and angiogenic mediators and a concomitant reduction in granuloma vascularization, but that CXCR3-targeted chemokines are not sufficient to induce granuloma necrosis in a mouse model of mycobacteria-induced immunopathology.
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MESH Headings
- Animals
- Capillaries/pathology
- Chemokines/genetics
- Chemokines/physiology
- Gene Expression Profiling
- Granuloma, Respiratory Tract/immunology
- Granuloma, Respiratory Tract/microbiology
- Granuloma, Respiratory Tract/pathology
- Immunohistochemistry
- In Situ Hybridization/methods
- Interferon-gamma/genetics
- Interferon-gamma/metabolism
- Lung/immunology
- Lung/microbiology
- Lung/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mycobacterium avium
- Necrosis
- Oligonucleotide Array Sequence Analysis
- Receptors, CXCR3
- Receptors, Chemokine/genetics
- Receptors, Chemokine/metabolism
- Receptors, Interferon/genetics
- Receptors, Interferon/metabolism
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/pathology
- Interferon gamma Receptor
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33
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Srivastava M, Meinders A, Steinwede K, Maus R, Lucke N, Bühling F, Ehlers S, Welte T, Maus U. Mediator responses of alveolar macrophages and kinetics of mononuclear phagocyte subset recruitment during acute primary and secondary mycobacterial infections in the lungs of mice. Pneumologie 2007. [DOI: 10.1055/s-2007-967244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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34
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Aly S, Wagner K, Keller C, Malm S, Malzan A, Brandau S, Bange FC, Ehlers S. Oxygen status of lung granulomas in Mycobacterium tuberculosis-infected mice. J Pathol 2006; 210:298-305. [PMID: 17001607 DOI: 10.1002/path.2055] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is often assumed that Mycobacterium tuberculosis (Mtb)-induced granulomatous lesions, particularly those undergoing central caseation, are anoxic, and that the survival of Mtb in these lesions requires the integrity of its non-oxidative respiratory pathways. Using the hypoxia marker pimonidazole, we now provide immunohistochemical evidence that in the most frequently used animal model system of inbred mice Mtb-induced granulomas, even after more than one year of aerogenic infection, are not severely hypoxic. In contrast, chronic aerosol infection with M. avium strain TMC724 was associated with hypoxia surrounding necrotizing granuloma centres. Direct measurements of oxygen tension with a flexible microelectrode in mouse lungs chronically infected with Mtb disclosed a wide range of oxygen partial pressures in different parts of the lungs which, however, rarely approached the anoxic conditions consistently found in necrotizing tumours. We further show that an Mtb mutant, defective in nitrate reductase (narG) necessary for survival under anaerobic conditions in vitro, can persist in the lungs of chronically infected mice to a similar extent as wild-type Mtb. These findings have important implications for the use of the mouse model of Mtb infection in developing eradication chemotherapy and for evaluating putative mechanisms of chronic persistence and latency of Mtb.
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Weyhers H, Ehlers S, Hahn H, Souto EB, Müller RH. Solid lipid nanoparticles (SLN)--effects of lipid composition on in vitro degradation and in vivo toxicity. DIE PHARMAZIE 2006; 61:539-44. [PMID: 16826974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Solid lipid nanoparticles (SLN) composed of two different lipid matrices were produced to assess their in vivo toxicity in mice. Matrix substances were (i) Compritol (glycerol behenate), a physiological lipid with GRAS status (generally recognized as safe [FDA]), and (ii) cetyl palmitate, a less physiological compound. Physicochemical data proved the suitability of SLN batches for intravenous administration. To assess the in vivo toxicity of produced batches, 400 microl SLN dispersion (lipid content 10% [m/m]) were administered to mice via a bolus injection for six times within a period of 20 days (high dose administration). Additionally, a multiple low dose administration was performed with Compritol-SLN as well (200 microl SLN dispersion, lipid content 2.5% [m/m]). Hepatic and splenic tissues were analysed histologically. In vivo results were dependent on the lipid matrix, as well as on the dose administered. For cetyl palmitate containing SLN no pathological results were obtained, while high dosed Compritol containing formulations led to accumulation of the lipid in liver and spleen and subsequently to pathological alterations. These alterations were found to be partially reversible within six weeks after completing intravenous administration. Liver architecture was nearly recovered. In contrast, low dosed Compritol SLN were well tolerated. Lipid accumulation and pathological alterations of high dosed Compritol SLN were attributed to the slow degradation of the Compritol matrix which could be shown by performing in vitro studies in human plasma.
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36
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Sander P, Rezwan M, Walker B, Rampini SK, Kroppenstedt RM, Ehlers S, Keller C, Keeble JR, Hagemeier M, Colston MJ, Springer B, Böttger EC. Lipoprotein processing is required for virulence of Mycobacterium tuberculosis. Mol Microbiol 2005; 52:1543-52. [PMID: 15186407 DOI: 10.1111/j.1365-2958.2004.04041.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Lipoproteins are a subgroup of secreted bacterial proteins characterized by a lipidated N-terminus, processing of which is mediated by the consecutive activity of prolipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (LspA). The study of LspA function has been limited mainly to non-pathogenic microorganisms. To study a potential role for LspA in the pathogenesis of bacterial infections, we have disrupted lspA by allelic replacement in Mycobacterium tuberculosis, one of the world's most devastating pathogens. Despite the presence of an impermeable lipid outer layer, it was found that LspA was dispensable for growth under in vitro culture conditions. In contrast, the mutant was markedly attenuated in virulence models of tuberculosis. Our findings establish lipoprotein metabolism as a major virulence determinant of tuberculosis and define a role for lipoprotein processing in bacterial pathogenesis. In addition, these results hint at a promising new target for therapeutic intervention, as a highly specific inhibitor of bacterial lipoprotein signal peptidases is available.
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37
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Dmitriev BA, Toukach FV, Holst O, Rietschel ET, Ehlers S. Tertiary structure of Staphylococcus aureus cell wall murein. J Bacteriol 2004; 186:7141-8. [PMID: 15489425 PMCID: PMC523189 DOI: 10.1128/jb.186.21.7141-7148.2004] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The recently described scaffold model of murein architecture depicts the gram-negative bacterial cell wall as a gel-like matrix composed of cross-linked glycan strands oriented perpendicularly to the plasma membrane while peptide bridges adopt a parallel orientation (B. A. Dmitriev, F. V. Toukach, K. J. Schaper, O. Holst, E. T. Rietschel, and S. Ehlers, J. Bacteriol. 185:3458-3468, 2003). Based on the scaffold model, we now present computer simulation studies on the peptidoglycan arrangement of the gram-positive organism Staphylococcus aureus, which show that the orientation of peptide bridges is critical for the highly cross-linked murein architecture of this microorganism. According to the proposed refined model, staphylococcal murein is composed of glycan and oligopeptide chains, both running in a plane that is perpendicular to the plasma membrane, with oligopeptide chains adopting a zigzag conformation and zippering adjacent glycan strands along their lengths. In contrast to previous models of murein in gram-positive bacteria, this model reflects the high degree of cross-linking that is the hallmark of the staphylococcal cell wall and is compatible with distinguishing features of S. aureus cytokinesis such as the triple consecutive alteration of the division plane orientation and the strictly centripetal mode of septum closure.
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38
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Gieffers J, van Zandbergen G, Rupp J, Sayk F, Krüger S, Ehlers S, Solbach W, Maass M. Phagocytes transmit Chlamydia pneumoniae from the lungs to the vasculature. Eur Respir J 2004; 23:506-10. [PMID: 15083745 DOI: 10.1183/09031936.04.00093304] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chlamydia pneumoniae, a major cause of community-acquired pneumonia, primarily infects the respiratory tract. Chronic infection of nonrespiratory sites, such as the vascular wall, the brain or blood monocytes, requires evasion from the lungs and spreading via the bloodstream. The cell types involved in dissemination are insufficiently characterised. In this study, New Zealand White rabbits were infected intratracheally with C. pneumoniae, and lung manifestation and systemic dissemination were monitored by polymerase chain reaction and immunohistochemistry. Infection of the lungs was characterised by an early phase dominated by granulocytes and a late phase dominated by alveolar macrophages (AM). Granulocytes, AM and alveolar epithelial cells acted as host cells for chlamydiae, which remained detectable for up to 8 weeks. AM transported the pathogen to the peribronchiolar lymphatic tissue, and subsequently C. pneumoniae entered the spleen and the aorta via dissemination by peripheral blood monocytes. In conclusion, Chlamydia pneumoniae-infected alveolar macrophages transmigrate through the mucosal barrier, and give the pathogen access to the lymphatic system and the systemic circulation. Infected peripheral blood monocytes are the vector system within the bloodstream and transmit the infection to the vascular wall. This is the first description of granulocytes acting as a reservoir for Chlamydia pneumoniae early in infection.
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39
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Ehlers S. Role of tumour necrosis factor (TNF) in host defence against tuberculosis: implications for immunotherapies targeting TNF. Ann Rheum Dis 2003; 62 Suppl 2:ii37-42. [PMID: 14532147 PMCID: PMC1766754 DOI: 10.1136/ard.62.suppl_2.ii37] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Studies in mouse infection models clearly demonstrate tumour necrosis factor (TNF) to be a critical component of both the antibacterially protective and the inflammatory immune response to Mycobacterium tuberculosis. It is therefore not surprising that treatment of patients-for example, those with rheumatoid arthritis-with biological agents interfering with TNF activity have shown an increased risk of reactivating tuberculosis. However, conceivably, TNF targeting biological agents can be developed that because of their particular mode of action and their specific pharmacodynamics may be less likely to have this side effect.
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40
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Hellmich B, Ehlers S, Csernok E, Gross WL. Update on the pathogenesis of Churg-Strauss syndrome. Clin Exp Rheumatol 2003; 21:S69-77. [PMID: 14740430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Churg-Strauss syndrome (CSS) is a rare form of systemic vasculitis occurring in patients with asthma. The cause of CSS is unknown, and yet little data are available regarding its pathogenesis. The presence of a marked tissue- and blood-eosinophilia, as well as secretory products of eosinophils in blood and tissues, implicates a pathogenetic role of eosinophil granulocytes. Prolonged survival of eosinophils due to inhibition of CD95-mediated apoptosis by soluble CD95 seems to contribute to eosinophilia in CSS. Although the mechanisms involved in eosinophil-activation in CSS have not been elucidated, recent data suggest a possible role of T lymphocytes secreting eosinophil-activating cytokines. This review describes the current insights into the pathogenesis of CSS in the light of its putative nature as a type 2 granulomatous disease. Recent clinical, experimental and epidemiologic data regarding the possible role of inflammatory cells and their secretory products, anti neutrophil cytoplasm antibodies (ANCA), epidemiologic factors and anti-asthma treatments are summarized.
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Abstract
The histopathological hallmark of infections with Mycobacterium tuberculosis is the development of centrally necrotizing granulomatous lesions. Granulomas are focal accumulations of mononuclear cells in various states of differentiation, in which the local activation of mycobacteria-infected macrophages by specific T cells takes place. On the one hand, this assures efficient containment of mycobacterial growth and demarcation of the infectious focus. On the other hand this is associated with the displacement of and irreversible damage to functionally vital organ tissue (predominantly in the lungs). New insights, emerging from animal models of infection, into the dynamic mechanisms regulating the induction, maintenance and caseation of tuberculous granulomas explain why highly effective anti-inflammatory therapies, e. g. administration of anti-TNF monoclonal antibodies, may result in reactivation of tuberculosis.
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42
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Schwinzer R, Witte T, Hundrieser J, Ehlers S, Momot T, Hunzelmann N, Krieg T, Schmidt RE, Wonigeit K. Enhanced frequency of a PTPRC (CD45) exon A mutation (77C-->G) in systemic sclerosis. Genes Immun 2003; 4:168-9. [PMID: 12618866 DOI: 10.1038/sj.gene.6363894] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A point mutation in exon A (C to G transversion at position 77) of human PTPRC (CD45) has recently been associated with the development of multiple sclerosis (MS) for at least a subgroup of patients. In the present report, we studied the frequency of the 77C-->G transversion in two other autoimmune diseases namely systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). The mutation was found with significantly enhanced frequency in patients suffering from SSc suggesting that PTPRC could play a role as susceptibility gene not only in MS but also in other autoimmune diseases. Further understanding of the mode of interaction of mutant PTPRC with other susceptibility genes may uncover mechanisms common in various autoimmune disorders.
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43
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Ehlers S, Benini J, Held HD, Roeck C, Alber G, Uhlig S. Alphabeta T cell receptor-positive cells and interferon-gamma, but not inducible nitric oxide synthase, are critical for granuloma necrosis in a mouse model of mycobacteria-induced pulmonary immunopathology. J Exp Med 2001; 194:1847-59. [PMID: 11748285 PMCID: PMC2193571 DOI: 10.1084/jem.194.12.1847] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The immunological basis of tuberculin-induced necrosis, known for more than a century as "Koch's phenomenon," remains poorly understood. Aerosol infection in mice with the highly virulent Mycobacterium avium strain TMC724 causes progressive pulmonary pathology strongly resembling caseating necrosis in human patients with tuberculosis. To identify the cellular and molecular mediators causing this pathology, we infected C57BL/6 mice and mice selectively deficient in recombinase activating gene (RAG)-1, alphabeta T cell receptor (TCR), gammadelta TCR, CD4, CD8, beta2-microglobulin, interferon (IFN)-gamma, interleukin (IL)-10, IL-12p35, IL-12p35/p40, or iNOS with M. avium by aerosol and compared bacterial multiplication, histopathology, and respiratory physiology in these mice. The bacterial load in the lung was similarly high in all mouse groups. Pulmonary compliance, as a surrogate marker for granulomatous infiltrations in the lung, deteriorated to a similar extent in all groups of mice, except in alphabeta TCR-knockout (KO) and IL-12-KO mice in which compliance was higher, and in IFN-gamma and inducible nitric oxide synthase-KO mice in which compliance was reduced faster. Progressive caseation of pulmonary granulomas never occurred in alphabeta TCR-KO, IL-12-KO, and IFN-gamma-KO mice and was reduced in CD4-KO mice. In summary, alphabeta TCR(+) cells and IFN-gamma are essential for the development of mycobacteria-induced pulmonary caseous necrosis. In contrast, high mycobacterial load and extensive granulomatous infiltration per se are not sufficient to cause caseation, nor is granuloma necrosis linked to the induction of nitric oxide.
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MESH Headings
- Animals
- Cytotoxicity, Immunologic
- Gene Expression Regulation/immunology
- Granuloma/immunology
- Granuloma/pathology
- Humans
- Interferon-gamma/genetics
- Interferon-gamma/immunology
- Mice
- Mice, Knockout
- Mycobacterium avium/immunology
- Necrosis
- Nitric Oxide Synthase/genetics
- Nitric Oxide Synthase/immunology
- Nitric Oxide Synthase Type II
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocyte Subsets/immunology
- Tuberculosis, Pulmonary/genetics
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/pathology
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Reiling N, Klug K, Krallmann-Wenzel U, Laves R, Goyert S, Taylor ME, Lindhorst TK, Ehlers S. Complex encounters at the macrophage-mycobacterium interface: studies on the role of the mannose receptor and CD14 in experimental infection models with Mycobacterium avium. Immunobiology 2001; 204:558-71. [PMID: 11846219 DOI: 10.1078/0171-2985-00093] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The initial interactions between mycobacterial cell wall components and receptor structures on the surface of macrophages may be critical in determining the outcome of infection. They may trigger the ingestion and digestion of microorganisms, but they may also promote the intracellular persistence and growth of mycobacteria. Using Mycobacterium avium as a model system, three approaches of different complexities were used to analyse some structural features and some functional consequences of M. avium interacting with the macrophage mannose receptor or CD14, a pattern recognition receptor. Binding specificities of a recombinant, truncated extracellular portion of the mannose receptor were assayed in a novel ELISA-formatted system using viable M. avium cells as ligands. Infection with M. avium strains differing in their virulence were performed in murine bone marrow-derived macrophages and in mice with a targeted deletion of the CD14 gene. These parallel and converging approaches not only help define the molecular basis for understanding early events in the pathogenesis of mycobacterial infections, but are also necessary to ultimately determine the relevance of in vitro findings in the context of actual manifestations of disease in vivo.
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Wagner J, Ignatius R, Voss S, Höpfner V, Ehlers S, Funke G, Weber U, Hahn H. Infection of the skin caused by Corynebacterium ulcerans and mimicking classical cutaneous diphtheria. Clin Infect Dis 2001; 33:1598-600. [PMID: 11568853 DOI: 10.1086/322969] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2001] [Revised: 05/10/2001] [Indexed: 11/03/2022] Open
Abstract
Extrapharyngeal infections caused by Corynebacterium ulcerans have rarely been reported previously, and diphtheria toxin production has usually not been addressed. This case demonstrates that strains of C. ulcerans that produce diphtheria toxin can cause infections of the skin that completely mimic typical cutaneous diphtheria, thereby potentially providing a source of bacteria capable of causing life-threatening diseases in the patient's environment. Therefore, it is recommended to screen wound swabs for coryneform bacteria, identify all isolates, carefully assess possible toxin production, and send questionable strains to a specialist or a reference laboratory.
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Raichle KA, Christensen AJ, Ehlers S, Moran PJ, Karnell L, Funk G. Public and private self-consciousness and smoking behavior in head and neck cancer patients. Ann Behav Med 2001; 23:120-4. [PMID: 11394553 DOI: 10.1207/s15324796abm2302_6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Patients who continue to use tobacco following treatment for head and neck cancers are at a greater risk for cancer recurrence and earlier mortality. This study examined the unique effects of public and private self-consciousness and negative affect on smoking behavior in a sample of 40 patients with cancers of the head and neck. Measures of public and private self-consciousness and negative affect were administered and assessments of past and current smoking behavior were obtained. Only public self-consciousness was a significant predictor of continued smoking following oncologic treatment. Specifically, individuals with low levels of public self-consciousness were nearly 13 times more likely to continue smoking compared to those with relatively higher levels of public self-consciousness. This pattern is interpreted in the context of previous theorizing that suggests individuals high in public self-consciousness are more likely to discontinue habitual behavior that is perceived as socially undesirable or incorrect.
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Reiling N, Blumenthal A, Flad HD, Ernst M, Ehlers S. Mycobacteria-induced TNF-alpha and IL-10 formation by human macrophages is differentially regulated at the level of mitogen-activated protein kinase activity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:3339-45. [PMID: 11544323 DOI: 10.4049/jimmunol.167.6.3339] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The clinical course of mycobacterial infections is linked to the capacity of pathogenic strains to modulate the initial antimycobacterial response of the macrophage. To elucidate some of the mechanisms involved, we studied early signal transduction events leading to cytokine formation by human monocyte-derived macrophages (MDM) in response to clinical isolates of Mycobacterium avium. TNF-alpha production induced by M. avium was inhibited by anti-CD14 mAbs, but not by Abs against the macrophage mannose receptor. Analysis of mitogen-activated protein (MAP) kinase activation (extracellular signal-regulated kinase 1/2, p38, and c-Jun NH(2)-terminal kinase) showed a rapid phosphorylation of all three subfamilies in response to M. avium, which was inhibited by anti-CD14 Abs. Using highly specific inhibitors of p38 (SB203580) and MAP kinase kinase-1 (PD98059), we found that activation of the extracellular signal-regulated kinase pathway, but not of p38, was essential for the M. avium-induced TNF-alpha formation. In contrast, IL-10 production was abrogated by the p38 inhibitor, but not by the MAP kinase kinase-1 inhibitor. In conclusion, M. avium-induced secretion of TNF-alpha and IL-10 by human macrophages is differentially regulated at the level of MAP kinase activity.
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Pearl JE, Saunders B, Ehlers S, Orme IM, Cooper AM. Inflammation and lymphocyte activation during mycobacterial infection in the interferon-gamma-deficient mouse. Cell Immunol 2001; 211:43-50. [PMID: 11585387 DOI: 10.1006/cimm.2001.1819] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Interferon-gamma is a pivotal cytokine in the protective response to tuberculosis. In its absence rampant bacterial growth results in tissue destruction and death. While macrophage activation is key, this pleiotropic cytokine has other secondary but significant roles. To investigate these roles, both intravenous and aerosol infection of the IFN-gamma gene disrupted (GKO) mouse was performed. For the first time we describe the very similar growth of bacteria, during the initial phase of infection, between control and GKO mice. During this initial phase, however, very different histopathologic consequences between control and GKO mice were observed. Key observations included an early increased accumulation of granulocytes and a much more rapid and pronounced interstitial pneumonia in the GKO mice. As infection developed, GKO mice mounted an antigen-specific response; however, lymphocyte activation was much more rapid in these mice. Of interest is the fact that this increased rapidity occurred prior to significant differences in bacterial number. Taken together these data support a role for IFN-gamma in limiting both initial cellular recruitment and acquired lymphocytic responses to mycobacterial infection. This role may be key in surviving the kind of chronic stimulatory disease caused by Mycobacterium tuberculosis.
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Ehlers S, Reiling N, Gangloff S, Woltmann A, Goyert S. Mycobacterium avium infection in CD14-deficient mice fails to substantiate a significant role for CD14 in antimycobacterial protection or granulomatous inflammation. Immunology 2001; 103:113-21. [PMID: 11380699 PMCID: PMC1783221 DOI: 10.1046/j.1365-2567.2001.01214.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD14 is a pattern-recognition receptor implicated in the inflammatory response to microbial components such as lipopolysaccharide, peptidoglycan and lipoarabinomannan. In this work, we made use of CD14-deficient (CD14-/-) mice to evaluate the relative importance of CD14 in response to infection with viable, intact cells of Mycobacterium avium in vitro and in vivo. Following co-incubation of either bone marrow-derived macrophages (Mphi) or thioglycollate-elicited peritoneal Mphi from CD14-/- mice with viable M. avium, tumour necrosis factor (TNF) production was significantly reduced and delayed compared to TNF secretion by infected CD14+/+ Mphi. However, following intravenous infection with a M. avium strain of either high virulence (TMC724) or intermediate virulence (SE01), there was no difference in the bacterial loads of lungs, livers or spleens at 3, 5 and 8 weeks postinfection in CD14-/- mice when compared with syngeneic CD14+/+ mice. At these time-points, TNF and interferon-gamma (IFN-gamma) mRNA expression in the liver was similar in infected CD14+/+ and CD14-/- mice, and granuloma formation and expression of inducible nitric oxide synthase within granuloma Mphi was the same in both mouse groups. In conclusion, although the absence of CD14 results in significantly reduced and delayed TNF production in response to stimulation with M. avium in vitro, there is no evidence that CD14 plays a significant role in either the antibacterial defence or the chronic granulomatous reaction to M. avium infection in vivo.
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Ehlers S, Richter E. Differential requirement for interferon-gamma to restrict the growth of or eliminate some recently identified species of nontuberculous mycobacteria in vivo. Clin Exp Immunol 2001; 124:229-38. [PMID: 11422199 PMCID: PMC1906046 DOI: 10.1046/j.1365-2249.2001.01509.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In recent years, a number of newly identified species of the genus Mycobacterium (M.) have been isolated from tissues of both immunocompetent and immunocompromised patients, e.g. M. celatum, M. intermedium, M. interjectum, M. bohemicum, M. conspicuum, M. confluentis, M. heidelbergense, M. lentiflavum, and M. branderi. Little is known about their in vivo virulence characteristics and the host factors predisposing to infection with these strains. In an effort to elucidate the pathogenesis of these nontuberculous mycobacterial species, BALB/c and syngeneic IFNgamma-deficient (GKO) mice were intravenously infected with 106 colony forming units of each of these species, and bacterial growth in infected organs and the development of splenomegaly and granulomatous liver lesions were examined for a period of 3 months. Based on their in vivo virulence, mycobacterial strains could be divided into three major groups: (i) Most species examined either grew progressively or persisted at plateau levels in the livers and spleens of immunocompetent mice, and their growth was increased in GKO mice. (ii) M. heidelbergense, M. intermedium and another species not officially accorded separate taxonomical status were eliminated in BALB/c mice, but persisted in GKO mice. (iii) M. confluentis, M. lentiflavum and another novel species were eradicated even in the absence of IFNgamma. Nontuberculous mycobacterial species differed widely in their capacity to induce splenomegaly and lymphadenopathy in GKO mice. In conclusion, IFNgamma is a crucial determinant of infection outcome with most, but not all opportunistic mycobacterial species.
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