Thomas Tschernig

Universität des Saarlandes, Saarbrücken, Saarland, Germany

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Publications (191)621.01 Total impact

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    ABSTRACT: Surfactant protein A has been shown to enhance opsonization and clearance of Staphylococcus aureus in vitro. Here, the phagocytosis of alveolar S. aureus was investigated in vivo using intravital microscopy. Fluorescence labelled S. aureus Newman cells were intratracheally administered to anesthetized mice and the alveolar surface was observed for fifteen minutes. Confirming previously reported in vitro data, surfactant protein A-deficient mice showed a significantly reduced uptake of bacteria compared to wild-type mice.
    Respiratory research. 08/2014; 15(1):85.
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    ABSTRACT: Moxifloxacin is a synthetic antibacterial agent belonging to the fluoroquinolone family. The antimicrobial activity of quinolones against Gram-positive and Gram-negative bacteria is based on their ability to inhibit topoisomerases. Quinolones are described to have immunomodulatory features in addition to their antimicrobial activities. It was the goal of this study to examine whether a short term treatment with moxifloxacin modulates the inflammation during a subsequently induced bacterial infection in an animal model METHODS: Mice were treated with moxifloxacin or saline for two consecutive days and were subsequently intranasally infected with viable or heat-inactivated bacterial pathogens (Streptococcus pneumoniae, Pseudomonas aeruginosa) for 6 and 24 hours. Measurements of cytokines in the lungs and plasma were performed. Alveolar cells were determined in bronchoalveolar lavage fluits.
    Respiratory research. 07/2014; 15(1):82.
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    Respiratory research 06/2014; 15(1):73. · 3.64 Impact Factor
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    ABSTRACT: A neuroimmune crosstalk between dendritic cells (DCs) and airway nerves in the lung has recently been reported. However, the presence of DCs in airway sensory ganglia under normal and allergic conditions has not been explored so far. Therefore, this study aims to investigate the localisation, distribution and proliferation of DCs in airway sensory ganglia under allergic airway inflammation.
    Respiratory research. 06/2014; 15(1):73.
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    ABSTRACT: Ventilator-induced lung injury (VILI) contributes to morbidity and mortality in acute respiratory distress syndrome (ARDS). Particularly pre-injured lungs are susceptible to VILI despite protective ventilation. In a previous study, the endogenous peptide adrenomedullin (AM) protected murine lungs from VILI. We hypothesized that mechanical ventilation (MV) contributes to lung injury and sepsis in pneumonia, and that AM may reduce lung injury and multiple organ failure in ventilated mice with pneumococcal pneumonia. We analyzed in mice the impact of MV in established pneumonia on lung injury, inflammation, bacterial burden, hemodynamics and extrapulmonary organ injury, and assessed the therapeutic potential of AM by starting treatment at intubation. In pneumococcal pneumonia, MV increased lung permeability, and worsened lung mechanics and oxygenation failure. MV dramatically increased lung and blood cytokines but not lung leukocyte counts in pneumonia. MV induced systemic leukocytopenia and liver, gut and kidney injury in mice with pneumonia. Lung and blood bacterial burden was not affected by MV pneumonia and MV increased lung AM expression, whereas receptor activity modifying protein (RAMP) 1-3 expression was increased in pneumonia and reduced by MV. Infusion of AM protected against MV-induced lung injury (66% reduction of pulmonary permeability p<0.01; prevention of pulmonary restriction) and against VILI-induced liver and gut injury in pneumonia (91% reduction of AST levels p<0.05, 96% reduction of alanine aminotransaminase (ALT) levels p<0.05, abrogation of histopathological changes and parenchymal apoptosis in liver and gut). MV paved the way for the progression of pneumonia towards ARDS and sepsis by aggravating lung injury and systemic hyperinflammation leading to liver, kidney and gut injury. AM may be a promising therapeutic option to protect against development of lung injury, sepsis and extrapulmonary organ injury in mechanically ventilated individuals with severe pneumonia.
    Critical care (London, England) 04/2014; 18(2):R73. · 4.72 Impact Factor
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    ABSTRACT: Macrophages are equipped with several receptors for the recognition of foreign particles and pathogens. Upon binding to these receptors, particles become internalized. An interaction of particles with macrophage surface receptors is accompanied by an increase in cytosolic calcium concentration. This calcium is provided by intracellular stores and also by an influx of external calcium upon activation of the calcium channels. Nevertheless, the role of calcium in phagocytosis remains controversial. Some researchers postulate the necessity of calcium in Fc-receptor-mediated phagocytosis and a calcium-independent phagocytosis of complement opsonized particles. Others refute the need for calcium in Fc-receptor-mediated phagocytosis by macrophages. In this study, the influence of external calcium concentrations and thapsigargin on the phagocytosis of polystyrene latex beads by the macrophage-like cell lines MH-S (murine) and differentiated U937 (human) was analyzed. The phagocytosis efficiency was determined by flow cytometry and was evaluated statistically by ANOVA test and Dunett's significance test, or ANOVA and Bonferroni's Multiple Comparison. Acquired data revealed an external calcium-independent way of internalization of non-functionalized polystyrene latex beads at free calcium concentrations ranging from 0 mM to 3 mM. The phagocytosis efficiency of the cells is not significantly decreased by a complete lack of external calcium. Furthermore, the presence of thapsigargin, known to lead to an increase of cytosolic calcium levels, did not have a significant enhancing influence on bead uptake by MH-S cells and only an enhancing effect on bead uptake by macrophage-like U937 cells at an external calcium concentration of 4 mM. The calcium-independent phagocytosis process and the decrease of phagocytosis efficiency in the presence of complement receptor inhibitor staurosporine lead to the assumption that besides other calcium independent receptors, complement receptors are also involved in the uptake of polystyrene beads. The comparison of the phagocytosis efficiencies of both cell types in bivalent cation-free HBSS buffer and in cell medium, leads to the conclusion that it is more likely that other media ingredients such as magnesium are of greater importance for phagocytosis of non-functionalized polystyrene beads than calcium.
    BMC pharmacology & toxicology. 03/2014; 15(1):16.
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    ABSTRACT: Caveolin-1 is one of the important regulators of vascular permeability in inflamed lungs. Podocalyxin is a CD34 protein expressed on vascular endothelium and has a role in podocyte development in the kidney. Few data are available on the expression of caveolin-1 and podocalyxin in lungs challenged with Toll-like receptor 2 (TLR2) agonists such as mycoplasma-derived macrophage activating lipopeptide or with immune modulators such as Fms-like tyrosine kinase receptor-3 ligand (Flt3L), which expands dendritic cell populations in the lung. Because of the significance of pathogen-derived molecules that act through TLR2 and of the role of immune modulators in lung physiology, we examine the immunohistochemical expression of caveolin-1 and podocalyxin in lungs from rats challenged with a 2-kDa macrophage-activating lipopeptide (MALP-2) and Flt3L. Normal rat lungs expressed caveolin-1 in alveolar septa, vascular endothelium and airway epithelium, especially along the lateral borders of epithelial cells but not in alveolar macrophages. MALP-2 and Flt3L decreased and increased, respectively, the expression of caveolin-1. Caveolin-1 expression seemed to increase in microvessels in bronchiole-associated lymphoid tissue (BALT) in Flt3L-challenged lungs but not in normal or MALP-2-treated lungs. Podocalyxin was absent in the epithelium and alveolar macrophages but was present in the vasculature of control, Flt3L- and MALP-2-treated rats. Compared with control and MALP-2-treated rats, Flt3L-treated lungs showed greater expression of podocalyxin in BALT vasculature and at the interface of monocytes and the endothelium. These immunohistochemical data describing the altered expression of caveolin-1 and podocalyxin in lungs treated with MALP-2 or Flt3L encourage further mechanistic studies on the role of podocalyxin and caveolin-1 in lung inflammation.
    Cell and Tissue Research 01/2014; · 3.68 Impact Factor
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    ABSTRACT: The activation of inflammasome signaling mediates pathology of acute Pseudomonas aeruginosa pneumonia. This suggests that the inflammasome might represent a target to limit the pathological consequences of acute P. aeruginosa lung infection. Pannexin-1 (Px1) channels mediate the activation of caspase-1 and release of IL-1β induced by P2X7 receptor activation. The approved drug probenecid is an inhibitor of Px1 and ATP release. In this study, we demonstrate that probenecid reduces infection and inflammation in acute P. aeruginosa pneumonia. Treatment of mice prior to infection with P. aeruginosa resulted in an enhanced clearance of P. aeruginosa and reduced levels of inflammatory mediators, such as IL-1β. In addition, probenecid inhibited the release of inflammatory mediators in murine alveolar macrophages and human U937 cell-derived macrophages upon bacterial infection but not in human bronchial epithelial cells. Thus, Px1 blockade via probenecid treatment may be a therapeutic option in P. aeruginosa pneumonia by improving bacterial clearance and reducing negative consequences of inflammation.
    International Journal of Medical Microbiology. 01/2014;
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    ABSTRACT: Porous polyethylene (Medpor(®)) is frequently used in craniofacial reconstructive surgery. Rapid vascularization of the biomaterial crucially contributes to its adequate incorporation without complications. Macrophage-activating lipopeptide-2 (MALP-2) is a toll-like receptor (TLR)-2/6 agonist with pro-angiogenic properties. Herein we analyzed, whether local single-shot application of MALP-2 improves the angiogenic host tissue response to Medpor(®). Medpor(®) (3 x 3 x 0.25mm) was implanted into dorsal skinfold chambers of BALB/c mice topically exposed to different MALP-2 doses (0.1μg and 0.5μg) or vehicle (control). The vascularization of the implants and the inflammatory foreign body reaction was analyzed using intravital fluorescence microscopy, histology and immunohistochemistry over 14 days. MALP-2 treatment dose-dependently improved the vascularization of Medpor(®), as indicated by a significantly higher functional microvessel density at the border and center of the implants when compared to controls. This was associated with a temporary increase of adherent leukocytes in host tissue venules during the first 3 days after implantation. At day 14, implants in MALP-2-treated chambers were surrounded by a granulation tissue, which exhibited a significantly higher density of CD31-positive microvessels and number of F4/80-positive macrophages when compared to controls. Additional biomaterial-free chambers did not show any signs of angiogenesis when treated with MALP-2. This indicates that locally applied MALP-2 effectively stimulates the early vascularization of Medpor(®) without inducing any local or systemic side effects. Accordingly, this easy approach may further improve the rapid incorporation of this biomaterial at the implantation site.
    Acta Biomaterialia. 01/2014;
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    ABSTRACT: The cytosolic Nucleotide Oligomerization Domain (NOD)-like receptors NOD-1 and NOD-2 are important contributors to the intracellular recognition of pathogens including Chlamydophila pneumoniae, but little is known about their influence on allergen-induced airway inflammation. In BALB/c mice, we observed that infection with C. pneumoniae prior to systemic sensitization with ovalbumin (OVA) and local OVA airway exposure diminished airway hyperresponsiveness. Thus, the impact of NOD1 agonist FK156 and NOD2 agonist muramyl dipeptide (MDP) given 6 hours prior to each sensitization or airway challenge was evaluated regarding airway hyperresponsiveness (AHR), OVA-specific plasma immunoglobulins, bronchoalveolar lavage fluid (BALF) differentials and cytokines. Further, spleen dendritic cells (DCs) of FK156-treated mice were isolated and cocultured with OVA-specific T cells isolated from DO11.10 mice, and T cell proliferation was quantified subsequent to OVA restimulation. Additionally, T cell proliferation was investigated in vivo in lungs and lymph nodes of FK156-treated and OVA-exposed DO11.10 mice. FK156 but not MDP reduced AHR and pulmonary eosinophilic infiltration, if given prior to OVA sensitization or challenge, while Th2 cytokines were not diminished. DCs from FK156-treated mice evoked less OVA-specific T cell proliferation as compared to solvent-treated controls. Similarly, antigen-specific T cell activation in lung tissue was diminished after FK156 treatment. We conclude that NOD1 activation reduced AHR in allergen-induced lung inflammation, which was accompanied by a reduction of allergen-specific T cell proliferation.
    American Journal of Respiratory Cell and Molecular Biology 11/2013; · 4.15 Impact Factor
  • Foot & Ankle International 09/2013; · 1.47 Impact Factor
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    ABSTRACT: Little is known about the normal immune cell profile in the lungs of infants without pulmonary disease. Normal lung samples obtained at autopsy of 10 infants that died either due to incidental or inflicted causes or non-pulmonary diseases were stained for antibodies against B and T lymphocytes, macrophages, NK cells, cytotoxic cells, dendritic cells and mast cells. Cells were quantified in the airway epithelial layer, inner layer (between the epithelium and the outer smooth muscle border), outer layer (between the outer smooth muscle border and the external limits of the airway) and alveolar septa. Basement membrane or alveolar septa lengths were assessed by image analysis. Results were expressed as cells/mm. The median age of patients was 6.8 months, ranging from 11 to 840 days. The inner layer of the airways was the region with the smallest density of cells. There was a predominance of cells related to the innate immunity such as CD56+, Granzyme B+ and CD68+ cells in the epithelial layer and alveolar parenchyma. The outer layer and the lung parenchyma presented the highest cellular density. There were very few CD4+ T cells or dendritic cells in most of the lung compartments. The numbers of CD3+ T and granzyme B+ cells correlated positively with age. There was a compartmentalization of immune cells along airways and parenchyma, which may be related to the development of innate and acquired lung defense mechanisms.
    Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft 06/2013; · 1.96 Impact Factor
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    ABSTRACT: OBJECTIVES: Pneumonia is associated with a high morbidity and mortality worldwide. Streptococcus pneumoniae remains the most common cause of pneumonia, and pneumococcal antibiotic resistance is increasing. The purified bacteriophage endolysin Cpl-1 rapidly and specifically kills pneumococci. We tested the hypothesis that a single dose of recombinant aerosolized Cpl-1 would rescue mice with severe pneumococcal pneumonia. METHODS: Female C57Bl/6 mice (aged 8-12 weeks) were transnasally infected with pneumococci. When severe pneumonia was established 24 h after infection, mice were treated with 25 μL of aerosolized Cpl-1. Survival was monitored for 10 days and the pulmonary and systemic bacterial burdens were assessed. Furthermore, cytokines were quantified in bronchoalveolar lavage fluid, and lung morphology was analysed histologically. RESULTS: The endolysin efficiently reduced pulmonary bacterial counts and averted bacteraemia. Although concentrations of inflammatory cytokines were increased shortly after Cpl-1 inhalation, mice recovered rapidly, as shown by increasing body weight, and inflammatory infiltrates resolved in the lungs, leading to a reduction in mortality of 80%. CONCLUSIONS: Administration of Cpl-1 by inhalation may offer a new therapeutic perspective for the treatment of pneumococcal lung infection.
    Journal of Antimicrobial Chemotherapy 04/2013; · 5.34 Impact Factor
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    ABSTRACT: BACKGROUND: TLR-2 is expressed on the surface of leucocytes, lung and liver tissue and initiates the activation of immune response after interaction with components of the bacterial cell wall. In this experiment we investigated whether immunostimulation with TLR-2 agonists under conditions of sterile inflammation (hemorrhagic shock (HS)) may affect the immune response and remote organ inflammation.
    Journal of Inflammation 04/2013; 10(1):17. · 2.55 Impact Factor
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    ABSTRACT: Background: The effect of cigarette smoke (CS) on the phagocytosis of alveolar macrophages is discussed controversially on the basis of in vitro experiments. In this short report we describe the in vivo observations that we have performed.Methods: For this purpose mice were exposed to CS for three consecutive days. One day later the fluorescent microspheres were administered intratracheally and the lung surface was investigated using long-distance fluorescence microscopy.Results: We found that the numbers of neutrophils which engulfed particles was increased in the CS group as compared to controls. The overall phagocytic activity was not significantly different after CS exposure. Conclusions: In conclusion the phagocytosis of alveolar macrophages and neutrophils after short time CS exposure was not affected. Further investigations will need to look for the effects of long-term CS exposure and the phagocytosis of living bacteria.
    Pneumologie 03/2013;
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    ABSTRACT: Procalcitonin is regarded as a valuable marker for sepsis in living persons and even in post-mortem investigations. At the Institute of Legal Medicine, 25 autopsy cases with suspected bacterial infectious diseases or sepsis were examined using the semi-quantitative PCT-Q(®)-test (B.R.A.H.M.S., Germany) in 2010 and 2011. As controls, 75 cadavers were used for which there was no suspicion of a bacterial infectious disease or sepsis. Femoral blood was cultured from the cases and from controls, and samples from the brain, heart, lungs, liver, spleen and kidneys were examined histologically for findings seen in sepsis. Twelve cases in the sepsis/infectious disease group (48%) were classifiable as sepsis following synopsis of PCT levels, autopsy results, and histopathological and microbiological findings. This study shows that the semi-quantitative PCT-Q(®)-test is a useful supplementary marker in routine autopsy investigations, capable of classifying death as due to sepsis.
    Forensic science international 02/2013; · 2.10 Impact Factor
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    Thomas Tschernig, Michael Kasper, Reinhard Pabst
    Thorax 01/2013; · 8.38 Impact Factor
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    ABSTRACT: Microparticles (MP) and fibres can be inhaled and cause inflammatory lung diseases. So far MP and fibres have not observed directly in the lung of living animals. A direct visualisation of particles and fibres would be important to study interactions with local and immigration host cells. In this methodical report latex beads were used as model particles for, e.g. nanoparticles, dusts, pollen or bacteria and were investigated using intravital fluorescence microscopy. Intravital fluorescence microscopy of the lung periphery is challenging because of the constant movement of the lung tissue and the heart. Chest window techniques have been described for investigation of lung vessels. For investigation of MP in larger areas of the lung surface this study presents an open chest-technique. Fluorescent MP were instilled into the trachea and could be observed in the alveoli of the right lung. Abundant numbers of MP were found within alveolar macrophages indicating that they are actively engulfed. Using the same setup also fluorescence labelled bacteria and its phagocytosis could be observed as shown in preliminary experiments. In conclusion, we present a method to analyse MP/fibres and its interaction with local and immigrating host cells in the living lung.
    Experimental and toxicologic pathology: official journal of the Gesellschaft fur Toxikologische Pathologie 01/2013; · 1.43 Impact Factor
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    ABSTRACT: Bronchopulmonary dysplasia (BPD) presents a major threat of very preterm birth and treatment options are still limited. Stem cells from different sources have been used successfully in experimental BPD, induced by postnatal hyperoxia. We investigated the effect of umbilical cord blood mononuclear cells (MNCs) in a new double-hit mouse model of BPD. For the double-hit, date mated mice were subjected to hypoxia and thereafter the offspring was exposed to hyperoxia. Human umbilical cord blood MNCs were given intraperitoneally by day P7. As outcome variables were defined: physical development (auxology), lung structure (histomorphometry), expression of markers for lung maturation and inflammation on mRNA and protein level. Pre- and postnatal normoxic pups and sham treated double-hit pups served as control groups. Compared to normoxic controls, sham treated double-hit animals showed impaired physical and lung development with reduced alveolarization and increased thickness of septa. Electron microscopy revealed reduced volume density of lamellar bodies. Pulmonary expression of mRNA for surfactant proteins B and C, Mtor and Crabp1 was reduced. Expression of Igf1 was increased. Treatment with umbilical cord blood MNCs normalized thickness of septa and mRNA expression of Mtor to levels of normoxic controls. Tgfb3 mRNA expression and pro-inflammatory IL-1β protein concentration were decreased. The results of our study demonstrate the therapeutic potential of umbilical cord blood MNCs in a new double-hit model of BPD in newborn mice. We found improved lung structure and effects on molecular level. Further studies are needed to address the role of systemic administration of MNCs in experimental BPD.
    PLoS ONE 01/2013; 8(9):e74740. · 3.53 Impact Factor
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    ABSTRACT: Reconstruction of critical size bone defects represents a major challenge in orthopaedic surgery. Insufficient angiogenesis is a limiting factor for engraftment of large-scale tissue transplants. Transplantation or stimulation of local mesenchymal stem cells (MSCs) represents a potential solution to enhance angiogenesis. We recently identified angiogenic properties for the Toll-like receptor (TLR) 2/6 agonist MALP-2 and now investigated if MALP-2 could be used to stimulate MSCs in order to promote angiogenesis in vitro and in vivo. Human MSCs from the bone marrow of healthy subjects were isolated, cultured and expanded in vitro and were shown to be positive for mesenchymal stem cells markers as well as for the MALP-2 receptors TLR2 and TLR6. MALP-2 directly enhanced migration but not proliferation of human MSCs. Conditioned medium from MALP-2 stimulated MSCs significantly increased proliferation, migration and tube formation of endothelial cells. Analysis of the conditioned medium from MSCs revealed that MALP-2 stimulation enhanced the secretion of several chemokines and growth factors including vascular endothelial growth factors (VEGF) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Finally, we studied MALP-2 effects on MSCs in a sheep model of tissue engineering in vivo. Therefore, MSCs were isolated from the iliac crest of black head sheep and co-cultivated with MALP-2 ex vivo. Implantation of autologous MSCs within a scaffold cylinder into the M. latissimus dorsi significantly enhanced vessel density of these constructs after 6 months. We here present the first evidence that TLR2/6-dependent stimulation of MSCs promotes angiogenesis in vitro and in vivo offering a novel strategy for therapeutic angiogenesis, e.g., for tissue engineering of bone.
    European cells & materials 01/2013; 26:66-79. · 4.56 Impact Factor

Publication Stats

2k Citations
621.01 Total Impact Points

Institutions

  • 2010–2014
    • Universität des Saarlandes
      • Institut für Medizinische Mikrobiologie und Hygiene
      Saarbrücken, Saarland, Germany
  • 2008–2013
    • Charité Universitätsmedizin Berlin
      Berlín, Berlin, Germany
  • 2005–2011
    • Fraunhofer Institute for Toxicology and Experimental Medicine ITEM
      • Department of Airway Immunology
      Hannover, Lower Saxony, Germany
  • 1995–2008
    • Hannover Medical School
      • • Institute for Functional and Applied Anatomy
      • • Centre for Anatomy
      Hannover, Lower Saxony, Germany
  • 2006
    • VU University Amsterdam
      • Department of Molecular Cell Biology and Immunology
      Amsterdamo, North Holland, Netherlands
  • 2004–2005
    • University of Veterinary Medicine Hannover
      • Institute of Pharmacology, Toxicology and Pharmacy
      Hanover, Lower Saxony, Germany
  • 2003
    • Universitätsmedizin Göttingen
      • Center for Anatomy
      Göttingen, Lower Saxony, Germany
    • University of Saskatchewan
      • Department of Veterinary Biomedical Sciences
      Saskatoon, Saskatchewan, Canada
  • 2002
    • University Hospital Essen
      Essen, North Rhine-Westphalia, Germany