Staphylococcus aureus controls interleukin-5 release in upper airway inflammation

Staphylococcus aureus is a frequent colonizer of the upper airways in chronic rhinosinusitis with nasal polyps, but also resides intramucosally, it has been shown that secreted staphylococcal proteins such as enterotoxins and serine proteases induce the release of cytokines such as IL-5. We have analyzed nasal polyp tissue freshly obtained during routine surgery, which did or did not contain cultivatable S. aureus, to study spontaneous IL-5 production by nasal polyp tissue over 24 and 72 h in tissue culture In S. aureus-positive samples we interfered by killing the bacteria using antibiotics or S. aureus specific intravenous staphylococcal phages (ISP), active or heat-inactivated. Phage-neutralizing antibodies were used to demonstrate the specificity of the phage-mediated effects We monitored S. aureus colony forming units, and identified S. aureus proteins by mass spectrometry We demonstrate that cultivatable S. aureus may be found in type-2 inflamed nasal polyps, the pathogen is replicating within 24 h and secretes proteins, including enterotoxins and serine proteases The presence of S. aureus was associated with a significantly higher release of IL-5 Killing of S. aureus by antibiotics or specific ISP significantly reduced the IL-5 release. The suppressive activity of the bacteriophage on IL-5 be abolished by heat inactivation or anti-phage antibodies. Biological significance In this study, we used high resolution mass spectrometry to identify S. aureus proteins directly in infected nasal polyp tissue and nasal polyp tissue incubated over 24 and 72 h in culture We discovered bacterial proteins including enterotoxins and serine proteases like proteins These experiments indicate a direct role of S. aureus in the regulation of IL-5 production in nasal polyps and may suggest the involvement of bacterial proteins detected in the tissues

TNF-related apoptosis-inducing ligand deficiency enhances survival in murine colon ascendens stent peritonitis

Katharina Beyer,1 Laura Stollhof,1 Christian Poetschke,2 Wolfram von Bernstorff,1 Lars Ivo Partecke,1 Stephan Diedrich,1 Stefan Maier,1 Barbara M Bröker,2 Claus-Dieter Heidecke1 1Department of General, Visceral, Thoracic, and Vascular Surgery, 2Institute of Immunology, University of Greifswald, Greifswald, GermanyBackground: Apart from inducing apoptosis in tumor cells, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) influences inflammatory reactions. Murine colon ascendens stent peritonitis (CASP) represents a model of diffuse peritonitis. Recently, it has been demonstrated that administration of exogenous TRAIL not only induces apoptosis in neutrophils but also enhances survival in this model. The aim of this study was to examine the impact of genetic TRAIL deficiency on the course of CASP.Methods: Peritonitis was induced in 6- to 8-week-old female TRAIL−/− mice as well as in wild-type mice. The sepsis severity score and survival of mice were monitored. Bacterial loads in blood as well as in the lymphoid organs were examined. Additionally, the number of apoptotic cells within the lymphoid organs was determined.Results: As early as 8 hours postinduction of CASP, TRAIL−/− mice were significantly more affected by sepsis than wild-type mice, as measured by the sepsis severity score. However, during the further course of sepsis, TRAIL deficiency led to significantly decreased sepsis severity scores, resulting in an enhanced overall survival in TRAIL−/− mice. The better survival of TRAIL−/− mice was accompanied by a decreased bacterial load within the blood. In marked contrast, the number of apoptotic cells within the lymphoid organs was highly increased in TRAIL−/− mice 20 hours after induction of CASP.Conclusion: Hence, exogenous and endogenous TRAIL is protective during the early phase of sepsis, while endogenous TRAIL appears to be detrimental in the later course of this disease.Keywords: CASP, mice, sepsis, TRAIL, inflammatio

Human antibody responses against non-covalently cell wall-bound Staphylococcus aureus proteins

Abstract Human antibody responses to pathogens, like Staphylococcus aureus, are important indicators for in vivo expression and immunogenicity of particular bacterial components. Accordingly, comparing the antibody responses to S. aureus components may serve to predict their potential applicability as antigens for vaccination. The present study was aimed at assessing immunoglobulin G (IgG) responses elicited by non-covalently cell surface-bound proteins of S. aureus, which thus far received relatively little attention. To this end, we applied plasma samples from patients with the genetic blistering disease epidermolysis bullosa (EB) and healthy S. aureus carriers. Of note, wounds of EB patients are highly colonized with S. aureus and accordingly these patients are more seriously exposed to staphylococcal antigens than healthy individuals. Ten non-covalently cell surface-bound proteins of S. aureus, namely Atl, Eap, Efb, EMP, IsaA, LukG, LukH, SA0710, Sle1 and SsaA2, were selected by bioinformatics and biochemical approaches. These antigens were recombinantly expressed, purified and tested for specific IgG responses using human plasma. We show that high exposure of EB patients to S. aureus is mirrored by elevated IgG levels against all tested non-covalently cell wall-bound staphylococcal antigens. This implies that these S. aureus cell surface proteins are prime targets for the human immune system