Mononuclear cell secretome protects from experimental autoimmune myocarditis

Aims Supernatants of serum-free cultured mononuclear cells (MNC) contain a mix of immunomodulating factors (secretome), which have been shown to attenuate detrimental inflammatory responses following myocardial ischaemia. Inflammatory dilated cardiomyopathy (iDCM) is a common cause of heart failure in young patients. Experimental autoimmune myocarditis (EAM) is a CD4+ T cell-dependent model, which mirrors important pathogenic aspects of iDCM. The aim of this study was to determine the influence of MNC secretome on myocardial inflammation in the EAM model. Methods and results BALB/c mice were immunized twice with an alpha myosin heavy chain peptide together with Complete Freund adjuvant. Supernatants from mouse mononuclear cells were collected, dialysed, and injected i.p. at Day 0, Day 7, or Day 14, respectively. Myocarditis severity, T cell responses, and autoantibody formation were assessed at Day 21. The impact of MNC secretome on CD4+ T cell function and viability was evaluated using in vitro proliferation and cell viability assays. A single high-dose application of MNC secretome, injected at Day 14 after the first immunization, effectively attenuated myocardial inflammation. Mechanistically, MNC secretome induced caspase-8-dependent apoptosis in autoreactive CD4+ T cells. Conclusion MNC secretome abrogated myocardial inflammation in a CD4+ T cell-dependent animal model of autoimmune myocarditis. This anti-inflammatory effect of MNC secretome suggests a novel and simple potential treatment concept for inflammatory heart disease

Ausschüttungssperren im HGB : (unter besonderer Berücksichtigung von gesellschaftsrechtlichen Aspekten und europäischen Entwicklungen)

Dagmar KollmannKlagenfurt, Alpen-Adria-Univ., Diss., 2005KB2005 06OeBB(VLID)241234

The role of cross-reactive antibodies in birch pollen-related food allergy and in delayed hypersensitivity to red meat

Two types of IgE-mediated food allergy can be distinguished: primary and secondary food allergy. The latter is the result of initial sensitization via non-gastrointestinal routes, e.g. the lung or skin, and subsequent cross-reactivity of allergen-specific IgE antibodies (Ab) with structural related proteins in particular foods. The aim of this thesis was to investigate such cross-reactive Ab in birch pollen-related food allergy, a highly prevalent secondary food allergy in Austria, and in delayed hypersensitivity to red meat, which has recently been reported in the United States. More than 70% of birch pollen-allergic individuals develop IgE Ab specific for the major birch pollen allergen Bet v 1 that cross-react with the structurally related apple allergen Mal d 1. Detection of allergen-specific IgE Ab is one important step in allergy diagnosis. Since the use of apple extracts bears several limitations for allergy diagnosis because they may lack intact Mal d 1 we investigated whether recombinant (r) Mal d 1 can improve this situation. We found that rMal d 1 enhances the sensitivity of detection of specific serum IgE. Furthermore, rMal d 1 increased the sensitivity of skin prick tests of apple-allergic individuals. Thus, in addition to in vitro diagnosis, one single isoform of recombinant Mal d 1 is a useful tool for in vivo diagnosis. Only recently, patients suffering from delayed type meat allergy have been reported who develop systemic reactions several hours after ingestion of red meat and display increased levels of IgE specific for the carbohydrate Galalpha1-3Galbeta1-4GlcNAc-R (alpha-gal). Tick bites have been considered to be responsible for primary sensitization to alpha-gal via the skin. We investigated 20 Austrian patients who experienced such reactions and characterized their alpha-gal-specific IgE and IgG responses in more detail. Bovine gamma globulin (BGG) was the protein in meat extract most frequently recognized by their IgE-Ab. Both IgE- and IgG-binding to BGG were completely abolished after pre-incubation with alpha-gal. This finding indicated that BGG-specific Ab selectively recognized the carbohydrate epitope without involvement of amino acid residues. IgG to alpha-gal are highly abundant natural Ab in humans. However, neither the depletion of autologous alpha-gal-specific IgG Ab nor the addition of alpha-gal-specific IgG Ab from non-allergic individuals changed the IgE-recognition of BGG of meat-allergic patients. Specific IgG-response in meat-allergic patients to alpha-gal was dominated by IgG1 and IgG3 Ab, whereas in patients with birch pollen-related apple allergy IgG4 Ab dominate the specific IgG-response to Mal d 1. In summary, we found that in patients with delayed meat-allergy the enhanced alpha-gal-specific IgE levels are accompanied by high levels of alpha-gal-specific IgG1 devoid of IgE-blocking activity. This subclass distribution is different from the subclass distribution in birch pollen-related food allergy and also distinct from natural alpha-gal-IgG responses in non-allergic individuals.IgE-mediierte Nahrungsmittelallergien können in zwei Gruppen unterteilt werden: in die primäre und die sekundäre Nahrungsmittelallergie. Letztere resultiert von einer primären Sensibilisierung über z.B. die Lunge oder die Haut, mit anschließender Kreuzreaktion von Allergen-spezifischen IgE Antikörpern (Ak) mit strukturell ähnlichen Proteinen in den entsprechenden Nahrungsmitteln. Das Ziel dieser Dissertation war es, die Rolle von solchen kreuzreaktiven Ak in der in Österreich sehr häufigen Birkenpollen-assoziierten Nahrungsmittelallergie, und in der kürzlich beschriebenen verspäteten Allergie gegen rotes Fleisch, zu erforschen. Mehr als 70% der BirkenpollenallergikerInnen entwickeln IgE Ak spezifisch für das Birkenpollen-Hauptallergen Bet v 1 welche mit dem strukturell verwandten Apfel-Hauptallergen Mal d 1 kreuzreagieren. Die Detektion von Allergen-spezifischen IgE Ak ist ein wichtiger Schritt in der Abklärung einer Allergie. Die Verwendung von Apfel-Extrakten ist aufgrund von Konzentrationsschwankungen von intaktem Mal d 1 jedoch sehr limitiert. Daher untersuchten wir, ob rekombinantes (r) Mal d 1 die Diagnostik verbessern kann. Wir konnten zeigen, dass rMal d 1 die Sensitivität sowohl in der spezifischen IgE-Analyse als auch in Hautpricktests erhöhte. Eine einzige Isoform von rMal d 1 kann daher in der in vitro Diagnostik und auch in der in vivo Diagnostik erfolgreich verwendet werden. Erst kürzlich wurden PatientInnen, welche mehrere Stunden nach der Aufnahme von rotem Fleisch systemische Reaktionen entwickeln und erhöhte IgE-Werte gegen das Zuckerepitop Galalpha1-3Galbeta1-4GlcNAc-R (alpha-gal) aufweisen, beschrieben. Zeckenbisse wurden als Ursache für die primäre Sensibilisierung über die Haut beschrieben. Wir haben die alpha-gal-spezifische IgE- und IgG-Reaktivität in 20 PatientInnen mit verspäteter Fleischallergie im Detail analysiert. Bovines Gammaglobulin (BGG) war das Protein im Fleischextrakt, welches am häufigsten von den IgE Ak der PatientInnen erkannt wurde. Sowohl die IgE-, als auch die IgG-Reaktivität, konnte durch Präinkubation der Seren mit alpha-gal komplett inhibiert werden. Diese Ergebnisse zeigen, dass BGG-spezifische Ak selektiv das Zuckerepitop erkennen. Obwohl natürlich vorkommende IgG Ak gegen alpha-gal im Menschen reichlich vorhanden sind, konnten weder die Entfernung von alpha-gal-spezfischem IgG, noch die Zugabe von alpha-gal-spezifischen IgG Ak von Nicht-Allergikern, die IgE-Reaktivität gegen BGG verändern. Die alpha-gal-spezifische IgG-Reaktivität in FleischallergikerInnen wurde von IgG1 und IgG3 dominiert, während in ApfelallergikerInnen die Mal d 1-spezifische IgG-Antwort von IgG4 dominiert wurde. Zusammenfassend konnten wir zeigen, dass die erhöhten alpha-gal-spezifische IgE-Werte in PatientInnen mit verspäteter Fleischallergie von hohen alpha-gal-spezifischen IgG1-Werten begleitet sind, welche keine inhibierende Funktion aufweisen. Die Subklassen-Verteilung unterscheidet sich von jenen PatientInnen mit Birkenpollen-assoziierter Nahrungsmittelallergie und auch von der natürlichen alpha-gal-spezifischen IgG-Reaktivität von Nicht-AllergikerInnen.submitted by Dagmar Kollmann, MDZusammenfassung in deutscher SpracheAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMedizinische Universität Wien, Dissertation, 2016OeBB(VLID)171508

Biliary Metabolome Profiling for Evaluation of Liver Metabolism and Biliary Tract Function Related to Organ Preservation Method and Degree of Ischemia in a Porcine Model

The development of surgical techniques, immunosuppressive strategies and new organ preservation methods have meant that transplant centers have to face the problem of an insufficient number of organs for transplantation concerning the constantly growing demand. Therefore, using organs from expanded criteria donors and developing new analytical solutions to find parameters or compounds that would allow a more efficient assessment of organ quality before transplantation are options for meeting this challenge. This study proposed bile metabolomic analysis to evaluate liver metabolism and biliary tract function depending on the organ preservation method and degree of warm ischemia time. The analyses were performed on solid-phase microextraction-prepared bile samples from porcine model donors with mild (heart beating donor [HBD]) and moderate warm ischemia (donation after circulatory death [DCD]) grafts subjected to static cold storage (SCS) or normothermic ex vivo liver perfusion (NEVLP) before transplantation. Bile produced in the SCS-preserved livers was characterized by increased levels of metabolites such as chenodeoxycholic acid, arachidonic acid and 5S-hydroxyeicosatetraeonic acid, as well as saturated and monounsaturated lysophosphatidylcholines (LPC). Such changes may be associated with differences in the bile acid synthesis pathways and organ inflammation. Moreover, it has been shown that NEVLP reduced the negative effect of ischemia on organ function. A linear relationship was observed between levels of lipids from the LPC group and the time of organ ischemia. This study identified metabolites worth considering as potential markers of changes occurring in preserved grafts

Biliary Metabolome Profiling for Evaluation of Liver Metabolism and Biliary Tract Function Related to Organ Preservation Method and Degree of Ischemia in a Porcine Model

The development of surgical techniques, immunosuppressive strategies and new organ preservation methods have meant that transplant centers have to face the problem of an insufficient number of organs for transplantation concerning the constantly growing demand. Therefore, using organs from expanded criteria donors and developing new analytical solutions to find parameters or compounds that would allow a more efficient assessment of organ quality before transplantation are options for meeting this challenge. This study proposed bile metabolomic analysis to evaluate liver metabolism and biliary tract function depending on the organ preservation method and degree of warm ischemia time. The analyses were performed on solid-phase microextraction-prepared bile samples from porcine model donors with mild (heart beating donor [HBD]) and moderate warm ischemia (donation after circulatory death [DCD]) grafts subjected to static cold storage (SCS) or normothermic ex vivo liver perfusion (NEVLP) before transplantation. Bile produced in the SCS-preserved livers was characterized by increased levels of metabolites such as chenodeoxycholic acid, arachidonic acid and 5S-hydroxyeicosatetraeonic acid, as well as saturated and monounsaturated lysophosphatidylcholines (LPC). Such changes may be associated with differences in the bile acid synthesis pathways and organ inflammation. Moreover, it has been shown that NEVLP reduced the negative effect of ischemia on organ function. A linear relationship was observed between levels of lipids from the LPC group and the time of organ ischemia. This study identified metabolites worth considering as potential markers of changes occurring in preserved grafts