Superantigen-induzierte Effekte auf die Expression des IL-2 Rezeptors und Proliferation von CD4- und CD8-positiven T-Zellen in der Ratte

Die Bindung bakterieller Superantigene (SAg) an T-Zellen mit spezifischen Vb-Isotypen in ihrem Rezeptor führt zu einer polyklonalen Aktivierung zahlreicher T-Lymphozyten. Im humanen System sind SAg die häufigste Ursache von Lebensmittelvergiftungen, welche einhergehen mit einem hohen Risiko des septischen Schocks. Bei Mäusen ist die immunstimulierende Wirkung der SAg hinreichend untersucht, wohingegen nur wenig bei Ratten bekannt ist. Die vorliegende Arbeit hat zum Ziel, die immunstimulatorische Wirkung von Staphylokokken Enterotoxin A (SEA) auf Lymphozyten verschiedener Immunorgane der Ratte in vivo zu charakterisieren. Hierüber liegen bisher keine systematischen Studien in der Literatur vor. Das Serum sowie die lymphatischen Organe (Milz, Thymus, mesenteriale Lymphknoten) wurden zu verschiedenen Zeitpunkten nach SEA-Applikation entnommen. Erhöhte IL-2 und IL-6 Serumspiegel zeigten den starken immunstimulatorischen Effekt von SEA. Die Lokalisation von IL-2 Rezeptor alpha mRNA mittels in-situ Hybridisierung in der periarteriolären lymphatischen Scheide (PALS) der Milz, einer Region, in der hauptsächlich T-Lymphozyten als Zelltyp vorliegen, unterstreicht die T-Zell-mediierte Immunstimulation. Die Laser-Capture-Microdissection (LCM) der PALS zeigte stark erhöhte IL-2 Rezeptor alpha mRNA Spiegel gemessen in der PCR, im Vergleich zu anderen Regionen der Milz. Signifikant erhöhte Zahlen von CD4+ als auch CD8+ Lymphozyten, die zusätzlich die IL-2 Rezeptor a-Kette (CD25) auf ihrer Oberfläche exprimierten, wurden in der FACS-Analyse gemessen. Der erwartete starke mitogene Effekt von SEA auf die IL-2 Rezeptor positiven Zellen wurde durch hohe Proliferationsraten von Splenozyten, Thymozyten und auch Zellen des mesenterialen Lymphknoten gezeigt. Insgesamt läßt sich SEA, in Homologie zum humanen Organismus, als ein potentes Mitogen für das periphere Immunsystem der Ratte charakterisieren

Arabidopsis BTB/POZ protein-dependent PENETRATION3 trafficking and disease susceptibility

The outermost cell layer of plant roots (epidermis) constantly encounters environmental challenges. The epidermal outer plasma membrane domain harbours the PENETRATION3 (PEN3)/ABCG36/PDR8 ATP-binding cassette transporter that confers non-host resistance to several pathogens. Here, we show that the Arabidopsis ENDOPLASMIC RETICULUM-ARRESTED PEN3 (EAP3) BTB/POZ-domain protein specifically mediates PEN3 exit from the endoplasmic reticulum and confers resistance to a root-penetrating fungus, providing prime evidence for BTB/POZ- domain protein-dependent membrane trafficking underlying disease resistance.The PENETRATION3 (PEN3/ABCG36/PDR8) ATP-binding cassette transporter of Arabidopsis thaliana is a crucial component of preinvasive defence against some fungal and bacterial non-host pathogens entering by direct penetration1,2,3,4. In above-ground organs, PEN3 is recruited to sites of pathogen attack at the cell surface3,4. In seedling roots, PEN3 polarly localizes to the epidermal outer membrane domain in the absence of pathogens5,6. Root epidermal cells display four major polar plasma membrane domains: the outer domain facing the environment, the inner domain oriented towards the cortical cell layer, the shootward-oriented, apical, and the root tip-oriented, basal, domain6. Proteins in the outer domain that function in regulating the transport of inorganic compounds include, for example, the NIP5;1 boric acid uptake channel7. Factors required for PEN3 and NIP5;1 trafficking from the trans-Golgi network to the outer domain have been identified8,9,10, and exocyst complex components promote polar tethering of several outer domain proteins9,11. However, factors that specifically mediate trafficking of polar outer membrane cargos involved in responses to root-penetrating pathogens remain to be discovered.In a genetic screen for mislocalization of PEN3 fused to green-fluorescent protein (PEN3- GFP) in the root epidermis of seedlings9, we recovered one recessive mutant in which PEN3-GFP localized to a cytoplasmic structure resembling the endoplasmic reticulum (ER) (Fig. 1a–d). This er-arrested pen3-1 (eap3-1) mutation indistinguishably affected localization of PEN3-GFP from that of PEN3-mCherry (Supplementary Fig. 1a,b), which colocalized with the ER-intrinsic chaperone BIP in the eap3-1 mutant (Supplementary Fig. 1c,d), corroborating an ER arrest of PEN3

Combined Blockade of ADP Receptors and PI3-Kinase p110β Fully Prevents Platelet and Leukocyte Activation during Hypothermic Extracorporeal Circulation

Extracorporeal circulation (ECC) and hypothermia are used to maintain stable circulatory parameters and improve the ischemia tolerance of patients in cardiac surgery. However, ECC and hypothermia induce activation mechanisms in platelets and leukocytes, which are mediated by the platelet agonist ADP and the phosphoinositide-3-kinase (PI3K) p110β. Under clinical conditions these processes are associated with life-threatening complications including thromboembolism and inflammation. This study analyzes effects of ADP receptor P2Y12 and P2Y1 blockade and PI3K p110β inhibition on platelets and granulocytes during hypothermic ECC. Human blood was treated with the P2Y12 antagonist 2-MeSAMP, the P2Y1 antagonist MRS2179, the PI3K p110β inhibitor TGX-221, combinations thereof, or PBS and propylene glycol (controls). Under static in vitro conditions a concentration-dependent effect regarding the inhibition of ADP-induced platelet activation was found using 2-MeSAMP or TGX-221. Further inhibition of ADP-mediated effects was achieved with MRS2179. Next, blood was circulated in an ex vivo ECC model at 28°C for 30 minutes and various platelet and granulocyte markers were investigated using flow cytometry, ELISA and platelet count analysis. GPIIb/IIIa activation induced by hypothermic ECC was inhibited using TGX-221 alone or in combination with P2Y blockers (p<0.05), while no effect of hypothermic ECC or antiplatelet agents on GPIIb/IIIa and GPIbα expression and von Willebrand factor binding was observed. Sole P2Y and PI3K blockade or a combination thereof inhibited P-selectin expression on platelets and platelet-derived microparticles during hypothermic ECC (p<0.05). P2Y blockade alone or combined with TGX-221 prevented ECC-induced platelet-granulocyte aggregate formation (p<0.05). Platelet adhesion to the ECC surface, platelet loss and Mac-1 expression on granulocytes were inhibited by combined P2Y and PI3K blockade (p<0.05). Combined blockade of P2Y12, P2Y1 and PI3K p110β completely inhibits hypothermic ECC-induced activation processes. This novel finding warrants further studies and the development of suitable pharmacological agents to decrease ECC- and hypothermia-associated complications in clinical applications

Reduction or de-escalation of dual antiplatelet therapy intensity or duration in patients with acute coronary syndromes undergoing percutaneous coronary intervention: A mini-review

© 2022 Farag, Jeyalan, Ferreiro, Jeong, Geisler and Gorog. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/Current guidelines for patients with acute coronary syndrome (ACS) recommend dual antiplatelet therapy (DAPT) for 12 months. Since bleeding is the main Achilles' heel of DAPT, in recent years several randomized controlled trials have evaluated the safety and efficacy of de-escalation of DAPT with respect to ischaemic and bleeding endpoints. These trials can be broadly divided into studies evaluating a shorter duration of DAPT, and those studies in which DAPT that includes a potent P2Y12 inhibitor, such as prasugrel or ticagrelor, is compared to less intense DAPT, mainly clopidogrel or reduced-dose prasugrel. We sought to evaluate the studies assessing de-escalation of DAPT in patients with ACS undergoing PCI. We review the studies evaluating the strategies of de-escalation of DAPT intensity and those evaluating a strategy of de-escalation of DAPT duration in ACS patients undergoing PCI. We summarize the limitations of studies to date, gaps in evidence and make recommendations for future studies.Peer reviewe

Geothermal Potential of the Brenner Base Tunnel—Initial Evaluations

Increasing demands on mobility and transport, but limited space above ground, lead to new traffic routes being built, even more underground in the form of tunnels. In addition to improving the traffic situation, tunnels offer the possibility of contributing to climate-friendly heating by indirectly serving as geothermal power plants. In this study, the geothermal potential of the future longest railway tunnel in the world, the Brenner Base Tunnel, was evaluated. At the Brenner Base Tunnel, warm water naturally flows from the apex of the tunnel towards the city of Innsbruck, Austria. In order to estimate its geothermal potential, hydrological data of discharge rates and temperatures were investigated and analyzed. The investigations indicated the highest geothermal potential in the summertime, while the lowest occurs during winter. It could be shown that these variations were a result of cooling during discharge through areas of low overburden (mid mountain range), where the tunnel atmosphere is increasingly influenced by the air temperatures outside the tunnel. Nevertheless, the calculations showed that there will be a usable potential after completion of the tunnel

Spectral-interference microscopy for characterization of functional plasmonic elements

Plasmonic modes supported by noble-metal nanostructures offer strong subwavelength electric-field confinement and promise the realization of nanometer-scale integrated optical circuits with well-defined functionality. In order to measure the spectral and spatial response functions of such plasmonic elements, we combine a confocal microscope setup with spectral interferometry detection. The setup, data acquisition, and data evaluation are discussed in detail by means of exemplary experiments involving propagating plasmons transmitted through silver nanowires. By considering and experimentally calibrating any setup-inherent signal delay with an accuracy of 1 fs, we are able to extract correct timing information of propagating plasmons. The method can be applied, e.g., to determine the dispersion and group velocity of propagating plasmons in nanostructures, and can be extended towards the investigation of nonlinear phenomena

Effect of Bruton's tyrosine kinase inhibitors on platelet aggregation in patients with acute myocardial infarction

Aims: Despite widespread use of dual antiplatelet therapy in acute myocardial infarction, there remains a residual risk of morbidity and mortality. Bruton's Tyrosine Kinase inhibitors have been found to inhibit platelet aggregation through the Glycoprotein VI collagen-mediated pathway. The Bruton's Tyrosine Kinase inhibitor, Ibrutinib is used in the management of haematological malignancies and another Bruton's Tyrosine Kinase inhibitor, ONO-4059 (also known as tirabrutinib), is in clinical development. This is an observational study to evaluate the effects of Ibrutinib and ONO-4059 on platelet aggregation after acute myocardial infarction. Methods and results: Twenty patients with a confirmed diagnosis of acute myocardial infarction were enrolled and blood samples obtained within 48 h of hospital admission. All patients were on dual antiplatelet therapy; aspirin plus a P2Y12 inhibitor (clopidogrel or ticagrelor). Blood samples were treated ex vivo with increasing concentrations of Ibrutinib (0, 0.5, 1, 2 μM) and ONO-4059 (0, 0.2, 0.5, 1 μM). Platelet aggregation was measured in response to collagen using a Multiplate analyser to estimate the area under the curve, with lower values indicating lower platelet aggregation. The median age was 63 years and 80% were male. The median area under the curve values for Ibrutinib concentrations 0 (control), 0.5, 1 and 2 mmol/l were 18.5, 8 (P = 0.0004), 4.5 (P < 0.0001) and 2 (P < 0.0001) units and for ONO-4059 concentrations 0 (control), 0.2, 0.5 and1μM, median area under the curve values were 13, 12 (P = 0.7), 6.5 (P = 0.0001) and 5.5 (P = 0.0004 compared to control). Conclusion: The Bruton's Tyrosine Kinase inhibitors, Ibrutinib and ONO-4059, show further inhibition of platelet aggregation in blood samples from patients with acute myocardial infarction, receiving dual antiplatelet therapy in a dose dependent manner. These results provide a rationale for Bruton's Tyrosine Kinase inhibitors to be tested as a potential new antiplatelet strategy for acute myocardial infarction