Zur Bedeutung des S100P im kortikalen Zytoskelett

S100 Proteine sind Ca2+-Sensoren, die über zumeist Ca2+-abhängige Interaktionen mit ihren Liganden, viele intra- und extrazelluläre Prozesse regulieren. Ein Ca2+-abhängiger Ligand des S100P ist das Plasmamembran-Aktinzytoskelett verknüpfende ERM-Protein Ezrin. Ezrin kann in einer inaktiven Konformation vorliegen, in der viele Ligandenbindungsstellen maskiert sind. Dies kann durch die Bindung von PIP2 und T567-Phosphorylierung sowie durch Bindung von S100P aufgehoben werden. In der vorliegenden Arbeit wurde das S100P-Ezrin Interaktionsmotiv definiert und gezeigt, dass die Bindung von S100P kompetitiv zur Bindung von PIP2 erfolgt, was vermutlich einen alternativen Aktivierungsmechanismus darstellt. Die Relevanz des Ca2+ für die S100P-Ezrin Interaktion wurde mittels einer permanent aktiven Ca2+-unabhängigen S100P Mutante analysiert. Zudem wurde verdeutlicht, dass die S100P-Ezrin Interaktion für die Tumorzellmigration relevant ist

MRP8 and MRP14, phagocyte-specific danger signals, are sensitive biomarkers of disease activity in cryopyrin-associated periodic syndromes

To assess the sensitivity of the phagocyte-specific molecules myeloid-related protein (MRP) 8 and MRP14 (calprotectin) for monitoring disease activity during anti-interleukin (IL)-1 therapies in patients with cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurological, cutaneous and articular (CINCA) syndrome

Alarmins MRP8 and MRP14 Induce Stress Tolerance in Phagocytes under Sterile Inflammatory Conditions

Hyporesponsiveness by phagocytes is a well-known phenomenon in sepsis that is frequently induced by low-dose endotoxin stimulation of Toll-like receptor 4 (TLR4) but can also be found under sterile inflammatory conditions. We now demonstrate that the endogenous alarmins MRP8 and MRP14 induce phagocyte hyporesponsiveness via chromatin modifications in a TLR4-dependent manner that results in enhanced survival to septic shock in mice. During sterile inflammation, polytrauma and burn trauma patients initially present with high serum concentrations of myeloid-related proteins (MRPs). Human neonatal phagocytes are primed for hyporesponsiveness by increased peripartal MRP concentrations, which was confirmed in murine neonatal endotoxinemia in wild-type and MRP14(-/-) mice. Our data therefore indicate that alarmin-triggered phagocyte tolerance represents a regulatory mechanism for the susceptibility of neonates during systemic infections and sterile inflammation

Teriflunomide treatment for multiple sclerosis modulates T cell mitochondrial respiration with affinity-dependent effects

International audienceInterference with immune cell proliferation represents a successful treatment strategy in T cell-mediated autoimmune diseases such as rheumatoid arthritis and multiple sclerosis (MS). One prominent example is pharmacological inhibition of dihydroorotate dehydrogenase (DHODH), which mediates de novo pyrimidine synthesis in actively proliferating T and B lymphocytes. Within the TERIDYNAMIC clinical study, we observed that the DHODH inhibitor teriflunomide caused selective changes in T cell subset composition and T cell receptor repertoire diversity in patients with relapsing-remitting MS (RRMS). In a preclinical antigen-specific setup, DHODH inhibition preferentially suppressed the proliferation of high-affinity T cells. Mechanistically, DHODH inhibition interferes with oxidative phosphorylation (OXPHOS) and aerobic glycolysis in activated T cells via functional inhibition of complex III of the respiratory chain. The affinity-dependent effects of DHODH inhibition were closely linked to differences in T cell metabolism. High-affinity T cells preferentially use OXPHOS during early activation, which explains their increased susceptibility toward DHODH inhibition. In a mouse model of MS, DHODH inhibitory treatment resulted in preferential inhibition of high-affinity autoreactive T cell clones. Compared to T cells from healthy controls, T cells from patients with RRMS exhibited increased OXPHOS and glycolysis, which were reduced with teriflunomide treatment. Together, these data point to a mechanism of action where DHODH inhibition corrects metabolic disturbances in T cells, which primarily affects profoundly metabolically active high-affinity T cell clones. Hence, DHODH inhibition may promote recovery of an altered T cell receptor repertoire in autoimmunity

The Good and the Bad: Monocytes’ and Macrophages’ Diverse Functions in Inflammation

Monocytes and macrophages are central players of the innate immune response and play a pivotal role in the regulation of inflammation. Thereby, they actively participate in all phases of the immune response, from initiating inflammation and triggering the adaptive immune response, through to the clearance of cell debris and resolution of inflammation. In this review, we described the mechanisms of monocyte and macrophage adaptation to rapidly changing microenvironmental conditions and discussed different forms of macrophage polarization depending on the environmental cues or pathophysiological condition. Therefore, special focus was placed on the tight regulation of the pro- and anti-inflammatory immune response, and the diverse functions of S100A8/S100A9 proteins and the scavenger receptor CD163 were highlighted, respectively. We paid special attention to the function of pro- and anti-inflammatory macrophages under pathological conditions

Kerncurriculum Erziehungswissenschaft - Konzepte und Erfahrungen

Vom 30. September bis zum 2. Oktober 2003 fand an der Universität Dortmund die Herbsttagung 2003 der Kommission Wissenschaftsforschung... statt. [Die Autoren] skizzieren die Vorträge und versuchen, den Ertrag an teilweise kontroversen Problemdefinitionen, Lösungsvorschlägen und Erfahrungen festzuhalten und Konsequenzen aufzuzeigen. Dabei ergeben sich - gewissermaßen quer zu den teils analytischen, teils programmatischen Vorträgen und Erfahrungsberichten - unterscheidbare, wenn auch aufeinander verweisende Problemfelder: Die Notwendigkeit eines Kerncurriculums Erziehungswissenschaft, die Frage nach der Beschränkung der akademischen Freiheit durch ein Kerncurriculum Erziehungswissenschaft, die Erfolgsbedingungen und Hindernisse bei der Implementation eines Kerncurriculums Erziehungswissenschaft an einem Hochschulstandort und schließlich die Diskussion um die möglichen, tatsächlichen und unbeabsichtigten Effekte der Umsetzung. (DIPF/Orig.

The alarmin Mrp8/14 as regulator of the adaptive immune response during allergic contact dermatitis

Item does not contain fulltextMrp8 and Mrp14 are endogenous alarmins amplifying inflammation via Toll-like receptor-4 (TLR-4) activation. Due to their pro-inflammatory properties, alarmins are supposed to enhance adaptive immunity via activation of dendritic cells (DCs). In contrast, analysing a model of allergic contact dermatitis (ACD) we observed a more severe disease outcome in Mrp8/14-deficient compared to wild-type mice. This unexpected phenotype was associated with an enhanced T-cell response due to an accelerated maturation of DCs in Mrp8/14-deficient mice. Accordingly, Mrp8, the active component of the heterocomplex, inhibits early DC maturation and antigen presentation in a TLR-4-dependent manner. Transfer of DCs purified from the local lymph nodes of sensitized Mrp8/14-deficient to wild-type mice determined the outcome of ACD. Our results link a pro-inflammatory role of the endogenous TLR-4 ligand Mrp8/14 to a regulatory function in adaptive immunity, which shows some similarities with the 'hygiene hypothesis' regarding continuous TLR-4 stimulation and decreased risk of allergy

Alarmins MRP8 and MRP14 Induce Stress Tolerance in Phagocytes under Sterile Inflammatory Conditions

Hyporesponsiveness by phagocytes is a well-known phenomenon in sepsis that is frequently induced by low-dose endotoxin stimulation of Toll-like receptor 4 (TLR4) but can also be found under sterile inflammatory conditions. We now demonstrate that the endogenous alarmins MRP8 and MRP14 induce phagocyte hyporesponsiveness via chromatin modifications in a TLR4-dependent manner that results in enhanced survival to septic shock in mice. During sterile inflammation, polytrauma and burn trauma patients initially present with high serum concentrations of myeloid-related proteins (MRPs). Human neonatal phagocytes are primed for hyporesponsiveness by increased peripartal MRP concentrations, which was confirmed in murine neonatal endotoxinemia in wild-type and MRP14−/− mice. Our data therefore indicate that alarmin-triggered phagocyte tolerance represents a regulatory mechanism for the susceptibility of neonates during systemic infections and sterile inflammation