NOD2, RIP2 and IRF5 Play a Critical Role in the Type I Interferon Response to Mycobacterium tuberculosis

While the recognition of microbial infection often occurs at the cell surface via Toll-like receptors, the cytosol of the cell is also under surveillance for microbial products that breach the cell membrane. An important outcome of cytosolic recognition is the induction of IFNα and IFNβ, which are critical mediators of immunity against both bacteria and viruses. Like many intracellular pathogens, a significant fraction of the transcriptional response to Mycobacterium tuberculosis infection depends on these type I interferons, but the recognition pathways responsible remain elusive. In this work, we demonstrate that intraphagosomal M. tuberculosis stimulates the cytosolic Nod2 pathway that responds to bacterial peptidoglycan, and this event requires membrane damage that is actively inflicted by the bacterium. Unexpectedly, this recognition triggers the expression of type I interferons in a Tbk1- and Irf5-dependent manner. This response is only partially impaired by the loss of Irf3 and therefore, differs fundamentally from those stimulated by bacterial DNA, which depend entirely on this transcription factor. This difference appears to result from the unusual peptidoglycan produced by mycobacteria, which we show is a uniquely potent agonist of the Nod2/Rip2/Irf5 pathway. Thus, the Nod2 system is specialized to recognize bacteria that actively perturb host membranes and is remarkably sensitive to mycobacteria, perhaps reflecting the strong evolutionary pressure exerted by these pathogens on the mammalian immune system

Observations of a mass occurrene of Macoma balthica larvae in midsummer

In 1995 the seasonal development of concentrations of both phytoplankton and larvae of the bivalve Macoma balthica was studied in the coastal zone behind the back-barrier island of Spiekeroog (German Wadden Sea). In July=August larvaereached maximum concentrations of about 1000 to 4200 ind.

Gesamtsynthese: Geschaeftsstelle Oekosystemforschung Wattenmeer. Bd. 3: Erfahrungsbericht eines interdisziplinaeren Verbundvorhabens Abschlussbericht

SIGLEAvailable from TIB Hannover: F01B586 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Gesamtsynthese Oekosystemforschung Wattenmeer - Erfahrungsbericht eines interdisziplinaeren Verbundvorhabens

Available from TIB Hannover: RN 8422(2002,45) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Oekosystemforschung Niedersaechsisches Wattenmeer. T. B: ELAWAT -Elastizitaet des Oekosystems Wattenmeer. Projektsynthese Abschlussbericht

The aim of the basic research part of the Ecosystem Research Lower Saxonian Wadden Sea was to detect fundamental ecological properties of this ecosystem. Therefore, the concept of ELAWAT (Resilience of the Wadden Sea Ecosystem) realized, for the first time in the history of ecosystem research, an approach based on stability properties. Processes and mechanisms relevant for a long-term preservation of the Wadden Sea were investigated. 12 projects were involved in this interdisciplinary approach. Field investigations and experiments were carried out in the back barrier tidal flat behind the island of Spiekeroog to detect temporal and spatial patterns and effects of disturbances. Most parameters revealed high variability. Therefore no reference situation can be named for the Wadden Sea. Instead, the 'state' of the Wadden Sea is its dynamic. Several abiotic components showed a resilience on intermediate scales, e.g. a return of basic morphological features of the tidal flats 6 months after a severe ice winter. Stability properties could also be named for biotic components of the Wadden Sea, being specific for the studied variables and scales. Mechanisms to react to disturbance events include a high functional morphology, high reproductive output and high mobility of the Wadden Sea biota. These stability mechanisms can only function in a natural system with an undisturbed tidal regime. To preserve this ecosystem, entire tidal basins shoule be protected to ensure a variety of habitats, source populations for recolonization and undisturbed dispersion. (orig.)SIGLEAvailable from TIB Hannover: F98B1440 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman