The first step against infection is the detection of microorganisms capable of causing disease. This is done through the recognition of molecular structures not shared by the host, but also present in other harmless or even useful microbes. A question that has puzzled scientists for many years is how the host knows exactly against which microbes to mount an immune response. But now, in the November issue of Nature Immunology, scientists describe for the first time an ingenious bacteria-recognition mechanism by epithelial cells, which allows the distinction to be made between dangerous and innocuous bacteria.
The innate immune system is the mammals’ first line of defence as it can be mobilised almost immediately, and so has a crucial role in the prevention and/or fight of infection. Key players in the recognition of bacteria are two families of receptors: Toll-like receptors (TLR), which are normally expressed in cell membranes, and the nucleotide-binding oligomerization domain (Nod) family, found in the cytoplasm.
A simple system by which the innate immune system can differentiate between pathogenic (disease-inducing) and non-pathogenic bacteria is by selective expression of these receptors. For example, TLR and Nod receptors, specific for bacterial molecular components, are expressed in sterile areas of the body like the internal organs, the bloodstream or the cytoplasm. The logic behind this is that if bacteria are found at those locations it would be as result of an infection and consequently an immune response should be mounted. This differential receptor expression however, can not explain how in places like the digestive system, where a varied population of both pathogenic and non-pathogenic extracellular bacteria exist, we are still able to discriminate and attack only the those which can induce disease.
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Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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