Bacteria (red) persuade skin cells (green)to let them in.
Bacteria give skin cells their marching orders.
Bacteria that cause potentially lethal ’flesh-eating’ infections make their entrance by telling skin cells to step aside. The bugs hijack the body’s signal for skin cells to become mobile.
Group A streptococci (GAS) normally infect the surface lining of the throat. But occasionally they penetrate skin or the tissues lining the airways, invading deep into the body and causing life-threatening disease.
"This generates a new dogma," says Lukas Huber, a cell biologist at the Molecular Pathology Research Institute in Vienna, Austria. Invading bacteria normally infect and destroy individual cells. "Clearly [GAS] are much smarter than that," he says.
GAS’ deceitful cloak resembles a signalling chemical called hyaluronic acid. This is released when cells must be rearranged - to heal wounded skin, for example. "The bacteria subvert this normal function," says Wessels.
Hyaluronic acid - or its bacterial doppelganger - binds to a receptor on the cell surface called CD44. When this happens " the junctions [between the cells] just open," says Huber.
Wolf in sheep’s clothing
Wessels and Cywes infected laboratory cultures of human skin with GAS. They saw the skin-cell membranes ’ruffling’, a sign that they had let go of their neighbours. A mutant form of GAS unable to produce the deceptive molecular coat was unable to penetrate skin.
Wessels and Cywes are now working to prevent GAS infection by blocking the CD44 receptors on cells, or interfering with GAS binding. They hope to gain an understanding of why GAS turn nasty, although that may have more to do with the infected individual than the bacteria, Wessels suspects.
"There are host issues that play a big role in who’s going to get the disease," says Elaine Tuomanen, an infectious disease expert at St Jude’s Children’s Research Hospital in Memphis, Tennessee.
In the meantime, Wessel’s team hopes to develop a treatment to prevent throat infections with GAS.
"That’s certainly where the money is," comments Tuomanen.
TOM CLARKE | © Nature News Service
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy
22.09.2017 | Physics and Astronomy