In a finding that broadens our understanding of how the immune system can detect infection, researchers have identified a previously unappreciated way in which bacteria can be recognized inside our cells.
Many bacteria cause disease by invading cells and creating a safe niche in which to replicate. Cells respond to the infection by activating the immune system, and a chief challenge for bacteria is to avoid immune detection. Prior research had shown that bacteria inside the cytosol (the cells expansive gel-like compartment) could be detected, but how bacteria within the cytosol are recognized has not been clear.
In the new work, Dr. John Brumell and colleagues at The Hospital for Sick Children studied the fate of Salmonella bacteria within the cytosol. These bacteria normally occupy vacuoles in host cells, but under some conditions they leave the vacuole and enter the cytosol. In this foreign environment, the bacteria were recognized by the ubiquitin system, a protein machine that applies molecular tags to cellular proteins to target them for destruction by the proteasome, essentially a molecular shredding device inside mammalian cells. These findings suggest that bacterial proteins are being destroyed by the proteasome within the cytosol during infection, and that this may play a key role in activation of the immune system. A surprising result came when Salmonella was compared with Listeria, a bacterium which normally occupies the cytosol. Listeria avoided recognition by the ubiquitin system by moving within this compartment. This suggests that Listeria and other bacteria that can colonize the cytosol do so in a manner that prevents activation of the immune system.
Heidi Hardman | EurekAlert!
Mass spectrometry sheds new light on thallium poisoning cold case
14.12.2018 | University of Maryland
Protein involved in nematode stress response identified
14.12.2018 | University of Illinois College of Agricultural, Consumer and Environmental Sciences
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
14.12.2018 | Power and Electrical Engineering
14.12.2018 | Physics and Astronomy
14.12.2018 | Physics and Astronomy