The study, published today in the journal Science, might lead to new medications aimed at helping patients with inflammatory bowel disease. The findings might also aid in understanding the effectiveness of probiotics – mixtures of beneficial bacteria that are added to food products – in boosting the immune system, said Dr. Lora Hooper, assistant professor of immunology and the paper's senior author.
Scientists have known for decades that microbial cells in the human gut outnumber the body's own cells by about 10 to 1. Humans offer a safe haven to these microbes because they help us to break down food that we can't digest by ourselves. But it hasn't been clear how we keep these microscopic gut dwellers from invading our tissues and causing infections.
To help answer this question, Dr. Hooper's research team used mice raised inside sterile plastic bubbles. Because they are never in contact with the outer, microbe-filled world, these mice do not have the bacteria that normally colonize the gut. By exposing these "germ-free" mice to different types of gut bacteria, the researchers were able to observe how the epithelial cells lining the intestine react to microbial invaders.
"We found that when the gut lining comes into contact with bacteria, it produces a protein that binds to sugars that are part of the bacterial outer surfaces," Dr. Hooper said. "Once bound, these proteins quickly destroy their bacterial targets. They're killer proteins with a sweet tooth."
The protein, called RegIIIgamma in mice and HIP/PAP in humans, belongs to a protein class called lectins, which bind to sugar molecules. These particular lectins' seek-and-destroy mission may help to create an "electric fence" that shields the intestinal surface from invading bacteria, Dr. Hooper said.
The findings of this study may offer researchers new clues about the causes of inflammatory bowel disease. Most healthy people have a friendly relationship with their gut microbes, but in patients with inflammatory bowel disease this tolerant relationship turns sour and the immune system mounts an attack on the gut's microbial inhabitants that can lead to painful ulcers and bloody diarrhea. What triggers this attack is not clear, but the fact that these patients have elevated HIP/PAP production suggests that they are coping with increased numbers of invading intestinal bacteria.
The study may also help scientists devise more effective treatments for intestinal infections. "We are now working to understand the mechanism by which the intestinal lining senses bacterial threats. What turns this protein antibiotic on?" Dr. Hooper asked. "We want to explore whether this is something we can stimulate artificially to stave off pathogenic infections."
Toni Heinzl | EurekAlert!
Make way for the mini flying machines
21.03.2018 | American Chemical Society
New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences