The study proposed a new model to explain how mammalian cells establish the sense of direction necessary to move, as well as the mechanism that a disease-causing form of E. coli bacteria employ to hijack that ability. Cells need to orient themselves for several basic processes, such as keeping biochemical reactions separated in space and, in the case of immune cells, pursuing pathogens. Importantly, disruption of the cell's sense of direction often leads to human disease.
"This is a great example of scientists from different fields of research coming together to solve a complex and important biological problem," said Dr. Neal Alto, assistant professor of microbiology and senior author of the study, published Feb. 17 in Cell.
Systems biology aims to discover and understand a "circuit theory" for biology – a set of powerful and predictive principles that will reveal how networks of biological components are wired to display the complex properties of living things. The rapidly emerging field requires experts in several scientific disciplines – including biology, physics, mathematics and computer science – to come together to create models of biological systems that consider both the individual parts and how these parts react to each other and to changes in their environment.
Scientists from UT Southwestern's microbiology department and the newly expanded Cecil H. and Ida Green Comprehensive Center for Molecular, Computational and Systems Biology teamed up to examine the problem collaboratively. They initially conceived a mathematical model for their hypothesis of how the cell would respond during an E. coli-induced infection and then tested their computational predictions in living cells.
"Bacteria inject protein molecules into human cells with a needle-and-syringe action," Dr. Alto said. "The human cell responds by producing a local actin-rich membrane protrusion at the spot where the bacteria attaches to the cell."
For healthy cells to move normally, these actin polymers push against a cell's membrane, protruding and propelling the cell in one direction or another. When E. coli molecules are injected, however, actin polymers rush to the site infection and help bacterial molecules both move within the cell and establish an internal site of infection.
Robert Orchard, graduate student of microbiology and the study's lead author, said: "By asking 'How does a bacterial pathogen from outside the cell regulate the host cells' actin dynamics within the cell?' we have uncovered a fundamentally new molecular circuit involved in mammalian cell polarity and bacterial infection. These findings provide new insight into the regulatory mechanisms that control both disease-causing agents and normal mammalian cell behavior."
Other UT Southwestern researchers from the Green Center involved in the work were Dr. Steven Altschuler and Dr. Lani Wu, both associate professors of pharmacology; Dr. Gürol Süel, assistant professor of pharmacology; and Mark Kittisopikul, a student in the Medical Scientist Training Program.
The National Institutes of Health, the James S. McDonnell Foundation and The Welch Foundation supported the study. The researchers also received assistance from the UT Southwestern Live Cell Imaging Facility, which is supported in part by the National Cancer Institute.
This news release is available on our World Wide Web home page at www.utsouthwestern.edu/home/news/index.html
To automatically receive news releases from UT Southwestern via email, subscribe at www.utsouthwestern.edu/receivenews
Deborah Wormser | EurekAlert!
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering