Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cannibalistic Cells May Help Prevent Infections

05.08.2009
Infectious-disease specialists at UT Southwestern Medical Center have demonstrated that a cannibalistic process in cells plays a key role in limiting Salmonella infection.
Salmonella, the causative agent of salmonellosis, causes many of the intestinal infections and food-related illnesses reported in the U.S. About 600 people die each year as a result of these infections, accounting for roughly 30 percent of all reported food-related deaths. It is particularly dangerous among the elderly.

The new findings, available online and in an upcoming issue of the Proceedings of the National Academy of Sciences, are among the first to demonstrate that a process called autophagy (pronounced “aw-TAH-fah-gee”) prevents harmful bacteria such as Salmonella from becoming successful pathogens. The findings also suggest that decreases in autophagy – such as those that occur in the elderly and in certain patients with Crohn’s disease, an inflammatory bowel disorder – may lead to abnormalities in the way the intestinal tract deals with bacterial infections.

“It’s known that as you get older you become more susceptible to infectious diseases and also that autophagy decreases,” said Dr. Beth Levine, chief of the division of infectious diseases at UT Southwestern and senior author of the new study in PNAS. “In this paper, we’ve shown that signaling pathways that extend life and protect against bacterial invaders do so by triggering autophagy. This suggests that therapeutic strategies to increase autophagy may be effective in defeating harmful bacteria that can enter inside cells.”

Dr. Beth Levine -- www.utsouthwestern.edu/findfac/professional/0,2356,66821,00.html

Autophagy is the way cells devour their own unwanted or damaged parts. It is a highly regulated and completely normal process by which cells remain healthy by performing “routine housekeeping” and “garbage disposal.” Prior research has shown that the process appears to be an adaptive response that our bodies employ during times of stress or starvation, and which also helps protect our bodies against cancer and neurodegenerative diseases.

It’s unclear why older people become more susceptible to infections, but research has shown that autophagy does decrease with age. Dr. Levine, a professor of internal medicine and microbiology, said it is possible that by reversing or regulating this process, researchers could prevent the elderly and others with weakened immune systems from becoming more susceptible to infections.

For this study, the researchers studied the effects of Salmonella infections in two organisms they had genetically engineered to lack active autophagy genes. The organisms included Caenorhabditis elegans, a common research worm also known as a nematode, and Dictyostelium discoideum, a soil amoeba that functions much like certain cells in the human immune system.

In both cases, the animals with inactive autophagy genes fared far worse than those with active ones. Rather than being targeted for elimination, the Salmonella bacterium was able to invade the host cells, where it started replicating, Dr. Levine said.

She said the findings indicate that the autophagy process plays an important role in resistance to certain types of pathogens, specifically those that can enter inside our cells.

The next step, Dr. Levine said, is to begin studying the efficacy of a new autophagy-inducing molecule in treating a number of intracellular bacterial infections including salmonellosis, tuberculosis, tularemia and listeriosis.

Other UT Southwestern researchers involved in the study were Dr. Kailiang Jia, lead author and instructor in internal medicine; Dr. Muhammad Akbar, clinical instructor in internal medicine; Dr. Qihua Sun, research scientist in internal medicine; Beverley Adams-Huet, assistant professor of clinical sciences; Dr. Christopher Gilpin, assistant professor of cell biology; and Dr. Collin Thomas, a former research associate in internal medicine.

This study was supported by the National Institutes of Health and The Ellison Medical Foundation.

Visit www.utsouthwestern.org/infectiousdiseases to learn more about UT Southwestern’s clinical services for infectious diseases.

Kristen Holland Shear | Newswise Science News
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

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...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

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...

Im Focus: Bacterial Pac Man molecule snaps at sugar

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>