Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UT Southwestern research could lead to new treatments for IBD, viral infections

20.10.2011
The intestinal ecosystem is even more dynamic than previously thought, according to two studies by UT Southwestern Medical Center researchers published in the latest issue of Science.

Taken together, these studies provide a new understanding of the unique intestinal environment and suggest new strategies for the prevention of inflammatory bowel disease (IBD) and viral infections, the researchers said.

"Mammals have evolved ways to limit invasion by the naturally occurring bacteria that live in their intestines even as viruses have developed strategies to break through those defenses and cause infection," said Dr. Julie Pfeiffer, assistant professor of microbiology.

Dr. Pfeiffer is senior author of a new study that finds that, even after 100 years, the polio virus has tricks to reveal. It is well known that after oral ingestion and passage through the intestine, poliovirus can move throughout the body and occasionally cause paralysis. Her team showed that the virus uses the body's natural gut bacteria in order to become more infectious.

In the other study, senior author Dr. Lora Hooper, associate professor of immunology and microbiology and an investigator for the Howard Hughes Medical Institute (HHMI), reported that an antibiotic protein called RegIIIã acts like a sentry to keep the 100 trillion bacteria that live in the gut from causing digestive havoc, by maintaining a "demilitarized zone" in the layer of mucus that normally covers the inner surface of the intestines.

Bacteria in the intestine normally work to help the body digest and deliver nutrients from food after eating. A 50-micron zone of separation, about half the width of a human hair, lies between the bacteria that live in the gut and the intestinal wall. In addition to mucous, that zone contains biologically active molecules like the protein RegIIIã that Dr. Hooper's laboratory discovered in 2006.

Dr. Hooper and her colleagues showed for the first time how the protein works to police the intestinal demilitarized zone, preventing the naturally occurring bacteria from invading the wall of the intestine, where they can cause problems such as IBD.

"If too many bacteria invade this demilitarized zone, you get ramped up production of the protein RegIIIã and it pushes them back," Dr. Hooper said.

In people with IBD – in which inflammation and the body's response to it can result in painful ulcers and bloody diarrhea – the demilitarized zone is compromised and more bacteria come in contact with the intestinal lining, she explained.

Dr. Hooper's four-year study, which compared the intestinal health of mice that lacked the protein with that of normal mice, found that mice lacking the protein also lacked the protected space between the bacteria and the intestinal lining.

The researchers have patented RegIIIã as a potential antibiotic therapeutic, though further study is needed to determine if the protein could be developed to help people with IBD or related diseases.

In her study, Dr. Pfeiffer found that mice lacking the normal intestinal bacteria had half the death rate from polio as mice with intact gut bacteria. The findings were the opposite of what the researchers had expected because, like most people, they had expected the body's intestinal bacteria to offer protection from viral diseases as they have been shown to protect against bacterial infection, she explained.

So Dr. Pfeiffer's research team conducted a series of experiments to validate and expand that finding, all of which backed up the original conclusion. For instance, they found that virus exposed to bacteria could attach to human cells better than virus that lacked bacterial exposure.

Poliovirus is a very wasteful entity, with only about one in 200 viral particles able to cause infection. To determine whether bacteria could make poliovirus more efficient, Dr. Pfeiffer and colleagues incubated viruses in different warm environments to see how long they took to decay.

Virus incubated in salt water decayed over time, as expected. In contrast, virus incubated in any of several strains of bacteria became up to five times more infectious.

"Bacteria are literally activating the virus. There is nothing in that test tube that the virus can use for replication, so it must be increasing the viral infectivity," she said.

But the researchers wanted to delve deeper. They found that two different carbohydrates (polysaccharides) on the bacterial cell surface – lipopolysaccharide (LPS) and peptidoglycan – were able to spike poliovirus infectivity even in the absence of bacteria.

Other UT Southwestern researchers involved in Dr. Pfeiffer's study were lead author Dr. Sharon Kuss, postdoctoral researcher; Dr. Hooper; Gavin Best, research technician in microbiology; and Chris Etheredge, former research technician in microbiology. Researchers from Vanderbilt University also participated in the study, which was supported by grants from the National Institutes of Health and the Pew Scholars Program of the Pew Charitable Trust.

Other UT Southwestern researchers involved in Dr. Hooper's study included lead author Dr. Shipra Vaishnava, postdoctoral instructor in Dr. Hooper's lab; Dr. Miwako Yamamoto and Dr. Kari Severson, former postdoctoral fellows in immunology; Kelly Ruhn, research technician with the HHMI; Xiaofei Yu, graduate student in immunology; and Dr. Edward Wakeland, chairman of immunology. Researchers from Cornell University's Department of Microbiology also participated.

The research was supported by grants from the National Institutes of Health, the Crohn's and Colitis Foundation of America, Burroughs Wellcome Fund and the Howard Hughes Medical Institute.

Visit http://www.utsouthwestern.org/digestive to learn more about UT Southwestern's clinical services in digestive disorders, including IBD.

This news release is available on our World Wide Web home page at http://www.utsouthwestern.edu/home/news/index.html

To automatically receive news releases from UT Southwestern via email, subscribe at www.utsouthwestern.edu/receivenews

Debbie Bolles | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Health and Medicine:

nachricht Speed data for the brain’s navigation system
06.12.2016 | Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE)

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>