Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacterial Infections Alter Allergic Response

25.02.2003


Findings Support Hygiene Hypothesis



Researchers at National Jewish Medical and Research Center have gathered strong experimental support for the hygiene hypothesis, a proposed explanation for the worldwide rise in asthma and allergies. The research team, led by Richard Martin, M.D., found that early infection with the bacterium Mycoplasma pneumoniae reduced a mouse’s subsequent response to allergens. Alternatively, mice exposed to allergens prior to infection, developed a stronger allergic response. The research team is reporting its results in the March 2003 issue of the journal Infection and Immunity.

"For the first time, we have shown that a bacterial infection can modify the allergic response," said Dr. Martin, Vice Chair of the Department of Medicine at National Jewish. "Timing is everything, however. Our results suggest that M. pneumoniae, or a related pathogen, could help prevent asthma and other allergic diseases, but only if the infection occurs before a person is sensitized to an allergen."


Asthma and allergies have both been on the rise for several decades, especially in developed countries. The hygiene hypothesis has offered one explanation for this increase: compared with the past, children living in these countries today are exposed to fewer infectious organisms, which are necessary to properly train their developing immune systems. As a result, their immune systems overreact to relatively harmless irritants, leading to allergies and asthma.

So far, however, most evidence both for and against the hygiene hypothesis has been indirect and observational. The National Jewish research team sought more direct evidence using a mouse model of asthma and the bacterium M. pneumoniae, a common cause of community-acquired pneumonia.

In their study, Martin and his colleagues inoculated mice with either the bacterium or with a saline solution. Then all the mice were made allergic to the egg protein ovalbumin. Two weeks later, the mice were then exposed to the ovalbumin again, and their allergic response was evaluated.

On several measures, the mice that had been infected showed a milder reaction to the ovalbumin than did the control mice. Bronchial hyperresponsiveness (a measure of the "twitchiness" of the airways of these asthma-prone mice), levels of the cytokine IL-4, and total white cell count in the airways were all lower in the previously infected mice than in mice who were not infected. Levels of gamma interferon, which is associated with a healthy non-allergic immune response, were higher in the previously infected mice.

When mice were first sensitized and exposed to ovalbumin, then infected with bacteria, they showed greater bronchial hyperresponsiveness and airway inflammation than did control mice.

"Our results support the hygiene hypothesis," said lead author Hong Wei Chu, M.D. "Although mice are clearly different from humans, this kind of data, generated in a controlled experiment, adds important new evidence to help evaluate the hygiene hypothesis."


William Allstetter | EurekAlert!
Further information:
http://www.nationaljewish.org/news/hygiene_martin_022503.html
http://www.nationaljewish.org/faculty/chu.html
http://www.nationaljewish.org/faculty/martin.html

More articles from Health and Medicine:

nachricht Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

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...

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

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>