Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Bacterial Infections Alter Allergic Response


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:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke 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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>