Exposure to common environmental bacteria may be source of some allergic inflammation

Could some cases of asthma actually be caused by an allergic reaction to a common environmental bacteria? New research findings published in the Journal of Leukocyte Biology suggests that this idea may not be as far-fetched as it seems. In a research report appearing in the February 2012 print issue, researchers show a link between common environmental bacteria and airway inflammation. Specifically, their research suggests that some strains of Pseudomonas aeruginosa cause white blood cells to produce very high levels of histamine, which in turn leads to inflammation, a hallmark symptom of asthma.

"We hope that these findings in mice will encourage human-focused research regarding bacterial stimulation of production by , like , that are not traditionally associated with ," said George Caughey, M.D., a researcher involved in the work from the Veterans Affairs Medical Center and University of California in San Francisco. "Such research could improve our understanding of inflammation in bacterial infections, and help us to craft therapies for relief of inflammation and its consequences for short and long-term health."

To make this discovery, scientists studied the effect of two strains of pseudomonas bacteria on isolated mouse white blood cells tasked with killing bacteria, called neutrophils. Results showed that one strain killed the neutrophils, but the second strain produced substances that caused the neutrophils to increase their production of histamine significantly. To see if their discovery was applicable outside of the test tube, the histamine-stimulating strain was then used to infect mice to produce bronchitis and pneumonia. These mice experienced a significant increase of histamine in their airways and lungs. Additional work showed that the bacteria persuade neutrophils to produce histamine by causing them to make much more of the key enzyme in histamine synthesis (histidine decarboxylase) than neutrophils would otherwise do in the unstimulated state.

"Despite advances in diagnosing and treating the symptoms of asthma and allergy, our understanding of the underlying initiating events remains elusive," said John Wherry, Ph.D., Deputy Editor of the . "This report helps shed light on how an 'everyday organism' might trigger asthma and allergy from an immune cell type not normally thought to be involved in allergic disease."

More information: https://www.jleukbio.org

add to favorites email to friend print save as pdf

Related Stories

Rogue blood cells may contribute to post-surgery organ damage

Jun 26, 2011

A study from scientists at Queen Mary, University of London, sheds new light on why people who experience serious trauma or go through major surgery, can suffer organ damage in parts of the body which are seemingly unconnected ...

Recommended for you

A hybrid vehicle that delivers DNA

Nov 25, 2014

A new hybrid vehicle is under development. Its performance isn't measured by the distance it travels, but rather the delivery of its cargo: vaccines that contain genetically engineered DNA to fight HIV, cancer, ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.