Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Air pollution alters immune function, worsens asthma symptoms

06.10.2010
Exposure to dirty air is linked to decreased function of a gene that appears to increase the severity of asthma in children, according to a joint study by researchers at Stanford University and the University of California, Berkeley.

While air pollution is known to be a source of immediate inflammation, this new study provides one of the first pieces of direct evidence that explains how some ambient air pollutants could have long-term effects.

The findings, published in the October 2010 issue of the Journal of Allergy and Clinical Immunology, come from a study of 181 children with and without asthma in the California cities of Fresno and Palo Alto.

The researchers found that air pollution exposure suppressed the immune system's regulatory T cells (Treg), and that the decreased level of Treg function was linked to greater severity of asthma symptoms and lower lung capacity. Treg cells are responsible for putting the brakes on the immune system so that it doesn't react to non-pathogenic substances in the body that are associated with allergy and asthma. When Treg function is low, the cells fail to block the inflammatory responses that are the hallmark of asthma symptoms.

The findings have potential implications for altered birth outcomes associated with polluted air, much the same as those noted for the effects of cigarette smoke.

"When it came out that cigarettes can cause molecular changes, it meant the possibility that mothers who smoked could affect the DNA of their children during fetal development," said study lead author Dr. Kari Nadeau, pediatrician at Stanford's Lucile Packard Children's Hospital and an assistant professor of allergy and immunology at Stanford's School of Medicine. "Similarly, these new findings suggest the possibility of an inheritable effect from environmental pollution."

Forty-one participants came from the Fresno Asthmatic Children's Environment Study (FACES), a longitudinal study led by principal investigator Dr. Ira Tager, professor of epidemiology at UC Berkeley's School of Public Health, and co-principal investigator S. Katharine Hammond, UC Berkeley professor and chair of environmental health sciences. The researchers also recruited 30 children from Fresno who did not have asthma.

"I'm not aware of any other studies that have looked at how chemicals can alter cells so early in the regulatory process, and then connected that effect to clinical symptoms," said Tager. "There are people who still question the direct link between air pollution and human health, but these findings make the health impact of pollutants harder to deny."

Fresno was chosen because it is located in California's Central Valley, where trapped hot air mixes with high traffic and heavy agriculture to create some of the highest levels of air pollution in the country. It is also a region known for its high incidence of asthma: Nearly one in three children there have the condition, earning Fresno the nickname, "The Asthma Capitol of California."

The researchers compared the participants from Fresno with 80 children, half with asthma and half without, in the relatively low-pollution city of Palo Alto, Calif. The children were matched by age, gender and asthma status, among other variables. The children were tested for breathing function, allergic sensitivity and Treg cells in the blood.

Daily air quality data came from California Air Resources Board monitoring stations. The researchers calculated each child's annual average exposure to polycyclic aromatic hydrocarbons (PAH), a byproduct of fossil fuel and a major pollutant in vehicle exhaust.

The study found that the annual average exposure to PAH was 7 times greater for the children in Fresno compared with the kids in Palo Alto. Levels of ozone and particulate matter were also significantly higher in Fresno.

Not surprisingly, the study found that the children in Fresno had lower overall levels of Treg function and more severe symptoms of asthma than the children in Palo Alto. For example, the non-asthmatic children in Fresno had Treg function results that were similar to the children with asthma in Palo Alto.

The study authors correlated increased exposure to PAH with methylation of the gene, Forkhead box transcription factor (Foxp3), which triggers Treg cell development. Methylation effectively disables the gene's function, leading to reduced levels of Treg cells. The connection between Treg function and the severity of asthma symptoms held for children in both groups.

While previous studies have found associations between pollution – especially motor vehicle exhaust – and an increased risk of developing asthma, few have traced its molecular pathway so completely, the study authors said.

"The link between diesel exhaust and asthma could simply have been that the particulates were irritating the lungs," said Nadeau. "What we found is that the problems are more systemic. This is one of the few papers to have linked from A to Z the increased exposure to ambient air pollution with suppressed Treg cell levels, changes in a key gene and increased severity of asthma symptoms."

The researchers noted that Treg cells are important for other autoimmune disorders, so the implications of this study could go beyond asthma.

Other co-authors of the study are Dr. John Balmes, UC Berkeley professor of environmental health sciences; Elizabeth Noth and Boriana Pratt, UC Berkeley researchers at FACES; and Cameron McDonald-Hyman, research assistant at Stanford University's School of Medicine.

The National Institutes of Health, U.S. Environmental Protection Agency and the American Lung Association helped support this research.

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

Further reports about: Ambient Air Faces air pollutant health services immune system

More articles from Health and Medicine:

nachricht Correct antibiotic dosing could preserve lung microbial diversity in cystic fibrosis
22.02.2019 | Children's National Health System

nachricht Researchers find trigger that turns strep infections into flesh-eating disease
19.02.2019 | Houston Methodist

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: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>