Navigation Links
Ozone shuts down early immune response in lungs and body
Date:9/30/2007

DURHAM, N.C. As policy makers debate what levels of ozone in the air are safe for humans to breathe, studies in mice are revealing that the inhaled pollutant impairs the bodys first line of defense, making it more susceptible to subsequent foreign invaders, such as bacteria.

While it has long been known that exposure to ozone, a major component of urban air pollution, is associated with increased cardiovascular and pulmonary hospitalizations and deaths, the actual mechanisms involved remain unclear. New studies by Duke University Medical Center pulmonary researchers on the effects of ozone on the innate immune system, the bodys tripwire for foreign invaders, may provide part of the answer.

The Duke-led team found that ozone exposure in mice at levels approximating unhealthy levels for humans appears to enhance lung injury in response to bacterial toxins, but more importantly, it also appears to enhance programmed cell death in critical innate immune system cells that gobble up foreign invaders, keeping the airways clear.

Small amounts of inhaled foreign material can be relatively harmless, since they stimulate an appropriate innate immune response that protects the lungs, said John Hollingsworth, M.D., pulmonologist and lead author of study whose results appear Oct. 1 in the Journal of Immunology. However, it appears that ozone causes the innate immune system to overreact, killing key immune system cells, and possibly making the lung more susceptible to subsequent invaders, such as bacteria.

The innate immune system is the most primitive aspect of the bodys defenses. Its cells react indiscriminately to any invader. One of the key cells in the innate immune system is known as a macrophage, Greek for big eater.

For their experiments, the researchers had mice breathe either room air or air with levels of ozone meant to mirror what an exercising human would experience on a high, or unhealthy, ozone level day. After exposing all mice to the active portion of E. coli bacteria in aerosol form, the researchers studied how the innate immune system responded.

In the mice exposed to ozone, the airways of the lungs were hyperactive and we found higher concentrations of inflammatory cells, Hollingsworth said. But more significantly, ozone pre-exposure reduced the number of macrophages in the lung after secondary exposure to inhaled bacterial endotoxin. Exposure to ozone in this context had stimulated them to undergo programmed cell death, or apoptosis.

The researchers also found that the effect of the inhaled ozone was not limited to just the lungs. Mice exposed to ozone were also found to have lower levels of immune system cells circulating in the blood.

The Duke team plans further studies on the mechanisms behind ozones ability to induce cell death in macrophages in the lungs. They will also focus on the pollutants ability to interfere with system-wide immune responses.

The Environmental Protection Agency is in the final phases of reviewing and possibly updating the standards for allowable levels of ozone in the air. The current standard says that any amount greater than 85 parts per billion can be unhealthy for those at risk. Many medical groups, including the American Thoracic Society, recommend setting a stricter standard of 60 parts per billion, citing studies showing ozones adverse effects on health, especially in children and those with compromised health.


'/>"/>

Contact: Richard Merritt
Merri006@mc.duke.edu
919-660-1309
Duke University Medical Center
Source:Eurekalert

Related medicine news :

1. Elevated Ozone Levels Hurt Sperm Count
2. Instrument to reveal Information about Ozone Loss
3. Dr Ozones Past Catches up with Him
4. Ozone Treatment - A Good Alternative For Spinal Injury
5. Wellington Rest Home Shuts Down Due To Norovirus Outbreak
6. Gene linked to early puberty in girls
7. Cancer drugs in development nearly doubled since 1995
8. Nearly all asthma deaths preventable
9. Ductal lavage may detect early breast cancer
10. Doctors advice early anemia tests
11. Heart disease threat starts early in life for Diabetics
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/7/2016)... Dallas, Texas (PRWEB) , ... February 07, 2016 ... ... its new MyDecision™ program. MyDecision™ empowers employers and organizations with the tools and ... , MyDecision™ combines three elements to cut the cost of providing employee healthcare ...
(Date:2/6/2016)... ... 2016 , ... Shark Finds and Kevin Harrington, along with the ... campaign with Belly Bands. , Having a dog is great—except when it wets every ... find nothing works, get Belly Bands, the easiest way to stop dogs from ...
(Date:2/5/2016)... Lake City, UT (PRWEB) , ... February 05, 2016 , ... ... Activz Whole-Food Nutrition , announced that the much-anticipated feature with author Jahnavi Foster, specialist ... Cool Humans Amateur TV Network. , Each week, on his weekly Whole-Food Warrior TV ...
(Date:2/5/2016)... ... 05, 2016 , ... Looking for a last-minute Valentine’s Day gift for the ... toes. Foot massage, whether administered by a professional masseuse or a loved one, can ... Board of Multiple Specialties in Podiatry (ABMSP) has taken the upcoming Valentine’s Day ...
(Date:2/5/2016)... (PRWEB) , ... February 05, 2016 , ... ... independent PROSHRED franchises from across the country gathered at the La Valencia Hotel ... top performers. PROSHRED Chicago was named the year’s most outstanding franchise, walking ...
Breaking Medicine News(10 mins):
(Date:2/5/2016)... , February 5, 2016 ... Research report states that the global active pharmaceuticals ingredients ... is predicted to reach US$185.9 bn by 2020. It ... from 2014 to 2020. The title of the report ... Manufactured, by Geography, and by Therapeutic Area) - Global ...
(Date:2/5/2016)... Site Profile: --> ... Recognition People, announced their latest primary healthcare case study where speech ... times and to save the practice money. Site Profile: ... Challenge: --> ,- Wirral CCG ,- VoicePower client ... ,- Wirral CCG ,- VoicePower client since 2013 Challenge: ...
(Date:2/4/2016)... , Feb. 4, 2016  The Senior ... and Government Reform Committee Chairman Jason Chaffetz ... for holding today,s hearing , "Developments in ... price increases and growing questions about abusive pharmacy ... Chaffetz (R-UT) and Ranking Member Elijah Cummings ...
Breaking Medicine Technology: