Featured Research

from universities, journals, and other organizations

Why Cigarette Smoke Makes Flu, Other Viral Infections Worse

Date:
July 25, 2008
Source:
Yale University
Summary:
A new study could explain why the cold and flu virus symptoms that are often mild and transient in non-smokers can seriously sicken smokers. The study also identified the mechanism by which viruses and cigarette smoke interact to increase lung inflammation and damage.

A new study by researchers at Yale School of Medicine could explain why the cold and flu virus symptoms that are often mild and transient in non-smokers can seriously sicken smokers. The study also identified the mechanism by which viruses and cigarette smoke interact to increase lung inflammation and damage.

Until recently, scientists haven't been able to explain why smokers have more exaggerated responses to viral infections. Smokers have been more likely than non-smokers to die during previous influenza epidemics and are more prone to chronic obstructive pulmonary disease (COPD). Furthermore, children who are exposed to second-hand smoke have more severe responses when infected with respiratory synctial virus.

The prevailing view has been that cigarette smoke decreases anti-viral responses. But the Yale researchers—lead author Jack A. Elias, M.D., the Waldermar Von Zedtwitz Professor of Medicine and chair of internal medicine at Yale School of Medicine, and first author Min-Jong Kang, M.D., associate research scientist—found the opposite to be true.

Their experiments showed that the immune systems of mice exposed to cigarette smoke from as little as two cigarettes a day for two weeks overreacted when they were also exposed to a mimic of the flu virus. The mice's immune systems cleared the virus normally but the exaggerated inflammation caused increased levels of tissue damage.

"The anti-viral responses in the cigarette smoke exposed mice were not only not defective, but were hyperactive," said Elias. "These findings suggest that smokers do not get in trouble because they can't clear or fight off the virus; they get in trouble because they overreact to it."

"It's like smokers are using the equivalent of a sledge hammer, rather than a fly swatter, to get rid of a fly," said Elias.

The team found that mice with viral infections that had been exposed to cigarette smoke had accelerated emphysema and airway scarring. Elias and his team also defined the signaling pathway that mediates this exaggerated innate immune response.

"If the exaggerated responses are verified in human studies, it will be the first explanation for why viral infections are more serious in smokers," said Elias. "Once verified, we can find ways to prevent the destruction of lung tissue and the higher illness and death among smokers."

"These studies have identified molecular pathways that can explain how cigarette smoke exposure and viral infections interact to make breathing problems worse in diseases like COPD," said James P. Kiley, director, Division of Lung Diseases of the National Heart, Lung, and Blood Institute. "With further research, these findings may even lead to more effective drug treatments for COPD."

Other authors on the study included Chun Geun Lee, Jae-Young Lee, Charles S. Dela Cruz, Zhijian J. Chen and Richard Enelow.


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kang et al. Cigarette smoke selectively enhances viral PAMP– and virus-induced pulmonary innate immune and remodeling responses in mice. Journal of Clinical Investigation, 2008; DOI: 10.1172/JCI32709

Cite This Page:

Yale University. "Why Cigarette Smoke Makes Flu, Other Viral Infections Worse." ScienceDaily. ScienceDaily, 25 July 2008. <www.sciencedaily.com/releases/2008/07/080724175857.htm>.
Yale University. (2008, July 25). Why Cigarette Smoke Makes Flu, Other Viral Infections Worse. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2008/07/080724175857.htm
Yale University. "Why Cigarette Smoke Makes Flu, Other Viral Infections Worse." ScienceDaily. www.sciencedaily.com/releases/2008/07/080724175857.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins