Featured Research

from universities, journals, and other organizations

Newly Discovered Immune Defense May Be Impaired In Cystic Fibrosis Airways

Date:
December 6, 2006
Source:
University of Iowa
Summary:
A recent University of Iowa study reveals a new immune defense mechanism in normal airways and may help explain why people with cystic fibrosis are particularly susceptible to bacterial lung infections. The findings also may point the way to new approaches for treating the disease.

A recent University of Iowa study reveals a new immune defense mechanism in normal airways and may help explain why people with cystic fibrosis (CF) are particularly susceptible to bacterial lung infections. The findings also may point the way to new approaches for treating the disease.

The UI study shows how two enzymes generate and use reactive oxygen species (ROS) to destroy bacteria in normal airways. The team also found that this process is defective in airway tissue and cells containing the CF gene mutation. The study is published in the Nov. 2 online issue of the American Journal of Respiratory and Critical Care Medicine.

"Among the host defense systems that we know of in the airway, at least in cell culture and tissue explants, this is one of the most efficient antibacterial system we have identified," said Botond Banfi, M.D., Ph.D., UI assistant professor of anatomy and cell biology and senior study author. "The findings suggest that one reason for CF patients' weakened innate immunity might be the absence of this natural oxidative host defense mechanism."

Banfi added that correcting the problem by reconstituting the oxidative system might represent a totally new approach for preventing the onset of bacterial lung infections that often become chronic and eventually fatal in CF patients.

Working with airway cells and tissues from rats, cows and humans, the UI team uncovered the oxidative system, which produces hypothiocyanite -- a highly effective antibacterial compound. Banfi and his colleagues, including Patryk Moskwa, M.D., Ph.D., a UI postdoctoral fellow and first author of the study, showed that one airway enzyme (Duox) makes hydrogen peroxide and a second enzyme (lactoperoxidase) uses the hydrogen peroxide to convert a small molecule called thiocyanate into the bacteria-killing hypothiocyanite.

The UI researchers also showed that the critical thiocyanate cannot be transported across airway cells with the CF mutation, which means that hypothiocyanite is not produced. In other words, without thiocyanate the oxidative antibacterial system breaks down.

These results suggest that thiocyanate may not be present in the airway surface liquid of individuals with CF. Banfi and his colleagues intend to test that hypothesis by comparing thiocyanate levels in airway surface liquid from CF patients and from healthy individuals.

Thiocyanate is naturally present in body fluids like blood and saliva. Despite its name and its chemical relationship to cyanide, thiocyanate is not toxic. Hypothiocyanite is also harmless to human cells and tissues, but the UI team found that it is extremely efficient at killing bacteria including those most commonly associated with fatal lung infections in CF patients - Staphylococcus aureus and Pseudomonas aeruginosa.

"If we could reconstitute thiocyanate concentrations in the airway surface liquid, perhaps using a nebulizer, it might boost host defenses in CF patients and help prevent bacterial lung infections," Banfi said.

In addition to Banfi and Moskwa, the UI team included graduate student, Daniel Lorentzen; Katherine Excoffon, Ph.D., associate research scientist; Joseph Zabner, M.D., professor of internal medicine; Paul McCray, M.D., the Roy J. Carver Chair in Pulmonary Research and professor of pediatrics; and William Nauseef, M.D., professor of internal medicine. Corinne Dupuy at INSERM in Paris, France also was part of the research team.

The study was funded in part by the Cystic Fibrosis Foundation.


Story Source:

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


Cite This Page:

University of Iowa. "Newly Discovered Immune Defense May Be Impaired In Cystic Fibrosis Airways." ScienceDaily. ScienceDaily, 6 December 2006. <www.sciencedaily.com/releases/2006/11/061130191013.htm>.
University of Iowa. (2006, December 6). Newly Discovered Immune Defense May Be Impaired In Cystic Fibrosis Airways. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2006/11/061130191013.htm
University of Iowa. "Newly Discovered Immune Defense May Be Impaired In Cystic Fibrosis Airways." ScienceDaily. www.sciencedaily.com/releases/2006/11/061130191013.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
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