Featured Research

from universities, journals, and other organizations

Scientists uncover process enabling toxoplasmosis parasite to survive homelessness

Date:
September 23, 2010
Source:
Indiana University School of Medicine
Summary:
The parasite responsible for toxoplasmosis requires a stress response system that helps it survive the move to infect new cells, scientists have reported -- a discovery that could lead to new treatments to control the disease.

The image shows two Toxoplasma parasites outside of their host cell. The trails are proteins left behind when the parasite glides on the substrate used during the imaging process.
Credit: Courtesy Indiana University School of Medicine / Bradley Joyce

The parasite responsible for toxoplasmosis requires a stress response system that helps it survive the move to infect new cells, Indiana University School of Medicine scientists have reported, a discovery that could lead to new treatments to control the disease.

Parasites such as Toxoplasma gondii invade host cells, replicate and then must exit to find new host cells to invade. Traveling outside their host cell exposes the parasites to environmental stresses that limit how long they can remain viable while searching for new host cells.

The researchers found that the parasite triggers a stress response mechanism that alters protein production through phosphorylation of a factor called eIF2, which the Toxoplasma parasite uses to survive periods when it finds itself without a host cell. Phosphorylation is a cellular process in which a phosphate compound is added to a protein to alter its activity.

"Toxoplasma does not like to be homeless," said William J. Sullivan Jr., Ph.D., associate professor of pharmacology and toxicology. "Being deprived of the nutrients and shelter provided by the host cell is a serious stress on the parasite. Our research uncovered a critical pathway the parasite uses to survive the journey from one host cell to another."

The report is being published in the online early edition of the Proceedings of the National Academy of Sciences. In addition to Sullivan, the researcher team included Ronald C. Wek, Ph.D., professor of biochemistry and molecular biology; lead author and postdoctoral fellow Bradley Joyce, Ph.D., and Sherry F. Queener, Ph.D., professor of pharmacology and toxicology.

Based on earlier research, the group previously reported that the same response system is employed by the parasite when its host cell is stressed, which enables Toxoplasma to transform into a cyst surrounded by a protective barrier that can resist drugs and the body's immune system. Later, however, the parasite can emerge from its dormant state to strike when a patient's immune system is weakened.

"Our latest findings indicate that if we design new drugs that target this stress response pathway, these drugs may be effective against both acute and chronic Toxoplasma infection," says Dr. Sullivan.

An estimated 60 million people in the United States are infected with the toxoplasmosis parasite, but for most infection produces flu-like symptoms or no symptoms at all. However, for people with an impaired immune system -- such as those undergoing chemotherapy, heart transplants, or people with AIDS -- the disease can cause life-threatening complications including cardiopulmonary problems, blurred vision and seizures. Also, if a woman becomes infected for the first time shortly before or during pregnancy, there is risk of miscarriage or congenital birth defects.

Support for this research was provided through grants from the American Heart Association and the National Institutes of Health.


Story Source:

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


Journal Reference:

  1. Bradley R. Joyce, Sherry F. Queener, Ronald C. Wek, William J. Sullivan, Jr. Phosphorylation of eukaryotic initiation factor-2α promotes the extracellular survival of obligate intracellular parasite Toxoplasma gondii. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1007610107

Cite This Page:

Indiana University School of Medicine. "Scientists uncover process enabling toxoplasmosis parasite to survive homelessness." ScienceDaily. ScienceDaily, 23 September 2010. <www.sciencedaily.com/releases/2010/09/100920172740.htm>.
Indiana University School of Medicine. (2010, September 23). Scientists uncover process enabling toxoplasmosis parasite to survive homelessness. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2010/09/100920172740.htm
Indiana University School of Medicine. "Scientists uncover process enabling toxoplasmosis parasite to survive homelessness." ScienceDaily. www.sciencedaily.com/releases/2010/09/100920172740.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
Lion Cubs the Pride of San Diego Zoo

Lion Cubs the Pride of San Diego Zoo

Reuters - US Online Video (Sep. 13, 2014) Roars of excitement as a proud lioness shows off her four cubs at the San Diego Zoo Safari Park. Jillian Kitchener reports. Video provided by Reuters
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