Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study finds plant proteins control chronic disease in Toxoplasma infections

09.04.2013
University of South Florida-led research sheds light on malaria-related parasite's transition from acute to chronic stage

A new discovery about the malaria-related parasite Toxoplasma gondii -- which can threaten babies, AIDS patients, the elderly and others with weakened immune function -- may help solve the mystery of how this single-celled parasite establishes life-long infections in people.

The study, led by a University of South Florida research team, places the blame squarely on a family of proteins, known as AP2 factors, which evolved from the regulators of flowering in plants.

In findings published today in the Proceedings of the National Academy of Sciences, the researchers demonstrate AP2 factors are instrumental in flipping a developmental "switch" that transitions the parasite from a rapidly dividing form destructive to healthy tissue to a chronic stage invisible to the immune system. They identified one factor, AP2IX-9, that appears to restrict development of Toxoplasma cysts that settle quietly in various tissues, most commonly the host's brain.

A better understanding of how the switch mechanism works may eventually lead to ways to block chronic Toxoplasma infections, said study principal investigator Michael White, PhD, professor of global health and molecular medicine at USF Health and a member of the Center of Drug Discovery and Innovation, a Florida Center of Excellence at USF.

White and his colleagues are among the world's leading experts in T. gondii, combining approaches from biochemistry, genetics and structural biology to look for new ways to combat the parasitic disease toxoplasmosis.

No drugs or vaccines currently exist to treat or prevent the chronic stage of the disease. The T. gondii parasites may remain invisible to the immune system for years and then reactivate when immunity wanes, boosting the risk for recurrent disease.

"The evolutionary story of Toxoplasma is fascinating," White said. "We were blown away to find that the AP2 factors controlling how a flower develops and how plants respond to poor soil and water conditions have been adapted to work within an intracellular human parasite."

Ages ago the ancestors of malaria parasites genetically merged with an ancestor of plants, and the primitive plant donated its AP2 factors to the future malaria family.

"Our study showed that, like the AP2 factors help a plant survive a stressful environment, the AP2 factors of T. gondii help the parasite decide when the time is right to grow or when to form a tissue cyst that may lie dormant in people for many years," White said.

Toxoplasmosis, the infection caused T. gondii, is commonly associated with the medical advice that pregnant women should avoid contact with litter boxes. That's because infected cats play a big role in spreading the disease. The tiny organism thrives in the guts of cats, producing countless egg-like cells that are passed along in the feces and can live in warm moist soil or water for months.

People can acquire toxoplasmosis several ways, usually by exposure to the feces of cats or other infected animals, by eating undercooked meat of infected animals, or drinking water contaminated with T. gondii.

Up to 30 percent of the world's population is estimated to be infected with the T. gondii parasite. In some parts of the world, including places where sanitation is poor and eating raw or undercooked meat is customary, nearly 100 percent of people carry the parasite, White said.

Few experience flu-like symptoms because the immune system usually prevents the parasite from causing illness, but for those who are immune deficient the consequences can be severe.

The disease may be deadly in AIDS patients, organ transplant recipients, patients receiving certain types of chemotherapy, and infants born to mothers infected with the parasite during or shortly before pregnancy. Recently, toxoplasmosis has been linked to mental illness, such as schizophrenia and other diseases of dementia, and changes in behavior.

Because it is common, complex and not easily killed with standard disinfection measures, the toxoplasma parasite is a potential weapon for bioterrorists, White added.

The USF-led study was supported by grants from the National Institutes of Health. White's team worked with researchers at Princeton University, Albert Einstein College of Medicine, and Indiana University School of Medicine. Joshua Radke, a PhD student in the USF Health Department of Molecular Medicine, was a first author of the study.

Article citation: "ApiAP2 transciption factor restricts development of the Toxoplasma tissue cyst;" Joshua B. Radke, Oliver Lucas, Erandi K. DeSilva, YanFen Ma, William J. Sullivan, Jr., Louis M. Weiss, Manuel Llinas, and Michael W. White; Proceedings of the National Academy of Sciences; http://www.pnas.org/cgi/doi/10.1073/pnas.1300059110

USF Health's mission is to envision and implement the future of health. It is the partnership of the USF Health Morsani College of Medicine, the College of Nursing, the College of Public Health, the College of Pharmacy, the School of Biomedical Sciences and the School of Physical Therapy and Rehabilitation Sciences; and the USF Physician's Group. The University of South Florida is a global research university ranked 50th in the nation by the National Science Foundation for both federal and total research expenditures among all U.S. universities. For more information, visit http://www.health.usf.edu

Anne DeLotto Baier | EurekAlert!
Further information:
http://www.usf.edu

More articles from Life Sciences:

nachricht UNH researchers create a more effective hydrogel for healing wounds
21.11.2018 | University of New Hampshire

nachricht Removing toxic mercury from contaminated water
21.11.2018 | Chalmers University of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First diode for magnetic fields

Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.

Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Removing toxic mercury from contaminated water

21.11.2018 | Life Sciences

New China and US studies back use of pulse oximeters for assessing blood pressure

21.11.2018 | Medical Engineering

Exoplanet stepping stones

21.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>