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 The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>