Nav: Home

New study by Clemson scientists could pave way to cure of global parasite

May 18, 2020

CLEMSON, South Carolina - Clemson University scientists have taken another step forward in their quest to find a cure for a notorious parasite that has infected more than 40 million Americans and many times that number around the world.

A newly released study led by Zhicheng Dou of the College of Science provides evidence that disrupting heme production in Toxoplasma gondii could be an effective therapeutic strategy to control this common and sometimes deadly infection. Their work focuses on a metabolic pathway for heme production in the parasites. Heme is a key molecule that occurs naturally in almost all living organisms and allows blood to carry oxygen throughout our bodies.

Dou's collaborative research has been published in PLOS Pathogens, a high-profile microbiology journal. The study is titled "Toxoplasma gondii requires its plant-like heme biosynthesis pathway for infection."

"Toxoplasma is a eukaryotic pathogen, which means it shares similar metabolic pathways as human cells," said Dou, an assistant professor in the department of biological sciences. "For example, in this paper, we studied the heme metabolism in parasites. In our own cells, we have very similar pathways of heme production."

But in Toxoplasma, Dou's research found that heme metabolism carries some plant-like features.

"This is very interesting," said Dou, a faculty member in Clemson's Eukaryotic Pathogens Innovation Center (EPIC). "The parasite has a plant-like organelle inside. Part of the heme metabolism is encapsulated inside this organelle. Parasites have some plant-like genes and some animal-like genes. We call Toxoplasma parasite 'hybrid.' "

Toxoplasma is an extremely common parasite that can lie dormant for an infected person's entire lifetime. But for some people, it is far from harmless.

"Most people don't know they have the infection," Dou said. "Most people will not feel any symptoms because their immune system is strong enough to resist the infection. The parasite can hide in the human body. But if immunity is compromised, the parasite can be reactivated."

For example, the parasite poses a danger to cancer patients and organ transplant recipients who take immune-suppressing drugs as part of their treatment. In pregnant women, the parasite can affect the developing fetus.

After identifying the plant-like part of the heme biosynthesis pathway in the parasites, Dou's research focused on the possibility of using herbicides to inhibit the heme metabolism, denying the parasite an essential nutrient. In this proof-of-concept study, one class of herbicide was found to work.

"We found several herbicides within the same category that can inhibit the parasite's growth," Dou said.

The research started with a commercially available herbicide that was not sufficiently potent. Dou then called on a colleague to modify the original herbicide.

"I'm part of the same center that studies eukaryotic pathogens, but my training is very different than his," said Daniel Whitehead, an associate professor in the department of chemistry who is also a faculty member of EPIC. "My group is a synthetic organic chemistry group. What we specialize in is the ability to make molecules. I think his study uncovers a druggable target that might be useful to treat infections of Toxoplasma."

Dou's research uncovered what Whitehead called a "molecular scaffold" that can be built around to create more potent derivatives. Dou said the results are encouraging.

"He can generate new molecules in his lab, and we can test the new molecules in my lab, and we'll work together," Dou said. "Modify, test, modify, test."

Whitehead said the research highlights the purpose of EPIC.

"If we blend our expertise, we can accomplish things that neither one of us can accomplish alone," Whitehead said. "Without the co-mingling of expertise, these types of opportunities can be missed."
In addition to Dou and Whitehead, other contributors to the paper are Amy Bergmann, Katherine Floyd, Melanie Key, Carly Dameron, Kerrick C. Rees, and L. Brock Thornton from Clemson University and Iqbal Hamza from the University of Maryland. Bergmann and Floyd share first authorship in this publication. Bergmann, lab manager in the Dou lab, also conducts her own research. Floyd just received her B.S. degree from Clemson University, majoring in microbiology and biochemistry. She will start her Ph.D. training at Washington University in St. Louis this fall.

Clemson University

Related Parasites Articles:

How malaria parasites withstand a fever's heat
The parasites that cause 200 million cases of malaria each year can withstand feverish temperatures that make their human hosts miserable.
New studies show how to save parasites and why it's important
An international group of scientists published a paper, Aug. 1, 2020, in a special edition of the journal Biological Conservation that lays out an ambitious global conservation plan for parasites.
More flowers and pollinator diversity could help protect bees from parasites
Having more flowers and maintaining diverse bee communities could help reduce the spread of bee parasites, according to a new study.
How Toxoplasma parasites glide so swiftly (video)
If you're a cat owner, you might have heard of Toxoplasma gondii, a protozoan that sometimes infects humans through contact with contaminated feces in litterboxes.
Parasites and the microbiome
In a study of ethnically diverse people from Cameroon, the presence of a parasite infection was closely linked to the make-up of the gastrointestinal microbiome, according to a research team led by Penn scientists.
Clocking in with malaria parasites
Discovery of a malaria parasite's internal clock could lead to new treatment strategies.
Feeding bluebirds helps fend off parasites
If you feed the birds in your backyard, you may be doing more than just making sure they have a source of food: you may be helping baby birds give parasites the boot.
Scientists discover how malaria parasites import sugar
Researchers at Stockholm University has established how sugar is taken up by the malaria parasite, a discovery with the potential to improve the development of antimalarial drugs.
How malaria parasites become resistant to artemisinin antimalarial drugs
Malaria parasite mutations that inhibit the endocytoic appetite for a host's red blood cells may render them resistant to artemisinin, a widely used frontline antimalarial drug, according to a new study, which reveals a key molecular mechanism of drug resistance.
Study shows interactions between bacteria and parasites
A team at the Technical University of Munich (TUM) has completed the first study of the effects of a simultaneous infection with blood flukes (schistosomes) and the bacterium Helicobacter pylori -- a fairly common occurrence in some parts of the world.
More Parasites News and Parasites Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at     You can read The Transition Integrity Project's report here.