Research highlights potential way to combat toxoplasmosis parasite

March 23, 2017, University of Glasgow
Research highlights potential way to combat toxoplasmosis parasite
Credit: University of Glasgow

It lives inside one third of the UK population and is a common infection in cats, however until now scientists knew little about how the toxoplasmosis parasite communicated with its host.‌

New research, by the University of Glasgow's Wellcome Centre for Molecular Parasitology in collaboration with The University of Vermont, has revealed how the parasite uses a key protein to form a communication and ultimately continue the infection process.

The paper, which is published today in eLife, has identified a key "intracellular network of protein" that allows the toxoplasmosis to communicate with each other while inside the host. The research has also shown that disrupting this network leads to reduced replication of the parasite and an inability to leave the single – which ultimately halts infection.

Toxoplasma gondii is a parasite that commonly infects cats, but it is also carried by other warm-blooded animals, including humans. Up to one-third of the UK population is chronically infected with the parasite, although most experience few harmful effects.

However, women who become infected during pregnancy can pass the parasite to their unborn child. This can result in serious health problems for the baby such as blindness and brain damage. People who have compromised immunity, such as individuals infected with HIV, are also at risk of serious complications owing to the reactivation of dormant parasitic cysts in the brain.

Toxoplasma parasites must actively invade host so they can replicate and survive. During an infection, this replication is synchronised, meaning that all parasites in the host cell replicate at the same time.

Until now it was unknown how these parasites co-ordinated this tightly regulated process. However, through experimental work, the researchers have discovered that the protein actin helps the parasite cells form an extensive network that connects individual Toxoplasma parasites. When this protein is depleted in the parasite, not only does this network collapse, but the parasites also start to replicate out of synch and are trapped inside the host cell.

Professor Markus Meissner from the University of Glasgow, one of the lead authors of this study, said: "This work greatly increases our understanding of the Toxoplasma parasite, and provides an insight into how this potentially dangerous parasitic infection can be disrupted.

"When we first saw the formation of such an extensive network, we didn't believe our eyes and the first thing we discussed was if this is just an artefact. However, at the end all our control experiments demonstrated that it is very real. The major challenge was to convince some of our colleagues who were also looking into the role of actin in these parasites."

The findings could provide clues to new treatment for other parasite diseases, including malaria, which cause substantial morbidity and mortality worldwide.

Dr Aoife Heaslip, previously of the University of Vermont who is now an Assistant Professor at the University of Connecticut, said: "We've known for many years that actin was an important protein needed for parasite entry into host cells. However our recent discover that actin forms communication channels between parasites as they grow inside cells adds a whole new dimension to our understanding."

Explore further: Scientists reveal how immune system tags Toxoplasma capsule

More information: Javier Periz et al. F-actin forms an extensive filamentous network required for material exchange and parasite maturation, eLife (2017). DOI: 10.7554/eLife.24119

Related Stories

Scientists reveal how immune system tags Toxoplasma capsule

January 11, 2017

Scientists at the Francis Crick Institute have discovered how the host immune system deals with the prolific Toxoplasma parasite as it attempts to camouflage itself by hiding inside a capsule called a vacuole in human cells.

Study turns parasite invasion theory on its head

December 23, 2012

Current thinking on how the Toxoplasma gondii parasite invades its host is incorrect, according to a study published today in Nature Methods describing a new technique to knock out genes. The findings could have implications ...

Toxoplasmosis infection trick revealed by scientists

May 10, 2007

Toxoplasmosis is a parasitic disease, primarily carried by cats. It is transmitted to humans by eating undercooked meat or through contact with cat faeces. It is particularly dangerous for pregnant women, whose foetuses can ...

Recommended for you

Microplastics may enter foodchain through mosquitoes

September 19, 2018

Mosquito larvae have been observed ingesting microplastics that can be passed up the food chain, researchers said Wednesday, potentially uncovering a new way that the polluting particles could damage the environment.

In a tiny worm, a close-up view of where genes are working

September 19, 2018

Scientists have long prized the roundworm Caenorhabditis elegans as a model for studying the biology of multicellular organisms. The millimeter-long worms are easy to grow in the lab and manipulate genetically, and have only ...

Social animals have tipping points, too

September 18, 2018

In relatively cool temperatures, Anelosimus studiosus spiders lay their eggs and spin their webs and share their prey in cooperative colonies from Massachusetts to Argentina. Temperatures may vary, but the colonies continue ...

Why do we love bees but hate wasps?

September 18, 2018

A lack of understanding of the important role of wasps in the ecosystem and economy is a fundamental reason why they are universally despised whereas bees are much loved, according to UCL-led research.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Mar 26, 2017
It's hard to believe that a parasite like this, which is able to control the behavior of rodents so successfully that they gain weight and become sexually attracted to cat urine in order to make their way into the cat's stomach so the parasite can continue its life cycle, is having no effect on the behavior of humans who become infected by it. Science won't find what it doesn't look for. A parasite that infects thirty percent and more of the global human population as well as numerous other mammals who pick it up from the environment, should be getting a very close look by far greater numbers of researchers than are actually doing so.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.