Turning a toxoplasma protein into a tool against infection

May 10, 2017
Toxoplasmosis is a parasitic disease that most severely affects people with a weakened immune system. Caused by the parasite Toxoplasma gondii, it spreads due to consumption of undercooked meat and exposure to cat faeces. Credit: Kateryna Kon / 123rf

Toxoplasmosis is a parasitic disease that most severely affects people with a weakened immune system. Caused by the parasite Toxoplasma gondii, it spreads due to consumption of undercooked meat and exposure to cat faeces. Although it can be mild, causing only flu-like symptoms, it can lead to brain problems such as lesions and encephalitis, in addition to other neurological disorders. It is not generally spread between humans, but can be passed to an unborn child if a pregnant woman is infected.

Current treatment options for toxoplasmosis are limited. Yee-Ling Lau and colleagues at the University of Malaya wanted to investigate potential vaccine candidates to prevent infection.

T. gondii invades cells with the help of a protein, ROP1, which is secreted within the parasite. The team looked at whether exposure to this protein could protect mice that were later infected with T. gondii. Past studies have shown that ROP1 does create some in cell cultures and in animals, but until now, no one has gone on to infect vaccinated mice with live parasites to test the effectiveness of the immune response.

Lau and colleagues took groups of mice and gave them three vaccinations at twoweek intervals. Some received a ROP1 treatment intramuscularly or under the skin, while others received a placebo using the same two injection techniques. Each group of mice was later given lethal doses of a virulent T. gondii strain.

The mice that had received the ROP1 treatment survived longer than the controls, regardless of the method of vaccination. The vaccinated mice survived up to 16 days, whereas the controls all succumbed to T. gondii infection after just nine. The researchers caution, however, that none of the vaccinated had complete protection.

The team believes that the protection occurs through cell-mediated immune responses; meaning that the immunity is not generated by antibodies, but by the activation of molecules in the cell. Although this work is promising, further work needs to be done to investigate other agents that could be combined with ROP1 to achieve better results, or even complete protection against the .

Explore further: How a nasty, brain-eating parasite could help us fight cancer

Related Stories

How a nasty, brain-eating parasite could help us fight cancer

August 26, 2016
We've known since the turn of the 20th century that some infectious diseases are a major risk for developing specific cancers. More worryingly, about one-sixth of cancers worldwide are attributable to infectious agents. Globally, ...

Parasite proteins prompt immune system to fight off ovarian tumors in mice

July 22, 2016
Scientists identified the specific proteins secreted by the parasite Toxoplasma gondii that cause the immune system in mice to attack established ovarian tumors. The study, led by David Bzik of the Geisel School of Medicine ...

Researchers question lifelong immunity to toxoplasmosis

December 8, 2016
Medical students are taught that once infected with Toxoplasma gondii—the "cat parasite"—then you're protected from reinfection for the rest of your life. This dogma should be questioned, argue researchers in an Opinion ...

New study brings long-sought vaccines for deadly parasite closer to reality

December 13, 2012
One major cause of illness from food-borne diseases is the parasite Toxoplasma gondii (T. gondii). New insights into how the immune system combats T. gondii are provided in a study published by Cell Press December 13th in ...

Scientists find Huntington's disease mice respond differently to common infection

September 19, 2016
Casual conversation three years ago between University of Wyoming veterinary sciences and molecular biology researchers resulted in findings that show for the first time mice engineered to have the human genetic disorder ...

Recommended for you

Antibiotics warranted for kids with minor staph infections

September 26, 2017
The overuse of antibiotics has left some doctors questioning whether to give such drugs to children diagnosed with uncomplicated staph infections. Such infections often occur on the skin and look like a pus-filled bug bite.

Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections

September 22, 2017
Group A Streptococcus bacteria cause a variety of illnesses that range from mild nuisances like strep throat to life-threatening conditions including pneumonia, toxic shock syndrome and the flesh-eating disease formally known ...

Ecosystem approach makes urinary tract infection more treatable

September 22, 2017
The biological term 'ecosystem' is not usually associated with urinary tract infections, but this should change according to Wageningen scientists.

Residents: Frontline defenders against antibiotic resistance?

September 22, 2017
Antibiotic resistance continues to grow around the world, with sometimes disastrous results. Some strains of bacteria no longer respond to any currently available antibiotic, making death by infections that were once easily ...

Individualized diets for irritable bowel syndrome better than placebo

September 21, 2017
Patients with irritable bowel syndrome who follow individualized diets based on food sensitivity testing experience fewer symptoms, say Yale researchers. Their study is among the first to provide scientific evidence for this ...

Superbug's spread to Vietnam threatens malaria control

September 21, 2017
A highly drug resistant malaria 'superbug' from western Cambodia is now present in southern Vietnam, leading to alarming failure rates for dihydroartemisinin (DHA)-piperaquine—Vietnam's national first-line malaria treatment, ...

0 comments

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.