Jul 31, 2024 12:00:00

A new technology has been developed to deliver drugs to the brain by using the parasite 'Toxoplasma gondii' that invades the brain and manipulates the host

Toxoplasma gondii, a parasite that infects almost all warm-blooded animals, is known to infect humans from cats and other animals, affecting men's mental disorders and making the human host sexually attractive . Research has been reported on a technology that takes advantage of the properties of Toxoplasma to deliver therapeutic drugs to the brain.

Engineering Toxoplasma gondii secretion systems for intracellular delivery of multiple large proteins therapeutic to neurons | Nature Microbiology
https://www.nature.com/articles/s41564-024-01750-6

Brain-Invading Parasite Could Be Hacked to Deliver Meds in Your Head : ScienceAlert
https://www.sciencealert.com/brain-invading-parasite-could-be-hacked-to-deliver-meds-in-your-head

Getting into the brain is hard drugs. Maybe a parasite can do the job
https://www.sciencenews.org/article/toxoplasma-drugs-brain-parasite

The brain has a membrane called the blood-brain barrier, which acts as a barrier to prevent pathogens in the blood from invading the brain and central nervous system. This protects the brain from harmful substances, but it also blocks almost all proteins, making it difficult to deliver drugs that could be useful in treating brain diseases to the brain.

On the other hand, Toxoplasma is a parasite that can penetrate the blood-brain barrier, enter the brain and cause symptoms such as encephalitis, and has even acquired the ability to produce neurotransmitters in the brain and control the host.

Shahar Bracha, a neuroscientist at the Massachusetts Institute of Technology, wondered if they could take advantage of this ability of Toxoplasma and use it to their advantage. They fused GRA16, a protein that Toxoplasma uses to manipulate host cells, with MeCP2, a protein used to treat a neurodevelopmental disorder called

Rett syndrome .

They then infected brain organoids with the modified Toxoplasma and found that the organism released useful proteins into the brain cells.

Furthermore, when the research team injected the modified Toxoplasma into the bodies of mice, Toxoplasma infected the brain as intended and began to release 'MeCP2-GRA16' there. However, inflammation in the mouse brain was minimal, so the research team concluded that 'infection with Toxoplasma and the release of the fusion protein did not cause a dangerous immune response.'

It is estimated that 25-30% of the world's population is infected with Toxoplasma, and in many cases the infection is asymptomatic. However, if an immune-compromised person becomes infected with Toxoplasma, there is a risk of developing severe toxoplasmosis. It is also known that Toxoplasma can cause premature birth or miscarriage in pregnant women, and can cause congenital disorders in babies, so it is by no means a safe parasite.

Still, the researchers see promise in Toxoplasma as a way to deliver useful proteins to the brain. 'We believe that the development of Toxoplasma as a genetic tool, elucidation of its mechanism of infection, and continued research in other biotechnology fields will further deepen our understanding of its suitability as a drug vector and stimulate further research into various applications,' they said.