Researchers Turn Common ‘Cat Parasite’ Into Brain Drug Delivery Tool

An international team of scientists led by researchers from Tel Aviv and Glasgow universities have engineered the “cat parasite” Toxoplasma gondii to deliver drugs to the human brain.

The study was led by Prof. Oded Rechavi from the Department of Neurobiology and the Sagol School of Neuroscience at Tel Aviv University, together with his PhD student Dr. Shahar Bracha, and with Prof. Lilach Sheiner, an Israeli scientist and toxoplasma expert at the University of Glasgow. 

Toxoplasma gondii can infect a vast variety of organisms, but reproduces only in the guts of cats. It is very effective in infecting humans, and an estimated third of the global population will have been infected at some point in their lives. 

Rechavi explains that a healthy immune system has only limited access to the brain while it is fighting off disease due to what is called the the blood-brain barrier (BBB). The parasite, however, remains in the brain throughout the carrier’s lifetime, surviving in a dormant state, without reproducing. 

This, the TAU team realized, made it a perfect candidate for a novel approach: genetically engineering Toxoplasma gondii to secrete therapeutic proteins.

“The parasite’s ability to pass through the BBB and communicate with the neurons, combined with our ability to engineer the parasite, generate a golden opportunity for solving the great therapeutic challenge of delivering medications to the brain,” says Sheiner.

The breakthrough could have far-reaching implications for a range of severe diseases. In their current study, the researchers showed the delivery of a protein called MeCP2, whose deficiency is associated with Rett syndrome, a rare genetic neurological disorder that affects language and coordination, growth and movement.  

The researchers have set up a company named Epeius, in collaboration with TAU’s technology transfer company Ramot and with the Glasgow University’s research and innovation services, in order to ensure the safe and effective implementation of the method of drug delivery and genetic editing.

The results of the study were published in the leading scientific journal Nature Microbiology.