Scottish researchers unveil potential new drug target for toxoplasmosis

Researchers from the University of Glasgow have discovered a potential new drug target for the parasitic disease, toxoplasmosis.

The parasitic disease, caused by the Toxoplasma parasite, is generally transmitted through under-cooked meat, soil or from contact with cat faeces. It can pose severe risk for specific patient populations, such as paediatrics and those with compromised immune systems.

This new research from a team based in Glasgow, published in PLOS Pathogens, has identified a key enzyme, thioredoxins, in the parasite that is critical for its survival. Using this information, the team are looking at ways to target the enzyme — through collaboration with industry — in order to treat the disease.

“More and more studies highlight the parasite’s sensitivity to redox imbalance – a key function of the enzyme we have studied,” explained Dr Sheiner, from the University’s Wellcome Centre for Molecular Parasitology. “Targeting the thioredoxin enzyme may make them vulnerable at stages of their life that are important for infection and dissemination. Finding enzymes in the parasite that that we can target, and that don’t influence the human host, unravels this potentially deadly parasite’s Achilles’ heel.”

Furthermore, the research team are hopeful that their work into this parasite may be useful as an experimental model that could assist in the learning of malaria parasitic biology.

Sheiner added: “Our original interest in this research was not in drug discovery, rather we are excited to learn about how parasites work and how evolution provided them with special tools to serve their parasitic life style. But, as in this case, we are obviously very happy if we stumble across promising targets for new drugs.”

“Around a third of the UK population are thought to carry the Toxoplasma parasite. Normally a dormant parasite, it can lead to serious neurological harm when ‘awakened’ in people with compromised immunity, like HIV patients, or those with an immature immune system, like infants and unborn children,” commented Michael Chew, from Wellcome’s Infection and Immunobiology team. “This research is a great example of how basic, discovery science can lead to new drug targets for dangerous diseases.”

A new treatment for this parasitic disease would be welcomed by patient groups, particularly in light of the price increase to one of the main treatments, Daraprim, that happened in 2015 — Turing Pharmaceuticals raised the price of the drug from $13.50 to $750 a tablet. Additionally, current treatments often have toxic side effects and do not address the underlying dormant form of the parasite.