Your Brain Parasite Isn’t Making You Sick. Here’s Why.
The UVA researchers found that the parasite, Toxoplasma gondii, is kept in check by brain defenders called microglia. These microglia release a unique immune molecule, IL-1a, that recruits immune cells from the blood to control the parasite in the brain, the scientists discovered. This process works so well that very few people develop symptomatic toxoplasmosis, the disease the parasite causes.
Understanding the role of microglia is essential because they are normally the only immune cells inside the brain. The new finding reveals how they recruit help when needed, and that discovery could apply to any brain condition with an immunological component – including brain injury, Alzheimer’s disease, stroke, multiple sclerosis and more.
“Microglia must die to save the brain from this infection,” said researcher Tajie Harris of UVA’s Department of Neuroscience and the interim director of the Center for Brain Immunology and Glia, or BIG. “Otherwise the IL-1a remains stuck inside the microglia and wouldn’t alert the immune system that something is wrong.”