One in three people can be a carrier of the brain parasite Toxoplasma gondii. This parasite has a trick to survive: it can infect CD8+ T cells, which are the key defenders of the immune system. Still, most people never get sick. New research from UVA Health reveals why. When a parasite attacks these immune cells, the cells trigger a self-destruct mechanism. The latter is driven by the enzyme caspase-8. Infected cells sacrifice themselves and destroy the parasite within them. The body thus has an effective mechanism to eliminate the parasite.