Brain Parasite Toxoplasma gondii Is Stopped by Immune Cells' Self-Destruct Switch

Researchers at UVA Health found that the brain parasite Toxoplasma gondii can infect CD8+ T cells, but these immune cells use the enzyme caspase-8 to trigger a self-destruct mechanism that kills the infected cell and the parasite inside. In mice lacking caspase-8 in their T cells, brain parasite levels were higher and outcomes worse, indicating caspase-8 is crucial for limiting brain infection. With about a third of people believed to carry T. gondii, most cases are asymptomatic, though toxoplasmosis remains a risk for the immunocompromised. The study, published in Science Advances, enhances understanding of how the immune system controls the parasite and why T cells’ self-destruction can prevent brain persistence.