Monday, March 14, 2016
Visualizing a Parasite Crossing the Blood Brain Barrier
An estimated 30 percent of the world’s population is chronically infected with the parasite Toxoplasma gondii. Most people live with the infection without noticeable effect, but it can be life-threatening for people with suppressed immune systems, such as people on cancer therapies or who have HIV/AIDS. Pregnant women can also pass an infection to their unborn children, putting the babies at risk of severe neurological disease.
It’s known that “Toxo” can affect the brain, even influencing the behavior of its hosts. But scientists have debated exactly how the parasite crosses the blood-brain barrier, a physical obstacle intended to keep pathogens out of the brain.
Researchers from the University of Pennsylvania School of Veterinary Medicine and colleagues from across the country have identified how the parasite makes its way in. Using a powerful imaging technique that allowed the scientists to track the presence and movement of parasites in living tissues, the researchers found that Toxoplasma infects the brain’s endothelial cells, which line blood vessels, reproduces inside of them, and then moves on to invade the central nervous system.