Seeking answers from a mysterious parasite
Toxoplasma gondii is a common parasite often spread by cats. Most people who are infected in Europe or North America show no symptoms at all, and only a few suffer from encephalitis or ocular toxoplasmosis, which can cause blindness. However, in South America, toxoplasmosis is associated with much more severe symptoms. Jeroen Saeij, an MIT associate professor of biology, is trying to determine just why this parasite has such varied effects. Toxoplasma gondii comes in dozens of different strains, each of which produce slightly different versions of the proteins required to infect a cell. “In the end, what we really want to know, on a molecular level, is what are the Toxoplasma proteins that affect virulence or modulation of the host cell, and with what host proteins do they interact?” Saeij says. His lab has characterized many such interactions, in hopes that a better understanding of the immune response to Toxoplasma gondii will...