Toxoplasma parasite remodels host cell surfaces to trigger invasion

Researchers at the Whitehead Institute have discovered that the single-celled parasite Toxoplasma gondii actively remodels the surface of mammalian host cells to facilitate its own invasion. The study, published in The EMBO Journal, reveals that the parasite does not merely look for existing entry points but instead reorganizes surface sugars and cholesterol to create specialized membrane patches.

This remodeling process triggers the discharge of specialized organelles called rhoptries. These organelles release cargo into the host cell to manipulate cellular machinery and establish the receptors necessary for entry. This mechanism allows the parasite to complete its invasion process in less than a minute.

The findings provide insight into how apicomplexan parasites, a group that includes the agents responsible for malaria and cryptosporidiosis, identify and commit to entering host cells. Sebastian Lourido, an associate professor at MIT and member of the Whitehead Institute, noted that the host cell is not a passive entity but is actively remodeled by the parasite to achieve the necessary conditions for entry.