Behaviour of microtubules in cells infected with Toxoplasma gondii.

Toxoplasma gondii proliferates within the parasitophorous vacuole of the host cell. Simultaneously with parasite division and vacuolar development, lipids traffic and change in the spatial distribution of organelles of the host cell cytoplasm occur. Using fluorescence microscopy, and antibodies recognizing tubulin, we showed that microtubules change their distribution during host cell infection by tachyzoites of T. gondii. In addition, transmission electron microscopy of thin sections and replicas of partially extracted cells showed that host cell microtubules concentrate around the parasitophorous vacuole. Such microtubules distribution was evident in early infection times and was more prominent after 24 h of infection, when parasitophorous vacuole was completely surrounded by microtubules. However, the meshwork microtubule filaments became slack or absent after 72 h of infection of host cell. Colchicine and taxol treatment altered the shape of the parasitophorous vacuole containing tachyzoites. These observations suggest a close association between microtubules and intravacuolar development of parasites.