Behaviour of microtubules in cells infected with Toxoplasma gondii

Toxoplasma gondii proliferates within the parasitophorous vacuole of the ho st cell. Simultaneously with parasite division and vacuolar development, li pids traffic and change in the spatial distribution of organelles of the ho st cell cytoplasm occur. Using fluorescence microscopy, and antibodies reco gnizing tubulin, we showed that microtubules change their distribution duri ng host cell infection by tachyzoites of T.gondii. In addition, transmissio n electron microscopy of thin sections and replicas of partially extracted cells showed that host cell microtubules concentrate around the parasitopho rous vacuole. Such microtubules distribution was evident in early infection times and was more prominent after 24h of infection, when parasitophorous vacuole was completely surrounded by microtubules. However, the meshwork mi crotubule filaments became slack or absent after 72h of infection of host c ell. Colchicine and taxol treatment altered the shape of the parasitophorou s vacuole containing tachyzoites. These observations suggest a close associ ation between microtubules and intravacuolar development of parasites.