Toxoplasma gondii, the causative agent of toxoplasmosis, is
capable of actively penetrating and multiplying in any nucleated cell
of warm-blooded animals. Its survival strategies include escape from
fusion of the parasitophorous vacuole with host cell lysosomes and
rearrangement of host cell organelles in relation to the
parasitophorous vacuole. In this article we report the rearrangement of
host cell organelles and elements of the cytoskeleton of LLCMK2 cells,
a lineage derived from green monkey kidney epithelial cells, in
response to infection by T. gondii tachyzoites. Transmission
electron microscopy made on flat embedded monolayers cut horizontally
to the apical side of the cells or field emission scanning electron
microscopy of monolayers scraped with scotch tape before sputtering
showed that association of mitochondria to the vacuole is much less
frequent than previously described. On the other hand, all
parasitophorous vacuoles were surrounded by elements of the endoplasmic
reticulum. These data were complemented by observations by laser
scanning microscopy using fluorescent probes from mitochondria and
endoplasmic reticulum and reinforced by three-dimensional
reconstruction from serial sections observed by transmission electron
microscopy and labeling of mitochondria and endoplasmic reticulum by
fluorescent probes.