Historically, scientists in Brazil has significantly contributed to the biology, cultivation and structural organization
of the pathogenic protozoan
Toxoplasma gondii
and its interaction with host cells, starting with the description of
the protozoan by Splendore in 1908. The intracellular and extracellular corpuscoli observed in rabbits, corresponded
to what we now as tachyzoites. Later on, a pioneering method to grow
T. gondii in tissue cultures was developed by
Guimarães and Meyer, 1942. They also observed for the first time
T. gondii by transmission electron microscopy and
made the initial description of the cytoskeleton of
T. gondii by observing negatively stained cells. In the 1980’s, the
relation of the cytoskeleton with the sub-pellicular microtubules was reveled by freeze-fracture. More recently, several
Brazilian groups have analyzed in detail basic aspects of the early interaction of the protozoan with the host cell, such
as the role of protein phosphorylation, transfer of host cell surface components to the protozoan and genesis and organization
of the parasitophorous vacuole. Tachyzoites strategically inhibit nitric oxide production during active invasion
of activated macrophages. In vitro studies on the sexual cycle of
T. gondii using primary cultures of cat enterocytes
and the egress from host cells are being carried out. Perspectives are that the contribution of Brazilian science to the
knowledge on
T. gondii biology will continue to flourish in years to come.
