ABSTRACT
Toxoplasma gondii is a ubiquitous protistan parasite of animals. Unlike other protistan parasites such as Leishmania and Trypanosoma, the surface of T. gondii tachyzoites does not contain a significant amount of glycoconjugates. Hughes has reviewed the literature on oxidative killing of intracellular T. gondii mediated by macrophages, and suggests that more than one pathway is involved in parasite destruction. The fluidity in the cell membrane lipid layers of T. gondii tachyzoites is different to that of a range of other cell systems, due to differences in the lipid composition. Although excretory/secretory antigens constitute as many as 90% of the T. gondii antigens circulating in the serum of infected hosts, they have received little attention compared with the amount of research carried out on surface antigens. Lymphocyte transformation was first used to assess the cell-mediated immune response to T. gondii in humans almost 20 years ago.
