Toxoplasma gondii' plastid as a drug target

Abstract

Toxoplasmosis is a public health concern caused by the protozoan parasite Toxoplasma gondii, which can infect all warm-blooded mammals, including humans, due to its zoonotic transmission and widespread distribution. This obligate intracellular parasite is included in the phylum Apicomplexan, characterized by the presence of an apical complex, responsible of host cell invasion, and the presence of a non-photosynthetic plastid of endosymbiotic origin, the apicoplast. The discovery of this organelle, which can be detected in some apicomplexan parasites, have permitted to identify different metabolic pathways, whose disruption can affect the viability of this parasite. Indeed, some housekeeping and non-housekeeping functions of the parasite are linked to this bacterium-like organelle. For years, many drugs have been clinically used on the treatment and control of toxoplasmosis in humans and animals. Some of these drugs, were effective against prokaryotic pathogens and surprisingly, were also efficient against the unicellular eukaryote T. gondii, although their targets were still unknown. After, the discovery of the apicoplast, the action of these compounds could be linked to the inhibition of metabolic pathways and housekeeping functions of the apicoplast. Several studies made this possible, testing the action of these drugs mainly in murine and tissue culture models. Though, promising data have been collected, more effort is still needed to understand the action of these compounds that target different functions of these organelle of endosymbiotic origin.