Apicomplexa is a phylum consisting of unicellular, obligate, intracellular protozoan parasites, which includes various human pathogen species such as Plasmodium spp. (causative agents of malaria), Toxoplasma gondii (cause of toxoplasmosis) and Cryptosporidium spp. (cause of cryptosporidiosis). Apicomplexan parasites trigger disease associated with an uncontrollable expansion of parasite biomass resulting in inflammation and host cell destruction.Although, apicomplexan parasites usually present a sexual cycle within the definitive host, the pathogenesis of these parasites in humans results from the ongoing asexual replication cycles within the host’s cells. Persistence in the human host and dissemination to other hosts is dependent on the ability of these parasites to differentiate into forms that will invade specific cellular niches. Host response to infection is not only key to controlling the acute phase of these infections but also contributes to parasite differentiation into life-long persistent forms of these parasites associated with chronic pathologies. To overcome host responses, to disseminate and persist, parasites have thus developed strategies to modulate immune and metabolic host pathways.Therefore, the apicomplexan parasite ability to proliferate, differentiate and the ability of the host to respond to the infection are crucialto the pathogenesis of these parasites.

In the team, we aim to understand, in both Plasmodium and T. gondii, the molecular determinants controlling the ability of these parasites to (i) proliferate and (ii) persist in the host. Moreover, we investigate host responses to parasite infection. We also exploit the accumulated knowledge on the basic mechanisms that we described to identify new therapeutic targets and compounds that will expand the therapeutic arsenal to treat the debilitating diseases caused by these parasites.