Grant: Operating Grant

Apicomplexan parasites cause significant morbidity and mortality in humans and animals. The two most important genera with respect to human health are Toxoplasma and Plasmodium, the etiological agents of toxoplasmosis and malaria, respectively. Unlike many parasitic diseases, Toxoplasma infections are highly prevalent in developed countries. In fact, one of the largest global water-borne outbreaks of toxoplasmosis occurred in Victoria, British Columbia that affected more than 4000 individuals. Toxoplasma infections produce a wide array of disease states with the most serious derived from congenital transmission, which can result in abortion, neonatal death and fetal abnormalities. Children that survive prenatal infection are likely to suffer a significantly reduced quality of life displaying neurological deficiencies such as mental retardation. Nearly 20% of chronic stage patients develop severe ocular disease and recent investigations suggest that toxoplasmic cysts, originally thought to be asymptomatic, are known to increase risk of brain cancer and neurological impairments such as schizophrenia. Plasmodium spp. are devastating pathogens that place nearly half the human population at risk of malaria, leading to more than 250 million cases yearly with over one million deaths, of which 85% are children under the age of five. Given the clear impact on human health, novel treatments targeting Apicomplexa are desperately needed. A major obstacle, however, is the ability of these parasites to evade the host immune response by taking refuge inside host cells. Determining how these parasites achieve this is central to controlling their pathogenesis. The objective of our research, therefore, is to characterize the strategies used by Apicomplexan parasites initially engage and ultimately invade host cells.