The Role of Host- and Parasite-Encoded Kinases in Toxoplasma-Host Interactions

Over the past few years a common theme has emerged in which microbial pathogens grow and cause disease by either expressing their own repertoire of kinases, or by regulating the activity of host-encoded kinases. Toxoplasma gondii is an obligate intracellular parasite that is capable of infecting most nucleated cell types in warm-blooded animals. Within its intermediate hosts, T. gondii exists as two interconvertable stages: dormant bradyzoites, and replicative disease-causing tachyzoites. Tachyzoite growth is achieved by a lytic cycle that is composed of repeated rounds of parasite invasion, replication, and egress. Each of these steps requires the coordinated activity of host and parasite-encoded kinases. In addition to the parasite's lytic cycle, T. gondii-encoded kinases and related pseudokinases that are secreted into the host cell have been identified as key virulence factors. These findings will be highlighted in this chapter, and emerging questions will be discussed.