FIGURE 1: Schematic representation of Toxoplasma / host interactions, with a particular focus on the control of host apoptosis.

The tachyzoite form actively invades its host cell and establishes itself in a parasitophorous vacuole in which it will multiply before egressing, and as a consequence destroy its host. Through the course of infection, the parasite is able to sequentially secrete rhoptry (ROP) and dense granule (GRA) proteins that will lead to the extensive modification of its host cell. Host organelles are recruited around the parasitophorous vacuole, potentially to serve as a nutrient source. The parasite is also able to modulate host protein expression by acting on host signaling pathways and transcription factors. This will influence host survival by altering the expression of key regulators of apoptosis, but as yet unidentified parasite effectors are also able to directly inhibit host apoptosis by interfering with apoptosome formation. MOMP: mitochondrial outer membrane permeabilization.