Figure 1.

Toxoplasma gondii induces host tolerance and resistance mechanisms in successful infections. In the absence of a strong restrictive immune response the host succumbs to Toxoplasma overgrowth early in infection (left quadrants). Without tolerance mechanisms the host is susceptible to inflammation-induced pathology, even if parasite replication effectively restricted (lower right quadrant). Both resistance and tolerance mechanisms are necessary for host survival (upper right quadrant). This balance also benefits Toxoplasma by ensuring that the host survives long enough to enable bradyzoite cyst differentiation, a requirement for transmission to another host.