Induction and regulation of IL-12-dependent host resistance to Toxoplasma gondii

Resistance to the intracellular protozoan parasite Toxoplasma gondii is initiated by the induction of interleukin-12 (IL-12), which stimulates interferon (IFN)-gamma synthesis by natural killer (NK) cells and T lymphocytes. This review summarizes the work of our laboratory on the mechanisms by which the parasite triggers IL-12 synthesis, and how this response is regulated to avoid the lethal effects of excessive tissue inflammation. In addition, we present an overview of our studies investigating the mechanisms by which the IFN-gamma-produced as a consequence of IL-12 stimulation controls intracellular replication of the parasite in host cells.