Imaging T. gondii with parasite-specific antibodies, reporter parasites, and reporter hosts. A. Anti-Toxoplasma antibodies used to visualize bradyzoites (red) escaping from a cyst that is next to a CD8+ T cell (green) in the brain of an infected mouse. Nuclei are stained with DAPI (blue). (40x) B. Pru-GFP, a T. gondii strain engineered to fluoresce green, is shown after having invaded a cultured human foreskin fibroblast (HFF) (actin stained in red) (63x) C. Me49-RFP cysts and GFP + leukocytes (green) are visualized in live brain tissue in a DPE-GFP mouse using two-photon microscopy. D. OTI-GFP T cells (green) migrating along a fibrous network (blue) in a live brain infected with Pru-OVA, visualized by two-photon microscopy.