ΔTgPL3 and S1409 parasites are unable to disseminate in vivo.

In 2 independent experiments, 4 male NMRI mice were infected with 1000 T. gondii parasites. 3 days post infection (A) spleens and (B) lungs were removed and homogenized. Homogenate was serially diluted, added to HFF monolayers in duplicate, and plaqued for 7 days. The monolayers were stained with crystal violet and PFU/ml calculated. (C-F) Serum was collected from the same mice at 3 days post infection and cytokine levels of (C) IFNγ, (D) MCP1, (E) TNF and (F) IL6 were determined using a cytokine bead array kit (Biosciences). Cytokine analysis was repeated with female mice and shown is one representative experiment. Uninfected mice and mice infected with 1000 heat-killed parasites were used as negative controls * p<0.05, **p <0.01 and ***p<0.001.