Parasite load in liver, spleen, and lung tissues of infected mice. Wild type (WT) and CCR5−/− (CCR5 KO) mice were infected intraperitoneally with T. gondii tachyzoites. At 3 and 5 dpi, liver, spleen and lungs were collected and the parasite numbers in 50 ng of DNA determined by quantitative PCR. Bars represent the average for each experimental group (3 dpi, n = 5; 5 dpi, n = 9). RH-GFP (GFP): parasites transfected with GFP alone; RH-OE (OE): parasites transfected with TgCyp18HA and GFP.