Fig. 6.
Type I (RH strain) T. gondii suppresses ΗΒD2 gene expression in human primary IEC. (A) Human primary IEC were cultured in 24-well plates at a density of 3 × 105 cells/well and infected with the three T. gondii genotype strains at a MOI of 5. RNA from infected and noninfected cells was extracted at 3, 8, and 24 h postinfection. First-strand cDNA was synthesized using oligo(dT) primers and a RevertAid H Minus cDNA synthesis kit (Fermentas). Quantitative RT-PCR was performed using primers specific for ΗΒD2 using SYBR green supermix (Bio-Rad), as detailed in Materials and Methods. Results are expressed as relative gene expression levels. (B) Replication of parasites in human primary intestinal epithelial cells (HIPEC) and human fibroblast cells (HFF-1). After 24 h of infection with RH, 76K, and NED strains, cells were analyzed for [3H]uracil uptake. The data shown in the figure are represented in counts per minute.