Parasite and cell culture

All T. gondii strains used in this study were maintained by serial passage of tachyzoites in human foreskin fibroblast (HFF) monolayers cultured at 37°C in a humidified 5% CO₂ atmosphere. Strains used in this study are listed in Table S1. HFFs and human embryonic kidney 293T (HEK293T) cells were grown in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 2 mm glutamine and 50 mg mL⁻¹ each of penicillin and streptomycin. Human monocytic leukaemia cell line THP-1s were grown in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% FBS and 50 mg mL⁻¹ each of penicillin and streptomycin.