Hct 8 human ileocecal adenocarcinoma cells

Cryptosporidium parvum subtype IIdA19G1 oocysts were maintained in infected neonatal calves and stored in 2.5% K₂Cr₂O₇ solution at 4 °C after purification. As previously described, oocysts were excysted in 0.25% trypsin and 0.75% sodium taurocholate for 1 h with mixing every 5 min, followed by incubation at room temperature for 30 min [19 (link), 20 (link)]. HCT-8 human ileocecal adenocarcinoma cells (American Type Culture Collection, Manassas, VA) were maintained in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum, 4 mmol/l l-glutamine, 100 U/ml penicillin, and 100 U/ml streptomycin at 37 °C in a humidified 5% CO₂ incubator [18 (link)]. Cell monolayers in 24-well cell culture dishes were inoculated with 2.5 × 10⁶ purified sporozoites per well in DMEM. The sporozoite:host-cell ratio was 10:1.

HCT-8 human ileocecal adenocarcinoma cells (American Type Culture Collection, Manassas, VA) were maintained in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% fetal bovine serum, 4 mmol/l l-glutamine, 100 U/ml penicillin, and 100 U/ml streptomycin at 37 °C in a 5% CO₂ atmosphere. Cryptosporidium parvum subtype IIdA19G1 oocysts were maintained in infected neonatal calves and stored in a 2.5% K2Cr2O7 solution at 4 °C after purification. As previously described, the oocysts were placed in 0.25% trypsin and 0.75% sodium taurocholate for 1 h with mixing every 5 min, followed by incubation at room temperature for 30 min [26 (link), 27 (link)], three washes in phosphate-buffered saline (PBS), and then were resuspended.