In vitro and in vivo Cryptosporidium parvum infection

HCT-8 cells (ATCC) were maintained in RPMI supplemented with 10% FBS at 37°C and 5% CO₂. Wild-type Cryptosporidium parvum oocysts used in this study were purchased from Bunchgrass Farms (Dreary, ID). Parasites expressing Tandem mNeon were generated in a previous study [25 (link)]. For in vitro infections oocysts were incubated in a (1:3) bleach: water solution for 10 minutes at 4°C, centrifuged then resuspended in a 0.08% solution of sodium deoxytaurocholate and incubated at 16°C for 10 minutes. Oocysts were then washed in PBS and finally resuspended in infection media (complete RPMI with 1% FBS) and added directly to host cells.
C. parvum oocysts used for all in vivo experiments are mouse adapted mCherry and Nanoluciferase expressing [14 (link)]. Mice were infected with 50,000 C. parvum oocysts by oral gavage unless otherwise noted.