Protocol for the cryopreservation of Cryptosporidium isolates using enteroids.

A major bottleneck in the progress of Cryptosporidium research is the lack of accessible cryopreservation of Cryptosporidium oocysts. Here, we present a protocol for the cryopreservation of Cryptosporidium isolates using enteroids. We describe the steps for the establishment of enteroid cultures and cryopreservation of C. parvum-infected HCT-8 cultures. We then detail procedures for the recovery and propagation of frozen parasites using enteroids. For complete details on the use and execution of this protocol, please refer to Deng et al.1.

Cultivation, cryopreservation, and transcriptomic studies of host-adapted Cryptosporidium parvum and Cryptosporidium hominis using enteroids.

Cryptosporidium hominis and Cryptosporidium parvum are major causes of severe diarrhea. Comparative studies of them are hampered by the lack of effective cultivation and cryopreservation methods, especially for C. hominis. Here, we describe adapted murine enteroids for the cultivation and complete development of host-adapted C. parvum and C. hominis subtypes, producing oocysts infectious to mice. Using the system, we developed a cryopreservation method for Cryptosporidium isolates. In comparative RNA-seq analyses of C. hominis cultures, the enteroid system generated significantly more host and pathogen responses than the conventional HCT-8 cell system. In particular, the infection was shown to upregulate PI3K-Akt, Ras, TNF, NF-κB, IL-17, MAPK, and innate immunity signaling pathways and downregulate host cell metabolism, and had significantly higher expression of parasite genes involved in oocyst formation. Therefore, the enteroid system provides a valuable tool for comparative studies of the biology of divergent Cryptosporidium species and isolates.