Organoid-basedin vitrosystems to modelCryptosporidium parvuminfection in 2D and 3D

Abstract

Typical cancer cell-based culture systems cannot support the full life cycle ofCryptosporidium parvum, despite its monoxenous life cycle which is completed in the small intestine of a single host. There is a block to fertilization and zygote formationin vitro. In this paper, we adapted a 2D organoid derived monolayer system and a 3D inverted enteroid system for use inC. parvumculture. 3D inverted enteroids were successfully infected byC. parvumwithout the need for microinjection and supported subculture ofC. parvum. Using the 2D organoid derived monolayer (ODM) system, the infection can be maintained for at least 3 weeks with new oocyst production throughout. Fertilization was confirmed based on successful mating of two strains ofC. parvum.We demonstrated that the apparent block to fertilization in typical cell culture is overcome using ODMs.