DEVELOPMENT OF A BOVINE INTESTINAL ORGANOID MODEL OF CRYPTOSPORIDIUM PARVUM INFECTION

Abstract

Understanding infectious disease pathology is crucial for controlling transmission and developing therapies to prevent and cure the disease. Cryptosporidiosis, a gastrointestinal infectious disease caused by the protozoan parasite Cryptosporidium parvum (C. parvum), poses a persistent challenge to dairy production due to the economic losses associated with C. parvum-infected calves. The lack of in vitro culture systems that fully recapitulate host-pathogen interactions has hindered development of therapies for C. parvum infection in cattle. Recent development in intestinal organoids provides an opportunity to recapitulate in vivo physiology of the organ and culture conditions that permit host-pathogen interaction studies. In this study, we developed bovine intestinal organoids infected with C. parvum. Apical-out three-dimensional (3-D) organoids provided the apical side access for direct parasite infection, supported replication, but exhibited low viability and were unsuitable for long-term studies. In contrast, in air-liquid interface (ALI) two-dimensional (2-D) culture, different life stages of C. parvum were observed and supported. Additionally, immunostaining revealed differences in the abundance of major epithelial cell types in 2-D monolayer and ALI 2-D cultures. Paneth cells showed further differentiation in ALI 2-D cultures while the composition of enteroendocrine cells and goblet cells remained consistent with 2-D culture. These results indicate that ALI 2-D culture may serve as a reliable model for study of host-pathogen interactions, facilitating the development of therapies for cryptosporidiosis that improve dairy herd health and productivity.