Host cell actin remodeling in response to Cryptosporidium.

Cryptosporidium exhibits a complex strategy to invade and establish productive infection sites, involving complimentary parasite and host cell processes. While the work regarding host cell actin remodeling has greatly enhanced our understanding of the molecular pathways involved in the parasite induced actin reorganization, the specific function of host cell actin remodeling is still equivocal. We contend that host cell actin polymerization contributes to the development of productive C. parvum infection sites by generating membrane protrusion events, which may assist in the retention of the parasite at the apical surface within the unique extracytoplasmic niche. With our current understanding of the molecular pathways initiating actin remodeling upon C. parvum interactions with host cells, the next logical step is to determine the upstream events resulting in PI3K activation and the specific role of actin remodeling in parasite development, a process that may have implications beyond host-pathogen interactions.