A ATP-binding Cassette Transporter is Essential for Liver Stage Entry into Schizogony

sporozoites invade hepatocytes and transform into liver stages within a parasitophorous vacuole (PV). The parasites then grow and replicate their genome to form exoerythrocytic merozoites that infect red blood cells. We report that the human malaria parasite expresses a C-type ATP-binding cassette transporter, ABCC2, which marks the transition from invasive sporozoite to intrahepatocytic early liver stage. Using a humanized mouse infection model, we show that ABCC2 localizes to the parasite plasma membrane in early and mid-liver stage parasites but is not detectable in late liver stages. sporozoites invade hepatocytes, form a PV, and transform into liver stage trophozoites but cannot transition to exoerythrocytic schizogony and fail to transition to blood stage infection. Thus, ABCC2 is an expression marker for early phases of parasite liver infection and plays an essential role in the successful initiation of liver stage replication.