Disruption of the Plasmodium falciparum liver-stage antigen-1 locus causes a differentiation defect in late liver-stage parasites

Abstract

The malaria parasite Plasmodium falciparum infects humans and first targets the liver where liver-stage parasites undergo pre-erythrocytic replication. Liver-stage antigen-1 (LSA-1) is currently the only identified P. falciparum protein for which expression is restricted to liver stages. Yet, the importance of LSA-1 for liver-stage parasite development remains unknown. Here we deleted LSA-1 in the NF54 strain of P. falciparum and analysed the lsa-1(-) parasites throughout their life cycle. lsa-1(-) sporozoites had normal gliding motility and invasion into hepatocytes. Six days after infection of a hepatocytic cell line, lsa-1(-) parasites exhibited a moderate phenotype with an ~50% reduction..