Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasite Plasmodium knowlesi

作者:Moon Robert W; Sharaf Hazem; Hastings Claire H; Ho Yung Shwen; Nair Mridul B; Rchiad Zineb; Knuepfer Ellen; Ramaprasad Abhinay; Mohring Franziska; Amir Amirah; Yusuf Noor A; Hall Joanna; Almond Neil; Lau Yee Ling; Pain Arnab; Blackman Michael J; Holder Anthony A
来源:Proceedings of the National Academy of Sciences, 2016, 113(26): 7231-7236.
DOI:10.1073/pnas.1522469113

摘要

The dominant cause of malaria in Malaysia is now Plasmodium knowlesi, a zoonotic parasite of cynomolgus macaque monkeys found throughout South East Asia. Comparative genomic analysis of parasites adapted to in vitro growth in either cynomolgus or human RBCs identified a genomic deletion that includes the gene encoding normocyte-binding protein Xa (NBPXa) in parasites growing in cynomolgus RBCs but not in human RBCs. Experimental deletion of the NBPXa gene in parasites adapted to growth in human RBCs (which retain the ability to grow in cynomolgus RBCs) restricted them to cynomolgus RBCs, demonstrating that this gene is selectively required for parasite multiplication and growth in human RBCs. NBPXa-null parasites could bind to human RBCs, but invasion of these cells was severely impaired. Therefore, NBPXa is identified as a key mediator of P. knowlesi human infection and may be a target for vaccine development against this emerging pathogen.