citations

                    Adaptation of Plasmodium falciparum to humans involved the loss of an ape-specific erythrocyte invasion ligand
                

Authors:

William R. Proto, Sasha V. Siegel, Selasi Dankwa, Weimin Liu, Alison Kemp, Sarah Marsden,Zenon A. Zenonos, Steve Unwin, Paul M. Sharp, Gavin J. Wright, Beatrice H. Hahn,Manoj T. Duraisingh, Julian C. Rayner

In:

Source: Nat Commun.
Publication Date: (2019)
Issue: :

Research Area:

Parasitology

Cells used in publication:

Plasmodium falciparum: Species: unicellular; Tissue Origin:

Platform:

4D-Nucleofector® X-Unit

Experiment

For transfection, sorbitol-synchronised ring stage parasites (~?10% parasitemia, 2.5% haematocrit) were electroporated with 50?µg plasmid DNA and 25?µg Donor Template (PCR product) using a Lonza 4D-Nucleofector. Briefly, 100?µl of infected erythrocytes were washed and resuspended in 100?µl of Primary Cell Nucleofector Solution P3 (Lonza) supplemented with 12.5?mM ATP and DNA for transfection. The cell mixture was split into two Nucleocuvettes and electroporated using programme CM150. Cells were placed on ice for 2?mins then transferred to pre-warmed complete media for 3?h, before replacing media and returning to standard culture conditions.

Abstract

Plasmodium species are frequently host-specific, but little is currently known about the molecular factors restricting host switching. This is particularly relevant for P. falciparum, the only known human-infective species of the Laverania sub-genus, all other members of which infect African apes. Here we show that all tested P. falciparum isolates contain an inactivating mutation in an erythrocyte invasion associated gene, PfEBA165, the homologues of which are intact in all ape-infective Laverania species. Recombinant EBA165 proteins only bind ape, not human, erythrocytes, and this specificity is due to differences in erythrocyte surface sialic acids. Correction of PfEBA165 inactivating mutations by genome editing yields viable parasites, but is associated with down regulation of both PfEBA165 and an adjacent invasion ligand, which suggests that PfEBA165 expression is incompatible with parasite growth in human erythrocytes. Pseudogenization of PfEBA165 may represent a key step in the emergence and evolution of P. falciparum.