Identifying novelPlasmodium falciparumerythrocyte invasion receptors using systematic extracellular protein interaction screens

Abstract

The invasion of host erythrocytes by the parasite Plasmodium falciparum initiates the blood stage of infection responsible for the symptoms of malaria. Invasion involves extracellular protein interactions between host erythrocyte receptors and ligands on the merozoite, the invasive form of the parasite. Despite significant research effort, many merozoite surface ligands have no known erythrocyte binding partner, most likely due to the intractable biochemical nature of membrane-tethered receptor proteins and their interactions. The few receptor–ligand pairs that have been described have largely relied on sourcing erythrocytes from patients with rare blood groups, a serendipitous approach that is unsatisfactory for systematically identifying novel receptors. We have recently developed a scalable assay called AVEXIS (for AVidity-based EXtracellular Interaction Screen), designed to circumvent the technical difficulties associated with the identification of extracellular protein interactions, and applied it to identify erythrocyte receptors for orphan P. falciparum merozoite ligands. Using this approach, we have recently identified Basigin (CD147) and Semaphorin-7A (CD108) as receptors for RH5 and MTRAP respectively. In this essay, we review techniques used to identify Plasmodium receptors and discuss how they could beapplied in the future to identify novel receptors both for Plasmodium parasites but also other pathogens.

RH5–Basigin interaction plays a major role in the host tropism of Plasmodium falciparum

“…falciparum erythrocyte invasion depends on a partially redundant set of parasite ligands and erythrocyte receptors (14,(16)(17)(18), and there is experimental support for the suggestion that at least two of these interactions may be involved in P. falciparum Significance Plasmodium falciparum is responsible for almost all malariarelated deaths and belongs to a family of parasites that infect African apes. In their native habitat, these parasites exhibit strict host tropism, with human P. falciparum having never been found in wild-living chimpanzees and gorillas.…”

Elucidation of host–pathogen protein–protein interactions to uncover mechanisms of host cell rewiring

“…Regrettably, their lack of solubility and their necessity of remaining in lipid-rich environment highly impairs their interactome mapping via conventional methods such as AP-MS. To overcome these challenges, Glick Y et al introduced a screening method for HP interactions, adequate for transmembrane proteins [62] named the human Membrane Protein Array (MPA). Similarly, several studies have developed and applied Protein Micro Array technologies [63] including Nucleic Acid Programmable [64] or AVEXIS (AVidity-based Extracellular Interaction Screen) [65,66] to study soluble and transmembrane HP interactions (see supplementary table 1). …”

Pre-erythrocytic Stage of Malaria Infection and the Molecular Targets Available for Interventions

“…Studying the genetics of susceptible and non-susceptible population (Zimmerman et al, 2013) have led to the discovery of host factors that mediate malaria parasite erythrocytic infection (Bartholdson et al, 2013;Cowman et al, 2012;Wright and Rayner, 2014). Unfortunately, there are no known human populations resistant to pre-erythrocytic Plasmodium infection thereby necessitating the use of animal models and in vitro studies to identify host and parasite factors that mediate pre-erythrocytic infection.…”