Phospholipids (PLs) are essential components of biological membranes. The malaria parasite Plasmodium falciparum, uses its own metabolic machinery to synthetized PLs through a complex network of metabolic pathways. The most abundant PLs in the P. falciparum infected red blood cell are phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI) and they constitute the bulk of the lipids that form parasite membranes.

Based on lipidomics we recently obtained a comprehensive overview of the metabolism of the main PLs in P. falciparum. Our data raised new questions about the sources of PLs, the links between the multiple pathways and the existence of some specific enzymatic steps.

Our objective is to identify the bottlenecks, the compensatory effects and the interplay between the different PL pathways by lipidomic studies using deuterium-labelled precursors. The findings will allow us to select new therapeutic targets.

We previously identified the enzyme CCT (CTP:phosphocholine cytidylyltransferase) in the PC biosynthesis pathway as promising potential target. Our team determined the 3D structures of the PfCCT catalytic domain in the absence and in the presence of its substrates and its product.

Our objective is to identify and to optimize new PfCCT specific inhibitors with antimalarial activity using an integrated target-based approach combining screening of ligands and 3D structure determination.

Phosphoinositides (PPIs), the phosphorylated derivatives of PI, are quantitatively minor PLs with important functions in intracellular signalling and membrane identity. We identified the PPIs present in P. falciparum-infected erythrocytes and produced a catalogue of enzymes and binding proteins that are predicted in the Plasmodium proteome.

Our objective is to characterise lipid kinases, lipid phosphatases and PPI-binding proteins and to evaluate their potential as future drug targets.

Project 1: Evaluation of a new principle of antimalarial strategy through the chemical activation of the host cell specific mechano-sensitive ion channel Piezo1.

Piezo channels are mechanosensitive cation channels of higher eukaryotic organisms that are absent from Plasmodium species or other apicomplexan parasites. Red blood cells (RBCs) express only the Piezo1 channel. A link between Piezo1 function and malaria infection has first been shown using a mouse model. The protective phenotype has been linked to the hydration status of the RBCs. Most interestingly, this study also identified a new polymorphism in human Piezo1 that is very abundant in healthy people of African origin (about 30% of carriers). This polymorphism confers a reduction in RBC infection rates by P. falciparum in in vitro cultures. Currently very few compounds have been described to interfere with Piezo1 function, the most widely used being the Piezo1 activator Yoda1.

The aims of our project are the following:

• Characterisation of the protective effect of Piezo1 activation through chemical stimulation on falciparum infection.
• Identification and selection of new Piezo1 activators with potent antimalarial activity.
• Evaluation whether the chemical activation of Piezo1 of the human RBC could serve as a new principle of antimalarial strategy since we are targeting a host cell protein and not the parasite itself.

This project has been financed by a CNRS pre-maturation grant (150 k€, 2017-2019).

Project 2: Development of purine-analogues as potent antimalarial compounds, their mechanism of action, identification of the drug target, and improvement of their activity through rational drug design.

We have identified a novel series of AcycloNucleoside Phosphonates (ANPs) with significant antimalarial activity in vitro against asexual blood stages and efficacy in vivo (P. vinckei- and P. berghei-infected mice). The lead compound shows an antimalarial activity in the nanomolar range with a very high selectivity index. ANPs are structurally unrelated to existing drugs and they have an original mode of action.

Our first objective is to optimize the lead compound of this class and to design an orally administrable molecule that is suitable to be developed in the preclinical phase.

The second objective is to assess the inhibitory potential of the compound on the different stages of the life cycle of the Plasmodium parasite.

Our third objective is to decipher its mode of action by identifying and validating its therapeutic target.

This project has been financed by a pre-maturation grant (Région Occitanie, 120 k€, 2018-2019)

• Reem El-Monla (Post-doc, 2021-2022)
• Coralie Duclovel (PhD student, 2018-2022)
• Alicia da Silva (M1 student, 2021)
• Annemarie Fortuin (M1 student, 2022)
• Jeremy Vincent (M1 student, 2022)

2022
• Gomes AR, Marin-Menendez A, Adjalley S, Bardy C, Cassan C, Lee M, et al. A transcriptional switch controls sex determination in Plasmodium falciparum. Nature. 2022.

• Ward D, Gomes AR, Tetteh K, Sepulveda N, Gomez LF, Campino S, Clark TG. Sero-epidemiological study of arbovirus infection following the 2015–2016 Zika virus outbreak in Cabo Verde. Sci Reports. 2022

2021
• Gurung P, Gomes AR, Martins RM, Juranek SA, Alberti P, Mbang‐Benet D, et al.  PfGBP2 is a novel G‐quadruplex binding protein in Plasmodium falciparum. Cell Microbiol. 2021

2020
• Campos M, Ward D, Morales RF, Gomes AR, Silva K, Sepúlveda N, et al. Surveillance of Aedes aegypti populations in the city of Praia, Cape Verde: Zika virus infection, insecticide resistance and genetic diversity. Parasites and Vectors. 2020

• Gazanion E, Lacroix L, Alberti P, Gurung P, Wein S, Mergny JL, Gomes AR* and Lopez-Rubio JJ*, Genome wide distribution of G-quadruplexes and their impact on gene expression in malaria parasites. PLoS Genet. 2020. *Co-senior authorship

• Cheviet T, Wein S, Bourchenin G, Lagacherie M, Périgaud C, Cerdan R*, Peyrottes S.*, β-Hydroxy- A nd β-Aminophosphonate Acyclonucleosides as Potent Inhibitors of Plasmodium falciparum Growth. J Med Chem. 2020;*Co-senior authorship

2019
• Berger, O., Ortial, S., Wein, S., Denoyelle, S., Bressolle, F., Durand, T., Escale, R., Vial, H.J., Vo-Hoang, Y., 2019. Evaluation of amidoxime derivatives as prodrug candidates of potent bis-cationic antimalarials. Bioorg Med Chem Lett. 29(16):2203-2207. doi: 10.1016/j.bmcl.2019.06.045.

• Benavente ED, Gomes AR, Silva JR, Grigg MJ, Walker H, Barber B, William T, Yeo TW, Sessions PF, Ramaprasad A, Ibrahim A, Charleston J, …, Campino SG, Clark T., “Whole genome sequencing of amplified Plasmodium knowlesi DNA from unprocessed blood reveals genomic exchange events between Malaysian Peninsular and Borneo subpopulations”. Scientific Reports, (2019); 9(1):9873.

• He Y., Campino SG, Benavente ED, Warhurst D., Beshir K., Lubis I., Gomes AR, Feng J, Jiazhi W, Sun X, Huang F, Tang L, Sutherland C, Clark T., “Artemisinin resistance-associated markers in Plasmodium falciparum parasites from the China-Myanmar border: predicted structural stability of K13 propeller variants detected in a low-prevalence area”. Plos One, (2019); 14(3):e0213686 

• Stéphane Azoulay (ICN, Nice Sophia Antipolis) – Chemical synthesis of Piezo1 activators
• Corinne Buré (CBMN, UMR 5248 CNRS-University of Bordeaux) – Lipidomics of Plasmodium
• Oliver Billker (Wellcome Sanger Institute, Cambridge, UK, and MIMS, Umeå University, Sweden). – Analysis of PL metabolic pathways in Plasmodium genome-wide studies
• Dominique Douguet & Eric Honoré (IPMC, Nice Sophia Antipolis) – Piezo1 biology in Plasmodium
• Jean-François Guichou (CBS, UMR5048 – Inserm U1054, University of Montpellier) – X-Ray crystallography and structure-based drug design
• Ardem Patapoutian (The Scripps Research Institute, La Jolla, USA) – Piezo1 and malaria
• Suzanne Peyrottes (IBMM, University of Montpellier-CNRS-ENSCM) – Chemical synthesis of purine analogs
• Beata Vertessy (Institute of Enzymology, Hungarian Academy of Sciences, Budapest, Hungary) – Biochemistry and enzymology of Plasmodium PL enzymes
• Yen Vo-Hoang (IBMM, University of Montpellier-CNRS-ENSCM) – Antimalarial drug evaluation