title: A simple and predictive phenotypic High Content Imaging assay for Plasmodium falciparum mature gametocytes to identify malaria transmission blocking compounds.
abstract: Plasmodium falciparum gametocytes, specifically the mature stages, are the only malaria parasite stage in humans transmissible to the mosquito vector. Anti-malarial drugs capable of killing these forms are considered essential for the eradication of malaria and tools allowing the screening of large compound libraries with high predictive power are needed to identify new candidates. As gametocytes are not a replicative stage it is difficult to apply the same drug screening methods used for asexual stages. Here we propose an assay, based on high content imaging, combining "classic" gametocyte viability readout based on gametocyte counts with a functional viability readout, based on gametocyte activation and the discrimination of the typical gamete spherical morphology. This simple and rapid assay has been miniaturized to a 384-well format using acridine orange staining of wild type P. falciparum 3D7A sexual forms, and was validated by screening reference antimalarial drugs and the MMV Malaria Box. The assay demonstrated excellent robustness and ability to identify quality hits with high likelihood of confirmation of transmission reducing activity in subsequent mosquito membrane feeding assays.
authors.affiliation: Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, 4111 Nathan, Queensland, Australia.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Lucantoni
authors.affiliation: Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161 Roma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Silvestrini
authors.affiliation: Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161 Roma, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Signore
authors.affiliation: Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161 Roma, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Siciliano
authors.affiliation: TropIQ Health Sciences, Geert Grooteplein 28, huispost 268, 6525 GA Nijmegen, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Eldering
authors.affiliation: TropIQ Health Sciences, Geert Grooteplein 28, huispost 268, 6525 GA Nijmegen, The Netherlands.
authors.forename: Koen J
authors.initials: KJ
authors.lastname: Dechering
authors.affiliation: Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, 4111 Nathan, Queensland, Australia.
authors.forename: Vicky M
authors.initials: VM
authors.lastname: Avery
authors.affiliation: Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161 Roma, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Alano
mesh_terms: D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D004353:Drug Evaluation, Preclinical; D057166:High-Throughput Screening Assays; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology* / Q000635:transmission*; D018613:Microscopy, Confocal / Q000379:methods; D010641:Phenotype; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D000962:Antimalarials