Imaging-Based High-Throughput Screening Assay To Identify New Molecules with Transmission-Blocking Potential against Plasmodium falciparum Female Gamete Formation
OA Location
Author(s)
Type
Journal Article
Abstract
In response to a call for the global eradication of malaria, drug discovery has recently been extended to identify compounds that prevent the onward transmission of the parasite, which is mediated by Plasmodium falciparum stage V gametocytes. Lately, metabolic activity has been used in vitro as a surrogate for gametocyte viability; however, as gametocytes remain relatively quiescent at this stage, their ability to undergo onward development (gamete formation) may be a better measure of their functional viability. During gamete formation, female gametocytes undergo profound morphological changes and express translationally repressed mRNA. By assessing female gamete cell surface expression of one such repressed protein, Pfs25, as the readout for female gametocyte functional viability, we developed an imaging-based high-throughput screening (HTS) assay to identify transmission-blocking compounds. This assay, designated the P. falciparum female gametocyte activation assay (FGAA), was scaled up to a high-throughput format (Z′ factor, 0.7 ± 0.1) and subsequently validated using a selection of 50 known antimalarials from diverse chemical families. Only a few of these agents showed submicromolar 50% inhibitory concentrations in the assay: thiostrepton, methylene blue, and some endoperoxides. To determine the best conditions for HTS, a robustness test was performed with a selection of the GlaxoSmithKline Tres Cantos Antimalarial Set (TCAMS) and the final screening conditions for this library were determined to be a 2 μM concentration and 48 h of incubation with gametocytes. The P. falciparum FGAA has been proven to be a robust HTS assay faithful to Plasmodium transmission-stage cell biology, and it is an innovative useful tool for antimalarial drug discovery which aims to identify new molecules with transmission-blocking potential.
Date Issued
2015-03-23
Date Acceptance
2015-03-16
Citation
Antimicrobial Agents and Chemotherapy, 2015, 59 (6), pp.3298-3305
ISSN
1098-6596
Publisher
American Society for Microbiology
Start Page
3298
End Page
3305
Journal / Book Title
Antimicrobial Agents and Chemotherapy
Volume
59
Issue
6
Copyright Statement
© 2015 American Society for Microbiology. All Rights Reserved.
Subjects
Science & Technology
Life Sciences & Biomedicine
Microbiology
Pharmacology & Pharmacy
MALARIA TRANSMISSION
SEXUAL DEVELOPMENT
METHYLENE-BLUE
CONTINUOUS-CULTURE
IDENTIFICATION
PARASITES
DRUGS
GAMETOCYTOGENESIS
GAMETOCYTES
ARTESUNATE
Animals
Antimalarials
Female
High-Throughput Screening Assays
Inhibitory Concentration 50
Methylene Blue
Plasmodium falciparum
RNA, Messenger
Thiostrepton
0605 Microbiology
1108 Medical Microbiology
1115 Pharmacology And Pharmaceutical Sciences
Publication Status
Published