Screening the Pathogen Box for Molecules Active against Plasmodium Sexual Stages Using a New Nanoluciferase-Based Transgenic Line of P. berghei Identifies Transmission-Blocking Compounds

Abstract

Malaria remains an important parasitic disease with a large morbidity and mortality burden. transmission-blocking (TB) compounds are essential for achieving malaria elimination efforts. Recent efforts to develop high-throughput screening (HTS) methods to identify compounds that inhibit or kill gametocytes, the sexual stage infectious to mosquitoes, have yielded insight into new TB compounds. However, the activities of these compounds against gametes, formed in the first minutes of mosquito infection, are typically not assessed, unless screened in a standard membrane feeding assay, a labor-intensive assay. We demonstrate here the generation of a model for drug screens against gametes and fertilization. The new line, named , was genetically and pharmacologically validated and scalable for HTS. Screening the Pathogen Box from the Medicines for Malaria Venture using the new model identified promising TB compounds. The use of in different libraries of compounds may aid in the identification of transmission-blocking drugs not assessed in screens against asexual stages or gametocytes.

Computational Chemogenomics Drug Repositioning Strategy Enables the Discovery of Epirubicin as a New Repurposed Hit for Plasmodium falciparum and P. vivax

“…In vitro inhibition of P. berghei ookinete formation by conversion assay. The conversion assay evaluates a compound's potential of inhibiting ookinete formation in vitro (89). Briefly, BALB/c mice were infected intraperitoneally with a mutant P. berghei line expressing luciferase (nLuc) under a ookinetespecific promoter.…”

Repurposing of an old drug: In vitro and in vivo efficacies of buparvaquone against Echinococcus multilocularis

“…So far, the Pathogen Box has been screened against the nematode H. contortus ( Preston et al, 2016 ), the fungi Candida albicans and Cryptococcus neoformans ( Vila and Lopez-Ribot, 2016 ; Mayer and Kronstad, 2017 ), Plasmodium and the kinetoplastids Leishmania and Trypanosoma ( Calit et al, 2018 ; Dennis et al, 2018 ; Duffy et al, 2017 ), Neospora caninum ( Müller et al, 2017 ) , Mycobacterium abscessus and M. avium ( Jeong et al, 2018 ; Low et al, 2017 ), Toxoplasma gondii ( Spalenka et al, 2017 ), C. elegans ( Partridge et al, 2018 ), Entamoeba histolytica ( Mi-Ichi et al, 2018 ), and Giardia lamblia and Cryptosporidium parvum ( Hennessey et al, 2018 ). Interestingly, all compounds that exhibited activity against E. multilocularis were also active against at least one more pathogen other than the one it was selected for by MMV (with the exception of nitazoxanide), thus underlining the importance and potential of the concept of drug repurposing.…”

Whole-Cell Phenotypic Screening of Medicines for Malaria Venture Pathogen Box Identifies Specific Inhibitors of Plasmodium falciparum Late-Stage Development and Egress

“…Among the 400 antiparasitic molecules in the MMV Pathogen Box, 123 were originally reported to be active against blood-stage malaria parasites (3D7 strain), and of these, 72 molecules exhibited potency at nanomolar concentrations (EC 50 Ͻ 1 M; source, mmv.org/mmvopen/pathogen-box). However, additional molecules with potent antimalarial activity are likely to be present in the Pathogen Box collection, as reported in recent studies (10,12,16,17). It is apparent from these studies that the inhibitors can have shared or distinct phenotypic effects on different life cycle stages of Plasmodium spp., which formed the motivation for this study.…”