Objectives: As most available antimalarial drugs are ineffective against the Plasmodium falciparum transmission stages, new drugs against the parasite's gametocytes are urgently needed to combat malaria globally. The unique biology of gametocytes requires assays that need to be specific, to faithfully monitor anti-gametocyte activity, and to be easy to perform, cheap and scalable to high-throughput screening (HTS). Methods:We developed an HTS cell-based assay with P. falciparum gametocytes specifically expressing a potent luciferase. To confirm HTS hit activity for several parasite genotypes, the luciferase assay and the gametocyte lactate dehydrogenase (LDH) assay, usable on any parasite isolate, were compared by screening antimalarial drugs and determining IC50 values of anti-gametocyte hits from the 'Malaria Box' against early- and latestage gametocytes. Results: Comparison of the two assays, conducted on the early and on late gametocyte stages, revealed an excellent correlation (R2.0.9) for the IC50 values obtained by the respective readouts. Differences in susceptibility to drugs and compounds between the two parasite developmental stages were consistently measured in both assays. Conclusions: This work indicates that the luciferase and gametocyte LDH assays are interchangeable and that their specific advantages can be exploited to design an HTS pipeline leading to new transmission-blocking compounds. Results from these assays consistently defined a gametocyte chemical susceptibility profile, relevant to the planning of future drug discovery strategies.

A chemical susceptibility profile of the Plasmodium falciparum transmission stages by complementary cell-based gametocyte assays

CEVENINI, LUCA;MICHELINI, ELISA;RODA, ALDO;
2016

Abstract

Objectives: As most available antimalarial drugs are ineffective against the Plasmodium falciparum transmission stages, new drugs against the parasite's gametocytes are urgently needed to combat malaria globally. The unique biology of gametocytes requires assays that need to be specific, to faithfully monitor anti-gametocyte activity, and to be easy to perform, cheap and scalable to high-throughput screening (HTS). Methods:We developed an HTS cell-based assay with P. falciparum gametocytes specifically expressing a potent luciferase. To confirm HTS hit activity for several parasite genotypes, the luciferase assay and the gametocyte lactate dehydrogenase (LDH) assay, usable on any parasite isolate, were compared by screening antimalarial drugs and determining IC50 values of anti-gametocyte hits from the 'Malaria Box' against early- and latestage gametocytes. Results: Comparison of the two assays, conducted on the early and on late gametocyte stages, revealed an excellent correlation (R2.0.9) for the IC50 values obtained by the respective readouts. Differences in susceptibility to drugs and compounds between the two parasite developmental stages were consistently measured in both assays. Conclusions: This work indicates that the luciferase and gametocyte LDH assays are interchangeable and that their specific advantages can be exploited to design an HTS pipeline leading to new transmission-blocking compounds. Results from these assays consistently defined a gametocyte chemical susceptibility profile, relevant to the planning of future drug discovery strategies.
2016
D'Alessandro, Sarah; Camarda, Grazia; Corbett, Yolanda; Siciliano, Giulia; Parapini, Silvia; Cevenini, Luca; Michelini, Elisa; Roda, Aldo; Leroy, Didierl; Taramelli, Donatella; Alano, Pietro
File in questo prodotto:
File Dimensione Formato  
A chemical susceptibility.pdf

Open Access dal 17/02/2017

Tipo: Postprint
Licenza: Licenza per accesso libero gratuito
Dimensione 800.62 kB
Formato Adobe PDF
800.62 kB Adobe PDF Visualizza/Apri
dkv493supp.pdf

accesso aperto

Tipo: File Supplementare
Licenza: Licenza per accesso libero gratuito
Dimensione 515.32 kB
Formato Adobe PDF
515.32 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/551215
Citazioni
  • ???jsp.display-item.citation.pmc??? 28
  • Scopus 36
  • ???jsp.display-item.citation.isi??? 34
social impact