Document Type

Article

Journal or Conference Title

MBio

ISSN

2150-7511

Volume

8

Issue

3

First Page

e00303-17

Publication Date

5-9-2017

Department

Natural Sciences and Mathematics

Abstract

Current efforts to reduce the global burden of malaria are threatened by the rapid spread throughout Asia of Plasmodium falciparum resistance to artemisininbased combination therapies, which includes increasing rates of clinical failure with dihydroartemisinin plus piperaquine (PPQ) in Cambodia. Using zinc finger nucleasebased gene editing, we report that addition of the C101F mutation to the chloroquine (CQ) resistance-conferring PfCRT Dd2 isoform common to Asia can confer PPQ resistance to cultured parasites. Resistance was demonstrated as significantly higher PPQ concentrations causing 90% inhibition of parasite growth (IC90) or 50% parasite killing (50% lethal dose [LD50]). This mutation also reversed Dd2-mediated CQ resistance, sensitized parasites to amodiaquine, quinine, and artemisinin, and conferred amantadine and blasticidin resistance. Using heme fractionation assays, we demonstrate that PPQ causes a buildup of reactive free heme and inhibits the formation of chemically inert hemozoin crystals. Our data evoke inhibition of heme detoxification in the parasite’s acidic digestive vacuole as the primary mode of both the bisaminoquinoline PPQ and the related 4-aminoquinoline CQ. Both drugs also inhibit hemoglobin proteolysis at elevated concentrations, suggesting an additional mode of action. Isogenic lines differing in their pfmdr1 copy number showed equivalent PPQ susceptibilities. We propose that mutations in PfCRT could contribute to a multifactorial basis of PPQ resistance in field isolates.

Publisher Statement

Originally published as Dhingra, S. K., Redhi, D., Combrinck, J. M., Yeo, T., Okombo, J., Henrich, P. P., ... & Cooper, R. A. (2017). A Variant PfCRT Isoform Can Contribute to Plasmodium falciparum Resistance to the First-Line Partner Drug Piperaquine. mBio, 8(3), e00303-17.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Share

COinS