A Plasmodium falciparum genetic cross reveals the contributions of pfcrt and plasmepsin II/III to piperaquine drug resistance.

Abstract

Piperaquine (PPQ) is widely used in combination with dihydroartemisinin (DHA) as a first-line treatment against malaria parasites. Multiple genetic drivers of PPQ resistance have been reported, including mutations in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and increased copies of plasmepsin II/III (pm2/3). We generated a cross between a Cambodia-derived multi-drug resistant KEL1/PLA1 lineage isolate (KH004) and a drug susceptible parasite isolated in Malawi (Mal31). Mal31 harbors a wild-type (3D7-like) pfcrt allele and a single copy of pm2/3, while KH004 has a chloroquine-resistant (Dd2-like) pfcrt allele with an additional G367C substitution and four copies of pm2/3. We recovered 104 unique recombinant progeny and examined a targeted set of progeny representing all possible combinations of variants at pfcrt and pm2/3 for detailed analysis of competitive fitness and a range of PPQ susceptibility phenotypes, including PPQ survival assay (PSA), area under the dose-response curve (AUC), and a limited point IC50 (LP-IC50). We find that inheritance of the KH004 pfcrt allele is required for PPQ resistance, whereas copy number variation in pm2/3 further enhances resistance but does not confer resistance in the absence of PPQ-R-associated mutations in pfcrt. Deeper investigation of genotype-phenotype relationships demonstrates that progeny clones from experimental crosses can be used to understand the relative contributions of pfcrt, pm2/3, and parasite genetic background, to a range of PPQ-related traits and confirm the critical role of the PfCRT G367C substitution in PPQ resistance.

• Authors: John Kane, Xue Li, Sudhir Kumar, Katrina A Button-Simons, Katelyn M Vendrely Brenneman, Haley Dahlhoff, Mackenzie A C Sievert, Lisa A Checkley, Douglas A Shoue, Puspendra P Singh, Biley A Abatiyow, Meseret T Haile, Shalini Nair, Ann Reyes, Rupam Tripura, Tom Peto, Dysoley Lek, Stefan H I Kappe, Mehul Dhorda, Standwell C Nkhoma, Ian H Cheeseman, Ashley M Vaughan, Timothy J C Anderson, Michael T Ferdig
• Journal: bioRxiv : the preprint server for biology (bioRxiv) (Sep 17 2023) United States
• PMID: 37745488 (Publication Type: Preprint)