Single cell transcriptional changes across the blood stages of artemisinin resistant K13C580YmutantPlasmodium falciparumupon dihydroartemisinin exposure

Abstract

ABSTRACTArtemisinins have been a cornerstone of malaria control, but resistance inPlasmodium falciparum, due to mutations in theKelch 13gene, threaten these advances. Artemisinin exposure results in a dynamic transcriptional response across multiple pathways, but most work has focused on ring stages andex vivotranscriptional analysis, limiting evaluation of all life cycle stages. We applied single cell RNAseq to two unsynchronized isogenic parasite lines (K13C580and K13580Y) over 6 hrs after a pulse exposure to dihydroartemisinin (DHA). Transcription was altered across all stages, with the greatest occurring at the early trophozoite and mid ring stage in both lines. This response involved the arrest of metabolic processes and the enhancement of protein trafficking and the unfolded protein response. While similar, the response was enhanced in the K13580Ymutant, which may lead to the dormancy phenomenon upon treatment. Increased surface protein expression was seen in mutant parasites at baseline and upon drug exposure, highlighted by the increased expression ofPfEMP1andGARP,a potential therapeutic target. Antibody targeting GARP maintained anti-parasitic efficacy in mutant parasites. This work provides single cell insight of gene transcription across all life cycle stages revealing transcriptional changes that could initiate dormancy state and mediate survival.