title: High-throughput decoding of antitrypanosomal drug efficacy and resistance.
abstract: The concept of disease-specific chemotherapy was developed a century ago. Dyes and arsenical compounds that displayed selectivity against trypanosomes were central to this work, and the drugs that emerged remain in use for treating human African trypanosomiasis (HAT). The importance of understanding the mechanisms underlying selective drug action and resistance for the development of improved HAT therapies has been recognized, but these mechanisms have remained largely unknown. Here we use all five current HAT drugs for genome-scale RNA interference target sequencing (RIT-seq) screens in Trypanosoma brucei, revealing the transporters, organelles, enzymes and metabolic pathways that function to facilitate antitrypanosomal drug action. RIT-seq profiling identifies both known drug importers and the only known pro-drug activator, and links more than fifty additional genes to drug action. A bloodstream stage-specific invariant surface glycoprotein (ISG75) family mediates suramin uptake, and the AP1 adaptin complex, lysosomal proteases and major lysosomal transmembrane protein, as well as spermidine and N-acetylglucosamine biosynthesis, all contribute to suramin action. Further screens link ubiquinone availability to nitro-drug action, plasma membrane P-type H(+)-ATPases to pentamidine action, and trypanothione and several putative kinases to melarsoprol action. We also demonstrate a major role for aquaglyceroporins in pentamidine and melarsoprol cross-resistance. These advances in our understanding of mechanisms of antitrypanosomal drug efficacy and resistance will aid the rational design of new therapies and help to combat drug resistance, and provide unprecedented molecular insight into the mode of action of antitrypanosomal drugs.
authors.affiliation: London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Alsford
authors.forename: Sabine
authors.initials: S
authors.lastname: Eckert
authors.forename: Nicola
authors.initials: N
authors.lastname: Baker
authors.forename: Lucy
authors.initials: L
authors.lastname: Glover
authors.forename: Alejandro
authors.initials: A
authors.lastname: Sanchez-Flores
authors.forename: Ka Fai
authors.initials: KF
authors.lastname: Leung
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Turner
authors.forename: Mark C
authors.initials: MC
authors.lastname: Field
authors.forename: Matthew
authors.initials: M
authors.lastname: Berriman
authors.forename: David
authors.initials: D
authors.lastname: Horn
mesh_terms: D051397:Aquaglyceroporins / Q000172:deficiency / Q000378:metabolism; D004351:Drug Resistance / Q000235:genetics*; D000518:Eflornithine / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects; D006031:Glycosylation / Q000187:drug effects; D057166:High-Throughput Screening Assays; D006801:Humans; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008549:Melarsoprol / Q000494:pharmacology; D009547:Nifurtimox / Q000494:pharmacology; D010419:Pentamidine / Q000494:pharmacology; D034622:RNA Interference; D013498:Suramin / Q000494:pharmacology; D014344:Trypanocidal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D014346:Trypanosoma brucei brucei / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D014353:Trypanosomiasis, African / Q000188:drug therapy* / Q000235:genetics
chemical_list: D051397:Aquaglyceroporins; D014344:Trypanocidal Agents; D013498:Suramin; D010419:Pentamidine; D009547:Nifurtimox; D008549:Melarsoprol; D000518:Eflornithine