title: Defeating Leishmania resistance to miltefosine (hexadecylphosphocholine) by peptide-mediated drug smuggling: a proof of mechanism for trypanosomatid chemotherapy.
abstract: Miltefosine (hexadecylphosphocholine, HePC), the first orally active drug successful against leishmaniasis, is especially active on the visceral form of the disease. Resistance mechanisms are almost exclusively associated to dysfunction in HePC uptake systems. In order to evade the requirements of its cognate receptor/translocator, HePC-resistant Leishmania donovani parasites (R40 strain) were challenged with constructs consisting of an ω-thiol-functionalized HePC analogue conjugated to the cell-penetrating peptide (CPP) Tat(48-60), either through a disulfide or a thioether bond. The conjugates enter and kill both promastigote and intracellular amastigote forms of the R40 strain. Intracellular release of HePC by reduction of the disulfide-based conjugate was confirmed by means of double tagging at both the CPP (Quasar 670) and HePC (BODIPY) moieties. Scission of the conjugate, however, is not mandatory, as the metabolically more stable thioether conjugate retained substantial activity. The disulfide conjugate is highly active on the bloodstream form of Trypanosoma b. brucei, naturally resistant to HePC. Our results provide proof-of-mechanism for the use of CPP conjugates to avert drug resistance by faulty drug accumulation in parasites, as well as the possibility to extend chemotherapy into other parasites intrinsically devoid of membrane translocation systems.
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Juan Román
authors.initials: JR
authors.lastname: Luque-Ortega
authors.forename: Beatriz G
authors.initials: BG
authors.lastname: de la Torre
authors.forename: Valentín
authors.initials: V
authors.lastname: Hornillos
authors.forename: Jean-Mathieu
authors.initials: JM
authors.lastname: Bart
authors.forename: Cristina
authors.initials: C
authors.lastname: Rueda
authors.forename: Miguel
authors.initials: M
authors.lastname: Navarro
authors.forename: Francisco
authors.initials: F
authors.lastname: Amat-Guerri
authors.forename: A Ulises
authors.initials: AU
authors.lastname: Acuña
authors.forename: David
authors.initials: D
authors.lastname: Andreu
authors.forename: Luis
authors.initials: L
authors.lastname: Rivas
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage*; D002462:Cell Membrane / Q000378:metabolism; D057846:Cell-Penetrating Peptides / Q000008:administration & dosage*; D004352:Drug Resistance, Microbial; D007893:Leishmania donovani / Q000187:drug effects* / Q000502:physiology; D017737:Macrophages, Peritoneal / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000008:administration & dosage*; D010767:Phosphorylcholine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000378:metabolism; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000008:administration & dosage*
chemical_list: D000981:Antiprotozoal Agents; D057846:Cell-Penetrating Peptides; D010446:Peptide Fragments; D054322:tat Gene Products, Human Immunodeficiency Virus; C422951:tat peptide (48-60), Human immunodeficiency virus 1; D010767:Phosphorylcholine; C039128:miltefosine