title: In vivo imaging of trypanosome-brain interactions and development of a rapid screening test for drugs against CNS stage trypanosomiasis.
abstract: HUMAN AFRICAN TRYPANOSOMIASIS (HAT) MANIFESTS IN TWO STAGES OF DISEASE: firstly, haemolymphatic, and secondly, an encephalitic phase involving the central nervous system (CNS). New drugs to treat the second-stage disease are urgently needed, yet testing of novel drug candidates is a slow process because the established animal model relies on detecting parasitemia in the blood as late as 180 days after treatment. To expedite compound screening, we have modified the GVR35 strain of Trypanosoma brucei brucei to express luciferase, and have monitored parasite distribution in infected mice following treatment with trypanocidal compounds using serial, non-invasive, bioluminescence imaging. Parasites were detected in the brains of infected mice following treatment with diminazene, a drug which cures stage 1 but not stage 2 disease. Intravital multi-photon microscopy revealed that trypanosomes enter the brain meninges as early as day 5 post-infection but can be killed by diminazene, whereas those that cross the blood-brain barrier and enter the parenchyma by day 21 survived treatment and later caused bloodstream recrudescence. In contrast, all bioluminescent parasites were permanently eliminated by treatment with melarsoprol and DB829, compounds known to cure stage 2 disease. We show that this use of imaging reduces by two thirds the time taken to assess drug efficacy and provides a dual-modal imaging platform for monitoring trypanosome infection in different areas of the brain.
authors.affiliation: Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Elmarie
authors.initials: E
authors.lastname: Myburgh
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Coles
authors.forename: Ryan
authors.initials: R
authors.lastname: Ritchie
authors.forename: Peter G E
authors.initials: PG
authors.lastname: Kennedy
authors.forename: Alex P
authors.initials: AP
authors.lastname: McLatchie
authors.forename: Jean
authors.initials: J
authors.lastname: Rodgers
authors.forename: Martin C
authors.initials: MC
authors.lastname: Taylor
authors.forename: Michael P
authors.initials: MP
authors.lastname: Barrett
authors.forename: James M
authors.initials: JM
authors.lastname: Brewer
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Mottram
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000302:isolation & purification* / Q000627:therapeutic use; D001921:Brain / Q000469:parasitology* / Q000473:pathology; D004133:Diminazene / Q000627:therapeutic use; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005260:Female; D054884:Host-Pathogen Interactions; D007091:Image Processing, Computer-Assisted; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D036641:Microscopy, Fluorescence, Multiphoton; D013194:Staining and Labeling; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014352:Trypanosomiasis / Q000188:drug therapy / Q000469:parasitology* / Q000473:pathology
chemical_list: D000981:Antiprotozoal Agents; D008156:Luciferases; D004133:Diminazene