title: Quantitative bioluminescent imaging of pre-erythrocytic malaria parasite infection using luciferase-expressing Plasmodium yoelii.
abstract: The liver stages of Plasmodium parasites are important targets for the development of anti-malarial vaccine candidates and chemoprophylaxis approaches that aim to prevent clinical infection. Analyzing the impact of interventions on liver stages in the murine malaria model system Plasmodium yoelii has been cumbersome and requires terminal procedures. In vivo imaging of bioluminescent parasites has previously been shown to be an effective and non-invasive alternative to monitoring liver stage burden in the Plasmodium berghei model. Here we report the generation and characterization of a transgenic P. yoelii parasite expressing the reporter protein luciferase throughout the parasite life cycle. In vivo bioluminescent imaging of these parasites allows for quantitative analysis of P. yoelii liver stage burden and parasite development, which is comparable to quantitative RT-PCR analysis of liver infection. Using this system, we show that both BALB/cJ and C57BL/6 mice show comparable susceptibility to P. yoelii infection with sporozoites and that bioluminescent imaging can be used to monitor protective efficacy of attenuated parasite immunizations. Thus, this rapid, simple and noninvasive method for monitoring P. yoelii infection in the liver provides an efficient system to screen and evaluate the effects of anti-malarial interventions in vivo and in real-time.
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Miller
authors.forename: Sara
authors.initials: S
authors.lastname: Murray
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Vaughan
authors.forename: Anke
authors.initials: A
authors.lastname: Harupa
authors.forename: Brandon
authors.initials: B
authors.lastname: Sack
authors.forename: Michael
authors.initials: M
authors.lastname: Baldwin
authors.forename: Ian N
authors.initials: IN
authors.lastname: Crispe
authors.forename: Stefan H I
authors.initials: SH
authors.lastname: Kappe
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D007114:Immunization; D053208:Kaplan-Meier Estimate; D008099:Liver / Q000821:virology*; D008156:Luciferases / Q000378:metabolism*; D008163:Luminescent Measurements; D008288:Malaria / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D030781:Organisms, Genetically Modified / Q000235:genetics*; D010967:Plasmodium yoelii / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D008156:Luciferases