Fig 7. Protection against challenge with a heterologous T . cruzi strain. (A) Outline strategy. BALB/c mice were infected i.p. with bioluminescent trypomastigotes (CL Brener or JR strains) and subjected to curative benznidazole treatment initiated 36 days post-infection. 20 days after the end of treatment, they were re-infected as indicated below and monitored for a further 70 days. Bioluminescence-negative mice were then immunosuppressed and assessed by ex vivo imaging. (B) Ventral images of a representative drug-cured JR infected mouse (n = 6) following re-infection with the homologous JR strain. All images use the same log 10 -scale heat-map shown in Fig 2. (C) Total body bioluminescence (sum of ventral and dorsal images) of drug-cured JR infected mice re-infected with the JR strain (means ± SD). (D) Ex vivo bioluminescence imaging of organs and carcass of a control and re-infected mouse (non-protected). (E) Ventral images of a representative drug-cured CL Brener infected mouse (n = 6) following re-infection with the JR strain. (F) Total body bioluminescence of drug- cured CL Brener infected mice re-infected with the JR strain. (G) Ex vivo bioluminescence imaging of organs and carcass of a control and re-infected mouse (non-protected). (H) Ventral images of a representative drug-cured JR infected mouse (n = 6) following re-infection with the CL Brener strain. (I) Total body bioluminescence of drug-cured JR infected mice re-infected with the CL Brener strain. (J) Ex vivo bioluminescence imaging of organs and carcass of a control and re-infected mouse