Fig. 9

Anti-malarial treatment protects infected mice from pulmonary leakage and abrogates cross-presentation of malaria antigen by lungs endothelial cells. Comparison between PbAluc-infected C57BL/6 mice (untreated) (n = 4) and infected mice treated with artesunate and chloroquine (ART + CQ) at 5 and 6 dpi (5&6) (n = 5). All analyses were performed at 7 dpi. a Peripheral parasitemia. b Ex vivo quantification of parasite biomass in the lungs based on luciferase activity of PbAluc after perfusion. c Ratio of lung vascular leakage in vivo at 7 dpi measured by Tracer-653 dye. Total number of d CD8⁺T cells, e CD8⁺ LFA-1⁺ T and f Pb1-specific CD8⁺T cells accumulated in the lungs at 7 dpi. The data were pooled from two independent experiments. g Lung microvessels were isolated at 7 dpi from the naïve C57BL/6 (n = 4), untreated PbAluc-infected C57BL/6 mice (n = 6) and infected mice treated with ART + CQ at 5 and 6 dpi (n = 6) and sorted into two populations: CD45⁺31⁻ leukocytes and CD45⁻CD31⁺ endothelial cells. Each sorted population was tested for Pb1 cross-presentation by incubating with LR-BSL8.4a cells and staining with X-gal. The spot count was normalized per 50,000 cells and represented on a log scale. For ex vivo quantification of parasite biomass in the lungs in (b), the data were expressed on a log scale, with naïve C57BL/6 mice represented by a black dashed line. The black dashed line at y = 1 in (c) represents the ratio of tracer reading from naïve C57BL/6 mice (n = 3). The black dotted line in (d–f) represents the value of each respective cell population from naïve C57BL/6 mice for quantification of immune-cell populations in the lungs. The data represent the mean ± SD; *p < 0.05, **p < 0.001, by Mann Whitney test (a–f); *p < 0.05, ****p < 0.0001, ^ statistically significant compared to naive (p < 0.001, p < 0.0001), by ANOVA with Bonferroni’s post-test (g)