Fig. 7

Absence of IFN-γ prevents lung injury and hinders cross-presentation of malaria antigens by lungs microvessels. a Peripheral parasitemia and b ex vivo quantification of parasite biomass in the lungs based on luciferase activity after perfusion, of PbAluc-infected C57BL/6 (n = 4) and IFN-γ^−/− (n = 4) at 7 dpi. c Ratio of in vivo lung vascular leakage measured by Tracer-653 at 7 dpi (n = 4 in each group). d Total number of CD8⁺T, e CD8⁺ LFA-1⁺ T and f Pb1-specific CD8⁺T cells accumulated in the lungs at 7 dpi (n = 4). The data shown are representative of three independent experiments. g Lung microvessels were isolated from naïve C57BL/6 (N C57BL/6) (n = 3), naïve IFN-γ^−/− (N IFN-γ^−/−) (n = 4), PbAluc-infected C57BL/6 (n = 10) and PbAluc-infected IFN-γ^−/− (n = 9) mice at 7 dpi. Each population was tested for Pb1 cross-presentation. The spot count was normalized per 50,000 cells and represented on a log scale. h Representative histograms of lung endothelial cells (CD45⁻CD31⁺) from naïve C57BL/6 (n = 3) and IFN-γ^−/− (n = 3) mice (blue line), and PbAluc-infected C57BL/6 (n = 4) and IFN-γ^−/− (n = 5) mice (red line) at 7 dpi that were stained for MHC-I (H-2D^b). Graphs represent the geometric mean fluorescence intensities (GMFI) of MHC-Class I (H-2D^b) on CD31⁺ lung endothelial cells from naïve and infected (INF) mice. For ex vivo quantification of parasite biomass in the lungs in (b), data are expressed on a log scale, with naive mice represented by the black dashed line. The black dashed line at y = 1 in (c) represents the ratio of tracer reading from naïve mice (n = 3). The black dotted line in (d–f) represents the value of each respective cell population from naïve mice for quantification of the immune-cell populations in the lungs. The data represent the mean ± SD; NS: not statistically Significant, *p < 0.05, by Mann–Whitney test (a–f, h); *p < 0.05, **p < 0.01, ****p < 0.0001, by ANOVA with Bonferroni’s post-test (g)