Figure 2.

Leishmania infection correlates with lower number of AIF1⁺ macrophages in the spleen. C57BL/6 mice (n = 9) were intravenous injected with 10⁶ Leishmania donovani promastigotes. Control mice (n = 9) received PBS. 7 days after injection, spleen was collected from respective groups, each dissociated into single cell suspension and stained for flow cytometry. (A) Singlets were gated on CD45⁺ subsets to assess for F4/80 versus CD68 expression. (B) CD11b and AIF1 co-expression were assessed within each quadrant of the F4/80 versus CD68 populations in non-infected control versus Leishmania donovani infected groups. All gates were established using isotype controls. (C) Percentage of AIF1⁺ in the F4/80⁺CD68⁺ subsets is presented as a bar graph. (D) Parasite load within the spleen in control versus Leishmania donovani infected groups was measured by qPCR 7 days post-infection. Data shown as mean ± SEM representative of 3 independent experiments with 3 mice per group. (E) CellTracker-labeled Leishmania donovani parasites were injected into C57BL/6 mice (n = 10) and used to monitor frequency of infected macrophages every 3 days for 2 weeks. Control mice (n = 10) received PBS. Percentage of Leishmania donovani is determined by looking at frequency of CellTracker⁺ within CD11b^+/negF4/80⁺CD68⁺ macrophages of non-infected versus infected groups. Percentage of AIF1⁺ in CD11b^+/negF4/80⁺/CD68⁺macrophages was concomitantly determined in non-infected versus infected groups. Data shown as mean ± SEM representative of 2 independent experiments with 2 mice per group. Statistical significance was determined by unpaired t-test. *p < 0.05, **p < 0.01 and ns = not significant.