Figure 3

Infection of human macrophages with L. (V.) braziliensis (NO-susceptible - open bars and NO-resistant-closed bars) isolated from patients who were refractory to antimony therapy. (A) and (B) Monocyte-derived macrophages were infected with L. (V.) braziliensis promastigotes (5:1 ratio). At 2, 24, 72 and 120 h of culture the number of intracellular amastigotes(A) and the percentage of infected cells (B) was quantified microscopically as described in Methods. (C) and (D) Monocyte-derived macrophages were treated with LPS (100 ng/mL) plus IFN-γ (10 ng/mL) thirty minutes before the infection with L. (V.) braziliensis promastigotes. At 2, 24, 72 and 120 h of culture, (C) the number of intracellular amastigotes and (D) the percentage of infected cells was quantified microscopically. Each bar represents the mean ± SEM parasite loads in MDMs from three donors (Kruskal-Wallis test, Dunn's multiple comparison Test, * = p < 0.05).