Figure 4.

Treatment of L. major metacyclic parasites with NMS leads to successful C3 opsonization but not to increased uptake. L. major metacyclic promastigotes were either unopsonized (UNOPS) (A,B) or opsonized with NMS (A,B) or C3 deficient mouse serum (C3−/−) (B) were left unstained or stained with a rat anti-mouse C3 antibody, followed by a Cy3 conjugated anti-rat IgG secondary staining. (A) Flow cytometric analysis of C3 stained (black) and secondary alone (red) stained parasites. % positive cells within the gate are indicated. (B) Visualization of stained parasites was performed using the Nikon Eclipse fluorescent microscope. Overlays of bright-field and fluorescent microscopy images where generated using the Adobe Photoshop software. (C) Phagocytic capacity of UNOPS or NMS opsonized L.major metacyclic parasites was evaluated in simultaneous assays with UNOPS or NMS opsonized polystyrene beads. WT BMMP were infected with parasites or beads at an MOI of 10:1 for 30 minutes. Each condition was performed in triplicate and error bars represent standard deviation. * p<0.05. One representative of 2–3 independent experiments performed in triplicate is presented.