Fig. 6: Trypanolytic activity of immune serum from DKO-inoculated animals.

Serum collected from animals which were inoculated multiple times (at 16 weeks from first inoculation, upper right panel), after a single inoculation (at 20 weeks post inoculation, middle right panel) and after multiple immunizations WT + challenge (34 weeks after challenge, bottom right panel). WT RHM-derived trypomastigotes were used to analyze for the presence of Ab-mediated complement fixing activity. Both serum from multiple and single administrations of DKO parasites were able to induce trypanolytic activity. Dilution of the serum resulted in incrementally less trypanolytic activity as expected. Control reactions (left panels) included non-stained parasites, CFSE-stained parasites alone, stained parasites incubated in human complement alone and those incubated in non-immune control serum + human complement. Sera were pooled from 3–4 mice per group prior to analysis. See Supplementary Fig. 11 for gating strategy for flow cytometry.