Figure 3
PfTRAP interaction with human PDGFRβ can be disrupted by parasite and host directed antibodies. (A) Anti-PfTRAP mAb AKBR4 or AKBR6 was incubated with 1000 nM PfTRAP full ectodomain (ECD) or VWA + TSR fragment, or 10 nM of the known PDGFRβ ligand hPDGF-BB for 30 min before addition to hPDGFRβ transfected cells in the flow assay. Binding of the Full ECD and VWA + TSR fragments was reduced by approximately 80% and 90%, respectively, while binding of human PDGF-BB was unaffected. (B) hPDGFRβ-transfected cells were incubated with anti-PDGFRβ mAb 2C5 for 30 min before addition of staining reagents as above with analysis by flow cytometry. Blocking hPDGFRβ inhibited binding of both PfTRAP fragments as well as the known ligand human PDGF-BB. Data are normalized to appropriate isotype controls and represent the mean ± SD from four independent experiments. Analysis by One-way ANOVA with Dunnet’s multiple comparisons test (A), and Mann Whitney test (B); *p < 0.05, **p < 0.01 compared to the isotype control.
