Fig. 4

Neutralization of Nipah-pseudotyped VSV (NiVpp). a Varying concentrations of VLPs (0.1 μg/ml to 1 mg/ml, 1.3 × 10⁸ to 1.3 × 10¹² total particles/well) were incubated with enough NiVpp (designed to express Nipah G- and F-proteins and express Renilla luciferase) to produce 300,000 relative light units (RLU) in control wells in this assay. This mixture was then used in an infection of Vero cells, and RLU due to infection of cells by non-neutralized VSV (and are thus producing luciferase) are measured in each case. There is concentration-dependent neutralization in both cases, though neutralization by scFv26 VLPs is slightly better than neutralization by scFv66 VLPs. b A constant 1.5 ng/μl concentration (corresponding to ~2.0 × 10¹⁰ particles for the scFv-VLP fusions) of each potential neutralizer of NiVpp (shown on the horizontal axis) was incubated with NiVpp and used in an infection of Vero cells as in a. RLU was again measured from luciferase expression to determine neutralization. mAb26 G-specific monoclonal antibody (scFv parent), scFv26 NiVG-specific scFv, scFv66 NiVF-specific scFv, VLP-scFv26/scFv66 the two scFvs fused to MS2 VLPs