Figure 1.

Neutralization and binding characteristics of vaccination-induced macaque monoclonal antibodies (mAbs). (A) Bar chart representing the values of half-maximal inhibitory concentration ([IC₅₀] μg/mL) calculated after in vitro neutralization assay using Zaire ebolavirus (EBOV) glycoprotein (GP)-pseudotyped-virus performed with the 14 mAbs that were cloned. In gray are negative controls VRC01 and mAb114 used as a reference. Seven of 14 mAbs showed ability to neutralize in vitro. The IC₅₀ values were calculated from a total of 3 experiments run in triplicate. (B) Dot plots show the −log half-maximal effective concentration ([EC₅₀] μg/mL) representing binding of the 7 neutralizers identified in A to GP (filled circles) and GP_ΔMUC (empty circles). All of the mAbs tested bound GP_ΔMUC with greater potency compared with GP (P = .0097). The EC₅₀ values were calculated from a total of 2 experiments run in duplicate. (C) Immunoprecipitation of the 7 neutralizers performed with GP_THL. Four of seven mAbs were able to precipitate GP_THL. As control, input GP_THL is shown on a Coomassie-stained gel. (D) Western blot on the 4 mAbs identified in C performed with GP_ΔMUC and GP_THL. For mAb114, none of the mAbs tested were able to bind GP_THL by Western blot. As a positive control for GP_THL, binding of polyclonal serum is shown.