FIG. 5.

Antibodies from FR3 do not interfere with the interaction between gB and gH/gL, but they block cell-cell fusion. Nectin-1 cells transfected with gL and EYFP-tagged gB and gH/gL do not show BiMC in the absence of gD306 (a). In the presence of gD (b) and nonneutralizing MAbs (A22), BiMC and fusion occur (c). Neutralizing MAbs (d and e) do not affect the gB-gH/gL interaction. N, number of syncytia found on each coverslip (one coverslip per sample). (f) Syncytia formation quantification by luciferase assay. The extent of fusion was calculated as the percentage of no-antibody sample.