FIG 5.
Virus-cell fusion neutralization, cell-cell fusion inhibition, and neuraminidase (NA) inhibition data for representative sAbs. (A) Virus-cell fusion neutralization data. sAbs were preincubated for 30 min with replication-competent, GFP-labeled virus prior to infection at an MOI of 1.3. The anti-prefusion-specific sAb, 5D, was uniquely inhibitory among the anti-F-GCNt sAbs (dashed lines). All of the anti-HN sAbs (solid black lines) were inhibitory. (B) NA inhibition data generated from incubating soluble purified HN56–565 and anti-HN sAbs with MUNANA substrate. Only sAb F4 inhibited NA enzymatic activity. (C) Cell-cell fusion inhibition. F and HN were expressed in CHO-K1 cells and subsequently with CHO-K1 cells expressing T7 RNA polymerase in the presence and absence of inhibitors. Fusion was quantified using a luciferase reporter assay. AU, arbitrary units. (D) BHK cells expressing F and HN or F and HN1–117 stalk (41) at 15 h posttransfection were incubated with 200 nM sAb 1H for 4 h and photographed.