FIG 2.

Antibody-dependent enhancement in monocytic cell line THP-1 and primary cells. (A) RSV neutralization assay using FCGR-carrying THP-1 cells in the presence of serially diluted IVIg, human serum, or cord blood. (B) ADE is reported for the dilution at which infection is maximal (depicted by the arrow in panel A). Fc-binding sites of FCGRs were blocked by adding 3 μg/ml staphylococcal FLIPr-like protein to THP-1 cells during RSV neutralization assay. (D) RSV neutralization assay using cells that were isolated from human blood (human PBMCs). One representative graph of three PBMC donors is depicted. For other graphs, the means and standard deviations (SD) from ≥3 individual experiments are shown.