Figure 4.

In vitro binding of dengue poly‐immunoglobulin G scaffold (D‐PIGS) to C1q and U937 cells. (a) ELISA showing concentration‐dependent binding of various D‐PIGS fractions to immobilized C1q. Shown are titration curves for twofold serial dilutions of indicated PIGS fractions of monomeric IgG binding to C1q immobilized at 10 μg/mL. (b) Flow cytometry analysis of the binding of D‐PIGS to the surface of U937 human monocyte cells. Cells were incubated with 50 μg/mL of D‐PIGS or human monomeric or heat‐aggregated IgG (AHG) IgG as the negative and positive controls, respectively, for 2 h prior to analysis. Cells stained with the secondary antibody alone were used as the background control. 10 000 cells were analysed.