IVIg interacts with cytokines, LPS, and dendritic cells.
(A) Reactivity of IVIg with cytokines and LPS. Microtiter ELISA plates were coated with 1 μg/mL IL-4 (top graph), GM-CSF (middle graph), or LPS (bottom graph), blocked, and incubated with sequential dilutions of IVIg (0.008 to 25 mg/mL) followed by goat antihuman IgG coupled to horseradish peroxidase. The negative control consisted of human myeloma IgG protein. Values shown are the differences between the absorbance of specific binding and the background for each concentration and are represented as means of triplicate wells ± SDs. (B) IVIg binds to dendritic cells. Five-day-old DCs were incubated with 0.15 mM intact IVIg (left) or F(ab′)2 fragments (middle) of IVIg for 48 hours. The negative control consisted of human myeloma IgG protein (right). Binding of IVIg or F(ab′)2 fragments was then revealed using DTAF-conjugated goat antihuman IgG.
