Effects of human recombinant Fc protein on the synergistic enhancement of the production of IL-6 of peripheral blood monocytes by anti-Sm mAb and anti-RNP mAb.

Highly purified monocytes were cultured with various combination of anti-Sm mAb, anti-RNP mAb, control IgG1 or IgG3 (3 μg/ml) in the presence or absence of the human Fc blocker (Human BD Fc Block) (50 μg/ml). (A) After 24 hours the cells were harvested and stained with FITC-conjugated goat F(ab′)2 anti-mouse IgG, followed by analysis on flowcytometry. The mean fluorescence intensity (MFI) for specific anti-Sm mAb staining and anti-RNP mAb staining is indicated. Representative of 3 different experiments with similar results. (B) After 48 hours of incubation, the supernatants were assayed for IL-6. Mean values with standard deviation (error bars) of 3 different experiments are shown. Statistical significance was evaluated by paired t test.