Effect of IL-2, IL-12, and anti–IL-10 antibodies on IFN-γ and IL-10–mediated monocyte apoptosis. Monocytes (4 × 105 cells/mL) were cultured (in the absence of poly–L-lysine) in the absence or presence of various cytokines or anti–IL-10 neutralizing antibodies; percentages of apoptotic cells were assessed by flow cytofluorimetry analysis using the acridine orange nuclear dye. (A) Monocytes were cultured for 24 hours or 48 hours, as mentioned, in the presence of medium alone or of IL-2 (200 IU/mL), IL-12 (400 ng/mL), IL-10 (400 ng/mL), anti–IFN-γ (10,000 IU/mL). Histograms represent mean ± SD of three independent experiments. *P < .03. (B) Monocytes were cultured for 48 hours in the presence of medium alone (▨) or IFN-γ (10,000 IU/mL; ▪) in the absence (−) or presence (+) of IL-2 (200 IU/mL), IL-12 (400 ng/mL), or neutralizing antibodies to IL-10 (10 μg/mL). Results are from one representative experiment out of two. (C) Monocytes were cultured for 48 hours in the presence of medium alone (▨) or IL-10 (400 ng/mL) (▪) in the absence (−) or presence (+) of IL-2 (200 IU/mL), IL-12 (400 ng/mL), or neutralizing antibodies to IL-10 (10 μg/mL). Results are from one representative experiment out of two.
