IFN-γ expression by cord-blood-derived T cells after activation with mature DCs with or without the addition of anti-IL-10 neutralizing antibody. (A) Proliferation of cord blood-derived T cells induced by mature DCs, with or without the addition of anti-IL-10 neutralizing antibody. Cord blood-derived allogeneic T cells (1.5 × 10⁵cells) were cultured with LPS + IFN-γ-matured DCs (5 × 10³) from controls and HIGM3 patient 1 (see “Patients, materials, and methods”) in the presence of anti-IL-10 (10 μg/mL) to neutralize IL-10 action on the cells or with a control IgG antibody. After 5 days at 37°C, proliferation of alloreactive T cells was assessed by uptake of [³H]-thymidine. Results are expressed as mean cpm ± SD of triplicates. ^*Significant increase of thymidine incorporation after incubation with anti-IL-10 mAb as assessed by statistical analysis (P < .05). (B) IFN-γ production by alloreactive naive T cells induced to proliferate by mature DCs, with or without the addition of anti-IL-10 neutralizing antibody. Cord-blood-derived allogeneic T cells (1.5 × 10⁵ cells/well) were cultured with LPS + IFN-γ-matured DCs (5 × 10³) from controls or HIGM3 patient 1 (see “Patients, materials, and methods”), in the presence of anti-IL-10 (10 μg/mL) to neutralize IL-10 action on the cells or with a control IgG antibody. The supernatant was collected after 5 days at 37°C, and the production of IFN-γ was measured using ELISA. Cells used for this experiment correspond to those of the MLR assay described in panel A. Data are expressed in pg/mL (mean ± SD of triplicates). Asterisks indicate a significant increase of IFN-γ secretion after incubation with anti-IL-10 mAb as assessed by statistical analysis (P < .05). Results shown are representative of 2 independent experiments.