Figure 4. Effect of ATRA treatment on DC function and antigen-specific immune response.

A. MNC isolated from patients and donors were irradiated and cultured for 5 days in triplicates in U-bottom 96-well plates with 10⁵ allogeneic T cells at different ratios. ³[H]-thymidine (1 μCi) was added to each well 18 hr prior cell harvesting. Thymidine uptake was measured in liquid scintillation counter as described in Methods. The background values of T-cell proliferation were subtracted. Only one (1:1) ratio is shown. ** - statistically significant differences from control group (P<0.05). # - statistically significant differenced from pre-treatment level (p<0.05). B – D. MNC (2 × 10⁵/well) were incubated in triplicates with 0.1 μg/ml T-T (B), immobilized anti-CD3 antibody (C), or 5 μg/ml PHA (D) for 4 days. ³[H]-thymidine (1 μCi) was added to each well 18 hr prior cell harvesting. The background values (MNC incubated with medium alone) were subtracted. E. – The proportion of CD4⁺CD25⁺GITR⁺ T cells was evaluated. All abbreviations are as in Figure 2.