Antigen-specific conjugate formation and T-cell activation in vitro. (A) Wild-type dendritic cells (WT) or ADAP- deficient ovalbumin (OVA)-loaded mature dendritic cells (ADAP) were mixed with CFSE-loaded T cells from OT-II transgenic mice (ADAP sufficient). After co-incubation, conjugates were fixed by the addition of 1 % paraformaldehyde at different time points. The significant difference between the curves (P < 0.01) was assessed by statistical analysis using two-way ANOVA. The plots show the mean values of five independent experiments. (B) In the same experimental set-up described in (A), cells were harvested at the indicated time points, stained with anti-CD69 antibodies, and the numbers were measured by FACS. (C) BMDCs were matured in the presence of LPS and loaded with OVA, and mixed with T cells from OT-II transgenic mice in a ratio of 1:10. T-cell proliferation was evaluated after 3 days by measuring [3 H]thymidine incorporation (mean + SEM, n = 9).