Allogeneic T-cell responses to unstimulated or CpG-stimulated primary precursor B-ALL samples. A199 and A286 purified ALL cells were incubated without (▦) or with (▪) CpG 2006 for 48 hours, irradiated, and then incubated with healthy donor T cells at a ratio of 1:3 for 5 days. T-1, T-2, and T-3 represent 3 different T-cell donors. (A) The proliferative response of the allogeneic T cells is shown as the average count per minute (CPM) ± standard deviation for 3 independent experiments. The proliferation of unstimulated T cells alone and irradiated ALL cells alone was always less than 1000 CPM. (B) The levels of IFN-γ, IL-5, and IL-10 in the T-cell supernatants, as determined by CBA analysis. Results shown are the mean ± standard deviation for 3 independent experiments for A199, and a representative of 2 independent experiments for A286 (shown as mean ± standard deviation for 2 replicates). ^* indicates P < .05; ^** indicates P < .005.