Activation of resting B cells by an EBV-specific CD8⁺ T-cell line from donor MJC (P10) and five EBV-specific CD8⁺ T-cell clones (3aH11, 3bE10, 3C12, 3E8, and 3F11) derived from the MJC CD8⁺ T-cell line. Small resting B cells were purified from peripheral blood by positive selection with anti-CD19–coupled magnetic beads, as described in Materials and Methods, and cultured for 4 days with γ-irradiated T cells in the presence (▨) or absence (□) of plate-bound anti-CD3. Stimulation indices were calculated as the ratio of ³H-TdR uptake by B cells cultured with T cells divided by ³H-TdR uptake by B cells cultured without T cells. Background counts (typically <100 cpm) by control wells of irradiated T cells were subtracted before calculation of stimulation indices for B-cell proliferation.