Generation of cytotoxicity against aAg after repeated exposure to antigen. Donor cells were isolated and expanded in culture for 7 days and then stimulated with irradiated HLA-mismatched LCL for 2 stimulations (on a weekly basis) and then assayed against LCL stimulator target cells in a standard ⁵¹Cr-release assay. This figure shows representative data from donor 2 against 2 LCL (LCL1 and LCL2) where T_N (⋄) T_CM (□), T_EM (▴) and T_T (•) were compared.