Cytotoxic activity of clones 501 and 538 against a selected panel of allogeneic BLCLs. Clones 501 (A) and 538 (B) were used at different effector-target cell ratios in a standard 4-hour cytotoxicity assay. The following BLCLs were used as targets: BM21 (HLA-DPB1*1001, ▪); HSRSL (HLA-DPB1*1701, ▴); C212 (HLA-DPB1*4501, □); DKM366 (HLA-DPB1*1401, ○); OLL (HLA-DPB1*0301, ▵); BEL8-CC (HLA-DPB1*2001, stars); or patient BLCLs transduced with retroviral vector LDPB46SΔN (crosses). For complete HLA typing of target cells, see Table 1.