Screening of eluted AML peptide-specific CTL lines in a cytolytic assay. CTL lines were generated from the PBMC of a partially HLA-compatible donor (HLA class I typing A2/11; B7/27) seeded in 110 wells in microplates and stimulated with the pool of eluted peptides (HLA class I typing A2/28; B7/44). Cytolytic activity was analyzed after five stimulations on HLA-A-2/3; -B7/8 EBV-transformed target cells unpulsed (□) or pulsed () with AML peptides eluted from HAR blasts. There was cytolytic activity in 9 of 110 wells (CTL 1-9). The other wells had no such activity, as shown for well 10. We found that these results were consistent with two different inductions. The results shown are the means of duplicates and are representative of three cytolytic assay, for an effector:target (E:T) ratio of 40:1.