Recognition of malignant hematopoietic cells and solid tumor cell lines. Lysis of LB-ADIR-1F–expressing MM cells in heterogeneous bone marrow samples was measured using the CFSE assay at a 1:1 E/T ratio and leukemic blast cell populations using 4-hour 51Cr release assays at an E/T ratio of 20:1. Recognition by RDR2 is shown by ▪ and allo-A2 control CTLs by □. On the x-axis the malignant cell type and the SNP at nucleotide 78 of the ADIR gene are depicted. MM and leukemic cells expressing the LB-ADIR-1F epitope (CT or TT) were recognized by both CTLs whereas LB-ADIR-1F–negative (CC) targets were only lysed by control allo-A2 CTLs (A). A panel of HLA-A2–positive LB-ADIR-1F–expressing solid tumor cell lines was tested for lysis by RDR2 (▪) and control allo-A2 CTL (□) using 4-hour 51Cr release assays at an E/T ratio of 20:1. All tumor cell lines were lysed by LB-ADIR-1F–specific CTLs (B).
