Cytolytic activity of CD8+ minor H antigen-specific CTL clones DRN-7 and DRN-11. Clones DRN-7 and DRN-11 were isolated from an HLA A3+, HLA B7+ allogeneic HCT recipient (17). The CTLs were tested in a 4-hr 51Cr release assay against EBV-LCL derived from pretransplant recipient lymphocytes, EBV-LCL derived from the stem cell donor, dermal fibroblasts derived from the recipient, and AML cells from patient 10885 who was HLA A3+ but also HLA B7−. Data shown are for an effector-to-target ratio of 10:1. UPN, unique patient number.