The cytotoxic activity of HA-1–specific CTLs restricted by nonself HLA-A2 molecules against HLA-A2⁺ and HLA-A2⁻ target cells that naturally express the HLA-A2/HA-1 ligand.

The indicated target cells were used as hot targets for the allo–HLA-A2–restricted HA-1–specific CTLs in the presence of cold K562 cells or HLA-A2⁺, HA-1⁻ EBV-LCLs (cold target cell–to–hot target cell ratio = 20). The results are expressed as the mean value of the duplicate cultures at an effector-to–hot target cell ratio of 1:1.