A2/Melan-A multimer+ CD8+ allorestricted CTL clones derived from donor DR fail to significantly recognize DR self-targets. (A) The lytic activity of A2/Melan-A multimer+ CD8+ allorestricted CTL clones from DR was assessed on NA8 cells, as well as on DR-derived Epstein-Barr virus (EBV)-transformed cells as a source of autologous target cells. Data are shown for clone DR/A1B4; similar data (lack of reactivity toward DR EBV cells both in the absence or in the presence of peptide Melan-A 26-35 A27L) were obtained in the case of other DR allorestricted clones, as well as for the T cell line Bulk DR. (B) The ability of DR EBV cells to be specifically lysed by an HLA-A1-restricted polyclonal line specific for peptide Flu NP 44-52 in the presence, but not in the absence, of the latter was also assessed as an internal control.