Antigen recognition by CMV-specific CD8⁺ CTL clones isolated following stimulation with autologous fibroblasts infected with RV798. CMV-specific CD8⁺ CTL clones were tested for recognition of autologous fibroblasts either mock-infected (), infected with AD169 (□), or infected with RV798 (▪), in a chromium release assay. Autologous LCL infected with Vac/pp65 (▦), Vac/IE-1 (▨), Vac/pp150 (▧), and Vac/gB (▦) were used as target cells in the same assay to confirm specificity. Data are shown for 10 representative CTL clones from each of the 5 donors in proportions selected based on the relative frequency of antigen specificities shown in Table 2. The data are shown at an E/T ratio of 10:1. (A) Donor 1; (B) donor 2; (C) donor 3; (D) donor 5; (E) donor 7.