Autologous virus–infected targets are not lysed by IFN-γ⁺ CD8 T cell lines responding to HIV_IIIB virus and vice versa in samples from more advanced donors. Short-term cultures from IFN-γ⁺ cells responding to IIIB (a) or autologous virus (b) were tested against uninfected (black bars), IIIB (white bars), or autologous (gray bars) virus–infected primary CD4 T cell targets. Representative data for subjects from each CDC stage are depicted at effector/target ratios ranging from 1:1 to 5:1. Data are presented as mean of experiments performed in triplicate. The cytotoxicity assays confirm the results of TCRBV sequencing. There was cross-recognition of IIIB and autologous virus by two of the stage A donor cell lines, but not by the cell lines from more advanced donors.