Identity of virus-specific CD8 T cells. The CD7 profile of CD8 T cells was determined by 4-color flow cytometry. (A) CD8 T cells specific for HIV-1 were identified in PBMCs for subjects infected with HIV-1 using HLA-A2 tetramers with the HIV-1 Gag 77 to 85 peptide (n = 9) and the HIV-1 Pol 476 to 484 epitope (n = 6). (B) CD8 T cells specific for viruses were identified in PBMCs from patients infected with HIV-1 and healthy subjects as indicated by using HLA-A2 tetramers with the CMV pp65 495 to 503 epitope (n = 3), the EBV BMLF1 280 to 288 epitope (n = 8), and the influenza virus M1 58 to 66 epitope (n = 3). Mean and standard error of CD7^high (▪), CD7^low (▦), and CD7^negative (□) are shown.