Strong abilities of HIV-1–specific CTLs to suppress HIV-1 replication in HIV-1–infected macrophages and to kill them. (A-B) Ability of HIV-1–specific CTL clones to suppress HIV-1 replication in HIV-1–infected macrophages and in HIV-1–infected CD4⁺ T cells. Macrophages and CD4⁺ T cells from an HLA-B*5101⁺ donor and an HLA-B*3501⁺ donor were infected with JRFL or JR-Xh and NL-432 or NL-M20A, respectively, and then cocultured with each HIV-1–specific CTL clone at an E/T ratio of 1:1. HIV-1 p24 antigens in the supernatant were measured on day 9 after infection by use of an enzyme immunoassay. Data shown in the figure are averages of triplicate assays for each HIV-1–specific CTL clone. (C) Cytotoxic activity against HIV-1–infected macrophages. Macrophages from an HLA-B*5101⁺ donor and an HLA-B*3501⁺ donor were infected with JRFL or JR-Xh. JRFL-infected (56% of total cells were p24 antigen-positive), JR-Xh–infected (48% of total cells were p24 antigen-positive) macrophages were used as target cells at an E/T ratio of 2:1. Data shown in the figure are averages ± SD of triplicate assays for each HIV-1–specific CTL clones. (D) Cytotoxic activity against HIV-1–infected CD4⁺ T cells. CD4⁺ T cells from an HLA-B*5101⁺ donor were infected with NL-432 or NL-M20A. NL-432–infected (81.6% of total cells were p24 antigen-positive) and NL-M20A–infected (79.1% of total cells were p24 antigen-positive) were used as target cells at an E/T ratio of 2:1.