Different expression of HLA class I molecules and HIV-1 proteins between CD4⁺ T cells and macrophages infected with HIV-1. (A) Comparison of the susceptibility between CD4⁺ T cells and macrophages for cytotoxic activity of HIV-1–specific CTL clones. Cytotoxic activity of HLA-B*5101-restricted CTL clones was examined for CD4⁺ T cells and macrophages prepulsed with each epitope peptide at an E/T ratio of 2:1. Data shown in the figure are averages of triplicate assays for each CTL clone. (B-C) The expression of p24 and Nef proteins in JRFL-infected CD4⁺ T cells and macrophages. After p24⁺ cells had become 20% to 30% of the total cell population, these cells were lysed. The cell lysates (6 μg) were analyzed by Western blotting with anti-p24 or anti-Nef mAb. Relative protein expression indicates the ratio of the amount of the p24 and Nef proteins in JRFL or JR-Xh–infected macrophages to that in JRFL-infected CD4⁺ T cells per equal cell number. Data are shown as the average for 3 independent experiments. (D) The expression of p24 and Nef proteins in CD4⁺ T cells infected with either NL-432 or JRFL. Data are shown as the average ± SD for 3 independent experiments.