Selectivity of Fas-mediated apoptosis in cultures of lymphocytes from HIV-1–infected patients. (A) Fas-related apoptosis of CD4⁺ cells in culture of lymphocytes from patients with HIV-1 infection. Samples of lymphocytes from HIV-1–infected patients were untreated (ø) or cocultivated with CH11 MoAb (F ) for 3 days. The number of apoptotic cells were determined using two-color flow cytometry. Apoptotic cells were detected using TdT reaction; phenotype of cells was determined using CD4 or CD8 MoAb. Cells were gated to include only either CD4⁺ or CD8⁺ cells. The standard deviation of the mean is seen in brackets. (B) CD4/CD8 ratio of lymphocytes cocultivated with CH11 MoAb. Samples of PBMCs from the HIV-1–infected patients who were either untreated or cocultivated with CH11 MoAb. Columns represent the CD4⁺/CD8⁺ ratio of untreated (ø) and CH11-treated cells (F ). The standard deviation of the mean is shown in brackets.