FIG. 4.

Enhanced antibody inhibition on PBMCs occurs during the initial exposure of virus to antibody. HIV antibody-positive or-negative polyclonal IgG (0.5 mg/ml) was incubated with 4,500 TCID₅₀ of HIV_92US657 for 1 h and added to either PHA-stimulated CD4⁺ lymphocytes or to PHA-stimulated PBMCs (from the same donor). Cells were then washed either 4 days (A) or 1 h (B) later, and p24 in supernatant fluid was measured 7 days after infection. Data represent the mean plus SE from an experiment performed with two different donors and are representative of two independent experiments.