FIG. 3.

Whole IgG, but not F(ab′)₂, enhances virus inhibition on PBMC target cells. HIV_92US657 (4,500 TCID₅₀) was incubated with HIV antibody-positive or -negative polyclonal IgG (0.5 mg/ml) or similar molar concentrations of F(ab′)₂ and added to PHA-stimulated PBMCs or CD4⁺ lymphocytes. Cells were washed 4 days later, and p24 was measured in supernatant fluid 3 days later (7 days after infection). The percentage of inhibition was calculated as described in Materials and Methods. Data represent mean plus SE of three separate experiments. There was significantly less virus inhibition on PBMCs by the F(ab′)₂ than by whole IgG (P = 0.05).