FIG. 3.

Effect of the addition of V3 loop peptides in neutralization assays involving autologous primary isolates (A) or the TCLA strain HIV-1_MN/MT-4 (B). Peptide solutions at concentrations ranging from 0.4 to 50 μM were preincubated with serial dilutions of serum before the neutralization test was performed. The reciprocal dilution of serum corresponding to twice the neutralization titer of the serum was chosen for presenting the results. Values representative of those from at least three separate experiments with the MT-4 cell line and two separate experiments with PBMC are shown. □, no peptide; ▤, 50 μM Bx08-1; , 50 μM R21; , 2 μM peptide; ▧, 10 μM peptide; ■, 50 μM peptide.