FIG. 3.

gp120 chimera and deletion mutant binding to CCR5⁺ cells. L12 CCR5⁺ cells (10⁶) were incubated with soluble gp120-CD4 complexes (20 nM gp120 and 5 nM CD4-IgG2) in the absence (white bars) or presence (gray bars) of MAb PA14 (10 μg/ml), and binding was detected by flow cytometry analysis. The gp120 chimeras and deletion mutants are indicated along the x axis. Mutant gp120JR-FL-CD4-IgG2 binding to the cells is expressed as a percentage of wild-type JR-FL-CD4-IgG2 binding. The values shown are averages of three independent experiments.