Differential binding of RSC3 and RSC3Δ371I proteins and their ability to compete for CD4-binding site-specific antibodies in a neutralization assay.

(A) Post-SI plasma from all 21 superinfected women were tested for binding to RSC3 wildtype and RSC3Δ371I mutant gp120. Ratios (wildtype:mutant) of endpoint titers are shown in the far right column, with ratios >3 noted in red. Ratio was not calculated (-) when reciprocal endpoint titers were both <200. (B) QA013 ~5 years post-initial infection plasma tested against Q461d1, Q23, or DU156 alone (black) with the addition of RSC3 wildtype (dark blue) or mutant proteins (light blue).