FIG. 7.
Detection of anti-CD4-BS antibodies in HIV+ plasmas. (A) Recognition of WT gp120 and CD4-BS mutant gp120 by specific anti-gp120 MAbs. IgG-CD4, chimeric molecule that binds to the CD4-BS of gp120; b12, an antibody that binds to an epitope that overlaps the CD4-BS; 447D, anti-V3 antibody; 2G12, an antibody that binds to a complex conformational epitope on gp120 formed by mannose residues. Closed symbols denote WT gp120 and open symbols denote CD4-BS mutant gp120 as the antigen in the ELISA. (B) Recognition of WT gp120 by the flowthroughs from WT gp120 and the CD4-BS mutant gp120 shown for seven HIV+ subjects with distinct breadths of NAb responses. Non Dep, relative end-point ELISA antibody titers in plasma; gp120, flowthrough following plasma's mixing with beads coated with WT gp120; and gp120bs, flowthrough following plasma's mixing with beads coated with CD4-BS mutant gp120. Arrows indicate the relative titers of antibodies binding to the CD4-BS of gp120.