FIG. 10.
Competitive-inhibition ELISAs (upper panels) and the corresponding competitive inhibition of opsonophagocytic killing of GBS III (strain M781) by human PMNs in the presence of endogenous complement (lower panels) demonstrate the functional activity of IIIPS-specific antibodies that cross-react with Pn14 PS. The results shown are for sera from three volunteers immunized with unconjugated IIIPS that represent the observed categories of antibody specificity: left panels, all GBS IIIPS-specific antibodies cross-react with Pn14 PS (A21); middle panels, a subpopulation of GBS IIIPS-specific antibodies cross-react with Pn14 PS (B30); right panels, no GBS IIIPS-specific antibodies cross-react with Pn14 PS (A33). The upper panels show the percent inhibition of binding of IIIPS-induced IgG, as determined by comparison of A405/630 in the presence and absence of inhibitor. The lower panels show the percent reduction in CFU in the presence of inhibitors. The following inhibitors were used: Pn14 PS (filled squares), IIIPS (open squares), and III-HSA (open circles).