FIG 7 .

(A) ACP mediates adhesion of meningococci to human cells. Chang, Hep2, HUVEC, and meningioma monolayers were infected at an MOI of 100 to 200 with MC58, MC58 ∆ACP, and the MC58 ΔACP complemented (com) strains. Representative experiments for each cell line are shown, as reported by Virji et al. (15). Experiments were repeated 3 to 4 times for each cell line, and the patterns of association of the different bacterial strains were reproducible between experiments, regardless of any quantitative variations between experiments. (B) Anti-rACP serum inhibits bacterial association to epithelial cells. Chang epithelial cells were infected with different MOI of MC58 (ACP⁺) in the presence of decomplemented rabbit preimmune (1% vol/vol) and postimmune (1% vol/vol) anti-rACP serum, and bacterial association was measured after 3 h. The data are representative of n = 4 experiments, and the percentage of reduction in bacterial adherence was calculated from the following formula: 100 × (adherent bacteria with preimmune serum − adherent bacteria with postimmune serum)/adherent bacteria with preimmune serum. For both panels, the columns represent the mean associated bacterial numbers and the error bars show the standard deviations of the results determined with triplicate wells. *, P < 0.05.