FIG. 1.

(A) Relative adherence of NTHI strain 86-028NP to HeLa cells transfected to express human CEACAM1 (HeLa-CCM1) or to HeLa cells containing empty vector (HeLa-Neo) when epithelial cells were preincubated with increasing concentrations of either naïve rabbit serum or polyclonal rabbit anti-human CEA antibody. (B) Relative adherence of an NTHI isolate that expresses the P5 adhesin (strain 1128) or an isogenic mutant that does not (strain 1128f−) to HeLa-Neo or CCM1 cells after preincubation of the epithelial cells with rabbit anti-human CEA (left) or naïve rabbit serum (right). (C) Relative binding of soluble recombinant human CEACAM1 to synthetic peptides designed after the four predicted surface-exposed regions of the NTHI P5 adhesin, as measured by biosensor. Data are reported in mean resonance units (RU) ± standard deviations.