FIG. 2.

Ciliary attachment by Bvg⁺ B. bronchiseptica in the presence of SP-A. The number of phase-locked Bvg⁺ (RB53) that bound to ciliated RTEC following preincubation of both RB53 and RTEC cultures (gray bars), RTEC cultures alone (white bars), or RB53 alone (striped bars), all with final concentrations of 10 μg/ml of SP-A (A) or BSA (B), are compared to RB53 binding from Fig. 1 (black bars). Preincubation of both RB53 and RTEC cultures with SP-A significantly reduced RB53 binding within 30 s (*) and remained significantly lower throughout the experiment. Preincubation of RTEC alone with SP-A significantly reduced binding within 60 s (^), continuing throughout the experiment, whereas preincubation of RB53 alone significantly reduced binding at the 60-, 120-, 180-, and 240-s analysis points (#). In contrast, preincubation with BSA to assay a nonspecific protein block resulted in binding patterns most comparable to those for BSA-free binding (Fig. 2B). *, #, and ^ denote statistically significant differences at P < 0.05 compared to RB53 data redrawn from Fig. 1, and n ≥ 14 for all time points.