Figure 2.

Antibodies against B. pertussis key adhesins induced bacterial aggregation and inhibit adhesion. (A) Naïve control sera did not protect infected A549 cells which exhibited cluster formation and cell death (blue arrows) compared to confluent resting cells. Naïve sera did not induce bacteria aggregation (A1). Antisera containing antibodies against aP vaccine or single immunogens, FHA, and FIM, induced bacterial aggregation (red arrows) in 100% of tested sera as certain anti-FHA and anti-FIM mAbs induced bacterial aggregation (A2). (B) Specific anti-pertussis antibodies inhibit bacterial adhesion. After 48 h of co-culture, anti-FIM and anti-FHA mAb significantly inhibited bacteria adhesion compared to control anti-PRN mAb (white arrow) to A549 cells which was confirmed using bacteria enumeration on Bordet-Gengou plate (C). Mean ± SEM. ***p < 0.001 and **p < 0.01, n ≥ 3 experiments.