Role of Bordetella pertussis virulence factors in adherence to epithelial cell lines derived from the human respiratory tract

During colonization of the respiratory tract by Bordetella pertussis, virul ence factors contribute to adherence of the bacterium to the respiratory tr act epithelium. In the present study, we examined the roles of the virulenc e factors filamentous hemagglutinin (FHA), fimbriae, pertactin (Prn), and p ertussis toxin (FT) in the adherence of B. pertussis to cells of the human bronchial epithelial cell line NCI-H-292 and of the laryngeal epithelial ce ll line HEp-2. Using B. pertussis mutant strains and purified FHA, fimbriae , Prn, and PT, we demonstrated that both fimbriae and FHA are involved in t he adhesion of B. pertussis to laryngeal epithelial cells, whereas only FHA is involved in the adherence to bronchial epithelial cells. For PT and Prn , no role as adhesion factor was found. However, purified PT hound to both bronchial and laryngeal cells and as such reduced the adherence of B. pertu ssis to these cells. These data may imply that fimbriae play a role in infe ction of only the laryngeal mucosa, while FHA is the major factor in coloni zation of the entire respiratory tract.