Involvement of filamentous hemagglutinin in the adherence of Bordetella pertussis to human WiDr cell cultures.

Attachment of 35S-methionine-labelled Bordetella pertussis to monolayers of WiDr cells, an epithelium-like cell line from a human intestinal carcinoma, was examined. The amount of adherence was proportional to the density of the WiDr cells and to the concentration of B. pertussis in the assay. The amount of attachment of virulent strains Tohama phase I, 114 and 338 was much greater than the attachment of avirulent strains, Tohama phase III and 423 phase IV. Attachment of strain Tohama 325, a spontaneous mutant of Tohama I, and strains 353 and 354, Tn5 insertion mutants of 338 was also examined. These mutants have phenotypic properties similar to the parent strain, except the mutants are deficient in the production of the filamentous hemagglutinin (FHA). The FHA deficient mutants adhered to WiDr cells much less efficiently than the parent strains. Goat antibody to FHA inhibited, in a dose dependent manner, the attachment of Tohama I, but not of strain 325. At the same protein concentrations, normal goat antibody or goat antibody to the lymphocytosis-promoting factor had no effect on attachment. Preincubation of bacteria with FHA enhanced the attachment of Tohama I, Tohama 325, and Tohama III. These data support the involvement of FHA in the adherence of B. pertussis to human WiDr cell cultures.