Attachment of Fusobacterium nucleatum PK1594 to mammalian cells and its coaggregation with periodontopathogenic bacteria are mediated by the same galactose-binding adhesin

It has been shown that Fusobacterium nucleatum PK1594 coaggregates with Pro phyromonas gingivalis PK1924 through a galactose binding adhesin. In the pr esent study, attachment of F. nucleatum PK1594 to a variety of mammalian ce lls was characterized. F. nucleatum PK1594 attached to all eukaryotic cells tested, including human buccal epithelial cells, gingival and periodontal ligament fibroblasts, HeLa cells and murine lymphocytes, macrophages, and p olymorphonuclear leukocytes, These attachments were (i) inhibited by galact ose, lactose and N-acetylgalactosamine and (ii) inhibited by monoclonal ant ibody specific for the galactose-binding adhesin of F. nucleatum PK1594. In addition, a coaggregation-defective mutant of F. nucleatum PK1594 (PK2172) , which does not exhibit galactose binding activity, did not attach to the mammalian cells. Coaggregation of F. nucleatum PK1594 with P. gingivalis PK 1924 and Actinobacillus actinomycetemcomitans JP2, but not with other bact eria, showed a similar pattern with sugars, monoclonal antibody, and the ad hesin-deficient mutant. The results suggest that the attachment of F. nucle atum PK1594 to mammalian cells and its coaggregation with periodontal patho gens are mediated by the same galactose-binding adhesin.