title: Functional differences among FimA variants of Porphyromonas gingivalis and their effects on adhesion to and invasion of human epithelial cells.
abstract: Fimbriae of Porphyromonas gingivalis, a periodontopathogen, play an important role in its adhesion to and invasion of host cells. The fimA genes encoding fimbrillin (FimA), a subunit protein of fimbriae, have been classified into five types, types I to V, based on nucleotide sequences. We previously reported that P. gingivalis with type II fimA was strongly associated with adult periodontitis. In the present study, we compared the abilities of recombinant FimA (rFimA) types I to V to adhere to and invade human gingival fibroblasts (HGF) and a human epithelial cell line (HEp-2 cells) by using rFimA-conjugated microspheres (rFimA-MS). There were no significant differences in the abilities of the rFimA-MS to adhere to HGF; however, the adhesion of type II rFimA-MS to HEp-2 cells was significantly greater than those of other types of rFimA-MS. We also observed that type II rFimA-MS invaded epithelial cells and accumulated around the nuclei. These adhesion and invasion characteristics were eliminated by the addition of antibodies to type II rFimA and alpha5beta1-integrin. In contrast, Arg-Gly-Asp-Ser peptide and a synthetic peptide of proline-rich protein C had negligible inhibitory effects. Furthermore, P. gingivalis strain HW24D1 with type II fimA adhered to cells and invaded them more than strains with other fimA genotypes. These results suggest that type II FimA can bind to epithelial cells most efficiently through specific host receptors.
authors.affiliation: Department of Oral Microbiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-Osaka 565-0871, Japan. ichiro@dent.osaka-u.ac.jp
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakagawa
authors.forename: Atsuo
authors.initials: A
authors.lastname: Amano
authors.forename: Masae
authors.initials: M
authors.lastname: Kuboniwa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakamura
authors.forename: Shigetada
authors.initials: S
authors.lastname: Kawabata
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Hamada
mesh_terms: D000907:Antibodies, Bacterial / Q000378:metabolism; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D002460:Cell Line; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000382:microbiology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D036781:Fimbriae Proteins; D005456:Fluorescent Dyes; D014644:Genetic Variation; D005838:Genotype; D005881:Gingiva / Q000166:cytology; D006801:Humans; D008863:Microspheres; D018933:Pili, Sex / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D017469:Receptors, Fibronectin / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D017469:Receptors, Fibronectin; C063055:fimbrillin; D036781:Fimbriae Proteins