Outer membrane protein 100, a versatile virulence factor of Actinobacillus actinomycetemcomitans.
Actinobacillus actinomycetemcomitans (Aa) is one of the pathogenic bacteria involved in periodontal diseases. We have previously identified six major outer membrane proteins (Omps) of Aa Y4. Among them is an Omp with high molecular mass, designated Omp100, which has homology to a variety of virulence factors. Electron microscopic observation indicated that Omp100 is randomly localized on the cell surface of Aa. Aa Y4 has been shown to adhere and invade KB or normal human gingival keratinocytes. Anti-Omp100 antibody inhibited 50% of adhesion and 70% of invasion of Aa Y4 to KB cells. An Omp100 knock-out mutant had a decreased adhesion and invasion efficiency of 60%, compared with that of the wild type. Escherichia coli HB101 expressing Omp100 adhered twofold and invaded 10-fold more than the wild-type E. coli HB101. HB101 expressing Omp100 showed resistance to serum by trapping factor H, an inhibitor for C3b, with Omp100. Omp100 induced inflammatory cytokine responses of interleukin (IL)-8, IL-6 and tumour necrosis factor (TNF)alpha in epithelial cells, and induced IL-1beta and TNFalpha production in mouse macrophages. These results indicate that Omp100 is a versatile virulence factor that may demonstrate potential significance in the onset of periodontal diseases related to Aa.
Asakawa
Ryuji
R
Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Kasumi 1-2-3, Minami-ku, Hiroshima City, Hiroshima 734-8553, Japan.
Komatsuzawa
Hitoshi
H
Kawai
Toshihisa
T
Yamada
Sakuo
S
Goncalves
Reginaldo Bruno
RB
Izumi
Shunsuke
S
Fujiwara
Tamaki
T
Nakano
Yoshio
Y
Suzuki
Nao
N
Uchida
Yuushi
Y
Ouhara
Kazuhisa
K
Shiba
Hideki
H
Taubman
Martin A
MA
Kurihara
Hidemi
H
Sugai
Motoyuki
M
D000189:Actinobacillus Infections / Q000382:microbiology; D016976:Aggregatibacter actinomycetemcomitans / Q000378:metabolism / Q000472:pathogenicity* / Q000648:ultrastructure; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D017242:Complement Factor H / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D010510:Periodontal Diseases / Q000382:microbiology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; C493495:CFH protein, human; D016207:Cytokines; D011994:Recombinant Proteins; D037521:Virulence Factors; D017242:Complement Factor H