Antibody responses to Porphyromonas gingivalis hemagglutinin A and outer membrane protein in chronic periodontitis.
BACKGROUND
Hemagglutinin and outer membrane protein (OMP) are major virulence factors associated with colonization of Porphyromonas gingivalis in the gingival crevice. The genes for the 200-kDa antigenic protein (200-kDa AP) and 40-kDa OMP of P. gingivalis have been successfully cloned. Additionally, the 200-kDa AP gene has been shown to constitute the hemagglutinin A (hagA) gene of P. gingivalis. Therefore, this study was constructed to evaluate the distributions and serum levels of immnoglobulin G (IgG) antibodies specific for 200-kDa AP and 40-kDa OMP in periodontitis patients.


METHODS
Fifty patients with chronic periodontitis and 59 controls without periodontal destruction were enrolled in this study. We cloned the genes for 200-kDa AP and 40-kDa OMP from P. gingivalis and constructed the purified recombinant proteins. Serum levels of IgG subclass antibodies specific for both recombinant 200-kDa and 40-kDa OMP were determined in patients and controls by an enzyme-linked immunosorbent assay (ELISA).


RESULTS
The serum IgG subclass distribution for patients and controls was IgG1>IgG4>IgG2>IgG3 in the anti-200-kDa AP response, which was almost identical to that in the anti-40-kDa OMP response. The patient group showed significantly higher serum IgG responses to the 40-kDa OMP than the control group (P<0.01). In contrast, IgG subclass responses to the 200-kDa AP were not different between the patients and controls. Serum levels of antibodies reactive with both 200-kDa and 40-kDa proteins did not have a significant association with mean probing depth.


CONCLUSIONS
These results suggested that serum IgG responses against P. gingivalis OMP rather than the hagA may be more active in chronic periodontitis.
Kobayashi
Tetsuo
T
Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, and General Dentistry and Clinical Education Unit, Niigata University Medical and Dental Hospital, Niigata, Japan. kotetsuo@dent.niigata-u.ac.jp
Kaneko
Susumu
S
Tahara
Tomoyuki
T
Hayakawa
Mitsuo
M
Abiko
Yoshimitsu
Y
Yoshie
Hiromasa
H
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D037102:Lectins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000276:immunology / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000276:immunology*; D018709:Statistics, Nonparametric; D037521:Virulence Factors / Q000276:immunology
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D007074:Immunoglobulin G; D037102:Lectins; D037521:Virulence Factors; C114923:hemagglutinin A, Porphyromonas gingivalis