title: Gram-positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction.
abstract: OBJECTIVE
  Periodontitis is generally accepted to relate to gram-negative bacteria, and the host defense system influences its onset and progression. However, little is known about the relation between gram-positive bacteria and periodontitis. In this study, we topically applied gram-positive and gram-negative bacterial suspensions to the gingival sulcus in rats after immunization, and then histopathologically examined their influence on periodontal destruction.
  
  
  METHODS
  Rats previously immunized with heat-treated and sonicated Staphylococcus aureus or Aggregatibacter actinomycetemcomitans were used as immunized groups. The non-immunized group received only sterile phosphate-buffered saline. In each animal, S. aureus or A. actinomycetemcomitans suspension was applied topically to the palatal gingival sulcus of first molars every 24 h for 10 d. Blood samples were collected and the serum level of anti-S. aureus or anti-A. actinomycetemcomitans immunoglobulin G (IgG) antibodies was determined by enzyme-linked immunosorbent assay. The first molar regions were resected and observed histopathologically. Osteoclasts were stained with tartrate-resistant acid phosphatase (TRAP). The formation of immune complexes was confirmed by immunohistological staining of C1qB.
  
  
  RESULTS
  Serum levels of anti-S. aureus and anti-A. actinomycetemcomitans IgG antibodies in the immunized groups were significantly higher than those in the non-immunized groups were. The loss of attachment, increase in apical migration of the junctional epithelium, and decreases in alveolar bone level and number of TRAP-positive multinuclear cells in each immunized group were significantly greater than in each non-immunized group. The presence of C1qB was observed in the junctional epithelium and adjacent connective tissue in the immunized groups.
  
  
  CONCLUSIONS
  Heat-treated and sonicated S. aureus and A. actinomycetemcomitans induced attachment loss in rats immunized with their suspensions. Our results suggest that not only gram-negative but also gram-positive bacteria are able to induce periodontal destruction.
authors.affiliation: Department of Periodontology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Nagano
authors.forename: T
authors.initials: T
authors.lastname: Kaneko
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshinaga
authors.forename: T
authors.initials: T
authors.lastname: Ukai
authors.forename: A
authors.initials: A
authors.lastname: Kuramoto
authors.forename: S
authors.initials: S
authors.lastname: Nakatsu
authors.forename: K
authors.initials: K
authors.lastname: Oshino
authors.forename: I
authors.initials: I
authors.lastname: Ichimura
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000287:Administration, Topical; D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology; D016301:Alveolar Bone Loss / Q000276:immunology / Q000382:microbiology; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000936:Antigen-Antibody Complex / Q000032:analysis; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D003238:Connective Tissue / Q000276:immunology / Q000382:microbiology; D004846:Epithelial Attachment / Q000276:immunology / Q000382:microbiology; D005881:Gingiva / Q000276:immunology*; D018960:Hyaluronan Receptors / Q000032:analysis; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D024101:Mitochondrial Proteins; D008963:Molar / Q000382:microbiology; D010010:Osteoclasts / Q000276:immunology / Q000382:microbiology; D017622:Periodontal Attachment Loss / Q000276:immunology / Q000382:microbiology; D010518:Periodontitis / Q000276:immunology / Q000382:microbiology*; D051381:Rats; D011917:Rats, Inbred Lew; D013047:Specific Pathogen-Free Organisms; D013211:Staphylococcus aureus / Q000276:immunology*; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D000907:Antibodies, Bacterial; D000936:Antigen-Antibody Complex; D000942:Antigens, Bacterial; D015415:Biomarkers; C490195:C1qbp protein, rat; D018960:Hyaluronan Receptors; D007074:Immunoglobulin G; D007527:Isoenzymes; D024101:Mitochondrial Proteins; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase