Gram‐positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction. (8th November 2012)

• Record Type: Journal Article
• Authors: Nagano, F.; Kaneko, T.; Yoshinaga, Y.; Ukai, T.; Kuramoto, A.; Nakatsu, S.; Oshino, K.; Ichimura, I.; Hara, Y.
• Is Part Of: Journal of periodontal research. Volume 48:Number 4(2013:Aug.)
• Page Start: 420
• Page End: 427
• Publication Date: 2012-11-08
• Subjects: Periodontics -- Periodicals; 617.632
• DOI: 10.1111/jre.12021
• Languages: English
• ISSNs: 0022-3484

Abstract

<abstract abstract-type="main" id="jre12021-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jre12021-sec-0001" sec-type="section"> <title>Background and objective</title> <p>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.</p> </sec> <sec id="jre12021-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>Rats previously immunized with heat‐treated and sonicated <italic>Staphylococcus aureus</italic> or <italic>Aggregatibacter actinomycetemcomitans</italic> were used as immunized groups. The non‐immunized group received only sterile phosphate‐buffered saline. In each animal, <italic>S. aureus</italic> or <italic>A. actinomycetemcomitans</italic> 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‐<italic>S. aureus</italic> or anti‐<italic>A. actinomycetemcomitans</italic> 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.</p> </sec> <sec id="jre12021-sec-0003" sec-type="section"> <title>Results</title> <p>Serum levels of anti‐<italic>S. aureus</italic> and anti‐<italic>A. actinomycetemcomitans</italic> 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.</p> </sec> <sec id="jre12021-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Heat‐treated and sonicated <italic>S. aureus</italic> and <italic>A. actinomycetemcomitans</italic> 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.</p> </sec> </abstract>