Periodontal bone level and gingival proteinase activity in gnotobiotic rats immunized with Bacteroides gingivalis

Abstract

Bacteroides gingivalis is associated with various forms of periodontal disease. To assess the role of the immune response in modulating B. gingivalis-associated periodontal disease, the effect of immunization of B. gingivalis-induced periodontal bone loss was evaluated in gnotobiotic rats. Male Sprague-Dawley rats immunized with various doses of whole cells or sham-immunized with incomplete Freund's adjuvant were monoinfected with B. gingivalis in carboxymethylcellulose by gavage. Two additional groups served as either sham-immunized or untreated germ-free controls. Forty-two days after infection, all rats were killed, periodontal bone level was assessed morphometrically and radiographically, and gingival proteinase (mammalian collagenase and acid cathepsin) activity was assessed biochemically. B. gingivalis was present in oral samples from all monoinfected rats, and no contaminating bacteria were detected in any oral or fecal sample. Animals immunized with B. gingivalis cells had elevated serum and saliva antibodies to whole cells and partially purified fimbriae from B. gingivalis. Infected sham-immunized rats had significantly more periodontal bone loss than noninfected controls, whereas the periodontal bone level in infected rats immunized with 10(10) B. gingivalis cells was similar to that of the noninfected controls. The activities of gingival collagenase and cathepsin B and L were high in sham-immunized infected rats and low in all other animal groups. In conclusion, it is possible to reduce B. gingivalis-induced periodontal tissue loss in gnotobiotic rats by immunization.

Rat Model of Polymicrobial Infection, Immunity, and Alveolar Bone Resorption in Periodontal Disease

“…The bacteria used in this study were P. gingivalis 381, T. denticola ATCC 35404, T. forsythia ATCC 49307, and F. nucleatum ATCC 49256. P. gingivalis strain 381 was chosen due to its known role in alveolar bone resorption in adult periodontitis and its proven ability to colonize the oral cavities of rodents (12,19,21). All bacterial strains were grown under anaerobic conditions (85% N 2 , 10% H 2 , 5% CO 2 ) at 37°C in a Coy anaerobic chamber.…”

Immunization with the RgpA-Kgp Proteinase-Adhesin Complexes ofPorphyromonas gingivalisProtects against Periodontal Bone Loss in the Rat Periodontitis Model

“…They were left overnight in 3% (vol/vol) H 2 O 2 , air dried, and stained for 1 min in an aqueous solution of 0.1% (wt/vol) methylene blue to delineate the cementoenamel junction. The jaws were coded, and an investigator unfamiliar with the code measured horizontal bone loss using the morphometric method of Klausen et al (22,23). Bone loss data were statistically analyzed by a one-way classification analysis of variance with a post hoc Scheffe multiple comparison (M. Norusis, SPSS for Windows: base system user's guide, release 6.0, SPSS Inc., Chicago, Ill., 1993).…”

“…Group 4 was left unchallenged. The animals were challenged by inoculation using a 2.5-ml disposable syringe fitted with a 16-gauge gavage tube as described previously (22). A 1-ml sample of the P. gingivalis cell suspension was inoculated into each animal in the following manner: 0.75 ml was gavaged into animals by inserting the tube into the pharynx, 0.2 ml was deposited in the molar gingival area (50 l per quadrant), and 50 l was deposited in the colorectal area.…”

Immunization withPorphyromonas gingivalisCapsular Polysaccharide PreventsP. gingivalis-Elicited Oral Bone Loss in a Murine Model

“…Interestingly, this antigen also elicited a potent IgG response, and the animals immunized with P. gingivalis CPS were protected from P. gingivalis-elicited oral bone loss. To date, several P. gingivalis vaccine candidates have been reported to prevent P. gingivaliselicited oral bone loss (8,9,13,18,19,22,28) while other P. gingivalis antigens, such as LPS, do not appear to provide protection from subsequent P. gingivalis infection (5). Unexpectedly, we observed that mice immunized with P. gingivalis CPS develop an IgG response that recognizes P. gingivalis whole organisms.…”