title: Porphyromonas gingivalis infection-associated periodontal bone resorption is dependent on receptor activator of NF-κB ligand.
abstract: Porphyromonas gingivalis is one of the oral microorganisms associated with human chronic periodontitis. The purpose of this study is to determine the role of the receptor activator of nuclear factor-κB ligand (RANKL) in P. gingivalis infection-associated periodontal bone resorption. Inbred female Rowett rats were infected orally on four consecutive days (days 0 to 3) with 1 × 10(9) P. gingivalis bacteria (strain ATCC 33277). Separate groups of rats also received an injection of anti-RANKL antibody, osteoprotegerin fusion protein (OPG-Fc), or a control fusion protein (L6-Fc) into gingival papillae in addition to P. gingivalis infection. Robust serum IgG and salivary IgA antibody (P < 0.01) and T cell proliferation (P < 0.05) responses to P. gingivalis were detected at day 7 and peaked at day 28 in P. gingivalis-infected rats. Both the concentration of soluble RANKL (sRANKL) in rat gingival tissues (P < 0.01) and periodontal bone resorption (P < 0.05) were significantly elevated at day 28 in the P. gingivalis-infected group compared to levels in the uninfected group. Correspondingly, RANKL-expressing T and B cells in rat gingival tissues were significantly increased at day 28 in the P. gingivalis-infected group compared to the levels in the uninfected group (P < 0.01). Injection of anti-RANKL antibody (P < 0.05) or OPG-Fc (P < 0.01), but not L6-Fc, into rat gingival papillae after P. gingivalis infection resulted in significantly reduced periodontal bone resorption. This study suggests that P. gingivalis infection-associated periodontal bone resorption is RANKL dependent and is accompanied by increased local infiltration of RANKL-expressing T and B cells.
authors: Department of Immunology and Infectious Diseases, The Forsyth Institute, Cambridge, Massachusetts, USA. xhan@forsyth.org
authors: Xiaozhe
authors: X
authors: Han
authors: Xiaoping
authors: X
authors: Lin
authors: Xiaoqian
authors: X
authors: Yu
authors: Jiang
authors: J
authors: Lin
authors: Toshihisa
authors: T
authors: Kawai
authors: Karen B
authors: KB
authors: LaRosa
authors: Martin A
authors: MA
authors: Taubman
mesh_terms: D016301:Alveolar Bone Loss / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D000818:Animals; D016866:Bacteroidaceae Infections / Q000150:complications* / Q000276:immunology / Q000378:metabolism; D001862:Bone Resorption / Q000382:microbiology; D049109:Cell Proliferation; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005881:Gingiva / Q000378:metabolism; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008214:Lymphocytes / Q000502:physiology; D008439:Maxillary Diseases / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D010010:Osteoclasts / Q000502:physiology; D016966:Porphyromonas gingivalis; D053245:RANK Ligand / Q000378:metabolism*; D051381:Rats
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D053245:RANK Ligand