INTRODUCTION: We investigated receptor activator of nuclear factor-kappaB ligand (RANKL) expression by B lymphocytes during early and late aspects of the immune response to Aggregatibacter actinomycetemcomitans, a gram-negative, anaerobic bacterium associated with aggressive periodontal disease. METHODS: Expression of messenger RNA transcripts (tumor necrosis factor-alpha, Toll-like receptors 4 and 9, interleukins 4 and 10, and RANKL) involved in early (1-day) and late (10-day) responses in cultured rat splenocytes was examined by reverse transcription-polymerase chain reaction (RT-PCR). The immune cell distribution (T, B, and natural killer cells and macrophages) in cultured rat splenocytes and RANKL expression in B cells were determined by flow cytometric analyses. B-cell capacity for induction of osteoclast differentiation was evaluated by coculture with RAW 264.7 cells followed by a tartrate-resistant acid phosphatase (TRAP) activity assay. RESULTS: The expression levels of interleukins 4 and 10 in cultured cells were not changed in the presence of A. actinomycetemcomitans until cultured for 3 days, and peaked after 7 days. After culture for 10 days, the percentages of B and T cells, the overall RANKL messenger RNA transcripts, and the percentage of RANKL-expressing immunoglobulin G-positive cells were significantly increased in the presence of A. actinomycetemcomitans. These increases were considerably greater in cells isolated from A. actinomycetemcomitans-immunized animals than from non-immunized animals. RAW 264.7 cells demonstrated significantly increased TRAP activity when cocultured with B cells from A. actinomycetemcomitans-immunized animals. The addition of human osteoprotegerin-Fc to the culture significantly diminished such increases. CONCLUSION: This study suggests that B-lymphocyte involvement in the immune response to A. actinomycetemcomitans through upregulation of RANKL expression potentially contribute to bone resorption in periodontal disease.
INTRODUCTION: We investigated receptor activator of nuclear factor-kappaB ligand (RANKL) expression by B lymphocytes during early and late aspects of the immune response to Aggregatibacter actinomycetemcomitans, a gram-negative, anaerobic bacterium associated with aggressive periodontal disease. METHODS: Expression of messenger RNA transcripts (tumor necrosis factor-alpha, Toll-like receptors 4 and 9, interleukins 4 and 10, and RANKL) involved in early (1-day) and late (10-day) responses in cultured rat splenocytes was examined by reverse transcription-polymerase chain reaction (RT-PCR). The immune cell distribution (T, B, and natural killer cells and macrophages) in cultured rat splenocytes and RANKL expression in B cells were determined by flow cytometric analyses. B-cell capacity for induction of osteoclast differentiation was evaluated by coculture with RAW 264.7 cells followed by a tartrate-resistant acid phosphatase (TRAP) activity assay. RESULTS: The expression levels of interleukins 4 and 10 in cultured cells were not changed in the presence of A. actinomycetemcomitans until cultured for 3 days, and peaked after 7 days. After culture for 10 days, the percentages of B and T cells, the overall RANKL messenger RNA transcripts, and the percentage of RANKL-expressing immunoglobulin G-positive cells were significantly increased in the presence of A. actinomycetemcomitans. These increases were considerably greater in cells isolated from A. actinomycetemcomitans-immunized animals than from non-immunized animals. RAW 264.7 cells demonstrated significantly increased TRAP activity when cocultured with B cells from A. actinomycetemcomitans-immunized animals. The addition of humanosteoprotegerin-Fc to the culture significantly diminished such increases. CONCLUSION: This study suggests that B-lymphocyte involvement in the immune response to A. actinomycetemcomitans through upregulation of RANKL expression potentially contribute to bone resorption in periodontal disease.
Authors: N Udagawa; N Takahashi; E Jimi; K Matsuzaki; T Tsurukai; K Itoh; N Nakagawa; H Yasuda; M Goto; E Tsuda; K Higashio; M T Gillespie; T J Martin; T Suda Journal: Bone Date: 1999-11 Impact factor: 4.398
Authors: G J Seymour; R N Powell; K L Cole; J F Aitken; D Brooks; I Beckman; H Zola; J Bradley; G F Burns Journal: J Periodontal Res Date: 1983-07 Impact factor: 4.419
Authors: Srinivas R Myneni; Rajendra P Settem; Terry D Connell; Achsah D Keegan; Sarah L Gaffen; Ashu Sharma Journal: J Immunol Date: 2011-06-01 Impact factor: 5.422
Authors: Luciana S Branco-de-Almeida; Mikihito Kajiya; Cristina R Cardoso; Marcelo J B Silva; Kouji Ohta; Pedro L Rosalen; Gilson C N Franco; Xiaozhe Han; Martin A Taubman; Toshihisa Kawai Journal: FEMS Immunol Med Microbiol Date: 2011-06-16
Authors: Nadia Lo Iacono; Alessandra Pangrazio; Mario Abinun; Robbert Bredius; Marco Zecca; Harry C Blair; Paolo Vezzoni; Anna Villa; Cristina Sobacchi Journal: Clin Dev Immunol Date: 2013-05-15