Expression of receptor activator of nuclear factor-kappaB ligand by B cells in response to oral bacteria.
Expression of receptor activator of nuclear factor-kappaB ligand by B cells in response to oral bacteria.
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DOI：
10.1111/j.1399-302x.2008.00494.x
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发表时间：
2009-06
影响因子：
--
通讯作者：
Taubman MA
中科院分区：
文献类型：
--
作者：
Han X;Lin X;Seliger AR;Eastcott J;Kawai T;Taubman MA
我们研究了放线菌伴生菌免疫反应的早期和晚期B淋巴细胞核因子受体激活剂κB配体(RANKL)的表达。逆转录-聚合酶链式反应(RT-α)检测早期(1d)和晚期(10d)大鼠脾细胞中参与早期(1d)和晚期(10d)反应的信使RNA转录产物(肿瘤坏死因子α、Toll样受体4和9、白介素4和10以及RANKL)的表达。用流式细胞仪检测免疫细胞(T、B细胞、自然杀伤细胞和巨噬细胞)在培养的大鼠脾细胞中的分布及B细胞中RANKL的表达。通过与RAW 264.7细胞共培养，然后进行抗酒石酸酸性磷酸酶(TRAP)活性测定，评估B细胞诱导破骨细胞分化的能力。在伴放线放线菌存在下，培养细胞中IL-4和IL-10的表达水平直到培养3d才发生变化，并在7d后达到高峰。培养10d后，伴生放线菌可显著提高B细胞和T细胞的百分率、RANKL信使RNA转录本的百分率和表达RANKL的免疫球蛋白G阳性细胞百分率。从伴生放线菌免疫的动物中分离出的细胞中，这些增加比从未免疫的动物中分离出来的细胞要大得多。RAW 264.7细胞与伴生放线菌免疫动物的B细胞共培养时，TRAP活性显著增加。在培养中加入人骨保护素-Fc可显著减少这种增加。这项研究表明，B淋巴细胞通过上调RANKL的表达参与伴生放线菌的免疫反应，可能有助于牙周病的骨吸收。
We investigated receptor activator of nuclear factor-κB 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. Expression of messenger RNA transcripts (tumor necrosis factor-α, 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. 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. 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.