Yamaguchi M, Ukai T, Kaneko T, Yoshinaga M, Yokoyama M, Ozaki Y, Hara Y
Department of Periodontology, Unit of Translational Medicine, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
J Periodontal Res. 2008 Oct;43(5):549-55. doi: 10.1111/j.1600-0765.2008.01083.x. Epub 2008 Jul 4.
T cells and their cytokines are believed to be key factors in periodontal disease and bone resorption. We previously showed that T cells transferred to nude mice were related to inflammatory bone resorption in vivo. However, it has not been clarified whether T cells can induce bone resorption in the absence of B cells. In this study, we therefore investigated the ability of T cells to induce bone resorption without B cells, using both T cell- and B cell-deficient mice with severe combined immune deficiency (SCID).
Escherichia coli lipopolysaccharide (LPS) was injected into the gingivae of SCID mice reconstituted by T cells (SCID + T mice). Wild-type C.B-17 mice and SCID mice were used as control animals. Alveolar bone resorption and production of cytokines in the gingivae were then compared histopathologically and immunohistologically.
The degree of bone resorption in SCID + T mice was significantly greater than that in SCID mice but less than that in wild-type mice. The same tendency was found for expression of receptor activator of nuclear factor kappaB ligand. The number of interferon-gamma-positive cells in SCID + T mice was the highest of the three groups. In contrast, interleukin-4-positive cells were detected in wild-type mice but not in SCID + T and SCID mice.
The results suggest that T cells are able to promote LPS-induced bone resorption in the absence of B cells. The expressions of cytokines in the presence of B cells are quite different.
T细胞及其细胞因子被认为是牙周病和骨吸收的关键因素。我们之前发现，转移至裸鼠体内的T细胞与体内炎性骨吸收有关。然而，在缺乏B细胞的情况下T细胞是否能够诱导骨吸收尚未明确。因此，在本研究中，我们使用重度联合免疫缺陷（SCID）的T细胞和B细胞缺陷小鼠，研究了T细胞在无B细胞情况下诱导骨吸收的能力。
将大肠杆菌脂多糖（LPS）注射到由T细胞重建的SCID小鼠（SCID + T小鼠）的牙龈中。野生型C.B-17小鼠和SCID小鼠用作对照动物。然后通过组织病理学和免疫组织化学比较牙槽骨吸收情况以及牙龈中细胞因子的产生。
SCID + T小鼠的骨吸收程度显著高于SCID小鼠，但低于野生型小鼠。核因子κB受体活化因子配体的表达也呈现相同趋势。SCID + T小鼠中γ干扰素阳性细胞的数量在三组中是最高的。相比之下，在野生型小鼠中检测到白细胞介素-4阳性细胞，而在SCID + T小鼠和SCID小鼠中未检测到。
结果表明，在没有B细胞的情况下，T细胞能够促进LPS诱导的骨吸收。在有B细胞存在时细胞因子的表达有很大差异。
