Kaneko T, Okiji T, Kaneko R, Nör J E, Suda H
Pulp Biology and Endodontics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Dent Res. 2008 Jun;87(6):553-7. doi: 10.1177/154405910808700617.
Substantial numbers of dendritic cells have been detected in radicular granulomas. To test the hypothesis that local antigen presentation from dendritic cells to T-cells is involved critically in immunological responses within radicular granulomas, we compared characteristics of dendritic cells and macrophages by morphological and biological analyses. Under light microscopy, HLA-DR+ and CD68+ cells showed diverse profiles, including dendritic-shaped cells. Transmission electron microscopy revealed that HLA-DR+ dendritic cells, with long cytoplasmic processes and lacking distinct phagosomes, were concentrated in the lymphocyte-rich area. HLA-DR alpha-chain, CD83, and CD86 mRNAs from HLA-DR+ dendritic cells, and CD28 mRNA from CD28+ T-cells were up-regulated in lymphocyte-rich area. Scanning electron microscopy demonstrated that the density of gold particles on dendritic cells was higher than that on HLA-DR+ macrophages. These results suggest that dendritic cells in radicular granulomas are associated with local defense reactions as stronger antigen-presenting cells, as compared with macrophages.
在牙根肉芽肿中已检测到大量树突状细胞。为了验证树突状细胞向T细胞的局部抗原呈递在牙根肉芽肿内的免疫反应中起关键作用这一假说，我们通过形态学和生物学分析比较了树突状细胞和巨噬细胞的特征。在光学显微镜下，HLA-DR+和CD68+细胞呈现出多种形态，包括树突状细胞。透射电子显微镜显示，具有长细胞质突起且缺乏明显吞噬体的HLA-DR+树突状细胞集中在富含淋巴细胞的区域。来自HLA-DR+树突状细胞的HLA-DRα链、CD83和CD86 mRNA，以及来自CD28+ T细胞的CD28 mRNA在富含淋巴细胞的区域上调。扫描电子显微镜表明，树突状细胞上金颗粒的密度高于HLA-DR+巨噬细胞。这些结果表明，与巨噬细胞相比，牙根肉芽肿中的树突状细胞作为更强的抗原呈递细胞与局部防御反应相关。
