大鼠内毒素脂多糖刺激性牙髓炎中免疫反应细胞的动态变化

Time-sequenced alteration of immunocompetent cells in rat pulpitis induced by lipopolysaccharide

目的 研究牙髓在内毒素脂多糖刺激过程中的防御反应机制。方法 通过已建立的大鼠内毒素脂 多糖刺激性牙髓炎模型,利用3种单克隆抗体(ED1、ED2、OX6)和免疫组化手段,观察内毒素脂多糖感染性牙髓中 巨噬细胞、Ia抗原表达细胞的动态变化。结果 牙髓中组织细胞(ED2+细胞)在早期感受内毒素脂多糖(LPS)入 侵的同时,与Ia抗原表达细胞(OX6+细胞)和来自于血中的巨噬细胞一起参与了抵抗外来抗原刺激的防御反应。 Ia抗原表达细胞在LPS刺激后3d增加至最多,以后逐渐下降。以来源于血中的巨噬细胞为主的ED1+细胞,在整 个炎症过程中均可见大量浸润,细胞体积由小变大,形态由纺锤形,树枝状等变成圆形或椭圆形。结论 内毒素脂 多糖入侵牙髓后,牙髓中的组织细胞动员Ia抗原表达细胞和巨噬细胞,开展以非特异性免疫为基础的抗原特异性 免疫反应。

Objective To study the defensive response mechanism of pulp against the invasion of anaerobic bacteria endotoxins. Methods An experimental animal model of lipopolysaccharide-induced pulpitis was utilized to observe the time-sequenced alteration of macrophages and Ia antigen-expressing cells by means of three monoclonal antibodies (ED1, ED2, OX6) and immunohistochemical staining. Results Together with Ia antigen-expressing cells (OX6 + cells) and blood-originated macrophages, the tissue cells in pulp (ED2 + cells) took part in the defensive responses against the irritation of exogenous antigens when stimulated by lipopolysaccharide at early stage. The number of Ia antigen-expression cells reached maximum on the third day after LPS stimulation and decreased thereafter. Massive infiltration of the ED1 + cells, mainly blood-originated macrophages, was found. Changes of size and shape of these cells was also observed. Conclusion Antigen-specific immune response, based on non-specific immune reaction, was developed by pulpal tissue after the invasion of bacterial endotoxin. The involving cells consist of Ia antigen-expressing cells and macrophages.