内毒素血症时小鼠肺泡巨噬细胞CD14和清道夫受体的表达

目的 探讨内毒素肺损伤时，肺泡巨噬细胞逐步由免疫防御型转变为效应型的分子机制。方法 建立内毒素肺损伤动物模型，免疫组化法观察肺泡巨噬细胞ＣＤ１４及清道夫受体（ＳＲ）表达的变化，并辅以计算机图像分析；同时检测肺体指数，肺组织的病理变化及动物存活率。结果 内毒素对ＣＤ１４的表达呈时间依赖性升高，但加大剂量并未使其进一步增加；ＳＲ呈时间及剂量依赖性降低。肺泡巨噬细胞ＳＲ、ＣＤ１４的表达变化与小鼠肺损伤程

Expression of CD14 and scavenger receptor in alveolar macrophages of mice with endotoxin-induced lung injury

Objective To study the molecular mechanism of the conversion of alveolar macrophages (AMs) from immune defensive cells to effective cells in mice with endotoxin induced lung injury. Methods The mouse model of endotoxemia was established with intravenous injection of lipopolysaccharide (LPS) of three different dosages. Expression of scavenger receptor (SR) and CD14 in AMs was observed with immunohistochemistry and analyzed with computer image system. Lung body index, pathological changes of lung tissues and the survival rate of the mice were studied. Results Expression of CD14 was increased while that of SR was decreased on the surface of AMs in a time dependent manner, but the former was not further increased with the increase of LPS dosage. Changes of SR and CD14 expression on AMs were paralleled with the severity of lung damages and the survival rate of the mice. Conclusion The down regulation of SR expression and up regulation of CD14 expression on surface of AMs might be one of important mechanisms of the conversion of AMs from immune defensive cells to effective cells in acute lung injury.