Singh N, Birdi T J, Antia N H
Foundation for Medical Research, Worli, Bombay, India.
Neuropathol Appl Neurobiol. 1997 Feb;23(1):59-67.
This study describes the changes occurring in vitro in nerve growth factor (NGF) production and expression of p75 by murine Schwann cells and neurofibroblasts, following infection with Mycobacterium leprae and in the presence of macrophage secretory products, using a semiquantitative ELISA. These parameters are compared in two strains of mice, Swiss White (SW) and C57B1/6, as they differ in their response to M. leprae infection; C57B1/6 is the 'resistant' strain. On infection, NGF levels remained unaltered in Schwann cells from both strains, while fibroblasts from C57B1/6 strain showed an increase in NGF production. Expression of p75 by Schwann cells was decreased on infection in both strains of mice. In vivo, this opposing effect of infection on NGF production and p75 expression by Schwann cells and neurofibroblasts may result in suboptimal amounts of NGF reaching neurons of the affected leprous nerves. Macrophage secretory products suppressed the production of NGF by infected neurofibroblasts from SW strain mice and the expression of p75 in Schwann cells from both strains. These results indicate that macrophages do not assist in nerve repair in leprosy and the differences in response to macrophage secretory products in the two strains suggests that different mechanisms of nerve repair operate in SW and C57B1/6 mice and presumably in lepromatous and tuberculoid patients.
本研究利用半定量酶联免疫吸附测定法（ELISA），描述了在感染麻风分枝杆菌以及存在巨噬细胞分泌产物的情况下，小鼠雪旺氏细胞和成纤维细胞体外产生神经生长因子（NGF）及p75表达的变化。在两种小鼠品系瑞士白化小鼠（SW）和C57B1/6中对这些参数进行了比较，因为它们对麻风分枝杆菌感染的反应不同；C57B1/6是“抗性”品系。感染后，两种品系雪旺氏细胞中的NGF水平均未改变，而C57B1/6品系的成纤维细胞显示NGF产生增加。两种品系小鼠感染后，雪旺氏细胞中p75的表达均降低。在体内，感染对雪旺氏细胞和成纤维细胞产生NGF及p75表达的这种相反作用，可能导致到达受影响麻风神经神经元的NGF量未达最佳水平。巨噬细胞分泌产物抑制了SW品系小鼠受感染成纤维细胞产生NGF以及两种品系雪旺氏细胞中p75的表达。这些结果表明，巨噬细胞无助于麻风病中的神经修复，两种品系对巨噬细胞分泌产物反应的差异表明，SW和C57B1/6小鼠以及大概瘤型和结核型患者存在不同的神经修复机制。
