Effects of parasites on the gene expression of nitric oxide synthase and cytokine in macrophages

寄生虫对巨噬细胞一氧化氮合酶和细胞因子基因表达的影响

基本信息

批准号：
09670259
负责人：
FUKUMOTO Soji
金额：
$ 1.98万
依托单位：
TOTTORI University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Nitric oxide (NO) is important in the ability of mouse macrophages to kill infectious organisms including parasites. An inducible form of NO synthase (iNOS) is responsible for high output generation of NO by macrophages after stimulation with cytokines and/or LPS.Chemoattactant peptides termed chemokine are important components of the inflammatory response. Alive plerocercoids of Spirometra erinaceieuropaei suppressed the mRNA expression of iNOS and JE, murine homologue of monocyte chemotactic protein-1, and nitrite production of macrophages stimulated with IFN-gamma and LPS in vitro. Excretory/secretory (ES) products from plerocercoids also suppressed the induced iNOS and JE mRNA and reduce nitrite production in a dose dependent manner.Then we examined that the effects of preculture with plerocercoids on iNOS, chemokines (IP-l0, JE, KC) and TNF-alpha gene expression in peritoneal macrophages. The expression of mRNA was detected by northern hybridization and autoradiography, and mRNA expression levels were read by molecular image analyser using a phosphorescence screen. The gene expression of IP-l0 and JE in macrophages stimulated with LPS for 3 h was apparently suppressed by 5 plerocercoids in a preincubation-time dependent manner. TNF-alpha mRNA expression was also suppressed by preincubation with 5 plerocercoids. The suuprressive effect of iNOS gene expression in macrophages stimulated with IFN-gamma and LPS for 24 h was also observed by preincubation of ES products in a preincubation-time dependent manner. This inhibitory effects of ES products continued until 72 h after removal of ES products. Judging from these results, we suppose that ES products from plerocercoids might suppress the iNOS and chemokine gene expression of macrophages in vivo, and suppress the host defense mechanism.

一氧化氮（NO）在小鼠巨噬细胞杀死包括寄生虫在内的传染性生物的能力中很重要。 NO合酶（INOS）的一种可诱导形式是用细胞因子和/或LPS刺激后，巨噬细胞的高输出生成NO的高输出生成。EmoAttactactant肽肽称为趋化因子是炎症反应的重要组成部分。螺旋体的生命螺旋体抑制了iNOS和JE的mRNA表达，单核细胞趋化蛋白-1的鼠同源物以及亚硝酸盐在体外用IFN-GAMMA和LPS刺激的巨噬细胞产生的巨噬细胞产生。来自Plerocerocoid的排泄/分泌物（ES）产品也抑制了诱导的iNOS和JE mRNA，并以剂量依赖性的方式降低亚硝酸盐的产生。通过北部杂交和放射自显影检测到mRNA的表达，并使用磷光筛选通过分子图像分析仪读取mRNA表达水平。在用LPS刺激的巨噬细胞中，IP-L0和JE的基因表达显然被5个pleroceroids以预孵育的依赖性方式抑制。通过与5个plerocercoid预孵育，TNF-Alpha mRNA表达也被抑制。还通过以预育时间依赖性方式预孵育ES产物，观察到了用IFN-GAMMA和LPS刺激的巨噬细胞中INOS基因表达的辅助作用。 ES产物的这种抑制作用一直持续到去除ES产物后的72小时。从这些结果来看，我们认为来自Pleroceroids的ES产物可能会抑制体内巨噬细胞的iNOS和趋化因子基因表达，并抑制宿主防御机制。