Matsuno R, Aramaki Y, Arima H, Adachi Y, Ohno N, Yadomae T, Tsuchiya S
School of Pharmacy, Tokyo University of Pharmacy and Life Science, Japan.
Biochem Biophys Res Commun. 1998 Mar 6;244(1):115-9. doi: 10.1006/bbrc.1998.8231.
The contribution of the complement receptor type 3 (CR3) to nitric oxide (NO) production from macrophages stimulated by LPS was investigated. When thioglycollate-elicited mouse peritoneal macrophages were stimulated with a high dose of LPS (10 micrograms/ml) in both the presence and absence of fetal calf serum, a source of LPS binding protein (LBP) necessary for the binding of LPS to CD14, NO production was observed. These findings suggest that CD14-dependent and CD14-independent signaling pathways for NO production are present in macrophages. Because binding and phagocytosis of bacteria by macrophages through the CR3 has been previously reported, we investigated whether the CR3 acts in CD14-independent signaling pathway for NO production. By flow cytometric analysis, the binding of FITC-labeled anti-CR3 monoclonal antibody (anti-CR3 mAb) to macrophages was inhibited by LPS. Anti-CR3 mAb induced iNOS protein and produced NO in a dose dependent manner. Further, NO production induced by anti-CR3 mAb was also inhibited by zymocel, beta-glucan with a high affinity to CR3. These results suggest that the CR3 molecule acts in a CD14-independent signaling pathway, and contributes to NO production by macrophages stimulated with high doses of LPS.
研究了补体3型受体（CR3）对脂多糖（LPS）刺激的巨噬细胞产生一氧化氮（NO）的作用。当用高剂量LPS（10微克/毫升）刺激经巯基乙酸盐诱导的小鼠腹腔巨噬细胞时，无论有无胎牛血清（LPS与CD14结合所需的LPS结合蛋白（LBP）的来源），均观察到NO的产生。这些发现表明巨噬细胞中存在依赖CD14和不依赖CD14的NO产生信号通路。由于先前已报道巨噬细胞通过CR3对细菌的结合和吞噬作用，我们研究了CR3是否在不依赖CD14的NO产生信号通路中起作用。通过流式细胞术分析，LPS可抑制异硫氰酸荧光素标记的抗CR3单克隆抗体（抗CR3 mAb）与巨噬细胞的结合。抗CR3 mAb以剂量依赖的方式诱导诱导型一氧化氮合酶（iNOS）蛋白并产生NO。此外，抗CR3 mAb诱导的NO产生也被zymocel（与CR3具有高亲和力的β-葡聚糖）抑制。这些结果表明，CR3分子在不依赖CD14的信号通路中起作用，并有助于高剂量LPS刺激的巨噬细胞产生NO。
