摘要
目的:研究脂多糖结合蛋白(LBP)抑制肽对脂多糖(LPS)与人单核巨噬细胞株U937细胞结合的抑制作用,从而探讨LBP抑制肽阻断内毒素信号转导通路的机制。方法:夹心ELISA检测LBP抑制肽与LPS的相对亲和力;流式细胞检测分析(FACS)异硫氰酸荧光素标记的LPS(FITC-LPS)与U937细胞的结合;ELISA检测U937细胞培养上清液中肿瘤坏死因子α(TNF-α)的含量。结果:在相同的浓度下,LBP抑制肽与LPS的亲合力比LBP高,约为LBP的1.15倍。LPS组平均荧光强度(MFI)明显高于对照组,LBP显著增强了LPS与U937细胞的结合,促进了LPS的内在化;LBP抑制肽组MFI显著低于LBP组(P<0.01),即P12减弱了FITC-LPS与U937细胞的结合。而且P12抑制了LPS诱导的U937细胞TNF-α的生成。结论:LBP抑制肽与LPS有一定的亲和力,LBP抑制肽与LBP的致炎位点竞争结合FITC-LPS,从而抑制LPS与单核巨噬细胞的结合,阻止了LPS的内在化,并显著降低了LPS诱导的TNF-α释放。
AIM： To investigate the inhibitory effect of P12, a kind of lipopolysaccharide （LPS） - binding protein （LBP） inhibitory peptide, on the binding of LPS to macrophage in vitro. METHODS： Human monocyte - like cell line （U937 cells） was grown in RPMI - 1640 and stimulated with PMA in order to induce their differentiation to macrophage stage. The relative affinity of P12 to LPS was determined by enzymelinked immunosorbent assay （ELISA）. The effects of P12 on the binding of LPS to U937 cells were determined by flow cytometry analysis. The production of tumor necrosis factor - alpha （ TNF - α） was measured by ELISA. RESULTS ： The relative binding activity of P12 to LPS was higher than that of LBP in the same mass concentration. P12 inhibited the binding of FITC -conjugated LPS （FITC- LPS） to U937 cells. The productions of TNF - αwas also significantly suppressed by P12. CONCLUSION： The results suggest that blockage of LBP at the inflammatory sites might attenuate LPS -induced circulatory shock.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2007年第7期1392-1395,共4页
Chinese Journal of Pathophysiology
基金
国家自然科学基金资助项目(No30170366)
关键词
U937细胞
脂多糖结合蛋白抑制肽
脂多糖类
U937 cells
Lipopolysaccharide- binding protein inhibitory peptide
Lipopolysaccharides
