多黏菌素B拮抗脂多糖的生物活性。

Polymyxin B antagonizing biological activity of lipopolysaccharide.

作者信息

Guo Yi-bin, Chen Li-ping, Cao Hong-wei, Wang Ning, Zheng Jiang, Xiao Guang-xia

机构信息

Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.

出版信息

Chin J Traumatol. 2007 Jun;10(3):180-3.

PMID:17535644

Abstract

OBJECTIVE

To investigate the mechanism of polymyxin B (PMB) antagonizing the biological activity of lipopolysaccharide (LPS).

METHODS

The affinity of PMB for LPS and lipid A was assayed by biosensor, and the neutralization of PMB for LPS (2 ng/ml) was detected by kinetic turbidimetric limulus test. The releases of TNF-alpha and IL-6 in murine peritoneal macrophages a (PMphi) after exposure to LPS (100 ng/ml) were detected, and the expression levels of TLR4, TNF-alpha and IL-6 mRNA in PMphi induced by LPS (100 ng/ml) were measured by RT-PCR.

RESULTS

PMB had high-affinity to LPS and lipid A with dissociation equilibrium constants of 18.9 nmol/L and 11.1 nmol/L, respectively, and neutralized LPS in a dose-dependent manner. Furthermore, PMB could markedly inhibit the expressions of TLR4, TNF-alpha and IL-6 mRNA and the release of cycokines in LPS-stimulated murine peritoneal macrophages.

CONCLUSIONS

PMB neutralizes LPS and inhibites the expression and release of cycokines in macrophages, in which the affinity of PMB for lipid A plays an important role.

摘要

目的

研究多黏菌素B（PMB）拮抗脂多糖（LPS）生物学活性的机制。

方法

采用生物传感器检测PMB与LPS及脂质A的亲和力，用动态比浊法鲎试剂检测法检测PMB对LPS（2 ng/ml）的中和作用。检测LPS（100 ng/ml）刺激后小鼠腹腔巨噬细胞中肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的释放情况，并用逆转录-聚合酶链反应（RT-PCR）检测LPS（100 ng/ml）诱导的小鼠腹腔巨噬细胞中Toll样受体4（TLR4）、TNF-α和IL-6 mRNA的表达水平。