Distribution and kinetics of lipoprotein-bound lipoteichoic acid
Distribution and kinetics of lipoprotein-bound lipoteichoic acid
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DOI：
10.1128/iai.71.6.3280-3284.2003
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发表时间：
2003-06-01
影响因子：
3.1
通讯作者：
van Deventer, SJH
中科院分区：
文献类型：
--
作者：
Levels, JHM;Abraham, PR;van Deventer, SJH
脂磷壁酸（LTA）是革兰氏阳性菌细胞壁的主要成分，是一种两亲性阴离子糖脂，其结构与革兰氏阴性菌的脂多糖（LPS）相似。LTA被认为是可能引发全身炎症反应综合征的主要免疫刺激成分之一。血浆脂蛋白已被证明可结合LPS，从而减轻宿主对感染的反应，但对于血浆脂质颗粒结合LTA的特性知之甚少。在本研究中，我们利用具有生物活性的荧光标记LTA和高效凝胶渗透色谱法，在模拟人体全血（离体）生理条件下检测了主要脂蛋白类别结合LTA的能力和结合动力学。来自10名人类志愿者全血中金黄色葡萄球菌LTA制剂的平均分布显示，>95%的LTA与总血浆脂蛋白按以下比例结合：高密度脂蛋白（HDL），68%±10%；低密度脂蛋白（LDL），28%±8%；极低密度脂蛋白（VLDL），4%±5%。脂蛋白对LTA的饱和容量超过150μg/ml。LTA的分布具有温度依赖性，在22 - 37°C之间结合最佳。脂蛋白结合LTA在10分钟内基本完成，随后LTA从HDL和VLDL重新分布到LDL。我们得出结论，HDL对LTA具有最高的结合能力，并提出LTA在血浆脂蛋白之间的负载和重新分布是一个特定的过程，与先前描述的LPS的过程非常相似。
Lipoteichoic acid (LTA), a major cell wall component of gram-positive bacteria, is an amphipathic anionic glycolipid with structural similarities to lipopolysaccharide (LPS) from gram-negative bacteria. LTA has been implicated as one of the primary immunostimulatory components that may trigger the systemic inflammatory response syndrome. Plasma lipoproteins have been shown to sequester LPS, which results in attenuation of the host response to infection, but little is known about the LTA binding characteristics of plasma lipid particles. In this study, we have examined the LTA binding capacities and association kinetics of the major lipoprotein classes under simulated physiological conditions in human whole blood (ex vivo) by using biologically active, fluorescently labeled LTA and high-performance gel permeation chromatography. The average distribution of an LTA preparation from Staphylococcus aureus in whole blood from 10 human volunteers revealed that >95% of the LTA was associated with total plasma lipoproteins in the following proportions: high-density lipoprotein (HDL), 68% +/- 10%; low-density lipoprotein (LDL), 28% +/- 8%; and very low density lipoprotein (VLDL), 4% +/- 5%. The saturation capacity of lipoproteins for LTA was in excess of 150 mug/ml. The LTA distribution was temperature dependent, with an optimal binding between 22 and 37degreesC. The binding of LTA by lipoproteins was essentially complete within 10 min and was followed by a subsequent redistribution from HDL and VLDL to LDL. We conclude that HDL has the highest binding capacity for LTA and propose that the loading and redistribution of LTA among plasma lipoproteins is a specific process that closely resembles that previously described for LPS.