INTERACTION OF LACTOFERRIN AND LIPOPOLYSACCHARIDE (LPS) - EFFECTS ON THE ANTIOXIDANT PROPERTY OF LACTOFERRIN AND THE ABILITY OF LPS TO PRIME HUMAN NEUTROPHILS FOR ENHANCED SUPEROXIDE FORMATION
INTERACTION OF LACTOFERRIN AND LIPOPOLYSACCHARIDE (LPS) - EFFECTS ON THE ANTIOXIDANT PROPERTY OF LACTOFERRIN AND THE ABILITY OF LPS TO PRIME HUMAN NEUTROPHILS FOR ENHANCED SUPEROXIDE FORMATION
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DOI：
10.1093/infdis/166.6.1375
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发表时间：
1992-12-01
影响因子：
6.4
通讯作者：
BRITIGAN, BE
中科院分区：
文献类型：
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作者：
COHEN, MS;MAO, JH;BRITIGAN, BE
乳铁蛋白是一种77 kDa的铁结合蛋白，具有多种不同的生物学功能。最近有报道乳铁蛋白与细菌脂多糖(LPS)相互作用，从而影响乳铁蛋白与髓系细胞的结合。我们还探讨了脂多糖和乳铁蛋白的另外两种潜在的相互作用。乳铁蛋白通过结合铁来防止羟基自由基的形成，即使在低pH值下也是如此。在pH为7.4和4.5的脂多糖存在下，乳铁蛋白可抑制铁催化的羟基自由基的形成。低浓度的内毒素可以用来“启动”中性粒细胞以增强其功能，例如形成受刺激的超氧阴离子。如果乳铁蛋白(由商业供应商提供)的脂多糖污染首先被减少，那么乳铁蛋白就会抑制中性粒细胞的脂多糖启动。无论使用载脂乳铁蛋白还是铁饱和乳铁蛋白，均可观察到对脂多糖启动的抑制作用。当中性粒细胞与其他血清蛋白(如白蛋白、载脂蛋白或铁饱和转铁蛋白)孵育时，也观察到类似的内毒素启动抑制。这些结果表明，不应期望内毒素影响乳铁蛋白的自由基生物学，乳铁蛋白是乳铁蛋白的重要生理功能。然而，乳铁蛋白抑制了内毒素的启动，这种作用需要在炎症实验模型中加以考虑。
Lactoferrin is a 77-kDa iron-binding protein to which a wide variety of divergent biologic functions have been ascribed. It has recently been reported that lactoferrin interacts with bacterial lipopolysaccharide (LPS) in such a fashion as to affect the binding of lactoferrin to myeloid cells. Two other potential interactions of LPS and lactoferrin were explored. Lactoferrin prevents hydroxyl radical formation by binding iron, even at low pH. Lactoferrin inhibited iron-catalyzed formation of hydroxyl radical in the presence of LPS at pH 7.4 and 4.5. Low concentrations of LPS can be used to "prime" neutrophils toward enhanced function, such as formation of stimulated superoxide anion. Lactoferrin inhibited LPS priming of neutrophils if LPS contamination of the protein (provided by commercial suppliers) was first reduced. Inhibition of LPS priming was observed whether apolactoferrin or iron-saturated lactoferrin was used. Similar inhibition of LPS priming was observed when neutrophils were incubated with other serum proteins (e.g., albumin, apotransferrin, or iron-saturated transferrin). These results show that LPS should not be expected to affect the free radical biology of lactoferrin, which is a crucial physiologic function of this protein. However, lactoferrin inhibits LPS priming, and this effect requires consideration in experimental models of inflammation.