Killing of Actinobacillus actinomycetemcomitans by human lactoferrin.
Killing of Actinobacillus actinomycetemcomitans by human lactoferrin.
复制标题
人乳铁蛋白杀死伴放线放线杆菌。
DOI：
10.1128/iai.56.10.2552-2557.1988
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发表时间：
1988
影响因子：
3.1
通讯作者：
Arnold,RR
中科院分区：
文献类型：
--
作者：
Kalmar,JR;Arnold,RR
伴生放线杆菌是一种挑剔的、兼性的革兰氏阴性杆菌，与心内膜炎、某些形式的牙周病和其他局灶性感染有关。人类中性粒细胞对伴生放线菌表现出杀菌活性，大部分氧依赖的杀菌作用归因于髓过氧化物酶-H_2O_2-卤化物系统。然而，其他中性粒细胞成分对杀伤活性的贡献尚不清楚。乳铁蛋白是一种铁结合糖蛋白，是中性粒细胞特异性颗粒的主要成分，也存在于粘膜分泌物中。在这份报告中，我们证明了人乳铁蛋白对伴生放线菌具有杀菌作用。杀灭活性需要一个不饱和的(无铁和阴离子)分子，在37摄氏度，浓度为1.9微米的情况下，在120分钟内活性下降2个对数。除了表现出浓度依赖性外，杀灭动力学还受到温度和pH的微小变化的影响。镁是一种二价阳离子，被认为可以稳定革兰氏阴性生物表面的脂多糖相互作用，它可以增强乳铁蛋白对伴生放线杆菌的杀灭作用，而其他阳离子，如钾和钙，则没有影响。我们的数据表明，乳铁蛋白有助于人中性粒细胞对放线菌伴生放线菌的杀灭，并可能在对抗这种潜在的牙周病原体的天然分泌防御中发挥重要作用。
Actinobacillus actinomycetemcomitans is a fastidious, facultative gram-negative rod associated with endocarditis, certain forms of periodontal disease, and other focal infections. Human neutrophils have demonstrated bactericidal activity against A. actinomycetemcomitans, and much of the oxygen-dependent killing has been attributed to the myeloperoxidase-H2O2-halide system. However, the contribution of other neutrophil components to killing activity is obscure. Lactoferrin, an iron-binding glycoprotein, is a major constituent of neutrophil-specific granules and is also found in mucosal secretions. In this report, we show that human lactoferrin is bactericidal for A. actinomycetemcomitans. Killing activity required an unsaturated (iron- and anion-free) molecule that produced a 2-log decrease in viability within 120 min at 37 degrees C at a concentration of 1.9 microM. Besides exhibiting concentration dependence, killing kinetics were affected by minor variations in temperature and pH. Magnesium, a divalent cation thought to stabilize lipopolysaccharide interactions on the surface of gram-negative organisms, enhanced lactoferrin killing of A. actinomycetemcomitans, while other cations, such as potassium and calcium, had no effect. Our data suggest that lactoferrin contributes to killing of A. actinomycetemcomitans by human neutrophils and that it may also play a significant role in innate secretory defense against this potential periodontopathogen.