Bortner C A, Miller R D, Arnold R R
Infect Immun. 1986 Feb;51(2):373-7. doi: 10.1128/iai.51.2.373-377.1986.
Lactoferrin, an iron-binding protein found in mucosal secretions and in specific granules of polymorphonuclear leukocytes, has been shown to be bactericidal for a variety of organisms. In this study, the effect of lactoferrin on Legionella pneumophila was investigated. Purified human apolactoferrin was bactericidal for the Knoxville 1 strain (serogroup 1), with a 4-log decrease in viability within 2 h at 37 degrees C. Killing was dependent on the iron-free state since iron-saturated lactoferrin had no activity. Guinea pig passage of this strain did not affect its sensitivity to lactoferrin. Treatment of the cells with dilutions of the lactoferrin resulted in correspondingly reduced killing. Activity was temperature dependent; there was no loss of viability at 1 or 22 degrees C and slightly enhanced killing at 41 degrees C. Addition of Mg2+ blocked bactericidal activity. In addition, mature human milk, a lactoferrin-containing mucosal secretion, was also bactericidal for L. pneumophila. As demonstrated with the purified lactoferrin, bactericidal activity was lost when the milk was iron saturated.
乳铁蛋白是一种存在于黏膜分泌物和多形核白细胞特定颗粒中的铁结合蛋白，已被证明对多种生物体具有杀菌作用。在本研究中，研究了乳铁蛋白对嗜肺军团菌的影响。纯化的人脱铁乳铁蛋白对诺克斯维尔1株（血清群1）具有杀菌作用，在37℃下2小时内活力下降4个对数。杀菌作用取决于无铁状态，因为铁饱和的乳铁蛋白没有活性。该菌株在豚鼠体内传代不影响其对乳铁蛋白的敏感性。用乳铁蛋白稀释液处理细胞会相应降低杀菌效果。活性取决于温度；在1℃或22℃时活力没有损失，在41℃时杀菌作用略有增强。添加Mg2 +会阻断杀菌活性。此外，成熟人乳是一种含有乳铁蛋白的黏膜分泌物，对嗜肺军团菌也具有杀菌作用。如纯化乳铁蛋白所示，当牛奶铁饱和时杀菌活性丧失。
