Jiang X, Baldwin C L
Department of Microbiology, Ohio State University, Columbus 43210.
Cell Immunol. 1993 May;148(2):397-407. doi: 10.1006/cimm.1993.1121.
Brucella abortus are Gram negative facultative intracellular bacteria, which survive and replicate in host macrophages. We have recently demonstrated that activation of macrophages with interferon-gamma increases their anti-brucella activities but does not result in elimination of intracellular brucellae. Here we demonstrate that iron-loaded macrophages have an enhanced capacity to kill or prevent replication of intracellular brucellae. Iron added bound to transferrin or as a salt, iron-nitrilotriacetate, can mediate the effect. Macrophages supplemented with iron-loaded transferrin in addition to activation with interferon-gamma can frequently eliminate the intracellular organisms by 48 hr after infection. The effect is apparent following phagocytosis of either nonopsonized or antibody-opsonized brucellae, and with both attenuated and virulent strains of B. abortus. The killing can be blocked by the hydroxyl radical scavengers mannitol and thiourea. This is consistent with the Haber-Weiss reaction, in which iron catalyzes the generation of hydroxyl radicals from hydrogen peroxide.
流产布鲁氏菌是革兰氏阴性兼性胞内细菌，可在宿主巨噬细胞中存活并复制。我们最近证明，用γ干扰素激活巨噬细胞可增强其抗布鲁氏菌活性，但不能导致胞内布鲁氏菌的清除。在此我们证明，铁负载的巨噬细胞具有增强的杀死或阻止胞内布鲁氏菌复制的能力。与转铁蛋白结合添加的铁或作为盐添加的次氮基三乙酸铁均可介导这种效应。除了用γ干扰素激活外，补充铁负载转铁蛋白的巨噬细胞在感染后48小时内通常可清除胞内细菌。无论是未调理或抗体调理的布鲁氏菌，以及流产布鲁氏菌的减毒株和强毒株，在吞噬后均可观察到这种效应。这种杀伤作用可被羟基自由基清除剂甘露醇和硫脲阻断。这与哈伯-韦斯反应一致，即铁催化过氧化氢产生羟基自由基。
